DOCSLIB.ORG

Inter and Intraspecific Interactions Between Red-Tailed Hawks and Great Horned Owls in Central Ohio1

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Inter and Intraspecific Interactions Between Red-Tailed Hawks and Great Horned Owls in Central Ohio1 Copyright © 1978 Ohio Acad. Sci. 0030-0950/78/0006-0323$1.5()/0 INTER AND INTRASPECIFIC INTERACTIONS BETWEEN RED-TAILED HAWKS AND GREAT HORNED OWLS IN CENTRAL OHIO1 MARK ANDREW SPRINGER, Department of Anatomy, Wright State University, Dayton, OH 45435 JOHN STEPHEN KIRKLEY,2 Department of Zoology, Ohio Weselyan University, Delaware, OH 43015 Abstract. Interspecific relationships between Red-tailed hawks and Great horned owls reveal distinct chronological activities that facilitate their inter-related nesting patterns. The hawk to owl ratio in the study area in 1976 was approximately 1.3 : 1. This proximal nesting may have had some effect upon Red-tailed Hawk success, in that Great Horned Owl predation on Red-tailed Hawks was related to their inter- specific nesting distances. Although Great Horned Owls partially depend upon Red- tailed Hawks for their nest sites (59%) and the diet of these two raptors do overlap in some prey selected, direct competition for these resources is minimized by the temporal segregation of their breeding chronologies and their daily activity patterns. OHIO J. SCI. 78(6): 323, 1978 Interspecific relationships between area located in Delaware County, Ohio. To- pography in Delaware County is flat to gently Great Horned Owls (Bubo virginianus) rolling and land is devoted largely to agricul- and Red-tailed Hawks (Buteo jamaicen- ture, with small percentages of pasture and sis) have raised many questions concern- woodlots. Most of the continuous woodlots ing the status of their coexistence. Pre- were located along the 3 major drainages traversing the study area from north to south. ceived as ecological counterparts, these To determine nesting populations of RTHs two large, cosmopolitan raptors reveal and GHOs, foot and aerial surveys were con- distinct chronological activities that al- ducted. The reproductive chronology was de- ternate their dominant-subordinate rela- veloped by interpolating hatch dates from known body weights of each nestling. Age of tionships, facilitate their inter-related the nestlings was determined by comparing nesting patterns, and stabilize their inter- body weights of each nestling to known growth specific competition and predation (Craig- rates of 5 nestling RTHs and 2 GHOs taken in head and Craighead 1965). Do Red- the study area in 1975 and 1976. This informa- tion together with the natural growth rates re- tailed Hawks and Great Horned Owls ported by Hoffmeister and Setzer, (1947) en- operate independently of one another, or abled reliable approximations of nestlings' age have their survival strategies mutually for the first 3 weeks of growth. Beyond this coevolved? Although little quantitative time, age was determined by the linear measure- ment of the 7th primary and/or overall size and information addresses the behavior of plumage development. Length of incubation, such mixed populations, studies which in- 34 days, was used for both GHOs (Baumgartner vestigate both species simultaneously 1939) and RTHs (Hardy 1939 and present may help to shed some light on such study). Length of nestlife for GHO's and RTHs was 45 days (Hoffmesister and Setzer questions. 1947) and 42 days (this study), respectively. Inter and intraspecific internest distances of STUDY AREA AND METHODS RTHs and GHOs were calculated by plotting Nesting populations of Red-tailed Hawks the location on topographical maps and cal- (RTH) and Great Horned Owls (GHO) were culating the linear measurements between nest studied from 1974 to 1976 on a 197 square mile sites. Manuscript received 16 August 1977 and in RESULTS AND DISCUSSION revised form 5 April 1978 (#77-63) The foot surveys and aerial surveys 2Affiliated with the Raptor Survey Project of the Ohio Biological Survey. Current address: revealed that density and productivity Utah State Dept. Botany, Logan, UT. of both raptors in 1976 were similar to 323 324 M. A. SPRINGER AND J. S. KIRKLEY Vol. 78 the averages of those values reported 21 February with a mean at 5 February. elsewhere in North America, but our Hatch dates ranged from 15 February to density figures for both species were 26 March with the mean at 10 March. considerably higher than those reported Fledging dates ranged from the last week previously in Ohio. In 1976 we located in March to the first week in May. 59 active GHO nests (1 pair/3.16 sq. mi.) Laying dates at 55 RTH nests in 1976 and 78 RTH nests (1 pair/2.39 sq. mi.). ranged from 6 March to 6 April with the Each season, the GHO is notably the mean at 16 March. Hatching dates first raptor to begin its nesting, and this ranged from 9 April to 10 May with the behavior, together with its noctural hunt- mean at 19 April. Fledging dates ranged ing abilities, has enabled it to dominate from the last week in May to the last over other nesting raptors (Craighead and week in June with the mean at 3 June. Craighead 1956). In the spring of 1976, A number of reasons for the staggering we noted that nesting of GHOs preceeded of nesting sequences have been proposed that of the RTHs by approximately 40 by Craighead (1956) and Orains and days (fig. 1). Laying dates at 26 GHO Kuhlman (1967). Perhaps the early nests in 1976 ranged from 12 January to nesting of the GHO reduces interspecific 130- Eggs •• • • • Hatchlings - Fledglings -• Potential Nest Lives Time FIGURE 1. Reproductive chronology of 63 Red-Tailed Hawk nests and 39 Great Horned Owl nests in Central Ohio, 1976. Here fledglings are denned as young ready to leave the nest; thus, maximum number of fledglings decreases as they leave the nest. Potential nest lives represent the total number of nestlings produced before inherent egg loss (7.3% and 8.8%) and nestling mortality (19.7% and 13%) for Red-Tailed Hawks and Great Horned Owls, respectively. Ohio J. Sci. INTERACTIONS BETWEEN RTH AND GHO 325 competition for prey species which both average internest distance of 2.9 km it and the RTH utilize, or perhaps prey (Hagar 1975) and 3.1 km (Mclnvaille species are more vulnerable during the and Keith 1974). The shortest distance early spring months (before new vegeta- between active GHO nests observed in tion provides sufficient cover). Others 1976 was approximately 0.9 km. Ad- postulate that early nesting is a mechan- jacent RTH nests were spaced an average ism by which GHOs obtain their limiting an average distance of 1.5 km apart, with resource, nest sites; therefore early nest- a minimum distance between active ing enables GHO to gain first access to nests of 0.6 km. The average internest old RTH nests before RTHs have a distance for RTH reported by other re- chance to reoccupy them (Craighead and searchers averaged 2.07 km (table 1). Craighead 1956, Orains and Kuhlman The relative densities of RTH and 1956). Whatever the reasons for its GHO populations can be expressed in existence, the staggering of the nest terms of a simplified ratio of active hawk activities is a widely reported phenome- to owl nests. Those previous studies non which may have evolved in response highest disparity of RTHs to GHOs oc- to the interspecific relationships of the curred in sparsely wooded study areas, GHOs and other nesting raptors. whereas those with the most equal num- Intraspecific nesting distances of GHOs ber of RTHs to GHOs occurred in heavily averaged 2.0 km, which was below the wooded areas (table 2). In contrast, our TABLE 1 Intra and Interspecific nesting distances (km) of Red-tailed Hawks (RTH) and Great Horned Owls {GHO). Avg. RTH Avg. GHO Avg. Internest Reference Internest Internest Distance Distance Distance RTH and GHO Springer & Kirkley (1978) 1.5 2.0 1 Hagar (1957) 1.8 2.9 — Mclnvaille & Keith (1974) 2.1 3.1 — Seidensticker & Reynolds (1971) 2.1 — — Smith & Murphy (1973) 3.3 — — Wiley (1975) 0.84 TABLE 2 Nesting densities of Red-tailed Hawks and Great Horned Owls with respect to percent wooded study area. GH Owl RT Hawk Density Density Researcher and Ratio (km2) (km2) (Study Site) % Wooded Hawk to Per Per Owl Nesting Nesting Nesting Pair Pair Kirkley & Springer (1978) 9.0 1.3:1 8.2 6.2 (OH) Mclnvaille & Keith (1974) 34.0 1.3:1 10.1 7.5 (Canada) Hagar (1957) 50.0 1.5:1 12.2 8.0 (NY) Orians & Kuhlman (1956) — 2.3:1 14.5 7.3 Cornman (1973) 3.0 5:1 82.9 24.9 Gates (1972) 0.3 10:1 108.8 10.6 (WI) 326 M. A. SPRINGER AND J. S. KIRKLEY Vol. 78 study area was not extensively wooded evidence indicates predation by GHOs. (9%) but supported the highest nesting GHO feathers were found in 3 nests, and density of RTHs and GHOs, as well as in 1 case, time lapse photography docu- having at 1.3:1 RTH to GHO ratio, mented the predation by the GHO. equal to that of the heavily wood study As a rough test to determine whether areas. We believe this was due, in part, the success of RTH nests was related to to our extensive coverage of the study their internest distance from GHOs, 69 area and not to any difference in habitat RTH nests were categorized according to per se. their distance from the nearest GHO Internest distances between nearest activity center using the following four RTH and GHO in 1976 averaged 1.0 km, categories: less than 0.5 km, between 0.5 which fell considerably below the aver- and 1.0 km, between 1.0 and 2.0 km, and ages of either hawk to hawk (1.5 km) or greater than 2.0 km. Scattergram plots owl to owl (2.0 km) nest distances.
Load more

Recommended publications
  • Owl Eyes Activity
    EXPAND YOUR SENSES! TRY USING YOUR OWLTEX T EYES Age Range: Grades K-5 Time: 10-15 minutes Location: Indoor or outdoor space Materials: Yourself, a place to stand where you can focus your eyes on a fixed object at eye level. Instructional video: https://www.youtube.com/watch? Barn Owl v=2js74vxOXfg&feature=youtu.be Illustrations by Amira Maddison USING YOUR “OWL EYES” ACTIVATES YOUR PERIPHERAL VISION What is peripheral vision? It’s the ability to see movement and objects outside of what your eyes are directly focused on. ACTIVITY PART 1: BECOMING AN OWL Start by finding a quiet place to go and stand. Take a little bit of time to start imagining that you are becoming an owl. Notice where your feet are positioned. Make sure they are firmly positioned on the ground. Imagine that your feet have become talons and they are gripped around the branch of a tree. You are tucked away in the tree, so no one else can see you. Now it’s time to take it all in and comfortably stare into the distance. If you are outside, make sure you can see the sky and the ground. If you are inside, make sure you can see the ceiling and the floor. Notice your eyes going soft and imagine that you can now see everything happening around you. For a few minutes, take it all in. To finish, take a big breath in and when you breathe out, release that feeling of becoming an owl. Next, you will work on activating your eyesight.
    [Show full text]
  • Educator's Guide
    Educator’s Guide the jill and lewis bernard family Hall of north american mammals inside: • Suggestions to Help You come prepared • essential questions for Student Inquiry • Strategies for teaching in the exhibition • map of the Exhibition • online resources for the Classroom • Correlations to science framework • glossary amnh.org/namammals Essential QUESTIONS Who are — and who were — the North as tundra, winters are cold, long, and dark, the growing season American Mammals? is extremely short, and precipitation is low. In contrast, the abundant precipitation and year-round warmth of tropical All mammals on Earth share a common ancestor and and subtropical forests provide optimal growing conditions represent many millions of years of evolution. Most of those that support the greatest diversity of species worldwide. in this hall arose as distinct species in the relatively recent Florida and Mexico contain some subtropical forest. In the past. Their ancestors reached North America at different boreal forest that covers a huge expanse of the continent’s times. Some entered from the north along the Bering land northern latitudes, winters are dry and severe, summers moist bridge, which was intermittently exposed by low sea levels and short, and temperatures between the two range widely. during the Pleistocene (2,588,000 to 11,700 years ago). Desert and scrublands are dry and generally warm through- These migrants included relatives of New World cats (e.g. out the year, with temperatures that may exceed 100°F and dip sabertooth, jaguar), certain rodents, musk ox, at least two by 30 degrees at night. kinds of elephants (e.g.
    [Show full text]
  • Black-Flies and Leucocytozoon Spp. As Causes of Mortality in Juvenile Great Horned Owls in the Yukon, Canada
    Black-flies and Leucocytozoon spp. as Causes of Mortality in Juvenile Great Horned Owls in the Yukon, Canada D. Bruce Hunter1, Christoph Rohner2, and Doug C. Currie3 ABSTRACT.—Black fly feeding and infection with the blood parasite Leucocytozoon spp. caused mortality in juvenile Great Horned Owls (Bubo virginianus) in the Yukon, Canada during 1989-1990. The mortality occurred during a year of food shortage corresponding with the crash in snowshoe hare (Lepus americanus) populations. We postulate that the occurrence of disease was mediated by reduced food availability. Rohner (1994) evaluated the numerical re- black flies identified from Alaska, USA and the sponse of Great Horned Owls (Bubo virginianus) Yukon Territory, Canada, 36 percent are orni- to the snowshoe hare (Lepus americanus) cycle thophilic, 39 percent mammalophilic and 25 from 1988 to 1993 in the Kluane Lake area of percent autogenous (Currie 1997). Numerous southwestern Yukon, Canada. The survival of female black flies were obtained from the car- juvenile owls was very high during 1989 and casses of the juvenile owls, but only 45 of these 1990, both years of abundant hare populations. were sufficiently well preserved for identifica- Survival decreased in 1991, the first year of the tion. They belonged to four taxa as follows: snowshoe hare population decline (Rohner and Helodon (Distosimulium) pleuralis (Malloch), 1; Hunter 1996). Monitoring of nest sites Helodon (Parahelodon) decemarticulatus combined with tracking of individuals by radio- (Twinn), 3; Simulium (Eusimulium) aureum Fries telemetry provided us with carcasses of 28 ju- complex, 3; and Simulium (Eusimulium) venile owls found dead during 1990 and 1991 canonicolum (Dyar and Shannon) complex, 38 (Rohner and Doyle 1992).
    [Show full text]
  • A Multi-Gene Phylogeny of Aquiline Eagles (Aves: Accipitriformes) Reveals Extensive Paraphyly at the Genus Level
    Available online at www.sciencedirect.com MOLECULAR SCIENCE•NCE /W\/Q^DIRI DIRECT® PHYLOGENETICS AND EVOLUTION ELSEVIER Molecular Phylogenetics and Evolution 35 (2005) 147-164 www.elsevier.com/locate/ympev A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level Andreas J. Helbig'^*, Annett Kocum'^, Ingrid Seibold^, Michael J. Braun^ '^ Institute of Zoology, University of Greifswald, Vogelwarte Hiddensee, D-18565 Kloster, Germany Department of Zoology, National Museum of Natural History, Smithsonian Institution, 4210 Silver Hill Rd., Suitland, MD 20746, USA Received 19 March 2004; revised 21 September 2004 Available online 24 December 2004 Abstract The phylogeny of the tribe Aquilini (eagles with fully feathered tarsi) was investigated using 4.2 kb of DNA sequence of one mito- chondrial (cyt b) and three nuclear loci (RAG-1 coding region, LDH intron 3, and adenylate-kinase intron 5). Phylogenetic signal was highly congruent and complementary between mtDNA and nuclear genes. In addition to single-nucleotide variation, shared deletions in nuclear introns supported one basal and two peripheral clades within the Aquilini. Monophyly of the Aquilini relative to other birds of prey was confirmed. However, all polytypic genera within the tribe, Spizaetus, Aquila, Hieraaetus, turned out to be non-monophyletic. Old World Spizaetus and Stephanoaetus together appear to be the sister group of the rest of the Aquilini. Spiza- stur melanoleucus and Oroaetus isidori axe nested among the New World Spizaetus species and should be merged with that genus. The Old World 'Spizaetus' species should be assigned to the genus Nisaetus (Hodgson, 1836). The sister species of the two spotted eagles (Aquila clanga and Aquila pomarina) is the African Long-crested Eagle (Lophaetus occipitalis).
    [Show full text]
  • Wallowa Wolverine Project: 2011‐2012 - April Progress Report
    Wallowa Wolverine Project: 2011‐2012 - April Progress Report Wallowa‐Whitman National Forest Field work began on 26 September 2011 and by the end of April 2012, we had established 26 camera stations in and adjacent to the Eagle Cap Wilderness in the Wallowa‐Whitman National Forest (Table 1). Access to camera sites was on foot, horse, snowmobile, ATV, skis, and snowshoes. The 6 camera stations that had wolverine visits in late winter 2011 were reestablished this season. Ten of the stations were below 6000’ elevation (4784’‐5820’). The remaining stations were located between 6014’ and 7373’ elevation. Additional stations may be added in May or June, depending on travel conditions in the mountains. One station was removed (WCAM1) because of its proximity to where the wolverine Stormy was trapped in December to prevent habituation of the wolverine to this site. Of the 26 established camera stations, 24 (92%) have been checked at least once (total=57 checks) and at these stations, there were 2,680 active camera days. One wolverine (Stormy; Fig.1‐3) has been photographed at 7 stations, including 4 stations where he was photographed in 2011. No other wolverines have been photographed to date. Eighteen other species have been detected at the camera stations (Table 2). Marten have been detected at 21 of the 24 (88%) stations that have been checked so far, and marten hair was collected at many of these stations and submitted for DNA analysis. We flew tracking flights on 6 days (Fig. 4), most in April, and have located wolverine tracks, or probable wolverine tracks, in 3 areas.
    [Show full text]
  • 2015 Disease Summary
    SUMMARY OF DISEASES AFFECTING MICHIGAN WILDLIFE 2015 ABSCESS Abdominal Eastern Fox Squirrel, Trumpeter Swan, Wild Turkey Airsac Canada Goose Articular White-tailed Deer Cranial White-tailed Deer Dermal White-tailed Deer Hepatic White-tailed Deer, Red-tailed Hawk, Wild Turkey Intramuscular White-tailed Deer Muscular Moose, White-tailed Deer, Wild Turkey Ocular White-tailed Deer Pulmonary Granulomatous Focal White-tailed Deer Unspecified White-tailed Deer, Raccoon, Canada Goose Skeletal Mourning Dove Subcutaneous White-tailed Deer, Raccoon, Eastern Fox Squirrel, Mute Swan Thoracic White-tailed Deer Unspecified White-tailed Deer ADHESION Pleural White-tailed Deer 1 AIRSACCULITIS Egg Yolk Canada Goose Fibrinous Chronic Bald Eagle, Red-tailed Hawk, Canada Goose, Mallard, Wild Turkey Mycotic Trumpeter Swan, Canada Goose Necrotic Caseous Chronic Bald Eagle Unspecified Chronic Bald Eagle, Peregrine Falcon, Mute Swan, Redhead, Wild Turkey, Mallard, Mourning Dove Unspecified Snowy Owl, Common Raven, Rock Dove Unspecified Snowy Owl, Merlin, Wild Turkey, American Crow Urate Red-tailed Hawk ANOMALY Congenital White-tailed Deer ARTHROSIS Inflammatory Cooper's Hawk ASCITES Hemorrhagic White-tailed Deer, Red Fox, Beaver ASPERGILLOSIS Airsac American Robin Cranial American Robin Pulmonary Trumpeter Swan, Blue Jay 2 ASPERGILLOSIS (CONTINUED ) Splenic American Robin Unspecified Red-tailed Hawk, Snowy Owl, Trumpeter Swan, Canada Goose, Common Loon, Ring- billed Gull, American Crow, Blue Jay, European Starling BLINDNESS White-tailed Deer BOTULISM Type C Mallard
    [Show full text]
  • Annual Report
    2016 ANNUAL REPORT 2016 Annual Report 1 Our Mission Ohio Wildlife Center is dedicated to fostering awareness and appreciation of Ohio’s native wildlife through rehabilitation, education and wildlife health studies. Table of Contents Our Work The Center operates the state’s largest, free native 2 Our Mission and Work wildlife animal hospital, which assessed and treated 3 Message from the Board Chair 4,525 wildlife patients from 54 Ohio counties in 2016. Now a statewide leader in wildlife animal rescue and and Executive Director rehabilitation, the Center includes a 20-acre outdoor 4 2016 Fast Facts for Wildlife Hospital Education Center and Pre-Release Facility in Delaware County. The free Wildlife Hospital is located in the lower 5 2016 Fast Facts for Education level of Animal Care Unlimited at 2661 Billingsley 6 Foundation Grants and Partnerships Road in Columbus. 7 Volunteer Impact A focal point of the Education Center is the permanent sanctuary for 59 animals, ranging from coyote and fox 8 The Barbara and Bill Bonner Family to hawks, owls, raccoons, turtles and a turkey. There Foundation Barn are 42 species represented and seven animal ambassador 9 Power of Partnerships species listed as threatened or species of concern in Ohio. 10 2016 Events The Pre-Release Facility is comprised of multiple flight enclosures, a waterfowl enclosure, a songbird aviary, 11 Financials and species-specific outdoor housing designed to 12 Wildlife Hospital Admissions support the final phase of rehabilitation for recovering hospital patients. Animals reside at the Pre-Release 14 Board of Trustees Facility with care and oversight as they acclimate to the 15 Thank you! elements.
    [Show full text]
  • Predator and Competitor Management Plan for Monomoy National Wildlife Refuge
    Appendix J /USFWS Malcolm Grant 2011 Fencing exclosure to protect shorebirds from predators Predator and Competitor Management Plan for Monomoy National Wildlife Refuge Background and Introduction Background and Introduction Throughout North America, the presence of a single mammalian predator (e.g., coyote, skunk, and raccoon) or avian predator (e.g., great horned owl, black-crowned night-heron) at a nesting site can result in adult bird mortality, decrease or prevent reproductive success of nesting birds, or cause birds to abandon a nesting site entirely (Butchko and Small 1992, Kress and Hall 2004, Hall and Kress 2008, Nisbet and Welton 1984, USDA 2011). Depredation events and competition with other species for nesting space in one year can also limit the distribution and abundance of breeding birds in following years (USDA 2011, Nisbet 1975). Predator and competitor management on Monomoy refuge is essential to promoting and protecting rare and endangered beach nesting birds at this site, and has been incorporated into annual management plans for several decades. In 2000, the Service extended the Monomoy National Wildlife Refuge Nesting Season Operating Procedure, Monitoring Protocols, and Competitor/Predator Management Plan, 1998-2000, which was expiring, with the intent to revise and update the plan as part of the CCP process. This appendix fulfills that intent. As presented in chapter 3, all proposed alternatives include an active and adaptive predator and competitor management program, but our preferred alternative is most inclusive and will provide the greatest level of protection and benefit for all species of conservation concern. The option to discontinue the management program was considered but eliminated due to the affirmative responsibility the Service has to protect federally listed threatened and endangered species and migratory birds.
    [Show full text]
  • Red Tailed Hawk
    FACT SHEET Red-Tailed Hawk COOL FACTS: Scientifi c name: Buteo jamaicensis Average weight: female: 31-51ounces; male: 25-45 ounces Average length: female: 19-25 inches; male: 17-22 inches Average wing span: 44-52 inches both sexes (3.5- 4.5 feet) Did you know? Most common hawk in North America. PHYSIOLOGY This is one of the largest birds you will see in North America. Even though the female of the species is larger than the male, the biggest female’s weight is only about 3 pounds. The oldest know Red-Tailed Hawk was 28 years and 10 months old. This species is blocky and broad in shape. A whitish underbelly with a dark brown band formed by horizontal streaks in feather patterning is present in most colour variations. The red tail, which gives this species its name, is uniformly brick-red above and light buff-orange below. The beak is short and dark and in the hooked, raptor shape. The head can sometimes appear small in size against the thick body frame. They have relatively short, broad tails and thick, chunky wings. The legs and the feet of the Red- Tailed Hawk are all yellow. The cry of the Red-Tailed Hawk is a two to three second hoarse, rasping scream, described as kree- eee-ar. This cry is often described as sounding similar to a steam whistle. This hawk soars; fl apping its wings as little as possible to conserve energy. Active fl ight is slow and deliberate, with deep wing beats. When soaring or fl apping its wings, it typically travels from 32 to 64 km/hr, but when diving it may exceed 190 km/hr.
    [Show full text]
  • Cottontail Rabbits
    Cottontail Rabbits Biology of Cottontail Rabbits (Sylvilagus spp.) as Prey of Golden Eagles (Aquila chrysaetos) in the Western United States Photo Credit, Sky deLight Credit,Photo Sky Cottontail Rabbits Biology of Cottontail Rabbits (Sylvilagus spp.) as Prey of Golden Eagles (Aquila chrysaetos) in the Western United States U.S. Fish and Wildlife Service Regions 1, 2, 6, and 8 Western Golden Eagle Team Front Matter Date: November 13, 2017 Disclaimer The reports in this series have been prepared by the U.S. Fish and Wildlife Service (Service) Western Golden Eagle Team (WGET) for the purpose of proactively addressing energy-related conservation needs of golden eagles in Regions 1, 2, 6, and 8. The team was composed of Service personnel, sometimes assisted by contractors or outside cooperators. The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the U.S. Fish and Wildlife Service. Suggested Citation Hansen, D.L., G. Bedrosian, and G. Beatty. 2017. Biology of cottontail rabbits (Sylvilagus spp.) as prey of golden eagles (Aquila chrysaetos) in the western United States. Unpublished report prepared by the Western Golden Eagle Team, U.S. Fish and Wildlife Service. Available online at: https://ecos.fws.gov/ServCat/Reference/Profile/87137 Acknowledgments This report was authored by Dan L. Hansen, Geoffrey Bedrosian, and Greg Beatty. The authors are grateful to the following reviewers (in alphabetical order): Katie Powell, Charles R. Preston, and Hillary White. Cottontails—i Summary Cottontail rabbits (Sylvilagus spp.; hereafter, cottontails) are among the most frequently identified prey in the diets of breeding golden eagles (Aquila chrysaetos) in the western United States (U.S.).
    [Show full text]
  • Masters of the Air What Are Birds of Prey? Birds of Prey, Or Raptors, Are Amazing Animals
    State of Illinois Illinois Department of Natural Resources Masters of the Air What are birds of prey? Birds of prey, or raptors, are amazing animals. They have large eyes that face forward, powerful talons and a hooked beak. Their food includes amphibians, birds, insects, mammals and reptiles. Scientists recognize eight major groups of birds as “birds of prey.” Buteos (large hawks) fly on wide, slow-beating wings which allow them to soar and search for prey. They perch on tree limbs and fence or telephone posts. Accipters (true hawks) have a long tail (like a rudder) and short rounded wings. When flying, they make several quick wing beats and then glide. True hawks are aggressive and very quick. Ospreys can be recognized by wings that appear to be “bent,” or angled, when they fly. Found near large bodies of water, they dive feet-first to catch fishes. Falcons have long, thin, pointed wings, a short bill and a streamlined body. They can fly very fast. Eagles are larger than hawks and have longer wings. Their bill is almost as long as their head. Harriers fly close to the ground. Their wings form a small “v” during flight. These birds have a long, thin body with long, rounded wings and long legs. Kites are medium-sized hawks with pointed wings. Their hooked beak helps them feed on their prey items, such as small mammals, reptiles and insects. Owls can turn their head around 270 degrees. Fringed outer wing feathers allow for silent flight. Their wings are rounded, and the tail is short.
    [Show full text]
  • Eastern Cottontail
    EASTERN COTTONTAIL This publication is available in alternativeRABBIT media on request. Penn State is an equal opportunity, affirmative action employer, and is committed to providing employment opportunities to all qualified applicants without regard to race, color, religion, age, sex, sexual orientation, gender identity, national origin, disability, or protected veteran status. © The Pennsylvania State University 2017 U.Ed. AGR 17-73 Corner of Park Ave. and Bigler Road • University Park, PA 16802 arboretum.psu.edu facebook.com/pennstatearboretum COTTONTAIL RABBIT DESCRIPTION Named for its characteristic “cotton-ball” tail, the Eastern cottontail is the most widespread species of rabbit in North America. Although most active on rainy or foggy nights, this animal’s brown fur provides excellent camou- NAME: Sylvilagus floridanus flage during the day. Because Eastern cottontails do not hibernate, they can be found in Pennsylvania year-round CONSERVATION STATUS: in open, grassy areas with shrubby cover. The long ears of extinct near least rabbits can move independently, enabling them to hear extinct in wild threatened threatened concern in two directions at once, as well as providing a cooling mechanism through an extensive network of blood vessels. EX EW CR EN VU NT LC DIET SIZE: 1.3–1.5 feet A common visitor to gardens, the Eastern cottontail rabbit enjoys eating grasses, herbs, flowers, fruit, and WEIGHT: 1.75–3.5 pounds vegetables. In the winter, this animal dines on twigs, bark, and plant buds. GROUP TERM: colony; nest THREATS NUMBER OF YOUNG: 3–8 Eastern cottontail rabbits are preyed upon by coyotes, foxes, bobcats, hawks, and even snakes. They may also HABITAT: open fields, meadows be hunted by humans for their meat and fur.
    [Show full text]