Journal of African Crane Research and Conservation

No 8 January 2012
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Journal of African Crane Research and Conservation
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Contents
Conflict in the Karoo with Blue Cranes and agricultural lands_____________________4
Storks’ diversity, flock characteristic, roosting ecology and fluctuation in numbers with
annual climatic change in Dinder National Park, Sudan___________________________5
Mondi adopts a Wattled Crane_______________________________________________6
Unusually large Blue Crane family___________________________________________7
The potential of vocal pair bond monitoring for the Blue Crane
(Anthropoides paradiseus)___________________________________________________8
The history and current status of Wattled Cranes in Zimbabwe___________________15
Eurasian Cranes Grus grus in Ethiopia________________________________________20
Summary of the 2010 annual KZN crane aerial survey__________________________26
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Therefore, there are mixed feelings about Blue Cranes on agricultural lands, but it is always appreciated to have
farmers who find cranes beneficial. It would be better if Blue Cranes can mainly occur in the natural area of the
Karoo, but it is still not known what their real effects are to agricultural lands in the Karoo. There is a need for
further studies.
References
Allan, D.G. 2005. Blue Crane. In: Hockey, P.A.R., Dean, W.R.J., Ryan P.G. (Eds.). 2005. Roberts Birds of
Southern Africa 7th Edition. Cape Town: Trustees of the John Voelcker Bird Book Fund. pp 309 to 311.
Allan, D.G. and Ryan, P.G. 1996. Morphometrics, Sex, Ratio, Molt, and Stomach Contents of Blue Cranes
in the Western Cape Province, South Africa. In: Beilfuss, R.D., Tarboton, W.R., Gichuki, N.N. (Eds.).
Proceedings 1994 African Crane and Wetland Training Workshop. Baraboo: International Crane Foundation. pp
337 to 388.
Colahan, B.D. 2005. Spurwinged Goose. In: Hockey, P.A.R., Dean, W.R.J., Ryan P.G. (Eds.). 2005. Roberts
Birds of Southern Africa 7th Edition. Cape Town: Trustees of the John Voelcker Bird Book Fund. pp 95 to 97.
Davies, G.B.P. and Allan, D.G. 2005. Egyptian Goose. In: Hockey, P.A.R., Dean, W.R.J., Ryan P.G. (Eds.). 2005.
Roberts Birds of Southern Africa 7th Edition. Cape Town: Trustees of the John Voelcker Bird Book Fund. pp 91 to 93
McCann, K. 2000. Blue Crane. In: Barnes, K.N. (Ed.). 2000. The Eskom Red Data Book of Birds of South Africa,
Lesotho ad Swaziland. Johannesburg: BirdLife South Africa. pp 92 to 94.
Skinner, J.D. and Smithers, R.H.N. 1990. The Mammals of the Southern African Subregion. Pretoria: University
of Pretoria.
Storks’ diversity, flock characteristic, roosting ecology and fluctuation in
numbers with annual climatic change in
Dinder National Park, Sudan
Omer Meina and Ibrahim M. Hashim
Storks were studied in Maya (meadow) ecosystem of Dinder National Park (DNP) during the dry season of 2009
and 2010. Our object was to determine their diversity, flock characteristics, roosting ecology and fluctuation in
numbers with annual climatic change.
Storks were identified by directly observing them in the mayas, using telescopes and binoculars. Their
numbers were determined by the double sampling procedure in which the researcher was trained to estimate
the number of storks in their flocks and then count them directly. This was repeated until the estimated numbers
were equal to or very close to the counted numbers. A regression model was then developed between the two
variables. Subsequently, the researcher only estimated the number of storks from which the counts were predicted.
The roosting ecology was studied in Maya ecosystem where herbaceous vegetation cover was determined by
the loop method, tree density by the nearest neighbor method. Crown diameters of trees were measured from
which crown areas were calculated.
Results of the study showed that eight species of storks occurred in DNP, including Abdim’s, Yellow-billed,
wooly-necked, African open-billed, Saddle-billed, the Black stork and the White stork. Among these, the latter
two species were Palearctic migrants whereas, Abdim’s, Wooly-necked, African open-billed and Yellow-billed
were locally migrant. The Marabou and the saddle-billed were resident in the park.
Three species of storks occurred in flocks. The largest flock was formed by the yellow-billed, the second in size
by the Marabou and the least by the open-billed. Juvenile/female ratio was relatively high for the Open-billed
(49%), but almost equal for the Yellow-billed (29%) and the Marabou (31%). Male/female ratio of yellow-billed
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was 51% and was unity for the remaining species, suggesting that Yellow-billed is polygamous whereas,
Open-billed and Marabou are monogamous.
Numbers of storks reported in Maya ecosystem varied considerably between the two years. In 2009 the total
numbers in respective summer and winter seasons were 8,053 and 8,380. In 2010, however, the numbers were
360 and 589, respectively. This decline in number was attributed to severe drought that struck the DNP in 2010.
No relationship was found between the roosting ecology and vegetation attributes. Marabou, the only stork
that roosted in DNP, showed affinity to a particular tree. Among the 10 species recorded in roosting sites, only
Balanites aegyptiaca was selected by the Marabou for roosting.
Mondi adopts a Wattled Crane
Chris Burchmore
The Wattled Crane is critically endangered in South Africa. Sighting a new pair and discovering a nest is
significant, and reporting the presence of eggs forms a vital part of conservation efforts.
In July 2009, a Wattled Crane nest containing two eggs was discovered by Mondi staff on the Homesdale Farm
near Greytown in the KwaZulu Natal Midlands. Wattled Crane can lay up to two eggs at a time and only one of
these is reared by the parents, the second is abandoned or eaten by predators.
The Endangered Wildlife Trust’s Threatened Grassland Species Programme, who assist the African Crane
Conservation Programme (ACCP), rescued the second egg for captive rearing as part of their conservation
efforts. Once the chick had hatched, she was named Andrea and sent to Gauteng to be puppet-reared at the
Johannesburg Zoo. Andrea is now fully grown and has been moved to the breeding centre for introduction to a
potential mate.
In August this year, while monitoring the nest, it was discovered that the Wattled Crane had again laid two eggs.
The second egg was consequently rescued and Mondi adopted the chick and named it Mhambi, which means
traveler. The company also donated R10 000 to cover the costs for the first year of its life.
“Wattled Cranes are the most highly endangered and rarest cranes on the African continent,” explains Viv
McMenamin, Mondi Forestry and Land Director. “Only 250 birds remain in South Africa, with the most significant
population residing in isolated pockets in KwaZulu Natal. Mhambi will become part of the recovery programme’s
breeding flock at the Bill Barnes Crane and Oribi Nature Reserve near Nottingham Road in KwaZulu-Natal. The
chicks from the breeding flock will subsequently be released into existing Wattled Crane flocks in an effort to
bolster the wild population”.
It is becoming increasingly apparent that setting aside areas to conserve functioning ecosystems, biodiversity
and rare or endangered species is vitally important. The Mondi Wetlands Programme (MWP) aims to bring about
the rehabilitation, wise use and sustainable management of South Africa’s wetlands.
“The MWP is playing a pivotal role in contributing towards the conservation of the Wattled Crane’s habitat. It
gives us great pleasure to know that the work of the programme is not only protecting ecological networks, but
also aiding the survival of the Wattled Crane,” says Viv.
The KwaZulu Natal Crane Foundation awarded Lake Merthley “Crane Custodian” status in February 2010 in
recognition of Mondi’s efforts to protect the birds and their habitat.
Saving the cranes without significant intervention it is likely that the wild Wattled Crane population will struggle to
recover from the decades of population decimation.
The vast majority of Wattled Cranes lay only one egg, but a small percentage will lay two. The second egg
merely serves as an insurance policy in case the first egg does not hatch. Soon after hatching, Wattled Crane
parents will lead the first chick away from the nest to avoid predation, and abandon the second egg. The chick
inside the second egg generally dies from hypothermia or is eaten by predators. The Wattled Crane Recovery
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Temporal comparison of call series
A comparison between 33 Blue Crane pairs is given in Table 3, where it shows the breeding status of each
pair, whether the pair members gave guard calls in series and whether there was either initial or continued
overlap in the call series. Of the 33 pairs, 20 had bred and seven had not bred at the time the recordings were
made. The breeding status of six pairs was unknown and they were therefore removed from further analysis.
Table 4.1 gives a comparison between pairs that had bred and those that had not bred, showing both the
number of pairs, as well as the percentage of pairs within each group that gave guard calls in series and
whether the call series showed initial and continued overlap. Of the 20 pairs that had bred, all 20 (100%)
gave guard calls in series. Two pairs (10%) showed initial overlap and none showed continued overlap in
their call series. Of the seven pairs that had not bred, three pairs (43%) gave guard calls in series and of
these three, one pair (33%) showed initial overlap and none showed continued overlap in their call series.
Table 1: Average mean, maximum, minimum and standard deviation values for intra-pair comparisons of
spectral and temporal Blue Crane guard call parameters.
Intra-pair values
Pairs (n=30)
Intra-pair fo
(Hz)
Intra-pair duration (msec)
Mean
336
75
Max
585
258
Min
117
2
SD
120.4
67.6
p-value
<0.0001
0.0764
Two-tailed, unpaired t-test
As no pairs showed continued overlap in their guard call series, Figure 3 only shows the percentage of pairs that
gave guard calls in series and that showed initial overlap in the call series, both for those pairs that had bred
and those that had not bred. It indicates that amongst the pairs that had bred the percentage that gave guard
calls in series were more than double compared to those that had not bred. Also, the percentage of pairs that
showed initial overlap in their guard call series was lower amongst the pairs that had bred than amongst those
pairs that had not bred.
Table 4.2 and Table 4.3 show the results for Fisher’s Exact Test that was performed to establish the significance
of guard call series and initial overlap of the call series for pair bond monitoring. The presence of a guard call
series proved to be statistically significant (p = 0.0020) for pair bond monitoring but initial overlap of the call
series was not statistically significant (p = 0.3563).
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Table 5: Background information on Blue Crane pairs that had not bred, including a short description on their
pair behaviour and the temporal comparison of their guard call series.
Pair name
Pair information
Pair behaviour
Guard call series
Joburg Zoo Parys pair
Older male who lost mate and No pair behaviour
was recently paired up with
young female
Guard called separately but no
guard calls in series
Tygerberg Zoo Gabriel & partner
Older male who has been Some pair behaviour
paired for several years with female of unknown age
Male guard called but female
gave no vocalizations
Tygerberg Zoo Pair 1
Male and female of unknown Some pair behaviour
age recently paired up
Male guard called but female
gave no vocalizations
Tygerberg Zoo Pair 2
Male and female of unknown Some pair behaviour
age recently paired up
Male guard called but female
gave no vocalizations
Monte Casino Pair 2
Young male and female,
recently paired up
Showed pair behaviour
Guard called in series with no
overlap
Joburg Zoo Kudu Pair
Male and female of unknown Showed pair behaviour
age who has been paired for
several years
Guard called in series with no
overlap
De Wildt Pair
Male and female of unknown Showed pair behaviour
age who has been paired for
several years
Guard called in series with initial
overlap but no continued overlap
Discussion
Spectral and temporal characteristics of the guard calls of Blue Crane pairs were compared to their breeding
status to determine the feasibility of its use in pair bond monitoring. Following is a discussion of each potential
monitoring technique, where after the potential of vocal pair bond monitoring is discussed.
Spectral comparison of call parameters
The intra-pair fundamental frequency values of 30 Blue Crane pairs were studied to determine whether
spectral intra-pair differences could predict a pair’s breeding potential. At the time the recordings were made, 20
of these pairs had bred and four pairs had not bred. This study showed that the intra-pair fundamental frequency
values were widely distributed, both for the pairs that had bred and those that had not. A spectral comparison of
intra-pair call parameter values would therefore not seem to be a reliable predictor of a pair’s breeding potential.
Temporal comparison of call series
As coordinated duets may show pair stability or commitment between the pair members, the breeding status of
33 Blue Crane pairs were compared as to whether they gave guard calls in series and to the amount of temporal
overlap within these call series (Table 3). Of the seven pairs that had not bred, four pairs (57%) gave no guard
calls in series; of the three pairs that did give call series one pair (33%) showed initial overlap and none showed
continued overlap.
The background information on the pairs that had not bred is given in Table 5, including a short description on
their pair behaviour and the temporal comparison of their guard call series. The relationship between the guard
call series and pair bond is evident in the first four pairs. These pairs showed little to no pair behaviour, including
guard calling in series. They were mostly recently paired up, and none of them had bred at that time. Although
also quite recently paired, Monte Casino Pair 2 showed both pair behaviour and gave guard calls in series. As
they were both still young birds, it could be assumed that in time they would therefore breed. The last two pairs,
however, have been paired for several years: they showed pair behaviour, including guard calling in series, yet
they had not bred. Although these two pairs warrants investigation as their behaviour is contradictory to the
majority, they form only 9% of the group that gave guard calls in series.
Thus, while all the pairs that had bred gave guard calls in series, these duets were given by less than half of the
pairs that had not bred (Figure 3). Only 10% of pairs that had bred showed any overlap in their guard call series.
Initial overlap within the call series of those pairs that had not bred is a third higher than for pairs that had bred.
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The history and current status of Wattled Cranes in Zimbabwe
Togarasei Fakarayi
Abstract
The Zimbabwe’s central watershed supports about 75% of the total population of Wattled Cranes
Bugeranus carunculatus found in Zimbabwe. Historically, several breeding pairs of Wattled Cranes used to occur
in the Northern-central, Northern part of the Eastern Highlands and Central-western parts of the country but the
majority of them have since disappeared in those regions. Recently the Wattled Cranes have been mainly
recorded in the Driefontein Grasslands Important Bird Area (IBA). This IBA provides the key foraging, breeding and
roosting habitats for Wattled Cranes in the central watershed. The surveys conducted in Driefontein since 2000 have
indicated a decline of Wattled Cranes population. Human disturbances especially wetland cultivation is thought
to have contributed to deterioration of some foraging and breeding habitats, and therefore resulted in population
decline. As a conservation response the local communities were engaged in crane conservation in an attempt to
regulate human activities in wetland habitats. This paper outlines the status of Wattled Cranes in Zimbabwe and
response measures taken to improve conservation of this globally threatened species in the Driefontein
Grasslands.
Key words: Bugeranus carunculatus, Driefontein Grasslands, Zimbabwe
The Wattled Crane Bugeranus carunculatus is a breeding resident of Zimbabwe’s central watershed where it
occupies sedge-lined dambos, pans and man-made dams in open grasslands. The central watershed, an area
encompassing Charter, Featherstone, Chivhu, Felixburg and Mvuma is the key stronghold for Wattled Crane in
Zimbabwe supporting about 100 Wattled Cranes. The highest density has been recorded in Felixburg area (QDS
1930 B4) where a total of 127 Wattled Cranes recorded in 1996 (Couto, 2000). Besides the central watershed,
the Wattled Crane used to occur in s Harare, Marondera, Mutorashanga and Wedza of the Mashonaland Plateau
(Chirara, 2011). Pairs were also found in parts of the Eastern Highlands, east of 32˚E. The Wattled Crane has
also been sighted in wetlands in Nkayi, Lupane and Hwange in the central-western part of the country. In 1995,
1996 and 1997, a pair was recorded at Mbazhe Pan Bird Sanctuary in Nkayi District of the Matabeleland North
Province (Mundy et al. 2000). In Hwange National Park and the surrounding wetland areas about 10 pairs were
sighted in 2009 (Parks Rangers. pers comm). However, this needs further investigation/survey to establish the
actual population. From the aerial and ground surveys conducted in the 1980’s and 1990’s, the estimated
maximum breeding population was 100 pairs, of which only 50 breeding sites were known (Mundy et al. 2001). The
Wattled Crane is classified as Vulnerable on the IUCN Red Data List (2011). They fall under the category of Specially
Protected Species under the Zimbabwe Parks and Wildlife Act of 9175 as amended in 1996 (Mundy. et al. 2001).
In recent years, the Wattled Cranes have been predominantly recorded in the Driefontein Grasslands (Fig. 1), and
this is also the key breeding and foraging area for Wattled Cranes. The total population was estimated through
ground surveys. Currently monitoring of Wattled Cranes is done through ground surveys and regular visits to
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the Driefontein area, and is carried out in conjunction with local communities who were trained to capture data
and keep records of crane sightings. In the past, the Driefontein Grasslands supported both the breeding pairs
and flocks. In drought years, flocks can number over 100 individuals (Irwin 1981). Large flocks were recorded
in the 1980’s including a flock of 87 counted in October 1989 (Francis 1990). Over the years, the New and Old
Driefontein Mission Dams were frequently used by a large flock of Wattled Cranes for foraging. These dams are
located in the Felixburg area, sharing the same stream (Shashe).The Old Driefontein Dam is about 6km SSW of
the new dam. In 2004 a flock of 31 Wattled Cranes was recorded at the New Driefontein Dam. These two dams
also support a significant number of breeding pairs.
Land use in the Driefontein Grasslands has changed from commercial cattle ranching by white farmers to mixed
farming by small scale farmers who were resettled in the area during the land resettlement programme of 2000.
This had negatively affected the survival of Wattled Crane which seemed to have integrated well with the cattle
ranching over the years. The Wattled Cranes have lost more than a quarter of their wetland habitats because
larges pieces of land were converted to crop cultivation. However, the conservation work carried out by BirdLife
Zimbabwe after the resettlement programme promoted the survival of Wattled Cranes in Driefontein Grasslands.
The Wattled Cranes seem to have adapted to the land use changes and human population increase although
there are indications of Wattled Crane population decline in the area. The reduction of Wattled Crane in the area
is thought to be due to temporary migration of cranes from their disturbed traditional sites to new sites with fewer
disturbances.
There are indications of Wattled Cranes moving from their original sites to new sites within the Driefontein
Grasslands presumably because of land use changes, habitat fragmentation and other human disturbances. In
some areas human disturbances are high especially at sites that are close to human settlements. Human activity
in form of uncontrolled market gardening is the major disturbance at some of the old sites. Other sites that are
in the form of man-made dams have broken dam walls, and therefore their water holding capacity is reduced.
The local communities lack resources to maintain these dams. Such disturbed and/or deteriorated sites are no
longer suitable habitats for crane breeding although they are used as foraging sites. A resident pair of Wattled
Crane can now look for a new site within the Driefontein Grasslands or the surrounding areas for breeding and
it can come back to the old site as a visitor. Generally the population of the Wattled Crane has been decreasing
since 2000 (table 1 below). The highest count of 138 Wattled Cranes was, however, recorded at the peak of the
resettlement programme in 2004. Since then, surveys have indicated a general decrease in the population of
the Wattled Crane, with the lowest record being 34 birds from the April 2009 survey (Chirara, 2011). About 103
sites were explored during the 2009 survey. Although the results of the surveys reflected low numbers, most
villagers had confirmed regular sightings of more than 70 Wattled Cranes especially during the beginning of the
wet season (November).
Based on previous records and current information gathered from villagers, there is a possibility of Wattled
Cranes migrating to areas surrounding the Driefontein Grasslands within the central watershed during the winter
season. Some of the breeding pairs that fail to secure a conjusive breeding site might look for a site with fewer
disturbances for breeding in the surrounding areas. Also the flocks are thought to migrate and occupy sites
where they can get sufficient food. Such movements might have attributed to low numbers of Wattled Cranes
recoded during recent surveys (2008-2010) as compared to records obtained before 2008. However, the
Wattled Cranes are thought to come back to the old sites for food during the wet season. There is less
competition for food and territorial sites among breeding pairs during the wet season because soil penetrability
is high in most parts of the Driefontein, and food is in abundance during this season. That could be reason why
local villagers reported sightings of large numbers of Wattled Cranes in the wet season. This notion needs to be
investigated further. The Driefontein Grasslands still provides suitable foraging and roosting grounds for Wattled
Cranes. However, the breeding sites for Wattled Cranes are decreasing due to disturbances at sites that are
close to human settlement, lack of maintenance of dams, and deterioration of other sites that are affected by
veld fires. If such sites are restored, there is a high potential that they can be recolonised by the breeding pairs.
Over the past ten years, BirdLife Zimbabwe (BLZ) has engaged the local communities in the conservation of
cranes and wetlands in the Driefontein Grasslands. The aim of the BLZ’s conservation project is to promote
conservation of wetlands for the benefit of cranes and people. In 2004, two Site Support Groups were
established at Shashe and Daviot to help with the conservation of cranes and wetlands in their
respective areas. In an effort to improve the livelihood status of these communities and reduce wetland loss, BLZ
established two community gardens in 2004 and these are still functional. The gardens are in Shashe and
Daviot Villages and they are managed by Site Support Groups in these villages. Two more Site Support Groups
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were also set up at Chipisa and Chinyaure Villages in August 2009. The Site Support Groups have been
playing a pivotal role in spreading education and awareness messages on crane and habitat conservation
to other community members. BLZ has also involved the Site Support Groups in crane monitoring through
training on data capture and record keeping. More interest towards crane conservation was generated
among the Site Support Groups members. BirdLife Zimbabwe has launched a Bird Awareness Programme
in local schools to support Wattled Crane conservation. The Bird Awareness Programme is an environmental
education and awareness programme of BirdLife Zimbabwe developed for young pupils. The programme is
implemented in schools where awareness on birds, habitats, sites and biodiversity conservation in a changing
climate is raised. To date 15 schools are in the programme in Driefontein Grasslands. The programme was
instrumental in building relationship between communities and cranes in Driefontein through wide spread
awareness and education on the ecological, socio-economic and cultural value of cranes and wetlands in the area.
Currently, the Wattled Cranes in the Driefontein Grasslands co-exist with humans and share the same
wetlands and grasslands. The survival of Wattled Crane is therefore in the hands of people who are
living with this bird species. Although the human population in the area has increased, the Wattled Crane
continues to breed. From 2000 to 2005, breeding was generally good with a maximum of 12 successful
breeding pairs each with a fledged immature recorded. However, the breeding rate decreased from
2006 to 2009 where a maximum of five successful breeding pairs were noted. This might be due to high
disturbances at breeding sites. In 2010, the breeding rate has improved and seven successfully breeding
pairs were recorded during a snap survey carried out in November. From the information gathered from the
communities the number of successfully breeding pairs is thought to be more than 10. Most of the available
breeding sites were used by the breeding pairs in 2010 and the local communities through Site Support Groups
have played a pivotal role in protecting those sites from human disturbances. Although the overall population
is decreasing, about 70% of the remained total population constitute mostly breeding pairs. Therefore, if many
suitable breeding sites become available the breeding success of Wattled Cranes may increase.
The Wattled Crane in the Driefontein Grasslands is disturbed by uncontrolled veld fires, habitat loss due to
increased wetland cultivation, stream bank cultivation, and direct disturbances by human activities such as
fishing, market gardening and grass (thatch) collection. Uncontrolled veld fires are a serious threat that needs
urgent attention. In 2010, the veld fires were prevalent in Driefontein Grasslands as compared to previous years
before 2010. Most places in the Driefontein Grasslands were affected by veld fires. The major causes of fire
were local hunters who start up fires when hunting small animals such as mice and squirrels for food. Increased
poverty in the Driefontein area seems to be the major driving factor for threats to Wattled Cranes species and
their habitats because humans have limited alternatives for their livelihood and currently crop cultivation is the
key option for human survival. More than 80% of household income in Driefontein comes from the available
natural resources.
There is a high potential for Wattled Crane to rapidly recover its numbers and distribution in the country if
protection and habitat are provided. If funding becomes available, below are research and conservation
activities that should be implemented in Zimbabwe in the immediate future:
Conservation
1. Develop practices to improve productivity of pairs that are not reproductively successfully and the protection
of major habitats used by non-breeders.
2. Habitat management:
a) Repair broken walls of dams that are used as breeding and foraging sites by cranes
b) Carry out fire awareness campaigns before, during and after the fire season
c) Construct fire breaks around nesting areas
d) Establish and train fire fighting teams for each village and acquire fire fighting equipment
e) Influence organised agriculture by providing fencing materials and set up village cooperative
vegetable gardens outside wetlands
3. Help local communities to adopt viable livelihood options such as piggery and poultry so as to reduce
pressure on wetlands.
4. Expand and strengthen the education and awareness programme on crane conservation in Zimbabwe
5. Carry out a national Wattled Crane survey throughout the whole country.
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Research:
1. Determine the distribution and productivity of all territorial pairs in the Driefontein.
2. Using satellite telemetry, determine the distribution and ecology of sub-adult cranes by attaching
transmitters to pre-fledged juveniles.
3. Investigating the diet and feeding behaviour of Wattled Cranes in different habitats as influenced by
seasons and land use practices in Driefontein.
Table 1. The number of Wattled Cranes recorded in the Driefontein Grasslands between 2000 and 2010
(Adapted from Chirara, 2011).
Survey details
Pairs
Juveniles
Flocks
Total
Year
Month
Type of survey
2000
Oct
Ground
11
7
4
123
2002
August
Ground
-
-
-
37
2002
April
Ground
10
3
6
100
2003
Aug/Sep
Ground
9
0
3
55
2004
Sep / Oct
Ground
38
12
3
138
2005
Nov
Aerial
-
-
-
44
2005
Nov
Ground
30
9
3
87
2006
Sep
Ground
18
4
3
67
2006
Nov
Ground
17
4
3
72
2007
June
Ground
16
4
3
70
2007
Sep
Ground
13
3
1
44
2008
July
Ground
9
1
1
27
Nov
Ground
13
5
2
46
April
Ground
11
5
2
34
Nov
Ground
10
3
2
35
June
Ground
10
1
1
37
2009
2010
Figure 1: Location of the Driefontein Grasslands
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Fig. 2: Eurasian Cranes reaching their roost at Lake Gololcho during early afternoon
(photo: Günter Nowald)
Fig. 3: Distribution of foraging flocks of Eurasian Cranes
(based on GoogleEarth satellite image).
Most of the birds were feeding on stubble fields of Teff Eragrostis tef and other cereals (like maize) in a bigger
area around the roosts (Fig. 3). Teff is an important native food grain in Ethiopia and Eritrea.
Flock size
In 2007 and 2009, counts of individual flocks yielded 4,963 foraging Eurasian Cranes in 99 flocks and 3.833
cranes in 35 flocks, respectively (Table 2). The flock size varied between 2 (min) to 1.076 (max). Compared to
Europe, the Eurasian Crane flock sizes were small, with a median of only 7 and 22 birds, respectively.
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Disturbances, threats and major conservation problems
In Ethiopia birds are protected by religious customs and by law (Yohannes, 1996). Most people are usually
indifferent to birds, unless they are affected by them. In most of the cases, especially in the Rift
Valley, no sign for hunting or chasing of cranes was observed. Therefore, people can approach cranes
closely, also at their roosts (Fig. 5). In the area of Debre Zeit some farmers chased the birds away from
their fields and from roosts. It was reported, that children have to guard the fields before harvest and
can not attend school during this time of the year, which causes a negative attitude towards cranes.
In the Lake Tana region around Bahir Dar farmers do persecute birds, in particular cranes and geese
that damage their crops, although the extent of this behaviour is not clear (Francis & Aynalem, 2007).
Free roaming dogs also may disturb cranes at the roosts. However, this kind of disturbance was observed
only once (17th January 2007, South Team). Electric power lines can be dangerous at foggy or windy days.
Especially in the area of Akaki we heard about cranes killed by clashing with power lines (pers. comm. farmers,
2004). A more serious problem seems to be the increasing human population, the expansion of agriculture land,
the reduction of wetlands and changes in the water regime, thus an unsustainable use of natural resources.
The value of wetlands and the factors that guarantee for their persistence are largely unknown or ignored until
recently (Yohannes, 1996).
Fig. 5: Harmony at Lake Gololcho. Even at the roosts, cranes seemed not to
be disturbed by people.
In general, the results of the herein given condition assessment suggest that almost no area around the
lakes and other wetlands are free from human pressure and potential habitat loss or disturbance. Key issues
noted were the agricultural expansion and intensification (annual crops and livestock farming & ranching)
as well as over-exploitation and pollution by domestic and urban waste water, garbage and solid waste. The
massive growth of industrial flower and vegetables farms around Akaki, Chekeleka and at Lake Tana (Schröder,
2009) is an example for the threats mentioned above. These farms use a large area being originally used as
foraging areas by Cranes, and also use a high proportion of the wetland’s water. Probably these big farms also
use chemical pesticides.
Acknowledgments: For organizational help and assistance in the preparation of joint field work we would like
to thank Mengistu Wondafrash (EWNHS), Yilma Dellelegn (Freelance Consultant), Mihiret Ewnetu (Wildlife
Department of MoARD), Chere Enawgaw (Wildlife Department of MoARD), Berihu Gebremedhin (IBC),
Tewabe Ashenafi (EWNHS), Endale Wolde Tensai (EWNHS), Hassen Yussuf Kaariye (AL WABRA Dibatag
Research Project), Friedrich Wilhelmi (NABU/Al WABRA Dibatag Research Project), Itai Shanni (IOC, Israel),
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Carl-Albrecht von Treuenfels (CCG,
Germany, ICF), Hartwig Prange (CCG, Germany), Wolfgang
Beisenherz (NABU), Bernhard Walter (NABU), and Ian Francis (RSPB). We would like to thank Mr. Michael Modrow
(volunteer Crane Conservation Germany) for converting the different coordinate systems to WGS84, and Mr.
Norman Donner (scientific assistant at the Crane Information Centre) for preparing the ArcView figures of crane
distribution. The teams like to thank Lufthansa for providing transport for the foreign participants to and from
Ethiopia as well as the GTZ International Services for their support of field work in 2009 by providing a driver
and an off-road car. Last but not least Crane Conservation Germany and NABU in behalf of all European team
members like to thank their Ethiopian colleagues who prepared the field trips and shared their experiences in
the field.
5. References
FRANCIS, I. S. & S. AYNALEM 2007: Bird surveys around Bahir Dar-Lake Tana IBA, Ethiopia. Report of RSPB
Scotland, Aberdeen, UK, and Addis Ababa University, Biology Department, Ethiopia.
NOWALD, G. 2010: Colour marking and radio tracking of Eurasian cranes Grus grus in Germany and
Europe – an overview. Vogelwelt 131.
NOWALD, G., SCHRÖDER, W. & F. WILHELMI 2007: First survey of Eurasian Cranes Grus grus in Ethiopia.
Unpubl. Report Crane Conservation Germany – Crane Information Center Groß Mohrdorf.
YOHANNES, E. 1996: Status of Cranes and Wetlands in Ethiopia. In: BEILFUSS, R. D., W. R. TARBOTON & N.
N. GICHUKI (eds.): Proc. African Crane & Wetland Training Workshop. International Crane Foundation, Baraboo,
Wisconsin, U.S.A.: 75-79.
SCHRÖDER, W. 2009: Kranichland Äthiopien. Ornis 3/2009: 40-43.
WETLANDS INTERNATIONAL 2002: Waterbird Population Estimates - Third Edition. Wetlands International
Global Series No. 12, Wageningen (Niederlande).
Günter Nowald, Werner Schröder, Volker Günther & Shimelis Aynalem, Crane Conservation Germany
(Kranichschutz Deutschland) – Crane Information Center, Lindenstraße 27, D-18445 Groß Mohrdorf. E-Mail:
[email protected]
Summary of the 2010 annual KZN Crane aerial survey:
Tanya Smith1*, John Craigie2, and Kevin McCann3
The annual crane aerial surveys in KwaZulu-Natal has been performed over the past 18 years censusing all
three crane species. During 2010 the aerial survey was conducted over a 6 day period towards the end of July
totalling 23.2 hours of flying. A total of 435 Blue Cranes, 2 997 Grey Crowned Cranes and 226 Wattled Cranes
were sighted. Additional species sightings included 86 Oribi, 90 Denham’s Bustards, 317 Bald Ibis and 20
Secretary Birds. The 435 Blue Cranes sighted during the 2010 aerial survey is the fourth highest count through
the past 10 years, while the 2 997 Grey Crowned Cranes counted during the 2010 survey is the highest over
the last 10 years. The 226 Wattled Crane counted compares well with the previous 10 years indicating a
stable and possibly slightly increasing population. Sixty-one of the 70 known Wattled Crane breeding pairs in
KwaZulu-Natal were located during the 2010 survey, with four single Wattle Cranes being seen in addition to the
pairs. Eighteen pairs had nests, with 13 pairs having a clutch of 1 egg, 4 with a clutch size of 2 eggs and one
unknown clutch sizes. Seven pairs of Wattled Crane had unfledged chicks, all less than 10 weeks old, this is
noticeably fewer than the sixteen pairs that had unfledged chicks during last year’s flight. Four pairs still had 2009’s
youngster with them in the breeding territory.
Key words: Aerial survey, census, minimum count, Grey Crowned Crane, Blue Crane, Wattled Crane,
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Table 1: Results of the other species of interest recorded during the 2010 aerial survey. The numbers in the
brackets are the results from the 2009 aerial survey
Species
Denham's Bustard
Bald Ibis
Secretary Bird
Oribi
Midlands West
27
52
3
28
Midlands East
4
26
4
43
Underberg
38
183
5
0
Kokstad
10
31
8
15
Northern Natal
11
25
0
0
Total
90 (68)
317 (307)
20 (7)
86 (65)
Wattled Crane breeding status
Sixty-one of the 70 known breeding pairs in KwaZulu-Natal were located within their breeding territories during
the 2010 survey, compared to 66 during the 2009 survey, 63 during 2008, 60 during 2007, 54 during 2006, 64
during 2005, 56 in 2004, 57 in 2003, 53 in 2002, 58 located in 2001 and only 46 during 2000 (refer to figure 6
below).
Figure 6: The total number of Wattled Crane breeding pairs recorded during each aerial
survey from 2000 to 2010.
Of the 61 pairs located, only 47.5 % were found in a ‘breeding state’, meaning they were either on a nest or had
a chick or juvenile with them at the time of the aerial survey. This proportion of pair found in a breeding state is
the lowest with the exception of the 2006 aerial survey (refer to figure 6 below).
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Figure 7: The percentage of Wattled Crane pairs recorded during each aerial survey
from 2002 to 2010, which were found to be in a state of breeding i.e. nesting or with a chick/juvenile.
Discussion
Population totals and distribution
From figure 2 it can be seen that the southern KZN region from Underberg to Kokstad is a vitally important
region for all three species of cranes, as this region accounts for more than 70% and 30% of the province’s
Grey Crowned and Wattled Crane population respectively. This area is dominated mostly by commercial
farming, mainly dairy, potato, maize and beef farming, as well as forestry. However, large areas of intact Moist
Drakensberg Foothill grasslands and permanent and seasonal wetlands exist and are predominately managed
for beef or to a lesser extent sheep grazing. This mixed land cover within this area provides ideal foraging
habitat and in some areas very good breeding habitat for all three species. The KZN midlands, both east and
west midlands as surveyed, still proves to be the stronghold for Wattled Cranes in the province as seen in figure
2, as more than 65% of the province’s population was recorded here. This area is utilised by breeding pairs as
well as the floater flocks of Wattled Cranes.
The results of the last ten years of aerial surveys suggests that the provinces’ population of Blue and Wattled
Crane are stable, with the Wattled Crane population possibly showing a slight increase. Over the last ten years
the provinces’ Grey Crowned Crane population has increased at an average rate of approximately 5.63 %
per year. The next few years of aerial survey counts may indicate when or if this population will reach carrying
capacity or if this growth rate will continue.
Wattled Crane breeding status
From figure 6 it can be seen that there has been a slight increase in the number of Wattled Crane pairs
located and recorded during the aerial surveys since 2000. The number of known Wattled Crane breeding pairs
has slowly increased from a known 63 breeding pairs in the late 1990’s to 70 known breeding pairs in 2010.
During the 2010 aerial survey eighteen pairs of Wattled Cranes were found to be nesting, with 13 pairs having
a clutch of 1 egg, 4 with a clutch size of 2 eggs and one with an unknown clutch size. Seven pairs of Wattled
Crane had unfledged chicks, all less than 10 weeks old and this is noticeably fewer than the sixteen pairs
that had unfledged chicks during the 2009 flight. Four pairs still had last year’s youngster with them in the
breeding territory. Therefore 47.5 % of the breeding pairs recorded on the 2010 survey were found to be in a
state of breeding i.e. nesting or with a chick or juvenile. Figure 6 shows a possible decline in the percentage of
Wattled Crane breeding pairs found in a state of breeding at the time of the aerial survey since 2002; however
this needs further investigation and research to determine whether there has been a slight shift in the time of the
year where the majority of Wattled Crane pairs start breeding.
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Conclusion
The 2010 aerial survey proved successful with the largest number of Grey Crowned Cranes being counted since
the inception of the annual aerial survey. This method is still an efficient and accurate method for locating and
recording cranes in a given area and is proving a suitable method to establish reliable population trends for
Grey Crowned and Wattled Crane within KwaZulu-Natal, especially with regards to Grey Crowned Crane as seen
by the R2 value of 0.82. However, in conjunction with trends in the Wattled Crane population the aerial survey
continues to prove successful in locating nests with 2 egg clutches to facilitate ‘second-egg’ collections as part
of the national ‘Wattled Crane Recovery Programme’. This method proves more unreliable for Blue Cranes
within the province and this is due to the time of the year the aerial survey is conducted and the low number of
Blue Cranes in the province. Blue Cranes will flock together in winter and if one or two large flocks are missed
on the aerial survey then the overall count is greatly affected. The annual crane aerial survey in KwaZulu-Natal is
the only of its kind in South Africa, in terms of surveying cranes. The annual aerial survey provides the platform
for which Ezemvelo KZN Wildlife can use to assess the ‘state of the environment’, and with additional input from
stakeholders like the Endangered Wildlife Trust and KZN Crane Foundation, provides a high confidence account
of the state of the crane populations within KwaZulu-Natal.
Acknowledgements
We would like to thank Ezemvelo KZN Wildlife for their generous support of this valuable conservation
monitoring project in KwaZulu-Natal and to Greg Nanni who is the pilot responsible for completing the aerial
survey safely. We would also like to thank all the counters for their time in assisting with this project. Lastly we
would like to thank ESKOM for their generous support of this valuable conservation project.
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Guidelines for Authors
Indwa is a journal for African crane research and conservation published annually by ACCP. The deadline for
submissions is 31 March. Indwa publishes full scientific papers and short notes, thesis abstracts and other
material relevant to crane conservation activities across Africa. Full paper article contributions will be sent to at
least one referee for review.
• Submission of an article is understood to imply that the article is original and is not being considered for
publication elsewhere.
• All contributions must be in English and sent to the Editor in electronic format, either on a disk or via email.
The first page should contain the title of the paper and author(s) name(s) and address (es), including the
person to whom correspondence should be
addressed. Number pages consecutively.
• Full papers/articles should follow the normal organization of other journals, including an abstract. A
minimum of 5 key words should also be included after the abstract. Tables should be simple, vertical lines
should not be used to separate columns. Figures and tables should have brief and self explanatory titles.
The text should include reference to the figures and tables.
• Photos or illustrations may be included in article. These must be sent electronically and should be of quality
300dpi or better.
• Cite reference in the convectional manner (refer to the journal Ostrich), in alphabetical order by author’s
name.
• All measurements should be metric. First mention of a species should be in the English vernacular followed
by the scientific binomial.
• Submit contributions to the Editor: Kevin McCann Email: [email protected]
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