HomeMy WebLinkAboutEAST RIDGE PDP - MODIFICATION OF STANDARD - 33-98C - SUBMITTAL DOCUMENTS - ROUND 1 - (4)LEGEND•
+ CDOW RAPTOR NESTSITE
+ MAP CONTROL POINT
City of Fort Collins
Raptor Nest Locations
W.,.W.W Colorado Department of Wildlife
Drawing Name. -
NU CDGW C RAPTOR NE9T9
Pmje°t Number
0943
Date
Od-01-0d
Ft. Collins, CO. s^••' y °� i
REFERENCES
Call, M. 1979. Habitat management guides for birds of prey. Technical Note No.338, U. S-
Bureau of Land Management, Denver.Service Center, Denver, CO. 69pp.
Greater Yellowstone Bald Eagle Working Group 1996. Greater Yellowstone Bald Eagle
Management Plan: 1995 update. Wyoming Game and Fish Department, Lander, WY. 47
pp.
Grier, J.W., F.J. Gramlich, 1. Mattisson, J,E. Mathisen, I.V. Kussman, J.B. Elder, and N.F.
Green. 1983. The bald eagle in the northern United States. Bird Cons. 1-44-66.
Holmes, Tamara L. 1993. Behavioral responses of grassland raptors to human disturbance MS
.Thesis. Colo. State Univ, Ft. Collins. 62p.
Holthuijzen, A.M.A., W.G. Eastland', A.R. Ansell, M.N. Kochert, R.D. Williams, and
L.S.Young. 1990. Effects of blasting on behavior and productivity of nesting prairie
falcons. Wildl. Soc. Bull. 18:270-281.
Martin, D.J. 1973. Selected aspects of burrowing owl ecology and behavior. Condor 75:446-
456.
Northern States Bald Eagle Recovery Team. 1983. Northern States Bald Eagle Recovery Plan.
U.S. Fish and Wildlife Service. 75p.
Reynolds, Richard, R.T. Graham, H.M. Reiser. 1992. Management recommendations for the
northern goshawk in the southwestern United States. Gen. Tech. Rep. RM-217- Ft.
Collins, CO. U.S. Dept of Agri., Forest Service, Rocky Mountain Forest and Range
Experiment Station. 90pp.
Richardson, Cary T. and C.K. Miller. 1997. Recommendations for protecting raptors from
human disturbance: a review. Wildl. Soc. Bull. 25(3):634-638.
Rocky Mountain/Southwest Peregrine falcon recovery Team. 1984. American peregrine falcon
Rocky Mountain/Southwest population recovery plan. U.S. Fish and Wildlife Serv. 105
pp
Squires, J.H., S.H. Anderson, and R. Oakleaf. 1993. Home range size and habitat use patterns of
nesting_ prairie falcons near oil developments in northeastern Wyoming. ' J. Field
Ornithology. 64:1-10.
Swenson, J.E. 1979. Factors affecting status and reproduction of ospreys in Yellowstone
National Park. J. Wildl. Manage. 43:595-601.
Thomsen, L. 1971. Behavior and ecology of burrowing owls on the Oakland Municipal Airport.
Condor 73:177-192.
5 i".:d l-: .i0_I,'d t'? of \42Z i,
BURROWING OWL
Nest Site:
No human encroachment or disturbance within 75 yards of the nest site from April 1 through July
31. This period is necessary to avoid disturbing nesting owls. However, owls may be present at
burrows up to a month before egg laying and several months after young have fledged. Therefore
it is recommended that efforts to eradicate prairie dogs or destroy abandoned ,towns not occur
between March 1 and October 31 when owls may be present. Although owls may occur
throughout a prairie dog colony, there is a propensity for them to frequent the colony margins and
buffer zones should be applied to the colony perimeter. Measures that protect and enhance
prairie dog colonies will benefit this species.
Buffers Documented in the Literature
Species
Period
Optimal
Distance
Authority
Incubation
Brood
Ferruginous Hawk
380-488 yd.
619-781 yd.
781 yd. (.45 mi.)
Holmes
Red-tailed Hawk
448-553 yd.
428-604 yd.
604 yd. (.34 mi.)
Holmes
Swainson's Hawk
171-203 yd.
309-382 yd.
382 yd. (.22 mi.)
Holmes
Prairie Falcon
500-1000 m
546-1093 yd.
1000m
1093 yd(62 mi.)
Holthuijzen et al.
Perch Buffers
The following buffers for perches were recommended by T. Holmes (1994) to prevent flushing of
90 % of raptors wintering in rangeland and agricultural habitats.
SPECIES BUFFER AREA
(Radius)
American Kestrel
75m
Merlin
125m
Prairie Falcon
160m
Rough -legged Hawk
210m
Ferruginous Hawk
140m
Golden Eagle
300m
i,, iUcSCi=.
FERRUGINOUS HAWK
Nest Site:
No surface occupancy * (beyond that which historically occurred in the area) within 1/2 mile
radius of the nest site, and associated alternate nests. Seasonal restriction to human
encroachment within 1/4 mile of the nest and any alternate nests from February 1 to July 15. This
species is especially prone to nest abandonment during incubation if disturbed. .
RED-TAILED HAWK
Nest Site:
No surface occupancy * (beyond that --which historically occurred in the area) within 1/3 mile
radius of the nest site, and associated alternate nests. Some members of this species have adapted
to urbanization and may tolerate human habitation to within 200 yards of their nest. Development
that encroaches on rural sites is likely to cause abandonment. Seasonal restriction to human
encroachment should be in effect from March 1 to July 15.
SWAINSON'S HAWK
Nest Site:
No surface occupancy * (beyond that which historically occurred in the area) within 1/4 mile
radius of the nest site, and associated alternate nests. Some members of this species have adapted
to urbanization and may tolerate human habitation to within 100 yards of their nest. Seasonal
restriction to human encroachment within 1/4 mile of the nest from April 1 to July 15.
PEREGRINE FALCON
Nest Site:
No surface occupancy * (beyond that which historically occurred in the area) within 1/2 mile of
the nest site. Seasonal restriction to human encroachment within 1/2 mile of the nest cliff(s)
from March 15 to July 31. A 1-mile buffer with a closure from February 1 to August 31 was
originally stipulated in the approved Recovery Plan, but recent field evidence suggests that the
zone can be reduced to 1/2 mile. Due to propensity to relocate nest sites, sometimes up to 1/2
mile along cliff faces, it is more appropriate to designate 'Nesting Areas' that encompass the cliff
system and a 1/2-mile buffer around the cliff complex.
PRAIRIE FALCON
Nest Site:
No surface occupancy * beyond that which historically occurred in the area) within 1/2 mile
radius of the nest site.
NORTHERN GOSHAWK
Reynolds- et al- (1993) proposed 30 acres for the nest, a post fledging family area of 420 acres,
and a foraging area of 5400 acres in size that encompasses habitat for squirrels, rabbits, jays,
woodpeckers and grouse. For purposes here, it seems that a buffer of 1/2 mile around the nest
should protect the integrity of the nesting and post fledging area. Occupancy of the nesting and
brood rearing area takes place from early March through late September.
ULI: i.r, Sill ct: ors, rr,...L.,
species will continue to occupy the area. Measurements are somewhat imprecise (fractions of a
mile) and reflect the need to maintain some flexibility to adjust buffer zones depending upon
intervening terrain and vegetation screens that obscure the activity, This document is intended to
be modified and refined as additional information becomes available, hence the need for a
revision date.
BALD EAGLE,
Nest Site:
Year round closure to surface occupancy *(beyond that which historically occurred in the area)
within 1/4 mile radius of nest. No human encroachment from November 15 through July 31
within 1/2 mile radius of the nest. This closure is more extensive than the Northern-States�Bald
Eagle Recovery Plan due to the generally open habitat used by Colorado's nesting bald eagles.
Aside from four Colorado sites in coniferous forests, all others are in cottonwood riparian zones
that don't have the vegetational density, and therefore obscurity offered by the habitats in the lake
states. Recent evidence suggests that pairs nesting at lower elevations frequent and maintain
their nests throughout the year. If it is necessary to work within the '/z mile buffer, the intrusion
should be restricted to August 15 through October 15.
Winter Night Roost:
Activity should be eliminated within ,1/4 mile radius of winter roosts between November 15 and
March 15. If periodic visits (such as oil well maintenance work) are required within the buffer
zone after development, activity should be restricted to the period between 1000 and 1400 hours
from November 15 to Match 15. Limited restrictions may be necessary out to 1/2 mile if there is
a direct line of sight from the roost to the activities.
Hunting Perch:
Diurnal Perches associated with important foraging areas should also be protected from human
encroachment. Preferred perches may be at varying distances from human encroachment and
buffer areas will vary. However, at least 2 management plans recommend zones that range from
1/8 mile (200 meters) to '/a mile (400 meters) depending upon topographic or vegetational
screening.
GOLDEN EAGLE
Nest Site:
No surface occupancy * (beyond that which historically occurred in the area) within 1/4 mile
radius of the nest site and associated alternate nests. Seasonal restriction to human encroachment
within 1/4 mile of the nest and any alternate nests from February 1 to July 15.
OSPREY
Nest Site:
No surface occupancy * (beyond that which -historically -occurred in the area) within 1/4mile-of
the nest site. Seasonal restriction to human encroachment within 1/4 mile of the nest from April
1 to August 31. Some osprey populations have habituated and are tolerant to human activity in ,
the immediate vicinity of their nests.'
rye r v(:..
G2 <lli<. ` C1�5. i(1<-.
J2iC�CJ.:Id:,�S. Sic.
APPENDIX A
RECOMMENDED BUFFER ZONES AND SEASONAL RESTRICTIONS
FOR COLORADO RAPTOR NESTS
*These zones and seasonal restrictions are recommended as guidance and may be
subject to change. They do not represent official Division policy
Prepared By
Gerald R. Craig
Colorado Division of Wildlife
Updated 1/18/02
Tolerance limits to disturbance varies among as well as within raptor species. As a rule,
ferruginous hawks and golden eagles respond at greater distances to human activities than do
ospreys and kestrels. Some individuals within a species also habituate and tolerate human
activity at a proximity that would cause the majority of the species to abandon their nests. Other
individuals become sensitized to repeated encroachment and react at greater distances. The
tolerance of a particular pair may change when a mate is replaced with a less.tolerant individual
and may cause the pair to react to activities that were previously ignored. Responses will also
vary depending upon the reproductive stage. Although the level of stress is the same, the pair
may be more sensitive during egg laying and incubation and more demonstrative when the chicks
hatch.
The term "disturbance" is also ambiguous and experts disagree on what actually constitutes a
disturbance. Reactions may be as subtle as elevated pulse rate and as extreme as vigorous
defense or abandonment. Impacts of disturbance may not be immediately evident. A pair of
raptors may respond to human intrusion by defending the nest, but well after the disturbance has
passed, the male may remain in the vicinity for protection rather than forage to feed the nestlings,
Golden Eagles rarely defend their nests; but merely fly a half mile or more away and perch and
watch. Chilling and over heating of eggs or chicks and starvation of nestlings can result from
human activities that appeared not to have caused an immediate response.
A `holistic' approach is recommended when protecting raptor habitat. While it is important for
land managers to focus on protecting nest sites, equal attention should focus on defining
important foraging areas that support the pairs nesting effort. Hunting habitat of many raptor
species are extensive and may necessitate interagency cooperation to assure the continued nest
occupancy. Unfortunately, basic knowledge of habitat use is lacking and may require
documentation through telemetry investigations or intensive observation. Telemetry is expensive
--
arid may be- di§ruptive so a more -practical approach is to assume that currentopenspace is
important and should be protected.
Although there are exceptions, the buffer areas and seasonal restrictions suggested here reflect an
informed opinion that if implemented, should assure that the majority of individuals within a
tG
J
Future p�.o..
N
y.
1 1°JOGaS�acelButtor
I Park
0.92 er.,
i
Single -Family
28 .a
S�,nte Fenul
�a Single -Family
Single
881
Single -
JAI
LEGEND
NATIVE UPLAND SEED MIX
z
-BUFFALO GRASS
-BLUE GRAMA
y
-PERENNIAL RYE
z
O
WETLAND BOUNDARY SEED MIX
-WESTERN WEATGRASS
V
-PRAIRIE CORDGRASS
-SWITCHGRASS
-YELLOW INDIANGRASS. HOLT
-SLENDER WHEATGRASS
CL
-BIG BLUESTEM, KAW
W
-CANADA WILD RYE
z
O
U
WILLOW STAKES
1
z
a
COTTONWOOD SAPLINGS
lW
V
UPLAND SHRUBS
Q O
-RABBITBRUSM
-APACHE PLUME
-POTENTILLA
-COTONEASTER
p
-ROCKY MT. JUNIPER
-SNOWBERRY (BETWEEN
N
UPLAND S DETENTION)
t+J
a
O
NiKJ1Ki. MAY.
i-_._ -- __..-_..___. �; o
COLORADO RAPTOR REGULATORY REVIEW
5. Woody plants shall be watered weekly during the first growing season, from Nlay until
September.
6. Scatter fallen trees and brush piles around open space parcel.
7. Plant a vegetation (scattered shrub) barrier between active recreation areas and
detention/open space
8. Use mechanical and chemical weed control until native vegetation is established
(both upland and detention areas).
Site Visit with Gerald Craig
A site visit with raptor expert Gerald Craig was conducted on December 17, 2003.
During this site visit the location of the existing nest was identified, available foraging
areas determined, and the above proposed mitigation was discussed. Mr. Craig felt that
the conceptual mitigation was a good approach and suggested that the plan as discussed
be presented to the City of Fort Collins. Minor adjustments to the plan were suggested
by Mr. Craig, including restricting construction within 300 feet of the nest site during the
breeding season and annually monitoring the nest site. These suggestions have been
incorporated into the mitigation plan.
References
Colorado Division of Wildlife (CDOW) 1997. Suggestions For Handling Burrowing
Owl Issues; Second Draft. Prepared by Dave Weber. 1313 Broadway, Denver. 2 pp.
Craig, G.R. 2002. Recommended buffer zones and seasonal restrictions for Colorado
Raptor Nests. Colorado Division of Wildlife. January 18, 2002.
Postovit, H.R. and B.C. Postovit 1987. Mining and energy development pp. 167-172 in.
Western raptor Management Symposium and Workshop. National Wildlife Federation
Scientific and Technical Series No. 12 Washington D.0 3420 pp.
Dechant, J. A., M. F. Dinkins, D. H. Johnson, L. D. Igl, C. M. Goldade, and B. R. Euliss.
2001. Effects of management practices on grassland birds: Swainson's Hawk.
Northern Prairie Wildlife Research Center, Jamestown, ND. Jamestown, ND:
Northern Prairie Wildlife Research Center Home Page.
www.npNvrc.usgs.o,ov/resource/literatr/grasbird/fpswha/fpswha.htm. (Version
29FEB2000).
Lt
COLORADO RAPTOR REGULATORY REVIEW
7. Detention pond slopes shall be seeded and mulched as per specification for other upland areas
of the project site.
8. **Outflow elevation is assumed to be final water surface elevation
9. Create a diverse prey habitat within the shrub/meadow area by grading the detention area
to create varying topography and microhabitat areas with slightly different soil
moisture characteristics, scattering brush piles randomly over uplands and detention
area
Plant Species
Number
Size
Elevation of Plants*
Box elder/Ater negundo
3
5 gal.
Soil Mounds
Peachleaf willow/Salix amygdaloides
3
5 gal.
Soil Mounds
Chokecherry/Prunii.s virginiana
3
5 gal.
Soil Mounds
ServiceberrylAmelanchier alnifolia
5
5 gal.
Side Slopes
Sandbar willow/Sa1Lr erigua
10
1 gal.
Depressions
Small -winged sedge/Carer praegracilis
150
2"
Depressions
Baltic rushlJuncus balticus
150
2"
Depressions
Threesquare bulrush/Scirpus americana
100
14"
Depressions
It is recommended that approximately half of the plants be planted in the first growing season,
and that the ponds water surface be reevaluated at this time. If the desired water surface elevation
is not maintained, it may be necessary to choose wetland species more tolerant of drier
conditions.
Suggested Planting Plan — Upland Areas ,
1. Use an upland native seed mix (available from seed distributors) on upland areas,
the attached wetland boundary seed mix within detention area, and broadcast both
seed mixes in the transition area between upland and detention.
2. Plant 2-3 small groves of fast growing tree saplings (cottonwoods) to provide
future perches/nest sites for raptors.
3. Plant shrubs and woody vegetation to provide wildlife cover and forage. Suggested
shrubs include rabbit brush, apache plume, potentilla, cotoneaster, rocky mountain
juniper, snow berry.
4. Plant willow stakes in patches in areas with seasonally moist soils.
�'1
COLORADO RAPTOR REGULATORY REVIEW
• Installation of earthen berms and vegetation, where appropriate, to create
separation from human use areas and wildlife habitat areas and to act as
visual/noise barriers.
• Annual nest monitoring. Nest monitoring will be discontinued after three
consecutive years of inactivity or documentation that the pair has moved.
Suggested Planting Plan-Shrub[Meadow Wetland Area
1. Place a minimum of 6" topsoil on detention pond and the slopes surrounding it. Soil should
be shaped into mounds with a natural appearance. These mounds may be 6" up to 18" higher
than the low areas between them, and should comprise about 35% of the regraded area. The
steepness of the slopes surrounding the pond should vary, for a more natural appearance and
the creation of diverse micro -habitat areas.
2. Drag or harrow pond bottom/shrub meadow area to prepare for seeding.
3. Drill or broadcast seed with the following seed mix. Double rate for broadcast seeding. All
seed must be guaranteed for purity and germination, free of noxious weeds, and supplied on a
PLS basis.
Seed Species
% of Mix
PLS/Acre
Giant mannagrass/Glviceria maxima
5%
1.0
Alkaligrass/Pucinnel/a distans
10%
1.5
Prairie cordgrass/Spartina pectinate
20%
3.0
Switchgrass/Panicum virgatum
25%
4.0
Western wheatgrass/Pascopyrum smithii
35%
5.0
Yellow indiangrass, holt
5%
1.2
Total
100%
15.7
4. Mulch with weed free straw at a rate of 2 ton/acre.
5. Plant the species listed in the following table between April and early June. For nursery
recommendations or other questions, contact biologist.
6. Plants must be planted at elevations indicated in table. Some plants should be placed in
clumps with individuals from 2 to 4 feet apart. Others should be scattered throughout the
detention pond bottom. Plants should be unevenly spaced.
7
COLORADO RAPTOR REGULATORY REVIEW
that the site is no longer an active nest site, then parcels within the 300-foot buffer
may be developed.
• Mitigate — East Ridge, LLC, has also committed to a comprehensive mitigation
plan that accounts for all aspects of raptor ecology, including adequate nesting
substrate, protection from predators and human disturbance and enhancement of
native open space to provide food resources.
Site Specific Raptor Mitigation Plan for the East Ridge Site includes the
following:
• Modification of the original site development plan to increase natural open space
areas, conserve important foraging areas, move human activity areas away from
raptor foraging areas, and protecting a 300-foot buffer area for the Swainson's
hawk nest.
• Permanent protection of the existing raptor nest tree as long as nest is occupied
and remains active. Protection will consist of maintaining the row of trees
containing the existing and alternate nest sites and establishing a 300-foot buffer
around the active nest. Development of commercial/residential parcels within
300 feet of the nest tree will only be considered in the event the existing active
nest is determined to be inactive.
• Construction of needed infrastructure, such as utilities and streets within 300 feet
of the active nest site will not be conducted during the breeding season (April 1 —
July 15)
• Conservation of more than 20 acres of natural open space, including wetland, wet
meadow, and upland habitats to provide habitat for rodent and songbird species
providing foraging opportunities for raptors nesting on the property and from the
adjacent property to the south.
• Detailed planting plan using native vegetation to create diverse food and cover
habitat for prey species (see Figure 1).
• Enhancing habitat for prey species by providing structural and vegetative
diversity to increase cover and food resources for rodent and songbird species.
Conservation and enhancement of prey habitat will also provide foraging areas for
American kestrels, northern harriers and wintering raptors.
COLORADO RAPTOR REGULATORY REVIEW
Natural History of Raptors nesting on or near the site
Swainson's hawk
Swainson's hawks typically arrive in Colorado between April and early May and,
nests between mid May and mid June (Andrews and Righter 1992, Kingery 1998). When
Swainson's Hawks arrive at their nesting sites, they may return to their original nests as
these hawks are noted to be monogamous. Research indicates that they have a high
degree of mate and territorial fidelity. This is an unusual occurrence in a long distance
migrant. Seven to 15 days after the birds arrive; the males begin constructing nests
(Dechant, et al. 2001). The nest consists of twigs and grasses and can take up to two
weeks to complete. New nests may be constructed, old nests refurbished, or the nests of
other species, including those of common raven, black -billed magpie, and American
crow. Nests are flimsy structures, usually smaller than the riests of the red-tailed hawk,
and often blow down after nesting season (Dechant, et al. 2001)
Clutch size ranges from one to four eggs, but averages two to three eggs. The
incubation period is 34 to 35 days, with the female incubating while the male brings food
(Dechant, et al. 2001).
Red-tailed Hawk
The red-tailed hawk inhabits open areas interspersed with patches of trees or other
elevated perch sites that provide a commanding view of the surrounding terrain in all
habitat types (Preston and Beane 1993). The overall abundance of red-tailed hawks has
increased in recent decades. Many red -tails in Colorado are year round residents others
arrive in mid -January through February. Breeding occurs in Colorado from March
through June and early July (Kingery 1998).
Mitigation Options
in
ERO recommends the'following options for addressing raptor issues on the East
Ridge property:
Avoid/Minimize —Design the project that avoid disturbance to the Swainson's
hawk nest sites (active and alternate sites) and important foraging areas for both
the Swainson's hawk and red-tailed hawk nesting south of the property. East
Ridge, LLC, the developer of the East Ridge Property, has committed to
preserving the active nest and a 300-foot buffer surrounding the nest tree. In the
event that it is determined that the Swainson's hawks have abandoned the site or
5
COLORADo RAPTOR REGULATORY REVIEW
Compliance Recommendations
The presence of a raptor nest on a project site presents numerous obstacles for
development. Raptors are large, high profile species that occupy large home ranges and
often elicit strong emotional reactions from the general public. In addition to complying
with the policies and regulations described above, many projects must also address public
relations issues. The following is a brief synopsis for complying with the above
regulations.
Active hawk or owl nest —The CDOW will often request avoidance, minimization
and mitigation (described below) for impacts to active nest sites. The CDOW typically
considers a nest active for 3 to 5 years after its last known occupancy. Avoidance
consists of complying with the recommended buffer zones. CDOW recommendations
are frequently adopted and implemented during the development review process. Fort
Collins requires a'/< mile buffer surrounding raptor nests. Strict enforcement of the City
of Fort Collins buffer zone standards on East Ridge is not a viable option
Site Specific Studies
Cedar Creek Associates conducted surveys and prepared an Ecological
Characterization Study Report for East Ridge Property to identify wetlands and other
ecological issues (Cedar Creek Associates 2000). Surveys were conducted in early
March and again in late August, 1999 with no evidence of raptor nesting activity such as
large stick nests or whitewash noted in any of the trees on the property (Cedar Creek
Associates 2000). Cedar Creek Associates performed a raptor nest survey in the spring
of 2003 and identified a potential nest structure, but no active nests were found at that
time. During a site visit in April of 2003, Gerald Craig and Doug Moore identified the
active Swainson's hawk nest described in this report. According to Gerald Craig
(personnel communication 17 Dec. 2003) this pair moved their nest from a large
cottonwood next to Timberline Road to a cottonwood further east within the same line of
mature trees. This nest was active in 2002. According to G. Craig an active red-tailed
nest exists along the Lake Canal, south of the project site. Great horned owls may also
nest in the vicinity.
4
COLOR, -,,Do RAPTOR REGULATORY REVIEW
within a species will continue to occupy the area. Measurements are somewhat imprecise
and reflect the need to maintain some flexibility to adjust buffer zones depending upon
intervening terrain and vegetation screens that obscure human activity. The following
buffers zones are recommended for raptors known to nest within or near the East Ridge
project site. The complete buffer zone guidance is provided in Appendix A.
Red -Tailed Hawk (Buteo Jamaicensis)
Nest Site: Typically a large stick nest near the top of a large mature tree. No
surface occupancy (beyond that which historically occurred in the area) within '/mile
radius of the nest site, and associated alternate nests. Some members of this species have
adapted to urbanization and may tolerate human habitation to within 200 yards of their
nest. Development that encroaches on rural sites is likely to cause abandonment.
Seasonal restriction to human encroachment should be in effect from March 1 to July 15.
Swainson's Hawk (Buteo Swainsont)
Nest Site: Typically a small stick and weed or twig nest, often on the periphery
of the canopy. No surface occupancy (beyond that which historically occurred in the
area) within'/4 mile radius of the nest site, and associated alternate nests. Some members
of this species have adapted to urbanization and may tolerate human habitation to within
100 yards of their nest. Seasonal restriction to human encroachment within'/4 mile of the
nest from April 1 to July 15.
Great Horned Owl (Bubo virginianus)
Nest Site: Great horned owls do not build their own nest but will use buildings,
tree cavities, cliffs ledges, and the nests of other raptors, magpies or other birds.
Great horned owls occur in lowland riparian forests and agricultural areas, and less
commonly in urban areas, foothill riparian forests, and coniferous forests. No buffer
zones or seasonal restrictions are recommended for this species, although the MBTA
prohibits removal or destruction of an active nest.
Local Regulations and Guidelines .
The City of Fort Collins, Colorado has adopted a raptor protection zone that is
implemented during the planning process for all new developments. This regulation is
based on state guidelines and consists of a 1/4 mile buffer around nest sites.
3
COLORADO RAPTOR REGULATORY REVIEW
Bald and Golden Eagle Protection Act
This Act imposes criminal and civil penalties on anyone (including associations,
partnerships and corporations) in the U.S. or within its jurisdiction who, unless excepted,
takes, possesses, sells, purchases, barters, offers to sell or purchase or barter, transports,
exports or imports at any time or in any manner a bald or golden eagle, alive or dead; or
any part, nest or egg of these eagles.
Migratory Bird Treaty Act
Originally passed in 1918, the MBTA commits to the protection "of the many species
of birds that traverse certain parts of the United States and Canada in their annual
migration. Unless permitted by regulations, the Act provides that it is unlawful to pursue,
hunt, take, capture or kill; attempt to take, capture or kill; possess, offer to or sell, barter,
purchase, deliver or cause to be shipped, exported, imported, transported, carried or
received any migratory bird, part, nest, egg or product, manufactured or not". In
Colorado all birds except for European starling, house sparrow, and rock dove (pigeon)
are protected under the MBTA.
State Regulation and Guidelines
According to the CDOW (Craig 2002) raptor species and individual raptors vary in
their tolerance limits to disturbance. Some individuals habituate and tolerate human
activity at a proximity that would cause the majority of the species to abandon their nests.
Other individuals become sensitized to repeated encroachment and react at greater
distances. A raptor's response also will vary depending upon the reproductive stage. A
breeding raptor pair may be more sensitive during egg laying and incubation and more
defensive of the nest site when the chicks hatch (Craig 2002). Thus the CDOW
recommends a "holistic" approach when protecting raptor habitat.(Craig 2002)' that
protects both nest sites and important foraging areas that support the pairs nesting effort.
One aspect of this approach is establishing buffer zones around active nest sites. State
guidelines are exactly that "Guidelines"; however, any project that goes through a
development review process generally needs to address raptor issues.
The buffer zones and seasonal restrictions suggested by CDOW (Craig 2002) reflect
an informed opinion that if implemented, should assure that the majority of individuals
2
EAST RIDGE R-82TOR MITIGATION PLAN
Introduction
The Migratory Bird Treaty Act (MBTA) protects raptors and other migratory birds,
including active nest sites. Additionally, the Colorado Division of Wildlife (CDOW) has
adopted guidelines/regulations that recommend restrictions on human disturbance within
specified buffer zones surrounding raptor nests. The City of Fort Collins has also
established a''/4 mile buffer around all red-tailed, ferruginous and Swainson's hawk nests
(Article 3.4.1 — Fort Collins Land Use Code)
Federal Regulatory Issues
There are three main federal regulations that pertain to raptor nest sites; The
Endangered Species Act (ESA), the Bald and Golden Eagle Protection Act, and the
Migratory Bird Treaty Act. Federal and state regulations pertain primarily to active nest .
sites, although theses regulations and guidelines differ in the definition of an active nest
as described below:
Federal: In the case of the MBTA, active refers to actual presence of birds at the
nest. That means that a nest that was active during the breeding season is inactive in the
fall and winter and could be "taken."
State: The state raptor biologist, Jerry Craig, believes that the nest should receive
protection for as long as birds return to it. If a nest has not been used for 3 years, the state
might give it less protection.
Endangered Species Act
The ESA provides broad protection for species of fish, wildlife and plants that are
listed as threatened or endangered in the U.S. or elsewhere. Provisions are made for
listing species, as well as for recovery plans and the designation of critical habitat for
listed species. The Act outlines procedures for federal agencies to, follow when taking
actions that may jeopardize listed species.
EAST RIDGE RAPTOR MITIGATION PLAN
FORT COLLINS, COLORADO
Prepared for -
East Ridge LLC
4190 N. Garland
Loveland, CO. 80538
Prepared by—
ERO Resources Corporation
1842 Clarkson Street
Denver, Colorado 80218
(303)830-1188
February 12,;D@<20o4