SPECIALIST STUDY – FAUNA

Transcription

CHAPTER 4
TERRESTRIAL FAUNA
Prepared by:
W R Branch
Coastal & Environmental Services
67 African Street
P O Box 934
Grahamstown
6140
N2 Wild Coast Toll Road between East London and Durban: Environmental Impact Assessment Report
TABLE OF CONTENTS
PAGE
SUMMARY
i
4.1
INTRODUCTION
1
4.1.1
Environmental impacts of roads
1
4.1.2
Limitations and exclusions
1
4.2
FAUNAL OVERVIEW
2
4.2.1
Methodology
2
4.2.2
Overview of Fauna
3
4.3
KEY ISSUES
15
4.3.1
Introduction
15
4.3.2
Issue 1 – Ecologically sensitive and protected areas
15
4.3.3
Issue 2 – Threats to biodiversity
19
4.3.4
Issue 3 – Threats to species of special concern
22
4.3.5
Issue 4 – Threats to animal movements
23
4.3.6
Issue 5 – Invasion by alien fauna
25
4.3.7
Issue 6 – Increased fire risk
25
4.3.8
Issue 7 – Chemical pollution
26
4.4
REGIONAL ASSESSMENT
27
4.4.1
Introduction
27
4.4.2
Section 1: East London to Komga Interchange
27
4.4.3
Section 2: Komga Interchange to Ngobozi
30
4.4.4
Section 3: Ngobozi to Umtata
30
4.4.5
Section 4: Umtata to Ndwalane
30
4.4.6
Section 5: Ndwalane up to and including Ntafufu River crossing
32
4.4.7
Section 6: Ntafufu River via Lusikisiki to Magwa Tea Estate
32
intersection
4.4.8
Section 7: Magwa intersection up to and including Msikaba River
34
crossing
4.4.9
Section 8: Msikaba River up to and including Mtentu River crossing
34
4.4.10
Section 9: Mtentu River up to and including Mtamvuna River crossing
34
4.4.11
Section 10: Mtamvuna River to Umkomaas Interchange
38
4.4.12
Section 11: Umkomaas Interchange to Isipingo Interchange
38
4.5
CONCLUSIONS
38
4.6
REFERENCES
39
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LIST OF TABLES
PAGE
Table 4.1:
Approximate Numbers of Species occurring in the road sections,
21
excluding birds and bats
Table 4.2:
Number of Species of Special Concern occurring in the road
22
sections, excluding bats
Table 4.3:
Summary of issues for Section 1: East London to Komga
28
Interchange
Table 4.4:
Summary of issues for Section 2: Komga Interchange to Ngobozi
29
Table 4.5:
Summary of issues for Section 3: Ngobozi to Umtata
31
Table 4.6:
Summary of issues for Section 4: Umtata to Ndwalane
31
Table 4.7:
Summary of issues for Section 5: Ndwalane up to and including
33
Ntafufu River crossing
Table 4.8:
Summary of issues for Section 6: Ntafufu River via Lusikisiki to
33
Magwa Tea Estate intersection
Table 4.9:
Summary of issues for Section 7: Magwa intersection up to and
35
including Msikaba River crossing
Table 4.10:
Summary of issues for Section 8: Msikaba River up to and
35
including Mtentu River crossing
Table 4.11:
Summary of issues for Section 9: Mtentu River up to and
36
including Mtamvuna River crossing
Table 4.12:
Summary of issues for Section 10&11: Mtamvuna River to
36
Umkomaas Interchange
Table 4.13:
Summary of issues for Section 11: Umkomaas Interchange to
37
Isipingo Interchange
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4.
TERRESTRIAL FAUNA
4.1
Introduction
The N2 Wild Coast Toll Road Project proposes to develop a toll road extending
approximately 550km from the Gonubie Interchange north of East London, to the Isipingo
Interchange south of Durban. The proposed route follows existing national and regional roads
along its entire length, except for the section between Ndwalane and Mtamvuna, where a new
road will be built within a proposed greenfields corridor. Specific project actions include the
rehabilitation and upgrading of existing road sections within the existing road reserve, and the
construction of numerous interchanges and seven toll plazas. Specific details of the proposed
route and planned project actions for the various sections are discussed in Chapter 1.
4.1.1
Environmental impacts of roads
Roads and their associated vehicle traffic may impact terrestrial fauna in diverse ways
(Pienaar 1968; Andrews 1990; Forman and Alexander 1998; Sheate and Taylor 1990;
Bellamy et al. 2000).
The main impacts during construction involve the loss and
fragmentation of habitats, with a consequent loss of biodiversity and possibly loss of species
of special concern. This may result from direct land clearance, or occur indirectly via loss or
changes in habitats due to consequent changes in drainage patterns, increased fire risk, or
secondary impacts associated with socio-economic factors resulting from changes in
surrounding land use. During the operational life of the road, small accumulative impacts
also occur, including ongoing road mortalities, increased disturbance (noise and light), dust
generation, air pollution, chemical contamination from petroleum and rubber products,
increased litter, changes in the incidence of fire, and the introduction of alien vegetation. All
of these factors may impact the surrounding fauna and ecological processes in different ways.
Due to the length of the proposed road route, it passes through varied vegetation types,
climatic zones, and regions of different historical and current land use practises. Together
these factors introduce regional differences in the impacts that the proposed road route will
have on the terrestrial fauna.
4.1.2
Limitations and exclusions
•
No detailed sampling survey of the proposed route was undertaken.
•
Due to previous historical neglect, faunal knowledge of the former Transkei region,
particularly the greenfields corridor, remains poor.
Terrestrial Fauna
1
Details of faunal diversity,
Sep-02
distribution and conservation status is not uniformly topical or comprehensive. Although
birds are relatively well-studied (e.g. Quickelberge 1989; Barnes 1998, 2000; Harrison et
al. 1997), other vertebrate groups lack modern syntheses for the region.
•
Taxonomic knowledge of many inconspicuous or non-charismatic groups in southern
Africa is poor and new taxa are still frequently discovered, e.g. a new species of reptile is
discovered in southern Africa every 1-2 months (Branch 2001).
•
National and international assessment of threatened taxa is restricted to well-known
groups, e.g. mammals, birds, butterflies.
•
Detailed project actions for the N2 Wild Coast Toll Road are still not finalised, and
discussion of impacts and recommendations for mitigation are, therefore, generic and not
site specific. The impacts of specific project actions, e.g. borrow pit sites, cut and fill
areas etc., will either be covered in the Environmental Management Plan (EMP) or in
subsequent reviews.
Due to these limitations it has been necessary to adopt a precautionary approach when
assessing faunal distributions and potential impacts.
4.2
Faunal overview
4.2.1
Methodology
As no detailed surveys were commissioned, the following assessment of faunal diversity in
the region is based on existing knowledge. Due to the limitations of this knowledge, it places
heavy emphasis on the more well-known vertebrate fauna.
Faunal Diversity
The known diversity of the vertebrate fauna and selected invertebrate fauna along the
proposed route was determined by literature review. Species known from the region, or from
adjacent regions whose preferred habitat(s) are known to occur within the road route, were
also included. Literature sources included:
•
Amphibians - Passmore and Carruthers (1995), Harrison et al. (2001).
•
Reptiles - Branch (1998), Broadley (1990).
•
Birds - Barnes (1998), Harrison et al. (1997).
•
Mammals - Skinner and Smithers (1990), Stuart and Stuart (1988), Kingdon (1997) and
Mills and Hex (1997).
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Additional faunal records for the region were derived from miscellaneous sources, e.g.
Cooper and Ledger (1989). The assessment of the surviving large mammal fauna along the
route draws from White (1999) and Skead (1987).
Species of Special Concern
The above faunal checklists were reviewed for the presence of Species of Special Concern
(SSC), including:
•
Threatened species, defined as: a) species listed in the Endangered or Vulnerable
categories in the revised South African Red Data Books (SA RDB - birds, Barnes 2000;
herpetofauna, Branch 1988; terrestrial mammals, Smithers 1986; butterflies, Henning
and Henning 1989) or listed in the Globally Threatened (GT) category of Important Bird
Areas of Southern Africa (Barnes 1998); b) species of special conservation concern (i.e.
taxa described since the relevant SA RDB, or whose conservation status has been
highlighted subsequent to 1984); c) species which are included in other international lists
(e.g. 1996 IUCN Red List of Threatened Animals, Ballie and Groombridge 1996); or d)
species included in Appendix 1 or 2 of the Convention of International Trade in
Endangered Species (CITES).
•
Sensitive species, defined here as those species listed in the Rare, Indeterminate or
Monitoring categories of the SA Red Data Books, and/or species listed in Globally Near
Threatened (GNT), Nationally Threatened (NT) or Nationally Near Threatened (NNT)
categories of Important Bird Areas of Southern Africa (Barnes 1998).
•
Endemic species, defined as those having 75% of their range occurring in the Eastern
Cape – KwaZulu-Natal region. Those species endemic to the Pondoland region were
highlighted.
4.2.2
Overview of Fauna
The distinctive flora of the Pondoland region is recognised as an important region of floral
endemism (Van Wyk and Smith 2001). The regional fauna has not been as extensively
studied and is not known to exhibit as many unique features. The area has been settled for
many centuries, and the fauna is usually considered impoverished due to overgrazing and
other man-induced impacts. However, due to previous political neglect, the region remains
poorly studied, except for the former enclave around Port St John and various coastal resorts
and reserves. A precautionary approach must therefore be adopted when assessing faunal
distributions and potential impacts. Many species, including SSC, may extend further inland
than currently known. They have therefore been considered even if their presence in the
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3
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proposed road route has not been confirmed. During the assessment of the significance of
impacts, however, only species (particularly SSC) whose presence was confirmed were used.
Vertebrate Faunal Diversity
Due to its extended length, faunal composition along the proposed road route shows regional
differences. The following discussion involves the total number of species occurring along
the whole route. The discussion of regional impacts, however, involved only those species
occurring in the relevant road section.
Amphibians
The Pondoland fauna is relatively poorly known, as is much of that of the former Transkei.
This is unfortunate as the region falls at an important transition zone between a southern
temperate amphibian fauna, and a tropical fauna that extends along the coastal littoral in
association with the warm waters of the Aghulas Current (Poynton 1990). The known
amphibian fauna includes approximately 30 species. New taxa may well still exist in the
poorly studied forest patches, river gorges and coastal grasslands. Species currently known
only from coastal locations may also have relict inland populations.
The taxonomy of a number of species requires resolution.
•
Spiny reed frogs of the Afrixalus knysna-spinifrons complex. They are found in disjunct
populations from the Sedgefield–Knysna region to Transkei–KwaZulu-Natal (Pickersgill
1996; Channing 2001). The assignment of former Transkei populations is problematic.
Specimens from Qolora–Port St Johns are assigned to A. knysnae by Channing (2001),
but to A. spinifrons by Pickersgill (1996). Both authors assign specimens from Port
Edward and the KwaZulu-Natal South Coast to A. spinifrons. Both species are to be
included as Vulnerable in the Frog Atlas and revised South African Red Data Book –
Amphibians (Harrison et al., in prep), and may therefore be affected by the proposed road
route.
•
Dainty frogs of the Cacosternum boettgeri complex. A number of taxa have been revived
from synonymy (e.g. C. platys from the southwestern Cape, Channing 2001; C. striatum
from Cobham, KwaZulu-Natal, Harrison et al. 2001). Other undescribed taxa are known
from grasslands in the former Transkei – KwaZulu-Natal border region (M. Burger, pers.
comm.). It is possible that cryptic taxa1 may occur in the Pondoland region, which have
been poorly sampled for these small frogs.
1
Taxa refers to families, genera or species.
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Reptiles
Approximately 60 species of reptile are recorded or are likely to occur along the proposed
route (Branch 1998). Whilst some are wide-ranging species, e.g. snakes such as boomslang
and puffadder, others have relatively restricted distributions. The taxonomy of a number of
taxa requires fuller resolution, and may involve hidden undescribed species that could be of
conservation concern. Besides the sensitive and localised species discussed below, a number
of other taxa show regional variation within the study area that may indicate the presence of
undescribed species.
•
Common slug-eating snake (Duberria lutrix): Some individuals in the former Transkei
coastal region are large and grey spotted, unlike slug-eaters elsewhere. They occur in the
Port St Johns region.
The taxonomic status of these specimens needs further study, as
they may represent an undescribed species.
•
Giant legless skink (Acontias plumbeus): The southern population around East London is
well-isolated from northern populations with no records known for the intermediate Wild
Coast region. It shows a number of subtle differences (Bourquin and Lambiris 1996)
from more typical northern populations and may represent a new species.
•
A small snake collected from the Bashee River Mouth (Broadley, pers.
comm.) is
currently unassignable to any other African snake and remains an enigma. Although it is
not known to occur along the proposed road route, and resolution of its scientific status
awaits the discovery of further specimens, the species may be present in the Umtata
region. Should it be discovered during road construction, attention to its conservation
status would require immediate attention.
•
Dwarf chameleons (Bradypodion sp.): Found in isolated populations in forest and thicket
habitats. The taxonomy of South African dwarf chameleons is problematic. A number of
new species have been recently proposed, although these await formal description. Raw
(1995) indicated that numerous undescribed species of dwarf chameleon occurred in the
eastern regions of South Africa. He later informally described and proposed names for
nine new species in the Eastern Cape – KwaZulu-Natal region, including new species
from the Mkambati Nature Reserve, Mtamvuna Nature Reserve and Oribi Gorge region
(Raw 2001). The status of these new species has not been formally recognised and
require urgent study. All three species have very restricted distributions and are of
conservation concern.
Birds
The former Transkei region has a rich avifauna (Quickelberge 1989; Harrison et al. 1997),
with nearly 500 species recorded from the region (approximately half of the species recorded
Terrestrial Fauna
5
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from the subcontinent). They include numerous sensitive and threatened species. The coastal
mosaic of grassland and forest habitats serves as an important area for montane species in
winter. Many Intra-African summer migrants also use the region both for breeding and in
transit to more southerly areas.
Mammals
The area of interest has a diverse mammal fauna with nearly 80 species recorded from the
region, comprising 11 insectivores, 19 bats, 3 primates, 2 lagomorphs, 19 rodents, 15
carnivores, antbear, 2 hyrax, bushpig, and 5-6 small antelope. However, much of the large
and medium-sized mammal fauna that previously occurred along the proposed road route is
now locally extinct or occurs in small fragmented populations, usually in isolated forests.
Skead (1987) notes records of five leopard killed in the Mkambati – Ntsimbini region
between 1952-1962, and it is possible that a few specimens still exist in the more inaccessible
kloof forests. With effective protection, leopard can repopulate areas relatively quickly, as
shown by the natural appearance of leopard in several Eastern Cape game lodges (e.g.
Shamwari) following conservation and increasing populations of natural prey.
Species of Special Concern
Invertebrates
Due to the sheer magnitude of the groups, invertebrates are rarely considered in detailed
assessments of environmental impacts, although butterflies are increasingly discussed. This is
more a reflection of the easy availability of field guides (e.g. Migdoll 1987) to the group and a
recent synopsis of threatened taxa (e.g. Henning and Henning 1989). These in turn result
more from the charismatic attraction of the group rather than to any distinctive or seminal role
that they play in ecosystem functioning. Although no regional Red Data Book exists for
many invertebrate groups, a number of species in diverse groups have been identified as being
of conservation concern and are discussed below.
•
Butterflies: Three rare butterflies from the Pondoland region are included in the South
African Butterfly Red Data Book (Henning and Henning 1989):
∗
Pondoland Charaxes (Charaxes pondoensis), Rare, Port St Johns, Mkambati NR.
∗
Amakoza Rocksitter (Durbania amakosa albescens), Rare, Margate.
∗
Southern Aslauga (Aslauga australis), Rare, East London, Mbashe River, Doutza
Pass, Port St Johns.
∗
•
Bicolored Abantis (Abantis bicolor), Rare, East London, Mbashe River, Port St Johns.
Pulmonate Molluscs: Two terrestrial slugs have been indicated as candidates for inclusion
in the IUCN ‘Red List’ of threatened species (Herbert 1997). These include:
Terrestrial Fauna
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∗
Chlamydephorus burnupi (known from a few scattered localities in KwaZulu-Natal,
and with a single record from Port St Johns).
∗
Chlamydephorus dimidius (known from a few scattered localities in KwaZulu-Natal,
and with a single southern record from Mtamvuna Gorge).
•
Cicadas: Due to their long, unusual life cycles, cicadas are known to be sensitive to
habitat fragmentation (Rodenhause et al. 1997). These large, noisy and enigmatic insects
show high levels of endemism and a number of new, highly-localised species have been
described from the former Transkei region (Villet 1997, 1999). Both are recorded from
coastal forest, thicket and forest fringes.
∗
Stagira pondoensis is known only from Port St Johns and nearby Vernon Crookes
Nature Reserve in KwaZulu-Natal.
∗
Nyara thanatotica, which occurs at Port St Johns and Bosbokstrand. This taxon is
taxonomically more important as it is a monotypic genus.
•
Millipeds: Like cicadas, millipeds often show high levels of endemism. Moreover, the
distribution of endemism is often discordant with that of other groups (Burgess et al.
1998). Although there is no updated review of southern African millipeds highlighting
threatened taxa, a new species has recently been described from forest habitat in the
Lusikisiki District (Alderweireldt 1998).
Amphibians
The recent provisional re-assessment of threatened South African amphibians (Harrison et al.
2001), using modern IUCN criteria, includes three species that may occur in the greenfields
corridor area:
•
Kloof frog (Natalobatrachus bonebergi) – Endangered.
•
Knysna spiny reed frog (Afrixalus knysnae) – Vulnerable.
•
Natal spiny reed frog (Afrixalus spinifrons) – Vulnerable.
A number of regional endemics occur along the route, and the following seven have been
confirmed:
•
Bush squeaker (Arthroleptis wahlbergi) – KwaZulu-Natal, reaching its southern limit at
Port St Johns;
•
Natal ghost frog (Heleophryne natalensis) – Eastern Cape to Mpumalanga escarpment,
reaching its southern limit Mtamvuna Gorge;
•
Natal chirping frog (Arthroleptella hewitti) – KwaZulu-Natal, reaching its southern limit
at Mkambati NR;
Terrestrial Fauna
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Sep-02
•
Forest tree frog (Leptopelis natalensis) – KwaZulu-Natal, reaching its southern limit at
Port St Johns (Plate 4.1);
•
Knysna spiny reed frog (Afrixalus knysnae) – Knysna, Port St Johns, Butterworth-Qolora;
•
Natal spiny reed frog (Afrixalus spinifrons) – Port Edward; and
•
Kloof frog (Natalobatrachus bonebergi) – Port St Johns to Ngoye Forest.
Five tropical species reach their southern limit in the region and these populations are,
therefore, also sensitive. They are:
•
Long reed frog (Hyperolius acuticeps) – Mkambati;
•
Water lily frog (Hyperolius pusillus) – Dwesa;
•
Dwarf puddle frog (Phrynobatrachus mababiensis) – East London;
•
Sharp-nosed grass frog (Ptychadena oxyrhynchus) – East London; and
•
Striped grass frog (Ptychadena porosissima) – East London.
Plate 4.1: The Forest tree frog (Leptopelis natalensis), reaches its southern limit at Port St
Johns
Reptiles
Although no species are currently included in the SA RDB for reptiles and amphibians
(Branch 1988), the status of several endemic species suggests that they are candidates for
inclusion in a modern revision. Many species have very restricted distributions that under
Terrestrial Fauna
8
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IUCN criteria would place them in Vulnerable or Endangered categories. These sensitive
species include:
•
Variable burrowing skink (Acontias poecilus). This localised species, only described in
1996, is known from five specimens from south-eastern KwaZulu-Natal (Leisure Bay,
Oribi Gorge and Umtentweni; Bourquin and Lambiris 1996) and a single specimen from
the Eastern Cape (Marembeni; Branch 1999). It burrows in humic soils of coastal forests,
and probably occurs in the coastal region around Port Edward and the Mkambati Nature
Reserve.
•
Dwarf chameleons (Bradypodion sp.).
A number of isolated populations of dwarf
chameleons occur in habitats along or adjacent to the proposed route. The poorly-known
Kentani dwarf chameleon (B. kentanicum) was described in 1937 and is known from few
specimens collected near Kentani (Hewitt 1937; Raw 2001). Other populations along the
proposed road route are known from Ngqeleni, Mkambati, Umtamvuna, Port Edward,
Oribi Gorge and Mahlangamkulu River. Some of these are considered to represent
undescribed new species (Raw 2001). They have been recorded from forest, bush clump,
riverine thicket and coastal grassland edge habitats.
•
Transkei dwarf chameleon (Bradypodion caffrum). This small chameleon is a Pondoland
coastal plateau endemic, described from Port St Johns and adjacent regions (Raw 2001).
•
Smith’s dwarf burrowing skink (Scelotes inornatus). A small legless burrowing skink
from coastal thicket and grassland from Amanzimtoti to the Umgeni Mouth.
•
Cape crag lizard (Cordylus microlepidotus). A population of this large lizard is common
in granite boulders in the Butterworth-Kentani region, and may represent a localised and
undescribed species or race (Branch 1998). It occurs on roadside granite rocks in the road
reserve bordering the existing N2 in the Butterworth region. Due to its association with
exposed rock cracks, the species may be impacted by future borrow pits associated with
road maintenance and construction.
•
Forest thread snake (Leptotyphlops sylvicolus). A very small snake, perhaps the smallest
in the world (to 110 mm), known from a few scattered forests in coastal KwaZulu-Natal,
and with a single record from Port St Johns.
Birds
A significant number of threatened (3 Endangered and 12 Vulnerable) and Near-Threatened
(12) species occur along the proposed road route, as well as 3 sensitive species dependent
upon forest habitat.
•
Blackrumped Buttonquail (Turnix hottentotta, Ingolwane), Nationally Endangered. A
cryptic species associated with high-rainfall damp grasslands in open or lightly wooded
Terrestrial Fauna
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country. Possibly a summer migrant. Eastern Pondoland is at the southern extremity of
the race. T. h. nana has sometimes been treated as a separate species. It was recorded
during the Bird Atlas survey from 3129BB and 3129BD, but not at Mkambati NR (Barnes
1998). The South African population is estimated at less than 1 000 individuals (Barnes
2000). It is considered uncommon, but is possibly overlooked (Quickelberge 1989). The
main threat is habitat loss, as grassland is converted to small agricultural plots, and long
grass is eradicated by too frequent fires (Barnes 2000).
•
Cape Parrot (Poicephalus robustus, Isikhwenene), Nationally Endangered and Endemic.
Inhabits patches of Afromontane Podocarpus forests, visiting coastal forest during the
fruiting season (e.g. Port St Johns). It is declining in numbers and the South African
population is estimated at less than 500 individuals (Barnes 2000). The main threats
include habitat loss and illegal collecting for the pet and muti trade. The northern
populations are now treated as a separate species – the grey-headed parrot.
•
Spotted Thrush (Zoothera guttata, Unomacetyacetyana), Globally Endangered.
This
secretive thrush inhabits coastal and scarp forest understorey. Most important areas for
species in the region includ the Umtamvuna NR, Mkambati NR, Egossa Forest (3129BC)
and Mtambalala Forest (3129BC) (Barnes 2000). Also recorded from Mbotyi and Port St
Johns. The South African population is estimated at 400-800 pairs (Barnes 2000) and the
main threats include habitat loss and fragmentation.
•
White-backed Night Heron (Gorsachius leuconotus), Vulnerable. This shy heron inhabits
heavily vegetated riverbanks. Recorded from Lusikisiki and Port St Johns (Quickelberge
1989), but there are few recent records from the Wild Coast region (Mkambati NR),
possibly indicating local extinction (Brookes 1984; Barnes 2000). The South African
population is estimated at 500-1 000 individuals (Barnes 2000). The main threat is
habitat loss and reduction in prey.
•
Cape Vulture (Gyps coprotheres, Ixhalanga), Vulnerable. The former Transkei remains
the stronghold of the species, which remains relatively common over the rugged terrain of
the eastern Pondoland (Quickelberge 1989). Breeding colonies remain at:
∗
confluence of Gcuwa and Bawa rivers, near Butterworth
∗
Collywobbles on the Mbashe River (largest breeding colony, 400+ birds)
∗
near Mount Ayliff
∗
lower reaches of Mtamvuna River (Umtamvuna NR)
∗
Mlengana (Execution Rock), between Umtata and Port St Johns
∗
Mtentu River, from Mkambati NR to 20km upstream
Terrestrial Fauna
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The South African population is estimated at approximately 4 000 pairs (Barnes 2000).
The main threat is high mortality caused by food shortages, poisoning, and electrocution
and collision with powerlines (Markus 1972; Van Rooyen and Ledger 1999).
•
Martial Eagle (Polemaetus bellicosus, Ukhozi), Vulnerable. Widespread in woodlands
and savanna, with scattered records throughout the former Transkei, including Port St
Johns, Umtamvuna NR and Mkambati NR. It is the largest eagle in the subcontinent, and
may have lost 20% of its regional population within the last three generations. The South
African population is estimated at less than 600 pairs (Barnes 2000). The main threats are
persecution from farmers, such as poisoning of suspected livestock predators, drowning in
farm dams, and electrocution on powerlines (Van Rooyen and Ledger 1999).
•
African Marsh Harrier (Circus ranivorus, Isigobodo), Vulnerable. Widespread and not
uncommon where suitable marshland and riverine habitat is present (Quickelberge 1989).
Records include Umtamvuna NR. The South African population is estimated at 3 0005 000 pairs and habitat loss and degradation are the main threats (Barnes 2000).
•
Grey Crowned Crane (Balearica regulorum, Ihem), Vulnerable. Widespread throughout
the former Transkei.
Prefers mixed wetland-grassland habitat.
The South African
population is estimated at 2 800-3 000 individuals, and the main threats are habitat loss
from overgrazing and frequent fires, collisions with powerlines, disturbance and hunting
pressures from dogs and humans (Barnes 2000).
•
African Finfoot (Podica senegalensis, Umngcana), Vulnerable. A widespread but rare
species.
It prefers well-vegetated edges of slow-moving rivers.
Recorded from
Umtamvuna NR and Mkambati NR. The South African population is estimated at 5001 000 individuals, and the main threats are habitat loss and declines in prey species
(Barnes 2000).
•
Stanley’s Bustard (Neotis denhami, Iseme), Vulnerable. A widespread but rare bustard
that prefers high rainfall, open sour grassland. Recorded from Luchaba NR near Umtata,
Umtamvuna NR and Mkambati NR. Present absence in eastern former Transkei has been
attributed to human disturbance (Quickelberge 1989). The South African population is
estimated at less than 5 000 individuals.
The main threats are habitat loss from
overgrazing and frequent fires, collisions with powerlines, disturbance and hunting
pressures (Barnes 2000).
•
Delegorgue’s Pigeon (Columba delegorguei, Indenga), Vulnerable. A very localised and
rare pigeon that prefers Afromontane and scarp forests. It is a non-breeding visitor to
coastal forests (Quickelberge 1989). Recorded from Goso Forest, Lusikisiki and Port St
Johns. The South African population is estimated at less than 700 individuals. The main
threat is habitat loss, especially the loss of understorey ground cover (Barnes 2000).
Terrestrial Fauna
11
Sep-02
•
Grass Owl (Tyto capensis, Isikhova), Vulnerable. A widespread but rare species that
hunts and nests in rank grassland. Recorded from Lusikisiki, Port St Johns (Quickelberge
1989), Umtamvuna NR and Mkambati NR (Barnes 1998). The South African population
is estimated at less than 5 000 individuals, and the main threats include habitat loss,
frequent fires and pesticides (Barnes 2000).
•
Mangrove Kingfisher (Halycon senegaloides, Isaxwila), Vulnerable. A large kingfisher,
restricted to coastal mangroves for feeding and to adjacent forests for breeding sites.
Recorded from Port St Johns (Quickelberge 1989). The South African population is
estimated at less than 500 individuals and the main threats has been the loss of mangrove
and forest habitat (Barnes 2000).
•
Natal Nightjar (Camprimulgus natalensis, Unyabayo), Vulnerable.
Prefers edges of
coastal vleis and marshes. Recorded from: Mzamba River (Quickelberge 1989) and
Umtamvuna NR (Barnes 1998). Barnes (2000) considers the species to have undergone a
range contraction as there were no records from the former Transkei during the Bird Atlas
period (1990-1996) and it had not been seen in southern KwaZulu-Natal (e.g. Oribi
Gorge) since 1980. However, Martin (2002) recently heard two specimens calling at
Mkweni Mouth, south of Port St Johns and a pair of small, boldly marked nightjars that
were probably this species were observed at Mkambati NR during the field survey (July
2002). The South African population is estimated at about 1 000 individuals, and the
main threat is considered to be habitat loss (Barnes 2000).
•
Southern Ground Hornbill (Bucorvus leadbeateri, Intsikizi), Vulnerable.
Previously
widespread but becoming increasingly rare, it prefers broad-leaved woodland and
grassland. Recorded from Lusikisiki, Port St Johns (Quickelberge 1989), Umtamvuna
NR and Mkambati NR (Barnes 1998). The South African population is estimated at
1 500-2 000 individuals, and the main threats are habitat loss, and persecution for the muti
trade (Barnes 2000).
•
Knysna Warbler (Bradypterus sylvaticus, Inkqotyana), Vulnerable and Endemic.
Restricted to forest patches and recorded from Port St Johns to Dwesa NR (Quickelberge
1989). South African population is estimated at less than 2 500 individuals and the main
threat is habitat loss (Barnes 2000).
Near-Threatened and Sensitive species include:
•
Black Stork (Ciconia nigra, Unocofu), Near-Threatened. Prefers pools in large rivers.
Recorded from East London, Port St Johns, Lusikisiki (Quickelberge 1989) and
Umtamvuna NR (breeding, Barnes 1998).
Terrestrial Fauna
12
Sep-02
•
Secretary bird (Sagittarius serpentarius, Ingxangxosi), Near-Threatened. Widespread in
the former Transkei in varied open habitats, including savanna and grasslands. Recorded
from Umtamvuna NR (Barnes 1998).
•
Crowned Eagle (Stephanoaetus coronatus, Ukhozi), Near-Threatened.
Prefers forest
habitats. Recorded from East London, Port St Johns (breeding, Quickelberge 1989),
Umtamvuna NR and Mkambati NR (Barnes 1998).
•
Black Harrier (Circus maurus, Isigobodo-esimnyama), Near-Threatened, Endemic.
Hunts over grassland. Recorded from East London, Port St Johns (Quickelberge 1989)
and Umtamvuna NR (Barnes 1998). Global population is less than 1 000 birds (Harrison
et al. 1997).
•
Lanner Falcon (Falco biarmicus, Ukhetshe), Near-Threatened. Widespread in the former
Transkei in varied open habitats. Recorded from Port St Johns, Umtamvuna NR and
Mkambati NR (Barnes 1998).
•
Blackwinged Plover (Vanellus melanopterus, Unotyhiniphi), Near-Threatened. Prefers
short and burnt grasslands. Recorded from Port St Johns, Umtamvuna NR and Mkambati
NR (Barnes 1998).
•
Blackbellied Korhaan (Eupodotis melanogaster), Near-Threatened. Prefers high rainfall,
dense grasslands. Recorded from Umtamvuna NR and Mkambati NR (Barnes 1998) at
the southern tip of its range.
•
Half-collared Kingfisher (Alcedo semitorquata, Isaxwila), Near-Threatened. Prefers wellvegetated riverbanks. The former Transkei coastal region forms a stronghold for the
species. Recorded from East London, Port St Johns, Umtamvuna NR and Mkambati NR
(Barnes 1998). Main threats include habitat loss.
•
Ground Woodpecker (Geocolaptes olivaceus, Umgximde), Near-Threatened, Endemic.
Prefers open, rocky habitats.
Recorded mainly from inland regions of the former
Transkei, but with a small breeding colony at Umtamvuna NR (Barnes 1998).
•
Knysna Woodpecker (Campethera notata, Isinqolamthi), Near-Threatened, Endemic.
Prefers forest habitats. Recorded from: East London, Kei River, (Quickelberge 1989),
Umtamvuna NR and Mkambati NR (Barnes 1998). The eastern race, C. n. relicta, was
described from Mbotyi, Lusikisiki. The South African population is estimated at 1 5005 000 individuals (Harrington et al. 1996), and the main threat is habitat loss (Barnes
2000).
•
African Broadbill (Smithornis capensis), Near-Threatened.
Prefers forest habitats.
Reaches southern limit of range at Umtamvuna NR (Barnes 1998).
•
Broadtailed Warbler (Schoenicola brevirostris, Umvokontshi), Near-Threatened. Prefers
coarse, dense grass on edge of marshy areas along Pondoland coast. Recorded from:
Terrestrial Fauna
13
Sep-02
Lusikisiki, Bizana (Quickelberge 1989), Umtamvuna NR and Mkambati NR (Barnes
1998) and is threatened by fires and overgrazing (Barnes 2000).
Mammals
Most of the threatened mammals along the proposed route inhabit forest habitats. They
include six Vulnerable and one Near-Threatened species (Smithers 1986), whist a further four
sensitive species depend on forest habitats.
•
Giant golden mole (Chrysospalax trevelyani), Vulnerable.
Inhabits forest habitats.
Recorded from East London and Port St Johns. Threats include habitat destruction and
feral hunting dogs. They appear to feed on giant earthworms (Microchaetus sp.)
•
Rough-haired golden mole (Chrysospalax villosus), Vulnerable. Roberts (1951) records
specimens from Tsolo and Tabase (3128DA), the latter occurring along the N2 Wild
Coast Toll Road route between Umtata and Ndwalane. Taylor (1998) notes that the
species occurs in disjunct populations (Eastern Cape, Natal Midlands and the
Wakkerstroom area of Mpumalanga). Few specimens have been collected since the
1960s and the species is considered possibly endangered in KwaZulu-Natal (Taylor
1998), threatened by both overgrazing and hunting dogs.
•
White-tailed mouse (Mystromys albicaudatus), Vulnerable.
Inhabits savanna and
grassland habitats. Widespread but rare. Taylor (1998) recorded few recent specimens
from KwaZulu-Natal.
•
Honey badger (Mellivora capensis), Vulnerable.
Widespread in South Africa but
becoming increasingly rare. Threats include persecution and habitat loss.
•
African wild cat (Felis lybica), Vulnerable. Widespread in varied habitats in South Africa
but becoming increasingly rare.
Threats include persecution, habitat loss and
hybridisation with feral domestic cats.
•
Aardvark (Orycteropus afer), Vulnerable. Widespread in varied habitats in South Africa
but becoming increasingly rare. Threats include persecution and habitat loss.
•
Oribi (Ourebia ourebi), Vulnerable.
Prefer open grassland with scattered cover.
Recorded from Umtamvuna NR. Threats include hunting and habitat loss.
•
Africa striped weasel (Poeciligale albinucha), Rare. Widespread in open woodland and
savanna in South Africa but becoming increasingly rare. Threats include persecution and
habitat loss.
•
Aardwolf (Proteles cristatus), Rare. Widespread in varied habitats in South Africa but
becoming increasingly rare. Threats include persecution and habitat loss.
Terrestrial Fauna
14
Sep-02
•
Serval (Felis serval), Rare. Found in the eastern coastal regions but extending inland in
association with moist habitats.
Threats include persecution and agricultural
development.
•
Samango monkey (Cercopithecus mitis), Rare.
Restricted to eastern coastal forests
although some populations adapt well to semi-urban areas (e.g. Port St Johns). The small,
highly-fragmented populations in the eastern coastal regions remaining are threatened by
continued hunting and habitat loss.
•
Thick-tailed bushbaby (Otolemur crassicaudatus), Rare. Southern populations have been
extensively fragmented (Bourquin 1988; Taylor 1998) and are susceptible to local
extinction. Its status in the former Transkei region is unknown, but it may remain in
forest fragments.
•
Tree hyrax (Dendrohyrax arboreus), Rare. Inhabits coastal forests and threats include
habitat loss, wood collecting and hunting. Taylor (1998) noted that although rarely seen,
surveys using tape recordings in KwaZulu-Natal showed the species to be more common
than believed.
•
Blue duiker (Philanthomba monticola), Rare. Inhabits forests, thicket and dense coastal
bush and is threatened by hunting and habitat loss.
4.3
Key issues
4.3.1
Introduction
This section reviews the issues arising from the construction and operation of the proposed
N2 Wild Coast Toll Road from East London to Durban that may impact faunal systems.
Specifically, the review identifies:
•
The presence of ecologically sensitive areas, including terrestrial and riparian systems;
•
areas of high biodiversity;
•
the presence of faunal migratory routes;
•
the conservation status of fauna along the proposed route and potential impacts on species
of special concern, including sensitive, endemic and protected species;
•
the potential for the invasion by alien species; and
•
the impact of increased fire risk and chemical pollution resulting from road traffic on the
indigenous fauna.
The extent, duration, probability and significance of issues are rated according to criteria
outlined in detail in Chapter 1 of this volume. Only species positively known to occur in the
Terrestrial Fauna
15
Sep-02
region, or that are considered extremely likely to occur in the region have been considered
when assessing significance.
Each issue is described initially, followed by a general
discussion of the impacts of the road on the issue. Further detail on the specific ratings of
impacts for each of the 11 defined road sections is presented in Section 4.4. This is largely
presented as a series of tables, prefaced by a brief discussion.
4.3.2
Issue 1 – Ecologically sensitive and protected areas
General Comments
The proposed route passes through regions subject to different histories and land use patterns.
Areas at the extremes of the route, e.g. the KwaZulu-Natal south coast and around East
London are relatively heavily populated, with areas of high urbanisation and diffuse suburban
development. The central section, however, that forms much of the area falling in the former
Transkei, has lower human densities but a long history of human occupation.
As a
consequence, the landscape is now much degraded from its natural condition with an
impoverished fauna.
In general terms, terrestrial fauna are linked to certain vegetation types, i.e. forest, grassland,
savanna, etc.
However, depending on the particular lifestyle of the animal concerned,
physical characteristics of the environment may be more important than the plant species that
define the vegetation types.
Thus, forest specialists may inhabit various forest types,
including Coastal, Afromontane or Riparian forest. Waterbirds and amphibians may utilise
varied aquatic systems, preferring swamps, streams, or fast-flowing rivers. Many lizards
inhabit rock cracks, and their distributions are linked to the underlying geology, rather than
the overlying plant communities.
By their nature, forest habitats are rarely confluent over large areas, particularly in areas such
as the former Transkei, where there has been a long history of human dependence upon
natural resources.
They remain as a fragmented archipelago of habitats, restricted to
relatively inaccessible south-facing gorges and steep river valleys. Species inhabiting forests
are usually highly adapted to the moisture, light and thermal regimes occurring within them.
Such specialist species rarely survive in other habitats, and as forests become lost and
increasingly fragmented, so does the specialist fauna inhabiting them. Forests, therefore,
contain the highest number of threatened taxa, and also harbour numerous endemic species.
In addition to specialists, well-wooded habitats such as forests, thickets and bushclumps also
serve as important nesting sites for many common birds, as well as temporary refugia and
corridors for migrating forest specialists, e.g. emerald cuckoo, blue duiker, serval, Samango
Terrestrial Fauna
16
Sep-02
monkey, etc. In the coastal region, where there is a mosaic of forest and grassland, many
bushclumps are situated on large termite mounds that serve as shelter for mongoose,
porcupines, aardvarks and other small mammals. They forage in the surrounding grasslands
at night, utilising the bushclumps and adjacent forests for shelter.
Wetlands also form fragmented and specialised habitats. They are essential breeding grounds
for many frogs, and serve as feeding grounds for threatened cranes, other waterbirds, otters
and numerous frog-eating snakes.
They are easily impacted by water abstraction for
commercial farming, siltation from soil erosion caused by overgrazing, pollution from urban
sewage, insecticide and herbicide run-off from agricultural lands, and petroleum spillage on
roads. With burgeoning human populations, isolated yet essential water sources are under
increasing pressure.
Although rarely subject to human pressure, rock outcrops and cliff faces often shelter a
specialist lizard fauna, and also serve as inaccessible, safe nesting sites for many birds,
particularly the endangered Cape Vulture. Rock outcrops may be blasted during construction
of road cuttings, or viewed as sources of in-fill during road construction. However, due to
their isolated habitats and the difficulties of moving between them, specialist rock-living
lizards are often highly endemic.
Rock outcrops should always be surveyed prior to
developments to determine whether they harbour endemic species.
Due to the habitat
diversity, rock outcrops often form faunal hotspots, particularly as they are naturally protected
from the historical impacts of overgrazing and excessive fire regimes.
Although the proposed road route bisects no protected reserves, various protected or
scientifically important areas do occur adjacent to the proposed road route. These areas are
important for the protection of biodiversity and/or threatened species, and the road’s
construction and operation may cause secondary impacts to them. The Mkambati Nature
Reserve (31°16’S, 29°59’E; c. 8000 ha) extends inland from the north-east Pondoland coast,
and is bounded by the Mtentu River in the north and the Msikaba River in the south. It
stretches inland approximately 5km along the Msikaba River and approximately 9.5km along
the Mtentu River. It is a fully protected Nature Reserve controlled by Eastern Cape Nature
Conservation, and includes an important breeding colony (40-70 pairs) of the Globally
Threatened Cape Vulture on cliffs overlooking the Mtentu River. Mtamvuna Nature Reserve
(31°00’S, 30°10’E; 3257 ha; KwaZulu-Natal provincial reserve, fully protected) is located
some 5km west of Port Edward and occupies the eastern side of a steep gorge on the
Mtamvuna River. It includes an important breeding colony (40–48 pairs) of the Globally
Threatened Cape Vulture.
Terrestrial Fauna
17
Sep-02
No existing National Parks occur in the vicinity of the proposed road route, although
discussion is presently underway for the establishment of the Pondoland National Heritage
Park (Hetherington 2001).
However, numerous socio-economic problems still block
agreement on the inland boundaries and controls to be implemented in the proposed park, and
it still awaits proclamation. If this project does come to fruition, the new reserve will have a
unique structure, incorporating formally protected areas, as well as traditional communal
lands. It will extend from the northern bank of the Mzimvubu River at Port St Johns to the
southern bank of the Mtamvuna River near Port Edward, and will incorporate the Mkambati
Nature Reserve.
Important Birds Areas (IBA) comprise a network of sites, at a biogeographic scale, that are
critical for the long term viability of naturally occurring bird populations (Barnes 1998). Two
IBAs which occur adjacent to, or in close proximity to, the proposed road route are the
Mkambati Nature Reserve (31°16’S, 29°59’E; c. 8000 ha; Eastern Cape provincial reserve,
fully protected) and Mtamvuna Nature Reserve (31°00’S, 30°10’E; 3257 ha; KwaZulu-Natal
provincial reserve, fully protected).
A number of other IBAs occur in close proximity to the proposed road route. These include
the Oribi Gorge Nature Reserve (30°43’S, 30°14’E; 1917 ha; KwaZulu-Natal provincial
reserve, fully protected), the Collywobbles Vulture Colony (32°00’S, 28°37’E; unprotected)
in a gorge of the Mbashe River in the Indutywa District, and the coastal, adjoining Dwesa and
Cwebe Nature Reserves (32°16’S, 28°53’E, fully protected Eastern Cape provincial reserves).
All lie some distance from the proposed toll road route and are unlikely to be negatively
impacted by its development.
Evaluation
Savanna and grassland habitats are usually interconnected, allowing easy movement for
fauna.
Habitats such as forests, thicket patches, wetlands and rock outcrops are more
sensitive due to their isolated and fragmented nature. Linear developments such as road
routes may bisect and thus increase the fragmentation of these habitats. In that they may
inhibit movement between such fragments, roads also increase the isolation. The distribution
of sensitive habitats along the road route is not uniform. Small wetlands, important to fauna
and local people, occur along the whole route and need to be considered on a specific basis.
Important forests and rock outcrops occur in the northern section from Tombo to Mtamvuna
River, and road construction in this region has the potential for the greatest faunal impact.
The proposed road corridor in this region travels north of the Vumise Forest Reserve. This
forest reserve must be protected from fire risk and changes to water quality and supply.
Terrestrial Fauna
18
Sep-02
Major bridge crossings are required at five deeply incised gorges, namely the Msikaba,
Mtentu, Mnyameni, Mpahlane Mzamba and Mzimvubu rivers.
The construction of the
bridges is complex due to the rugged nature of the local topography and the presence of
sensitive forest habitats in the gorges. Several alternative crossings for some bridges have
been identified (see section 3.6 in Chapter 3). The low-level bridge crossing the Mzimvubu
River is placed in the valley bottom in the floodplain.
The bridges across the Msikaba and Mtentu are cable-stay bridges that cross the deep river
gorges, whereas the others are incrementally launched. Several alternative crossings have
been identified for the Mtentu River within the identified corridor. The most suitable option
is indicated as alternative 5g4 on all maps (See Chapter 3 Section 3.6), which borders to the
north a sensitive area of mixed bedrock and wetland that is of both faunal and floral
significance. There are also extensive forest patches on the gorge slopes that should be
avoided during construction.
The larger bridges, particularly crossing the Msikaba, Mtentu and Mnyameni rivers, have
ecotourism potential and may serve as appealing sites for the development of rest spots,
viewpoints and associated projects.
For much of its route, the proposed route will have NO SIGNIFICANT impact on Issue 1 –
Ecologically sensitive and protected areas, as the proposed road route only comes into close
proximity to conservation areas and sites of scientific importance in the region between the
Mzimvuba River near Port St Johns and the Mtamvuna River near Port Edward. In this
region impacts are highly probable and will be negative. Although localised, potential
impacts may occur over the long term. Due to the importance of these sites, the impacts will
be severe and significance will be HIGH.
Impacts to sensitive forests, wetlands and rock outcrops are highly probable, and will be local
and negative in nature, and occur over the long term. The significance of these impacts may
vary from LOW to HIGH depending upon the local importance of the habitat and the
particular fauna that it harbours.
Recommendations
Careful design of the approaches and support pillars of the Mzimvubu River bridge is needed
to avoid impacts on sedimentation and estuarine functioning (See Chapter 5 for further
discussion).
Terrestrial Fauna
19
Sep-02
Care must be exercised in the development of rest spots and view points, to ensure that their
associated environmental impacts (e.g. erosion, litter, increased fire risk, etc.) do not impact
the surrounding forest, wetland and rock outcrop habitats.
Mitigation of impacts on forests has, in part, already occurred with the careful selection of the
road route, which avoids many sensitive habitats. Specific project actions associated with
construction, access roads, borrow pits and cut-and-fill construction must avoid sensitive
habitats. Natural drainage should be maintained, and the silt loads into rivers, streams and
wetlands must stay within normal limits.
4.3.3
Issue 2 – Threats to biodiversity
General Comments
The protection of the faunal and floral heritage of the former Transkei region is generally
poor, and the exploitation of forest and coastal resources has been unsustainable even in the
short term. Hunting of all animals in many areas continues (White 1999), although hunting is
largely confined to forests. This hunting pressure is compounded by the fact that the forest
fragments are already too small to maintain viable long term populations of large to mediumsized mammals. Target species have shown a decline, and the increased use of guns led
White (1999) to conclude that the remaining populations of indigenous mammals were under
severe threat. In addition, wild animals (e.g. monkeys, raptors and small carnivores, such as
jackal, caracal and even crowned cranes) were often viewed as pests on livestock and crop
fields and therefore killed. Predation by domestic animals generates an additional impact on
small vertebrates in the region.
Many secondary operational impacts are associated with increased vehicle traffic (see reviews
in Forman and Alexander 1998; Environmental Resources Management 1996). They can be
grouped into increased animal mortality, and disturbance:
•
Increased animal mortalities: Many animals are killed or injured whilst crossing roads.
This may occur during normal movements within their home range (e.g. viverids (Taylor
1971), snakes (Rosen and Lowe 1994) and hedgehogs (Huijser and Bergers 2000));
during annual breeding migrations (e.g. frogs, Fahrig et al. 1995); during seasonal
migrations (e.g. many birds); or when attracted to roads either for warmth (snakes and
lizards) or for food from previous road kills (e.g. vultures, crows and carnivores) or
visible, wind-accumulated seeds (many small granivorous passerines and rodents).
Awareness of this problem is not new (Stoner 1925; Dreyer 1935; Dickerson 1939) and
mortalities on roads, particularly in pristine areas, may impact significantly on long-lived,
Terrestrial Fauna
20
Sep-02
wide-ranging species. Tortoises in North America occur in significantly lower numbers
in areas transected by busy roads than they do in comparable habitats with no roads
(Nicholson 1978). Similarly, short-lived, explosive breeders, i.e. species that undertake
mass migrations to well-defined and long-established breeding sites (e.g. many
amphibians), are very susceptible to vehicles when crossing roads during their mass
breeding migrations. Roads situated next to wetlands may cause unsustainable rates of
mortality to breeding frogs, particularly toads and other large species. Populations can be
easily decimated at such times, and massive road mortality can soon lead to local
extinction (e.g. the Endangered Western Leopard Toad, Bufo pantherinus, in the
southwestern Cape; Harrison et al. 2001). Experience at Suikerbosrand Nature Reserve,
Gauteng, suggests that measures to reduce speeds on roads, such as posting reduced speed
limits to minimise inadvertent vehicle impacts with wildlife, are impractical to enforce.
For small amphibians, various solutions have been proposed (summarised in Langton
1989), including specially constructed tunnels and temporary restrictions (7-10 days) on
traffic movements at night along roads adjacent to breeding ponds. Such procedures are
already commonplace in European cities.
Large under-road culverts for stormwater
control may also serve as safe transit corridors for wildlife in areas of high impact.
•
Disturbance: Vehicle traffic is noisy and at night also involves considerable light
pollution from car headlights or road lighting in urban areas. Together these factors can
depress local populations of sensitive birds and large mammals. Animals differ in the
degree to which they tolerate such disturbance. Large breeding birds do not usually
tolerate continuous disturbance and breeding colonies of threatened birds, particularly
vultures, should be avoided. Increased noise and motor vibrations in wetlands may also
impact amphibian breeding choruses, but these will be very localised and many
amphibian species are surprisingly tolerant of vehicle noise. They are less tolerant,
however, of increased light levels (Buchanan 1993) and ponds adjacent to and illuminated
by road traffic or elevated lighting associated with road interchanges, toll plazas, or
service facilities have reduced amphibian populations.
The distribution of biodiversity within the region is not uniform (Table 4.1). Different
habitats have different carrying capacities, and biodiversity in closed-canopy forest and
grassland is usually low. Highest levels of biodiversity occur in habitat mosaics, particularly
in the coastal areas and river gorges. These differences in biodiversity associated with habitat
structure are compounded by a tropical-temperate transition that occurs along the generally
north-south axis of the proposed road route.
Tropical regions usually host a higher
biodiversity than temperate regions. The general subtraction of tropical diversity moving
Terrestrial Fauna
21
Sep-02
south along the coast of the former Transkei has been well-documented (e.g. Poynton 1990),
and is particularly noticeable in amphibians and birds, but also occurs with reptiles and
mammals.
Table 4.1: Approximate numbers of species occurring in the road sections, excluding birds
and bats.
Group
Sections
1
2
3
4
5
6
7
8
9
10
11
Amphibians
19
19
19
20
21
19
22
23
25
28
28
Reptiles
38
37
37
34
42
38
39
37
46
52
53
Mammals
45
38
38
38
50
38
47
43
48
42
42
Totals
102
94
94
92
113
95
108
103
119
122
123
Evaluation
Due to previous rural agricultural land use practice, biodiversity in the central inland areas of
the road route through the former Transkei have an impoverished biodiversity. Regions still
retaining high biodiversity occur in association with forest, thicket and grassland habitats in
the relatively pristine northern-central coastal region. Negative impacts to biodiversity are
highly probable and will occur over the long term and at a sub-regional scale. The severity
will range from slight to moderate, and the significance will vary from LOW to
MODERATE, depending upon the region and the particular fauna that it harbours.
4.3.4
Issue 3 – Threats to species of special concern
General Comments
Threatened species have been abstracted from South African Red Data Books (birds – Brooke
1984; Barnes 2000; mammals – Smithers, 1986; herpetofauna – Branch 1988; butterflies –
Henning and Henning 1989), the international IUCN Red List of threatened species (IUCN
2000). Updates and species for possible inclusion were obtained from the general literature
(e.g. pulmonates, Herbert 1997). The presence of endemic species was abstracted from
general distribution maps present in faunal surveys (see above). The distribution of the
numerous threatened and endemic species that may occur along sections of the proposed road
route are summarised in Table 4.2.
Terrestrial Fauna
22
Sep-02
Table 4.2: Numbers of species of special concern occurring in the road sections, excluding
bats.
Sections
Group
Butterflies
1
2
2
2
3
Slugs
Cicadas
1
4
5
6
7
8
9
10
1
3
2
1
1
1
1
1
1
1
1
1
1
1
1
3
1
Millipedes
11
1
Amphibians
Reptiles
2
1
2
1
2
2
2
2
2
2
Birds
8
7
6
7
20
19
15
16
17
15
12
Mammals *
6
5
5
6
7
6
6
6
7
6
5
Totals
16
14
14
17
38
32
25
26
28
25
17
Evaluation
The distribution of threatened species along the proposed road route is not uniform (Table
4.2). There is a concentration of threatened species in the region between the Mzimvubu
River near Port St Johns and the Mtamvuna River near Port Edward (sections 5 to 9 of the
road route).
Impacts during the construction of the proposed road (habitat loss and
fragmentation) and its operation (increased fire, disturbance, road mortality, risk of pollution,
etc.) all pose a threat to the survival of populations of threatened species. All impacts will be
negative. The significance of the impact will depend on the success of mitigation of the
primary impacts (habitat loss and fragmentation) during the design of the road route.
Secondary impacts during the operational phase, of high probability, will cause localised
mortalities over the long term.
The cumulative effect may have regional or national
significance depending upon the individual species impacted and their conservation status.
The severity, therefore, ranges from slight to severe, and the significance from LOW to
HIGH.
4.3.5
Issue 4 – Threats to animal movements
General Comments
Linear developments, such as roads and rail tracks, may disrupt the movement of species
within their normal home ranges, or the seasonal movements of migratory species. Habitat
fragmentation can have diverse consequences for ecosystems and their fauna and flora (see
review in Saunders et al. 1991). Apart from direct mortality associated with habitat loss and
Terrestrial Fauna
23
Sep-02
reduction of habitat quality, it can also lead to secondary effects resulting from disruption of
animal movements. This can rapidly impact small, non-flying animals and disruption of gene
flow can lead to loss of genotypic fitness and increased extinction potential (Gerlach and
Musolf 2000).
Habitat fragmentation may require species to make long movements between patches of
suitable habitat in search of mates, breeding sites or food. At such times they may suffer
increased mortality, either directly by road vehicles, or from their natural predators due to
unnatural exposure. Impacts on animal movements will be greatest in regions with high
habitat fragmentation, or where linear developments transect migratory paths.
Large
mammals that may have undertaken seasonal movements are locally extinct throughout the
road route, so this potential impact is no longer relevant in the region.
Reptiles and
amphibians do not undertake long distance migrations, but both groups may undertake short
seasonal movements. Many snakes and large monitor lizards favour high-lying, north-facing
rocky outcrops in which to overwinter. They undertake movements between these and their
summer foraging areas. Similarly, most frogs move to wetlands during the breeding season.
Some amphibians, particularly toads, are explosive breeders, and move en-masse to the
breeding ponds.
At such times they may suffer heavy casualties whilst crossing roads
(Langton 1989; Fahrig et al. 1995).
Where the breeding migrations of endangered
amphibians have been threatened by road traffic, the installation of under-road passes or even
temporary closure of the road during the frog breeding season, have been proposed (see
review and included articles in Langton 1989).
There is a significant movement of migratory birds, particularly Intra-African migrants,
between forest patches along the East Coast littoral region and escarpment forests. Some
forest species, such as spotted thrush, starred robin, bush blackcap, etc., undertake seasonal
movements within South Africa between their winter and summer breeding quarters. Other
species overwinter in central Africa (e.g. many cuckoos, some swallows) moving south to the
summer breeding grounds in South Africa during early spring. Most appear to make frequent,
short movements between patches of suitable habitat, often flying at night.
Palaearctic
waders, migrate between their Northern Hemisphere breeding grounds and southern Africa.
Their flight paths appear to be mainly coastal and are therefore unaffected by the proposed
road route.
Evaluation
Impacts on animal movements will be most significant for birds and mammals in regions with
high habitat fragmentation. For amphibians this impact will be greatest where the road runs
Terrestrial Fauna
24
Sep-02
adjacent to wetlands suitable for breeding. It is an impact of high probability that will be
negative due to increased mortality. It will be localised and occur over the long term, and the
significance will generally be LOW, but may become MODERATE in some areas where
forest fragments and wetlands occur. The most sensitive sections of road include the major
river crossings and forest patches in the Ndwalane to Mtamvuna region.
Recommendations
Mitigation depends firstly on ongoing assessment of the significance of road mortalities to
migratory species. Where breeding toads are being killed in unacceptable numbers, underroad culverts have been effectively installed in a number of European sites to allow their
movement across road barriers (Langton 1989; Yanes et al. 1995). Mortalities can also be
reduced by ensuring that vegetation levels in the road reserve are maintained at low heights.
4.3.6
Issue 5 – Invasion by alien fauna
General Comments
Linear developments such as roads create a suitable corridor for the invasion of alien species.
These may be carried passively into the region in vehicles.
The tropical house gecko
(Hemidactylus mabouia) has expanded its range throughout much of the KwaZulu-Natal
south coast (Bourquin 1987) and scattered towns in the Eastern Cape and Free State (Branch
1998). It is common in caravan parks to which it has been translocated in association with
road traffic. It is thought to be directly responsible for declines in coastal populations of the
Pondoland flat gecko (Afroedura pondolia) (Lambiris and Bourquin 1993). Alien birds, such
as the Indian Myna and House Crow, have also actively expanded their range in association
with urbanisation along road routes (Harrison et al. 1997), as have urban rodent pests such as
the house mouse (Mus musculus) and house rat (Rattus rattus). The Norway rat (Rattus
norvegicus) is larger and more aggressive than the house rat, but is currently restricted to
major cites and towns in the coastal region (Smithers 1983). It may prove a greater danger to
indigenous small mammals than its cousin. Both rats can serve as carriers of plague. In some
cases, e.g. the African cat (Felis lybica) and yellow-billed duck (Anas undulata) species are
threatened by hybridisation with introduced, closely-related domesticated species (e.g.
domestic cat and mallard, respectively).
Evaluation
Negative impacts due to the invasion of alien fauna to the region are highly probable. They
will initially be localised but will spread and occur over the long term. The significance will
generally be LOW, as the probable alien invaders (e.g. some birds, geckos and rodents)
Terrestrial Fauna
25
Sep-02
presently exist in urban situations throughout much of the route already. Mitigation usually
involves active culling programmes of problem animals undertaken by conservation
authorities. Control by road authorities is impracticable.
4.3.7
Issue 6 – Increased fire risk
General Comments
Fire in many ecosystems, particularly grasslands, is a natural phenomenon and prevents
thicket development. Fire in forest habitats is naturally infrequent. However, changes in
water flow dynamics following road construction may reduce the water table locally, drying
vegetation to unnatural levels and making it more susceptible to fire. Construction and
planning of roads should anticipate an increased fire risk.
Increased human population
growth in the area may also occur as a consequence of increased accessibility resulting from
the road development. This will also lead to an increase in accidental fires. Broken bottles at
rest stops can also initiate fires.
Evaluation
These negative impacts, in varying severity, will definitely occur along the whole route. All
impacts will be localised and of long term duration, and can affect local evolutionary patterns
(Thomas et al. 1998; Gerlach and Musolf 2000). The effects can also act synergistically and
reduce the quality of habitat available to birds and other animals alongside roads (Reijnen and
Foppen 1994; Reijnen et al. 1995, 1997). The severity of any impact will depend on aspects
such as the local topography, habitat type and fauna present, but are generally rated as slight
and of LOW significance. Fauna associated with forest and wetland habitats can be expected
to be most at risk, and impacts in regions with a high incidence of threatened species will be
more significant.
Recommendations
Mitigation measures include:
•
Regular maintenance of the road reserve where the road runs through, or adjacent to,
indigenous forests or wetlands should ensure that vegetation is cut short so that it serves
as an effective fire break.
•
Due to increased fire risk from broken bottles, cigarettes, etc., rest stops and other road
associated structures should not be situated adjacent to forests or wetlands, and should be
regularly cleaned.
Terrestrial Fauna
26
Sep-02
4.3.8
Issue 7 - Chemical pollution
General Comments
Heavy vehicle traffic is associated with increased local pollution resulting from exhaust
fumes, oil spillage and accumulation of rubber compounds from tyre wear. These pollutants
can cause localised impacts. Lead concentrations are higher in small terrestrial mammals
collected alongside roads than in bats caught in the same areas (Clark 1979). Sensitive
wetlands or patches of threatened vegetation may need protection from road surface water
run-off containing such pollutants. Frog diversity in ponds affected by pollution from road
run-off is depressed (Hecnar and Mcloskey 1996). Secondary effects can also occur from the
application of herbicides used to control plant growth in the road reserve and around
interchanges and toll plazas. The accumulation of herbicides and their residues in adjacent
wetlands can lead to developmental abnormalities in tadpoles and metamorphosing froglets
(Osano et al. 2002), and also masculinisation of female frogs (Dalton 2002).
Evaluation
Negative impacts from chemical pollution will definitely occur along the road route, and
with little change in severity between the different sections. Air pollution can, however, be
expected to be greater at road interchanges and toll plazas, since traffic concentrates and
slows down. All impacts will be localised and will occur over the long term. The severity
depends on aspects such as the local topography, habitat type and the fauna present, and
impacts can also act synergistically with others such as increased fire risk. These impacts are
generally rated as slight and of LOW significance.
Mitigation measures to be implemented include:
•
Limitations on the use of herbicides for the control of all plant growth in the road reserve
and toll plazas.
•
Road associated structures (e.g. toll plazas, interchanges) and amenities (e.g. garages and
shopping centres, etc.) should not be situated adjacent to sensitive habitats such as
wetlands and forest patches.
•
Stormwater outlets, particularly from toll plazas, should not drain into natural wetlands.
Terrestrial Fauna
27
Sep-02
4.4
Regional assessment
4.4.1
Introduction
Due to the diverse habitats and regions that the road passes through, the above key issues,
previously discussed in generic terms, are now evaluated for the 11 sections of the route.
Specific project actions associated with the sections are detailed in Chapter 1 of this volume.
4.4.2
Section 1: East London to Komga Interchange
All project actions within this section occur in the existing N2 road reserve and involve few
additional impacts on fauna.
The region has a long history of agricultural and urban
settlement and has a relatively low faunal diversity, with few threatened or sensitive species.
Increased road traffic will aggravate the existing impacts of road mortality, increased fire risk
and chemical pollution.
The various issues are all of LOW significance.
They are
summarised in Table 4.3.
4.4.3
Section 2: Komga Interchange to Ngobozi
Much of this section, particularly through the Kei Cutting section, has recently been
upgraded. All project actions within this section occur in the N2 existing road reserve and
involve few additional impacts on fauna. A proposed toll plaza occurs in the Ngobozi region,
is heavily over-grazed and faunally impoverished.
The region has a long history of
agricultural and urban settlement and has a relatively low faunal diversity, with few
threatened or sensitive species. Increased road traffic will aggravate the existing impacts of
road mortality, increased fire risk and chemical pollution. The significance of the various
issues is LOW. They are summarised in Table 4.4.
4.4.4
Section 3: Ngobozi to Umtata
All project actions within this section occur in the existing N2 road reserve and involve few
additional impacts on the fauna. It passes through a region which is heavily over-grazed and
faunally impoverished (Plate 4.2). The region has a long history of agricultural and urban
settlement and has a relatively low faunal diversity, with few threatened or sensitive species.
Increased road traffic will aggravate the existing impacts of road mortality, increased fire risk
and chemical pollution.
The significance of the various issues is LOW.
They are
Terrestrial Fauna
28
Sep-02
Table 4.3:
Summary of issues for Section 1: East London to Komga Interchange.
ISSUE/IMPACT
1. Sensitive habitat loss
2. Threats to biodiversity
3. Threats to SSC
4. Disruption of movement
5. Invasion of alien species
6. Increased fire risk
7. Chemical pollution
Table 4.4:
Temporal
Permanent
Significance
LOW
WITH MITIGATION
Severity
Significance
Slight
LOW
Permanent
Sub-regional
Definite
Slight
LOW
Slight
LOW
Permanent
Regional
Probable
Slight
LOW
Slight
LOW
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Permanent
Sub-regional
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Significance
LOW
WITH MITIGATION
Severity
Significance
Slight
LOW
LOW
Slight
LOW
LOW
Slight
LOW
Summary of issues for Section 2: Komga Interchange to Ngobozi.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
WITHOUT MITIGATION
Spatial
Cert.
Severity
Localised
Probable
Slight
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Permanent
WITHOUT MITIGATION
Spatial
Cert.
Severity
Localised
Probable
Slight
SubDefinite
Slight
regional
Regional
Probable
Slight
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Permanent
Subregional
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Temporal
Permanent
Permanent
29
Sep-02
Plate 4.2: The natural environment along section 3 of the route has been impacted as a result
of overgrazing.
4.4.5
Section 4: Umtata to Ndwalane
All project actions within this section occur in the existing R61 road reserve and involve few
additional impacts on the fauna. It passes through a region of rolling hills, with extensive
agricultural development but with sensitive drainage lines with patches of riparian vegetation.
Although the region has a long history of settlement and agriculture, faunal diversity remains
relatively high with a number of threatened or sensitive species. Increased road traffic will
aggravate the existing impacts of road mortality, increased fire risk and chemical pollution.
The significance of the various issues are LOW or MODERATE, depending on the type of
habitat which occurs and the fauna which these harbour. They are summarised in Table 4.6.
Terrestrial Fauna
30
Sep-02
Table 4.5:
Summary of issues for Section 3: Ngobozi to Umtata.
ISSUE/IMPACT
3. Threats to SSC
Table 4.6:
Temporal
Permanent
Severity
Slight
Significance
LOW
WITH MITIGATION
Severity
Significance
Slight
LOW
Permanent
Sub-regional
Definite
Slight
LOW
Slight
LOW
Permanent
Regional
Probable
Slight
LOW
Slight
LOW
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Permanent
Sub-regional
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Summary of issues for Section 4: Umtata to Ndwalane.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
WITHOUT MITIGATION
Spatial
Cert.
Localised
Probable
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Permanent
WITHOUT MITIGATION
Spatial
Cert.
Localised
Probable
Severity
Slight
Significance
LOW
WITH MITIGATION
Severity
Significance
Slight
LOW
Permanent
Sub-regional
Definite
Slight
LOW
Slight
LOW
Permanent
Regional
Probable
Slight
LOW
Slight
LOW
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Permanent
Sub-regional
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
31
Sep-02
4.4.6
Section 5: Ndwalane up to and including Ntafufu River crossing
This section forms the start of the greenfields corridor, and road construction will involve the
loss of varied habitats and the associated loss of biodiversity and threats to SSC. The road
will cause fragmentation of habitats with disruption of faunal movements. The bridge built
across the Mzimvubu River may cause disruption of riverine hydrodynamics (all other major
bridges are high-level bridges), whilst specific project actions associated with road
construction can impact adjacent areas outside the road reserve. The section passes through a
region of rolling hills with a mosaic of agricultural plots and sensitive drainage lines with
patches of riparian vegetation that are extensive in the more inaccessible river gorges. Faunal
diversity remains high and the region has a significant number of threatened, sensitive and
endemic species. The significance of the various issues is LOW, MODERATE or HIGH,
depending on the type of habitat which occurs and the fauna which these harbour. The latter
with mitigation (such as discussed in section 4.3) can be reduced to MODERATE. They are
4.4.7
Section 6: Ntafufu River via Lusikisiki to Magwa Tea Estate intersection
This section includes the existing R61 up to Lusikisiki and the existing concrete road from
Lusikisiki up to the Magwa Intersection. There is no greenfields construction in this section.
Upgrading and widening may involve the loss of varied habitats and the associated loss of
biodiversity and threats to SSC. Specific project actions associated with road construction
will impact adjacent areas outside the road reserve. The section passes through a region of
rolling hills with a mosaic of agricultural plots and sensitive drainage lines with patches of
riparian vegetation that are extensive in the more inaccessible river gorges. Faunal diversity
remains high, although the absence of large forest tracts means that there are low numbers of
threatened, sensitive and endemic species. The significance of the various issues is LOW or
MODERATE, depending on the type of habitat which occurs and the fauna which these
harbour. All impacts can be reduced to LOW with mitigation (as discussed in section 4.3).
Impacts are summarised in Table 4.8.
Terrestrial Fauna
32
Sep-02
Table 4.7:
Summary of issues for Section 5: Ndwalane up to and including Ntafufu River crossing.
ISSUE/IMPACT
3. Threats to SSC
Table 4.8:
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Severity
Moderately
Severe
Moderately
Severe
Permanent
Corridor
Definite
Permanent
Sub-regional
Definite
Permanent
Regional
Probable
Permanent
Corridor
Definite
Permanent
Sub-regional
Probable
Moderately
Severe
Slight
Permanent
Localised
Probable
Permanent
Localised
Probable
Significance
WITH MITIGATION
Severity
Significance
MODERATE
Slight
LOW
MODERATE
Slight
LOW
HIGH
Moderately
Severe
MODERATE
MODERATE
Slight
LOW
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Severe
Summary of issues for Section 6: Ntafufu River via Lusikisiki to Magwa Tea Estate intersection.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
Risk
Definitely
occur
Definitely
occur
WITHOUT MITIGATION
Spatial
Cert.
Risk
Definitely
occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
WITHOUT MITIGATION
Spatial
Cert.
Permanent
Corridor
Definite
Permanent
Sub-regional
Definite
Permanent
Regional
Probable
Permanent
Corridor
Definite
Permanent
Sub-regional
Probable
Severity
Moderately
Severe
Moderately
Severe
Moderately
Severe
Moderately
Severe
Slight
Permanent
Localised
Probable
Permanent
Localised
Probable
33
Significance
WITH MITIGATION
Severity
Significance
MODERATE
Slight
LOW
MODERATE
Slight
LOW
MODERATE
Slight
LOW
MODERATE
Slight
LOW
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Sep-02
4.4.8
Section 7: Magwa intersection up to and including Msikaba River crossing
This section involves an extensive greenfields corridor that passes through sensitive and varied habitats,
involving the Pondoland Centre of Plant Endemism, the Msikaba Sandstone Formation, and a series of
rugged river gorges. Road construction will involve the loss of varied and sensitive habitats and the
associated loss of biodiversity and threats to SSC. The road will cause fragmentation of habitats with
disruption of faunal movements. Specific project actions associated with road construction may impact
adjacent areas outside the road reserve (e.g. at borrow pits). The section passes through a region of rolling
hills with a mosaic of villages, agricultural plots and sensitive habitats. The latter include wetlands, drainage
lines with patches of swamp forest, extensive riparian vegetation in the more inaccessible river gorges, and
large areas of exposed sandstone bedrock. Faunal diversity remains high and the region has a significant
number of threatened, sensitive and endemic species. The significance of the various issues is LOW,
MODERATE or HIGH, depending on the type of habitat which occurs and the fauna which these harbour.
The latter with mitigation (as discussed in section 4.3) can be reduced to MODERATE (Table 4.9).
4.4.9
Section 8: Msikaba River up to and including Mtentu River crossing
This section of extensive greenfields corridor is similar to the previous section, and involves another large,
high-level bridge across the Mtentu River. Faunal diversity and impacts are similar. The significance of the
various issues is LOW, MODERATE or HIGH.
The latter with mitigation can be reduced to
MODERATE. They are summarised in Table 4.10.
4.4.10 Section 9: Mtentu River up to and including Mtamvuna River crossing
This section involves an extensive greenfields corridor that passes through sensitive and varied habitats,
involving the Pondoland Centre of Plant Endemism, the Msikaba Sandstone Formation, and a series of
rugged river gorges. Road construction will involve the loss of varied and sensitive habitats and the
associated loss of biodiversity and threats to SSC. The road will cause fragmentation of habitats with
disruption of faunal movements. The region includes numerous rock outcrops interspersed with drainage
lines. Specific project actions associated with road construction may impact adjacent areas outside the road
reserve. The section passes through a region of rolling hills with a mosaic of villages, agricultural plots and
sensitive habitats. The latter include wetlands, drainage lines with patches of swamp forest, extensive
riparian vegetation in the more inaccessible river gorges, and large areas of exposed sandstone bedrock.
Faunal diversity remains high and the region has a significant number of threatened, sensitive and endemic
species. The significance of the various issues is LOW, MODERATE or HIGH, depending on the type of
habitat which occurs and the fauna which these harbour. The latter with mitigation (as discussed in Section
4.3) can be reduced to MODERATE. They are summarised in Table 4.11.
Terrestrial Fauna
34
Sep-02
Table 4.9:
Summary of issues for Section 7: Magwa intersection up to and including Msikaba River crossing.
ISSUE/IMPACT
3. Threats to SSC
Table 4.10:
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Severity
Moderately
Severe
Moderately
Severe
Permanent
Corridor
Definite
Permanent
Sub-regional
Definite
Permanent
Regional
Probable
Permanent
Corridor
Definite
Permanent
Sub-regional
Probable
Moderately
Severe
Slight
Permanent
Localised
Probable
Permanent
Localised
Probable
Significance
MODERATE
MODERATE
WITH MITIGATION
Severity
Significance
Moderately
MODERATE
Severe
Slight
LOW
LOW
Moderately
Severe
Moderately
Severe
Slight
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Severe
HIGH
MODERATE
MODERATE
MODERATE
LOW
Summary of issues for Section 8: Msikaba River up to and including Mtentu River crossing.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
Risk
Definitely
occur
Definitely
occur
WITHOUT MITIGATION
Spatial
Cert.
Risk
Definitely
occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
WITHOUT MITIGATION
Spatial
Cert.
Severity
Moderately
Severe
Moderately
Severe
Permanent
Corridor
Definite
Permanent
Sub-regional
Definite
Permanent
Regional
Probable
Permanent
Corridor
Definite
Permanent
Sub-regional
Probable
Moderately
Severe
Slight
Permanent
Localised
Probable
Permanent
Localised
Probable
35
Significance
MODERATE
MODERATE
WITH MITIGATION
Severity
Significance
Moderately
MODERATE
Severe
Slight
LOW
LOW
Moderately
Severe
Moderately
Severe
Slight
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Severe
HIGH
MODERATE
MODERATE
MODERATE
LOW
Sep-02
Table 4.11:
Summary of issues for Section 9: Mtentu River up to and including Mtamvuna River crossing.
ISSUE/IMPACT
3. Threats to SSC
Table 4.12:
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Severity
Moderately
Severe
Moderately
Severe
Permanent
Corridor
Definite
Permanent
Sub-regional
Definite
Permanent
Regional
Probable
Permanent
Corridor
Definite
Permanent
Sub-regional
Probable
Moderately
Severe
Slight
Permanent
Localised
Probable
Permanent
Localised
Probable
Significance
MODERATE
MODERATE
WITH MITIGATION
Severity
Significance
ModeratelyS
MODERATE
evere
Slight
LOW
LOW
Moderately
Severe
ModeratelyS
evere
Slight
Slight
LOW
Slight
LOW
Slight
LOW
Slight
LOW
Severe
HIGH
MODERATE
MODERATE
MODERATE
LOW
Summary of issues for Sections 10: Mtamvuna River to Umkomaas Interchange.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
Risk
Definitely
occur
Definitely
occur
WITHOUT MITIGATION
Spatial
Cert.
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Permanent
WITHOUT MITIGATION
Spatial
Cert.
Localised
Probable
Severity
Slight
Significance
LOW
WITH MITIGATION
Severity
Significance
Slight
LOW
Permanent
Sub-regional
Definite
Slight
LOW
Slight
LOW
Permanent
Regional
Probable
Slight
LOW
Slight
LOW
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Permanent
Sub-regional
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Moderately
Severe
MODERATE
Slight
LOW
36
Sep-02
Table 4.13:
Summary of issues for Section 11: Umkomaas Interchange to Isipingo Interchange.
ISSUE/IMPACT
3. Threats to SSC
Terrestrial Fauna
WITHOUT MITIGATION
Risk
May occur
Definitely
occur
May occur
Definitely
occur
May occur
Definitely
occur
Definitely
occur
Temporal
Permanent
Permanent
WITH MITIGATION
Spatial
Cert.
Localised
Probable
Slight
LOW
Slight
LOW
Definite
Slight
LOW
Slight
LOW
Subregional
Severity
Significance
Severity
Significance
Permanent
Regional
Probable
Slight
LOW
Slight
LOW
Permanent
Corridor
Definite
Slight
LOW
Slight
LOW
Probable
Slight
LOW
Slight
LOW
Permanent
Subregional
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
Permanent
Localised
Probable
Slight
LOW
Slight
LOW
37
Sep-02
4.4.11 Section 10: Mtamvuna River to Umkomaas Interchange
All project actions within this section occur in the existing road reserve and involve few
additional impacts on the fauna. The route passes through a region of extensive urban
development, but which, due to its tropical location and the presence of adjacent protected
areas (e.g. Oribi Gorge NR), retains a diverse fauna, although with few threatened or sensitive
species. Increased road traffic will aggravate the existing impacts of road mortality, increased
fire risk and chemical pollution. The significance of the various issues is LOW. They are
4.4.12 Section 11: Umkomaas Interchange to Isipingo Interchange
All project actions within this section occur in the existing road reserve and involve few
additional impacts on the fauna. The route passes through a region of extensive urban
development, but which due to its tropical location and the presence of adjacent protected
areas, retains a diverse fauna, although with few threatened or sensitive species. Increased
road traffic will aggravate the existing impacts of road mortality, increased fire risk and
chemical pollution. The significance of the various issues is LOW. They are summarised in
Table 4.13.
4.5
Conclusions
The above report highlights issues that result in environmental impacts on the fauna along the
proposed road route. Based on these findings a number of recommendations can be made.
•
Most sensitive sections: It is evident from the distribution of biodiversity, presence of
threatened species and sites of scientific interest, that the proposed road construction and
operation in the greenfields section from Ndwalane to Mtamvuna has the potential for the
greatest faunal impact.
This is particularly true of the major river crossings, their
contained forests and the regions of wetland and bedrock mosaic on the west bank of the
Msikaba River and around the Mnyameni waterfall.
•
Most sensitive habitats: Many threatened species are forest and wetland specialists,
linked to these habitats either for breeding, feeding or shelter. Existing wetlands and
forest patches should be avoided wherever possible during road construction. Existing
hydrodynamics must be protected to ensure that water regimes to forest and wetland
habitats are maintained. The road reserve must be maintained to serve as buffer zones to
prevent the immediate impact of chemical pollution or increased fire risk.
Terrestrial Fauna
38
Sep-02
•
Monitoring of threatened species: A large number of threatened and sensitive species
have been recorded in the Port St Johns – Mtamvuna region (see Section 4.2.2). The
EMP for the road construction phase should highlight the conservation status of these
species and note that steps must be undertaken in conjunction with conservation
authorities to protect or translocate any populations encountered during project actions.
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SPECIALIST STUDY – FAUNA

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