Foto 13. Área boscosa dentro de la zona de vida Bosque Mojado

Transcription

Foto 13. Área boscosa dentro de la zona de vida Bosque Mojado
Foto 13. Área boscosa dentro de la zona de vida Bosque Mojado Subtropical.
Foto 14. Área de transecto localizado en el Municipio de Utuado dentro de la zona de
vida del Bosque Mojado Subtropical.
Foto 15. Vista panorámica del Bosque Mojado Subtropical en el Municipio de Adjuntas.
Foto 16. Suelo cubierto de hojarasca en el Bosque Mojado Subtropical, Adjuntas.
Foto 17. Un árbol de Ceiba localizado cerca de un transecto, dentro del Bosque Mojado
Subtropical.
Foto 18. Zona de transición entre un camino y área boscosa en el Municipio de Adjuntas.
Foto 19. Vista panorámica del Bosque Mojado Subtropical localizado en el Municipio de
Adjuntas.
Foto 20. Áreas abiertas de abruptas pendientes dentro del Bosque Mojado Subtropical al
norte del municipio de Peñuelas.
Foto 21. Bosque de mangles en la costa norte dentro de la zona de vida del Bosque
Húmedo Subtropical.
Foto 22. Humedal arbóreo de la costa norte en el Municipio de Toa Baja.
Foto 23. Manglar al fondo, dentro de la zona de vida del Bosque Seco Subtropical en el
Municipio de Peñuelas.
Foto 24. Bosque Mojado Subtropical, Municipio de Adjuntas.
Foto 25. Área de Bambú (Bambusa vulgaris) dentro del Bosque Mojado Subtropical.
Foto 26. Área de bosque del Municipio de Utuado dentro de la zona de vida del Bosque
Húmedo Subtropical.
Foto 27. Quebrada sin nombre localizada en la zona de vida del Bosque Húmedo
Subtropical en el Municipio de Peñuelas.
Foto 28. Salitral del Bosque Seco Subtropical en el Municipio de Peñuelas.
Foto 29. Nido de Guabairo (Caprimulgus noctitherus) depredado, localizado en el
Bosque Seco Subtropical en el Municipio de Peñuelas.
Foto 30. Área de transecto en el Municipio de Toa Baja.
Foto 31- Inicio e identificación de transecto en Utuado.
Foto 32. Transecto en área de mogote dentro del Bosque Húmedo Subtropical en el
Municipio de Vega Alta.
Foto 33. Transecto en área de manglar dentro del Bosque Húmedo Subtropical,
Municipio de Guaynabo.
APÉNDICE 2
Biological Evaluation of Potential Impacts Associated with the Via Verde
Pipeline Project on Endangered Raptors in Puerto Rico
Biological Evaluation of Potential
Impacts Associated with the Via Verde
Pipeline Project on Endangered
Raptors in Puerto Rico
Prepared for:
Asesores Ambientales
y Educativos (A.E.E)
By:
Tetra Tech, Inc
451 Presumpscot St.
Portland, Maine 04103
August 2010
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
TABLE OF CONTENTS
1.0
INTRODUCTION .................................................................................................. 3
2.0
BIOLOGICAL EVALUATION ................................................................................ 5
3.0
CONCLUSION AND RECCOMENDATIONS ..................................................... 10
4.0
REFERENCES ................................................................................................... 14
LIST OF FIGURES
Figure 1. Via Verde Pipeline Project, Puerto Rico ....................................................................... 4 LIST OF TABLES
Table 1. Detailed breakdown of potential occurrence for Broad-winged Hawks and Sharpshinned Hawks in Focal Area 1 along the proposed Via Verde Project .................... 12 Table 2. Detailed breakdown of potential occurrence for Broad-winged Hawks and Sharpshinned Hawks in Focal Area 2 along the proposed Via Verde Project .................... 13 2
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
1.0 INTRODUCTION
1.1
Overview
The Puerto Rican Electric Power Authority (PREPA) is proposing to develop a 91 mile pipeline
project (Via Verde) in Puerto Rico (Figure 1). To assist in compliance with the federal
endangered species act (ESA) of 1973, PREPA contracted Tetra Tech, Inc. (Tetra Tech) to
complete a Biological Evaluation (BE) to evaluate the effects of the proposed project on the
Puerto Rican Broad-winged Hawk (Buteo platypterus brunnescens) and Puerto Rican Sharpshinned Hawk (Accipiter striatus venator). Mr. Derek Hengstenberg, a recognized expert on
these raptor species and current avian biologist with Tetra Tech, conducted the evaluation.
1.2
Goals and Objectives
The goal of this Biological Evaluation was to determine if the proposed pipeline project would
likely adversely affect the federally listed Puerto Rican Broad-winged Hawk and Puerto Rican
Sharp-shinned Hawk. Specific objectives included 1) examine how each species would be
exposed to project activities and 2) determine if individuals and/or their habitat are likely to
respond in a negative manner to this exposure or if the effects of the project would be beneficial,
insignificant, or discountable.
1.3
GIS Analysis and Methods
Using the Via Verde Pipeline shapefile provided by Asesores Ambientales y Educativos (A.E.E),
endangered raptor habitats were assessed and classified based on known habitat requirements.
First, areas of the southern and northern coastal plains of Puerto Rico were removed from the
assessment area. The remaining areas of the Via Verde Pipeline occurred in the karst
topography and central mountain region of Puerto Rico; potential endangered raptor habitat.
Two Focal Areas were designated along the pipeline as having potential endangered raptor
habitat. The Focal Areas were divided into as either forested (i.e., potential habitats) or nonforested habitat (e.g., shrub, agricultural, developed, etc.) within 50 feet either side of the
pipeline center line; 100 foot right-of-way (ROW). Habitats within the ROW along the two Focal
Areas were heads-up digitized using color digital aerial photography from ESRI’s world imagery
database. The length of each habitat type with each focal area was assigned a linear distance
corresponding to the pipeline route distance. The area of evaluation was divided into two Focal
Areas (Figure 1). Table 1 and 2 provide an assessment of the potential occurrence of
endangered raptors and corresponding mileage marker for both Focal Areas. The following
address how particular sections/regions of the proposed Via Verde pipeline may affect each
species of raptor.
3
End (Mile 90.7)
Focal Area #2
Start (Mile 0.0)
Notes:
World Imagery of Puerto Rico obtained from
http://services.arcgisonline.com/arcgis/services
Legend
Via Verde Pipeline
Endangered Raptors Focal Area #1 (Miles 9.6 - 37.6)
Endangered Raptors Focal Area #2 (Miles 58.9 - 68.3)
0
2.5
5
10
Projection/Coordinate System:
North American Datum of 1983,
Puerto Rico State Plane, US Feet
15
Miles
20
±
Figure 1.
Via Verde Pipeline Project Layout
Prepared For:
Asesores Ambientales y Educativos
Prepared
By:
Date:
08/03/2010
Location of Project on Server: Z:_projects_PRPipeline_PDF_20100803_PRP_11X17Land_Fig1.pdf, BPA
Focal Area #1
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
2.0 BIOLOGICAL EVALUATION
The following biological evaluation includes the following:
•
•
•
•
•
•
•
•
•
A description of the proposed project
A description of the project area including identification of the specific “action area”
Species evaluated
An examination of the habitat characteristics of the forested regions (canopy type,
coverage, geographic preferences [e.g., distance to water, karst hills, etc.]) within
pipeline corridor route.
An evaluation of whether there are any of the examined forested communities suitable
for maintaining an endemic population of hawks within or immediately adjacent to the
pipeline corridor.
An evaluation of whether the forested areas identified constitute critical habitat or
suitable nesting habitat for the species.
An evaluation of the proposed temporary impacts and how it may preclude future use of
these areas by the hawks.
An assessment of the effects analysis
A set of recommended additional studies
Project Description
The Via Verde project consists of the construction of a high pressure gas pipeline from the
municipality of Peñuelas in the south, through the central mountain region, and along the
northern coast to the municipality of Guaynabo, Puerto Rico. The pipeline will run through the
municipalities of Peñuelas, Adjuntas, Utuado, Arecibo, Barceloneta, Manatí, Vega Baja, Vega
Alto, Dorado, Toa Baja, Catano, and Guaynabo. The pipeline will consist of a temporary right of
way of 100 feet (50 feet either side of the pipeline). The permanent right-of-way to be
maintained after construction will be reduced to 50 feet wide (25 feet either side of the pipeline).
After construction, the right-of-way corridor will be allowed to naturally revegetate.
Project and Action Area
The Via Verde pipeline runs through four of the six life zones of Puerto Rico. The zones are the
subtropical dry forest, lower montane wet forest, subtropical wet forest, and subtropical moist
forest. Both species of raptors have been reported from each of these life zones, except the
subtropical dry forest. Topography and elevation in the project area vary widely from the
southern and northern coast to the rugged karst region and upper elevation central mountain
region. Elevations within the project area range from 1 meter to 1,040 meters, with the highest
elevations occurring in the municipalities of Peñuelas and Adjuntas. The project area crosses
many hydrographic features including the Rio Grande de Arecibo and the Rio Grande de
Manatí.
The Via Verde also intersects or is located near at least two Important Bird Areas (IBA) of
Puerto Rico, the Karso del Norte IBA (PR 003) and the Cordillera Central IBA (PR 010). Both of
the IBA’s consist of state forests, protected natural areas, and unprotected zones. Broadwinged Hawks are known to occur within the Karso del Norte IBA and Sharp-shinned Hawks are
known to occur within the Cordillera Central IBA (Birdlife International 2010
5
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
Species Evaluated
As stated above, only the Puerto Rican Broad-winged and Sharp-shinned hawk were evaluated
as part of this Biological Evaluation. Both the Puerto Rican Broad-winged and Sharp-shinned
hawk are considered subspecies. Unlike their North American counterparts, both these
subspecies are non-migratory and remain year-round residents of Puerto Rico. Both the Puerto
Rican Broad-winged and Sharp-shinned hawk were listed as endangered in 1994, pursuant to
the Endangered Species Act of 1973. At this time, critical habitat has not been designated for
the two subspecies. In 1997, the US Fish and Wildlife Service established a recovery plan for
both the Puerto Rican Broad-winged Hawk and Sharp-shinned Hawk to aid in the protection and
help in the recovery of these species (U.S. Fish and Wildlife Service 1997). The recovery criteria
are to protect, enhance, and stabilize the existing population in Puerto Rico.
The Broad-winged Hawk and Sharp-shinned hawk are both endemic and uncommon woodland
raptors of Puerto Rico, with small populations restricted to montane forests of the Cordillera
Central, karst region, Sierra de Cayey, and the Sierra de Luquillo (Delannoy 1997). During the
last island-wide population census in 1991 and 1992, there were approximately 125 Sharpshinned Hawks and 150 Broad-winged Hawks identified (Delannoy 1997). Other studies have
studied these species in more detail but counts were restricted to areas where there are known
populations (Hengstenberg and Vilella 2004, 2005; Vilella and Hengstenberg 2006). There has
not been an island-wide count in close to 20 years for these species. During this time, there has
been a significant increase in the amount of secondary growth forests island-wide, mostly due to
a shift away from an agrarian based society. Previous studies indicated Broad-winged Hawks in
Puerto Rico have a limited geographic range and their abundance is higher in the karst region
compared to other life zones on the island (Delannoy 1997).
Broad-winged Hawks use forest habitats in the subtropical wet zone, the subtropical lower
montane wet forest and the subtropical moist zone. Broad-winged Hawks nest sites in Rio Abajo
were continuous tracts of closed-canopy forests intersected by small forest dirt roads. Broadwinged Hawks nested in mixed species timber plantations and mature secondary forest
(Delannoy and Tossas 2002; Hengstenberg and Vilella 2005). Nests were placed in the upper
reaches of large trees emerging from the canopy. Nest tree DBH, understory stem density, and
distance to karst cliff wall correctly classified nest sites (Hengstenberg and Vilella 2005).
Broad-winged Hawks hunt from perches just below the canopy where they can scan the ground
in search of prey. Broad-winged Hawks prey on small invertebrates, especially frogs and lizards,
although small birds as heavy as 200 g, rats, and centipedes also are consumed (Hengstenberg
and Vilella 2005). Although, Broad-winged Hawks spend a small proportional time in the air
soaring (i.e. aerial displays, territorial flights) it has not been documented whether Broad-winged
Hawks hunt in flight.
Karst topography adds much relief to the landscape, creating areas between limestone hills that
may harbor high concentrations of prey (Vilella and Hengstenberg 2006). In Puerto Rico, the
presence of continuous closed canopy forests may represent the principal structural feature
describing Broad-winged Hawks habitat suitability at the home range scale.
It appears that the Sharp-shinned Hawk population in Puerto Rico may be declining. From 1991
to 1992, the island-wide population of SSHAs was estimated at 130, which is quite a bit less
than the population estimate of 240 during a status survey in the 1980’s (Cruz and Delannoy
6
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
1986). Extant population of Sharp-shinned Hawks have been mostly found from the upland
forests (elevation of 200 meters or greater) of Puerto Rico including Maricao, Toro Negro,
Carite, and Luquillo. Sharp-shinned Hawks are noticeably absent from karst forests and coastal
plains.
Sharp-shinned Hawk habitat appears restricted to upper elevation habitat. Sharp-shinned
Hawks showed high site fidelity within subtropical wet forest and subtropical lower mountain
forest life zone. It appears that Sharp-shinned Hawks are selecting certain habitat other others
(Delannoy 1997). High stem density, closed-canopy, and tall-large diameter trees are important
habitat features for Sharp-shinned Hawks. Sharp-shinned Hawks prey mostly on birds (range of
3 grams to 180 grams) with females selecting larger prey items than males (Delannoy and Cruz
1999).
Human disturbance from road building and recreation has significantly impacted the nesting
success of Sharp-shinned Hawks in historical breeding areas. Delannoy (1997) recommended
some management techniques including: leaving an area of approximately 3.1 ha (7.8 acres)
undisturbed near a nest site and restricting activities near know nests during the breeding
season. Both species of forest raptors are susceptible to urban development, road construction,
energy projects, logging, recreation, botfly parasitism, and natural events such as hurricanes
and landslides.
Effects Analysis
Puerto Rican Broad-winged Hawk:
As noted above, the broad-winged hawk is dependent on closed canopy forest; therefore, any
actions that involve forest clearing in areas of suitable habitat may likely have a direct, and
possibly indirect adverse effect on this species. However, because areas outside of Focal Areas
1 and 2 traverse either segments containing little or no suitable habitat (areas containing karst
forests), or would disturb pre-existing non-forested habitat it is expected that there would be no
effect on Puerto Rican Broad-winged Hawks in these areas.
Based on a review of existing data, corridor sections within Focal Areas 1 and 2 contain karst
forest areas known to be preferred by this species. However, certain sections of Focal Areas 1
and 2 have not been directly surveyed for the presence and extent of broad-winged hawks. In
addition, project activities in these Focal Areas would involve direct clearing of the forest
canopy. As stated previously, forest clearing would create openings in the forest. Forest
clearing could potentially directly impact nest locations and courtship areas. Also, forest clearing
would directly remove those areas as foraging locations. Based on the extent of the existing
available habitat it is assumed that these changes may have only an insignificant impact on the
local population and subspecies as a whole. However, unless site specific surveys are
conducted it is currently not known whether any individuals or nest locations would be taken.
Therefore, it seems prudent that site specific surveys of nest locations and specific use of the
project corridor be undertaken in areas where the forest canopy would be cleared within Focal
Areas 1 and 2.
7
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
Site Specific Survey Recommendations:
Northern Coast: A smaller area of evaluation is between the towns of Manati and Vega Baja
where the proposed pipeline intersects karst topography of mogotes and sinkholes for a 9 mile
stretch of pipeline. The section from mile marker 59 to mile marker 68 is an overland pipeline
section through karst topography. There is potential Broad-winged Hawk habitat and a survey is
recommended for this area. The remaining coastal area from mileage marker 38 to 58 and 69
to 91 do not contain Broad-winged Hawk habitat. No surveys are recommended in these
sections.
Central Karst Region: The proposed Via Verde pipeline will pass through the Rio Abajo Forest
(karst region) where there is the highest abundance of Broad-winged Hawks nesting on the
island (Delannoy 1997; Hengstenberg and Vilella 2004, 2005). This forest is also home to a
recently re-introduced population of endangered Puerto Rican Parrots (Amazona vittata). In
2000 and 2001, one Broad-winged Hawk had a home range (Hengstenberg and Vilella 2004,
2005; Vilella and Hengstenbeg 2006) that encompassed area on both sides of Highway Route
10 in the northern section of Rio Abajo. In addition, the Puerto Rico Breeding Bird Atlas
recorded Broad-winged Hawks on a couple of their survey routes in this region: # 0608, # 0610,
# 0613, #0537, and #0687. Broad-winged Hawks in this stretch of pipeline, from mile marker 30
to 37.5 have been studied in the early 1990s and early 2000’s.
In this particular section, the pipeline is to be co-located in the same right-of-way as the
Highway Route 10. Due to the co-location of the Via Verde pipeline, there should not be any
greater disturbance to Broad-winged Hawks than the already existing highway. For this reason,
the pipeline in this section may affect but is not likely to adversely affect the Broad-winged
Hawk. We still recommend conducting a Broad-winged Hawk survey along the pipeline corridor
in this section to document presence/absence along the proposed route. Three survey points
should be established, one at the northern, one in the central portion, and one at the southern
extreme of the forest boundary to cover the Rio Abajo Forest section of pipeline.
Central Mountain Volcanic Region: The section of pipeline running just south of Rio Abajo
through the volcanic region to just north of Ponce in subtropical dry forest zone is a section that
needs to be evaluated for the Broad-winged Hawk. The evaluation area is a stretch of pipeline
of approximately 20 miles. This section contains a combination of upper elevation forests with
forested habitat and there have been historical and as well as recent records of Broad-winged
Hawks. The Puerto Rico Breeding Bird Atlas recorded birds from the Guaraguoa, Ponce survey
route (# 0987). In this section, the pipeline follows some roads but the majority of the pipeline
will be overland (through intact forests) and will require a temporary 100-foot corridor (in places
of forested habitat) during the construction process and then maintaining a 50-foot corridor. Due
to the limited data from this area, the occurrence during a breeding bird survey, historic
incidental observations, and potential habitat in this region, a Broad-winged Hawk survey is
recommended.
Southern Coastal Dry Forest Region: Broad-winged Hawks are not known from region of
Puerto Rico. No surveys are recommended from mile marker 0 to miler mark 9.67.
Puerto Rican Sharp-shinned Hawk
As noted above, the sharp-shinned hawk is likewise dependent on closed canopy forest;
therefore, any actions that involve forest clearing in areas of suitable habitat may likely have a
8
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
direct, and possibly indirect adverse effect on this species. However, because areas outside of
Focal Areas 1 and 2 traverse either segments containing little or no suitable habitat (areas
below 200 m elevation), or would disturb pre-existing non-forested habitat it is expected that
there would be no effect on Puerto Rican sharp-shinned hawk in these areas.
Based on a review of existing data, corridor sections within Focal Areas 1 and 2 contain forest
areas at elevations known to be preferred by this species. However, certain sections of Focal
Areas 1 and 2, particularly in the Central Mountain Volcanic Region – Cordillera Central, have
not been directly surveyed for the presence and extent of broad-winged hawks. In addition,
project activities in these Focal Areas would involve direct clearing of the forest canopy. As
stated previously, forest clearing would create openings in the forest. Forest clearing could
potentially directly impact nest locations and courtship areas. Also, forest clearing would
directly remove those areas as foraging locations. Based on the extent of the existing available
habitat it is assumed that these changes may have only an insignificant impact on the local
population and subspecies as a whole. However, unless site specific surveys are conducted it
is currently not known whether any individuals or nest locations would be taken. Therefore, it
seems prudent that site specific surveys of nest locations and specific use of the project corridor
be undertaken in areas where the forest canopy would be cleared within Focal Areas 1 and 2.
Site Specific Survey Recommendations
Of the 91 miles of pipeline proposed, approximately 20 miles is within potential Sharp-shinned
Hawk habitat in parts of Focal Area 1 (Figure 1). A no impact area was calculated from mileage
marker 30 to mileage marker 91 along the central and northern part of the pipeline and then
again from mileage marker 0 to 10 along the southern section. Sharp-shinned hawks are not
known from the karst region and are typically found at elevations greater than 900 feet.
Northern Coast: There should be no impact to Sharp-shinned Hawks from mileage marker 38
to mileage marker 91 along Via Verde Pipeline.
Central Karst Region: There should be no impact to Sharp-shinned Hawks in these sections of
the Via Verde Pipeline from mileage marker 30 to mileage marker 37.
Central Mountain Volcanic Region: The proposed Via Verde pipeline does not pass through any
commonwealth forests that support known Sharp-shinned Hawks. However, the pipeline
crosses stretches of continuous forest tracts in the Cordillera Central that may provide habitat
for the Sharp-shinned Hawk (mileage marker 10 to 30). According to the Puerto Rico Breeding
Bird Atlas, the Adjuntas Pueblo survey route (# 0910) confirmed the presences of Sharpshinned hawks. This survey route is in close proximity to the proposed path of the pipeline.
The moist/wet subtropical forested tracts of land that occur north of the subtropical dry forest life
zone and extend until the karst region near Lago Dos Bocas is the area that should be further
evaluated (Figure 2). In this section, the pipeline follows some mountainous roads but the
majority of the pipeline will be overland (through intact forests) and will require a temporary 100foot corridor (in places of forested habitat) to be cleared during the construction process and
then a 50-foot corridor maintained for the life of the project. In these interior forest sections, very
little data exists on Sharp-shinned Hawks. Although sporadic, the data suggest the occurrence
of Sharp-shinned hawks in these mountainous montane sections. Sections of pipeline that are
proposed for overland development and contain intact forest structure in the moist/wet lifezone
should be evaluated.
9
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
Southern Coastal Dry Forest Region: Sharp-shinned Hawks have not been reported from this
region of Puerto Rico. No surveys are recommended from mile marker 0 to miler mark 10.
3.0 CONCLUSION AND RECCOMENDATIONS
The results from our Biological Evaluation indicate that project activities within the pipeline
section within the two Focal Areas may adversely affect both endangered raptors if 1) either
species is nesting or specifically using the project corridor, or, 2) if found to be present, no
mitigation measures are employed to reduce the effects of project activities to being either
insignificant or discountable. Options for mitigation may include rerouting certain pipeline
segments to avoid direct impacts or other techniques to reduce impacts on these species.
Activities in the remaining areas of the proposed pipeline corridor (outside the two Focal Areas)
would constitute either a “no effect” or, at most, a “may affect, but not likely to adversely affect”
each species. Again, this is due to either the lack of suitable habitat and/or lack of forest
clearing.
Further studies are recommended within the Focal Areas to help provide sufficient data to make
this final effect determination. Results from the GIS analysis and data review, indicate that
sections of the Via Verde pipeline contain potentially suitable habitat for the Broad-winged Hawk
and Sharp-shinned Hawk, as well as, confirmed sightings and known breeding birds in the Focal
Areas.
Tetra Tech recommends that visual observations for Broad-winged Hawks and Sharp-shinned
Hawks be conducted in the Focal Area 1 (mile marker 9.67 to mile marker 37.5) and Focal Area
2 (mile marker 59 to mile marker 68). Focal Area 1 contains both karst and upper elevation
montane forests. In particular, the pipeline section from mile marker 10 to mile marker 30, very
little data exists on presence or absence of these two forest raptors. Both the Broad-winged
Hawk and Sharp-shinned Hawk have been incidentally observed in the upper mountain forests
between Utuado and Adjuntas in 2001 (personal communication) and during breeding bird atlas
surveys within the last ten years. Within the Rio Abajo section (mile marker 30 to mile marker
38) surveys for Broad-winged Hawks should be conducted to determine presence/absence.
Within Focal Area 2, between mile marker 59 and mile marker 68, the proposed pipeline
intersects karst topography. A Broad-winged Hawk survey would be recommended within this
section. As with any raptor surveys, all species of raptors should be recorded.
Raptor observations should be conducted from vantage points during the period of late
December to early March period, when both species of raptors are engaged in aerial courtship
and territorial displays (Delannoy 1997; Hengstenberg and Vilella 2004, 2005; Vilella and
Hengstenberg 2006). These displays and vocalizations usually occur above the canopy which
provides the observer the best opportunity to document presence or absence. Mid-May is a
good time to conduct follow-up post-fledgling surveys. Outside of the breeding season, both
species of raptors are very cryptic and most of their flights are below the canopy of the forest.
Observation points should be spaced every ½ mile to ensure the most accurate count of these
species. Surveys should occur over a month period to account for differences in timing of
displays for each species.
In areas where a Broad-winged or Sharp-shinned Hawk have been observed, a follow up nest
site surveys should be conducted to determine nest site location. These surveys should be
10
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
conducted using a combination of playback calls and grid searches. If a nest site is found, a
GPS coordinate should be taken and the U.S. Fish and Wildlife Service should be contacted.
In an effort to minimize potential impacts to forest structure, the amount of canopy clearing
should be minimized when possible. An area with an open understory with at least 75% canopy
cover will still provide foraging habitat for raptors. Construction activity should be restricted to
the non-breeding season (July to December) to minimize impacts to nesting birds and to
minimize impacts during their courtship aerial flights. If the opportunity arises on coffee
plantations (on-site or nearby mitigation) encouraging the use of shade-grown coffee is a
positive mitigation tool for conservation of forest raptors and their habitat. Shade-grown coffee
plantations provides suitable foraging habitat for both species of raptors.
During the construction process, having a specialized biologist familiar with both raptor species
conduct surveys ahead of the construction crews will help in determining presence or absence
for both species. If construction within the Rio Abajo Forest section occurs during the nonbreeding season, no impacts to Broad-winged Hawks would be anticipated.
11
Table 1. Detailed breakdown of potential occurrence for Broad-winged Hawks and Sharpshinned Hawks in Focal Area 1 along the proposed Via Verde Project
Focal Area
Segment
Start Mileage
End Mileage
1
1
9.67
1
2
9.87
1
3
10.03
1
4
10.20
1
5
10.38
1
6
10.70
1
7
10.76
1
8
11.20
1
9
11.38
1
10
12.68
1
11
12.86
1
12
15.34
1
13
15.49
1
14
16.22
1
15
16.27
1
16
16.90
1
17
17.05
1
18
17.56
1
19
17.70
1
20
18.19
1
21
18.24
1
22
18.97
1
23
19.03
1
24
19.99
1
25
20.28
1
26
20.38
1
27
20.51
1
28
20.61
1
29
20.68
1
30
20.77
1
31
20.97
1
32
21.09
1
21.19
33
1
34
22.03
1
35
22.18
1
36
22.69
1
37
22.79
1
38
22.97
1
39
23.04
1
40
23.22
1
41
23.29
1
42
23.43
1
43
23.47
1
44
23.98
1
45
24.06
1
46
24.19
1
47
24.45
1
48
25.07
1
49
27.30
1
50
27.37
1
51
27.51
1
52
29.66
1
53
29.78
1
54
30.09
1
55
36.63
1
56
36.70
Cover Class (F = Forested, N = Non‐Forested) BWHA/SSHA (X = Possible — = Not likely)
P ibl
N t lik l )
9.87
10.03
10.20
10.38
10.70
10.76
11.20
11.38
12.68
12.86
15.34
15.49
16.22
16.27
16.90
17.05
17.56
17.70
18.19
18.24
18.97
19.03
19.99
20.28
20.38
20.51
20.61
20.68
20.77
20.97
21.09
21.19
22.03
22.18
22.69
22.79
22.97
23.04
23.22
23.29
23.43
23.47
23.98
24.06
24.19
24.45
25.07
27.30
27.37
27.51
29.66
29.78
30.09
36.63
36.70
37.61
Length (mi)
Cover Class
BWHA
SSHA
0.20
0.16
0.16
0.18
0.33
0.06
0.44
0.18
1.30
0.18
2.49
0.14
0.74
0.05
0.63
0.15
0.50
0.14
0.49
0.05
0.73
0.06
0.96
0.29
0.10
0.13
0.10
0.07
0.09
0.20
0.12
0.10
0.83
0.16
0.51
0.09
0.18
0.07
0.19
0.06
0.15
0.04
0.51
0.08
0.13
0.25
0.63
2.23
0.07
0.14
2.14
0.12
0.31
6.55
0.07
0.91
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
—
—
Table 2. Detailed breakdown of potential occurrence for Broad-winged Hawks and Sharpshinned Hawks in Focal Area 2 along the proposed Via Verde Project
Focal Area
Segment
Start Mileage
End Mileage
2
1
58.93
2
2
59.02
2
3
59.06
2
4
59.16
2
5
59.27
2
6
59.29
2
7
60.67
2
7
60.69
2
8
60.84
2
8
60.90
2
9
61.01
2
9
61.09
2
10
61.18
2
11
62.40
2
12
62.54
2
13
63.72
2
14
63.80
2
15
63.85
2
16
63.88
2
17
64.54
2
18
64.63
2
19
64.68
2
20
64.76
2
21
64.77
2
22
64.83
2
23
65.20
2
24
65.23
2
25
65.28
2
26
65.33
2
27
65.51
2
28
66.09
2
29
66.81
2
30
66.91
2
31
66.94
2
32
67.03
2
33
67.07
2
34
67.14
2
35
67.28
2
36
67.33
2
37
67.48
2
38
67.79
2
39
67.94
2
40
68.20
Cover Class (F = Forested, N = Non‐Forested) BWHA/SSHA (X = Possible — = Not likely)
59.02
59.06
59.16
59.27
59.29
60.67
60.69
60.84
60.90
61.01
61.09
61.18
62.40
62.54
63.72
63.80
63.85
63.88
64.54
64.63
64.68
64.76
64.77
64.83
65.20
65.23
65.28
65.33
65.51
66.09
66.81
66.91
66.94
67.03
67.07
67.14
67.28
67.33
67.48
67.79
67.94
68.20
68.33
Length (mi)
Cover Class
BWHA
SSHA
0.10
0.04
0.10
0.11
0.02
1.38
0.02
0.14
0.06
0.11
0.08
0.09
1.22
0.14
1.18
0.08
0.05
0.03
0.66
0.09
0.06
0.08
0.01
0.06
0.37
0.03
0.05
0.05
0.18
0.59
0.72
0.09
0.04
0.09
0.04
0.07
0.15
0.05
0.14
0.32
0.15
0.26
0.13
N
F
N
F
N
F
N
F
F
N
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
F
N
—
x
—
x
—
x
—
x
x
—
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
x
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Biological Evaluation of the Via Verde Pipeline Project on
Endangered Raptors in Puerto Rico
4.0 REFERENCES
Birdlife International. 2010.
Important Bird Areas in the Caribbean- Puerto Rico.
http://www.birdlife.info/docs/CaribCntryPDFs/Puerto_Rico_(to_USA).pdf. Accessed 2
August 2010.
Cruz, A. and C. A. Delannoy. 1986. Status, breeding biology and conservation needs of the
Puerto Rican Sharp-shinned Hawk (Accipiter striatus venator). Final Report submitted to
U.S. Fish and Wildlife Service. Contract no. 14-16-0004-82-047.
Delannoy, C. A. 1997. Status of the Broad-winged Hawk and Sharp-shinned Hawk in Puerto
Rico. Caribbean Journal of Science 38: 20−26.
Delannoy, C.A. and A. Cruz. 1999. Patterns of prey abundance and use by male and female
Puerto Rican Sharp-shinned Hawks. Caribbean Journal of Science 35: 38–45.
Delannoy, C.A. and A. Tossas. 2002. Breeding biology and nest site characteristics of Puerto
Rican Broad-winged Hawks at Rio Abajo Forest. Caribbean Journal of Science 38: 20–
26.
Hengstenberg, D W. and F. J. Vilella. 2004. Reproductive biology, abundance and movement
patterns of the Broad-winged Hawk Buteo platypterus brunnescens in a moist limestone
forest of Puerto Rico. Final Report submitted to the U.S. Geological Survey under
Cooperative Agreement No. 14-45-009-1543-59.
Hengstenberg, D.W. and F. J. Vilella. 2005. Nesting ecology and behavior of Broad-winged
hawks in moist karst forests of Puerto Rico. Journal of Raptor Research 39: 404−416.
U.S. Fish and Wildlife Service. 1997. Puerto Rican Broad-winged Hawk and Puerto Rican
Sharp-shinned Hawk Recovery Plan. U.S. Fish and Wildlife Service, Atlanta, Georgia. 30
pp.
Vilella, F. J. and D. W. Hengstenberg. 2006. Broad-winged Hawk movements and habitat use
in a moist limestone forest of Puerto Rico. Ornithologia Neotropical 17: 563−579.
14
APÉNDICE 3
Overview of the Geology of the Proposed Vía Verde Natural Gas
Pipeline, Peñuelas to San Juan, Puerto Rico