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Cooper's Hawks (Accipiter cooperii) typically lay 3–5 eggs per clutch, rarely 6 eggs, and there are 2 accounts of 7-egg clutches and 1 record of a maximum 8-egg clutch for the species. Brood sizes of 3–5 young are common and the previous maximum brood count is 6 young. However, in 2019, we found an urban nest in Stevens Point, Wisconsin, with 7 eggs that resulted in a record high of 7 fledglings. We genetically confirmed that the attending male sired all the offspring and the attending female laid all 7 eggs. Larger body size of the tending adults may have been a factor in the exceptional reproduction reported here.

Cooper's Hawks (Accipiter cooperii) from approximately the northern third of the species' breeding range are considered migratory, hawks in the central portion are either migratory or resident, and hawks farther south are believed to be nonmigratory. We compared long-distance movements (>100 km between natal nest and encounter location) of Cooper's Hawks banded as nestlings at two different ranges of latitudes (>35° and 100 km from nests south of 35°N were from southern Arizona and southern Calif...

Raptors serve as the definitive host for several Sarcocystis species. The complete life cycles of only a few of these Sarcocystis species that use birds of prey as definitive hosts have been described. In the present study, Sarcocystis species sporocysts were obtained from the intestine of a Cooper's hawk (Accipiter cooperii) and were used to infect cell cultures of African green monkey kidney cells to isolate a continuous culture and describe asexual stages of the parasite. Two clones of the parasite were obtained by limiting dilution. Asexual stages were used to obtain DNA for molecular classification and identification. PCR amplification and sequencing were done at three nuclear ribosomal DNA loci; 18S rRNA, 28S rRNA, and ITS-1, and the mitochondrial cytochrome c oxidase subunit 1 (cox1) locus. Examination of clonal isolates of the parasite indicated a single species related to S. columbae (termed Sarcocystis sp. ex Accipiter cooperii) was present in the Cooper's hawk. Our results document for the first time Sarcocystis sp. ex A. cooperii occurs naturally in an unknown intermediate host in North America and that Cooper's hawks (A. cooperii) are a natural definitive host. (C) 2016 Elsevier Ireland Ltd. All rights reserved. National Science Foundation Historically Black Colleges and Universities Undergraduate Program [1505407]; Virginia Maryland College of Veterinary Medicine This work was supported by grant # 1505407 from the National Science Foundation Historically Black Colleges and Universities Undergraduate Program to ACR and an IRC grant from the Virginia Maryland College of Veterinary Medicine to DSL. Public domain – authored by a U.S. government employee

Plumajes Aberrantes en Accipiter cooperii Documentamos dos tipos de plumajes melanicos aberrantes, palido y oscuro, en tres individuos de Accipiter cooperii en estado silvestre. Capturamos y fotografiamos dos individuos de A. cooperii con plumaje palido en Dakota del Norte y un individuo de la misma especie en Virginia. Este es el primer estudio de muda de un individuo de A. cooperii de un plumaje aberrante juvenil palido a un segundo plumaje basico palido. Ademas, una de las dos crias macho presenta un plumaje palido como su madre, lo que sugiere que la aberracion es heredable. Tambien describimos el primer plumaje melanico oscuro para A. cooperii. [Traduccion del equipo editorial]

This file provides metadata and data files used in the analyses of female Cooper’s hawk demography and prey for the manuscript entitled “Demography and Metapopulation Dynamics of an Urban Predator” by Brian Millsap. The study was conducted primarily on a 72 km2 urban study area in northeastern Albuquerque, Bernalillo County, New Mexico, U.S.A. (N 35.1107°, W 106.6100°W) from February 2011 – August 2015. The author may be contacted at bmillsap@nmsu.edu or at 505-559-3963 if there are questions about these data or the study.&nbsp

Although hybrids between captive Accipiter species are known, and hybrids between wild Accipiter species in North America have long been suspected, none have been confirmed to date. Howeve...

We studied adult Cooper's hawks Accipiter cooperii on two study areas in north Florida from 1995 to 2001, an area dominated by large plantations managed for northern bobwhite Colinus virginianus and an area of mixed farmland and woods with no direct bobwhite management. We monitored 76 Cooper's hawk nesting attempts at 31 discrete nest areas, and radio-tagged 19 breeding males and 30 breeding females that we radio-tracked for up to 5 y. Nesting density (565 to 1,494 ha per occupied nest area) was comparable but productivity (1.8 and 2.8 young fledged per occupied and successful nest area, respectively) was lower than for the species elsewhere. Prey may have been more limiting than in other areas studied because chipmunks Tamias striatus, an important prey elsewhere, were absent. Annual Cooper's hawk survival averaged 84% for males and 81% for females, except in 1998 when survival was substantially lower. Average annual home-range size for male Cooper's hawks was 15.3 km2 inclusive of one nesting area. Female annual ranges averaged 30.3 km2, and included from three to nine nesting areas. Daily space use was similar between the sexes, but females had separate breeding and nonbreeding ranges whereas males were sedentary. Females used the same nonbreeding areas among years, but switched nesting areas 68% of the time compared with only 17% for males. Birds comprised 88% of the breeding and 98% of the nonbreeding season diet of Cooper's hawks by frequency. Important prey species all year were mourning doves Zenaida macroura, blue jays Cyanocitta cristata, and northern bobwhite; during summer, cattle egrets Bubulcus ibis, northern mockingbirds Mimus polyglottos and northern cardinals Cardinalis cardinalis were also important; and during autumn and winter, killdeer Charadrius vociferus, yellow-billed cuckoos Coccyzus americanus, and chickens were important. Female Cooper's hawks took larger prey than males; females were responsible for most cattle egret and chicken kills; whereas, males took most blue jays, killdeer, northern mockingbirds, and northern cardinals. Of avian prey brought to nests, 64% were nestling birds. Most adult male Cooper's hawks were adept at raiding bird nest boxes. Male Cooper's hawks captured 85% of the prey fed to nestlings. Female Cooper's hawks relied on males for food from early March until young were ≥12 d old, and 6 of 10 breeding females monitored intensively were never observed foraging for their broods. Most prey brought to nestling Cooper's hawks was captured within 2 km of nests, and foraging effort was consistent throughout the day. During the nonbreeding season, most prey captures occurred before 0900 hours or at dusk. Northern bobwhite made up 2% of male and 6% of female Cooper's hawk prey annually by frequency; this extrapolated to 18 bobwhite/year/adult Cooper's hawk on both study areas, 59% of which were captured between November and February. Outside the breeding season, male Cooper's hawks foraged evenly over their home range whereas females tended to focus on prey concentrations. Because female Cooper's hawks were so adept at finding and exploiting prey hotspots, perhaps the best strategy for reducing predation on bobwhite is habitat management that produces an even distribution of bobwhite across the landscape.

Life-history theory suggests that delayed maturation is beneficial to birds when costs of breeding early in life are high. We compared selected aspects of the biology of male Cooper's Hawks (Accipiter cooperii) that began breeding at 1 year of age (SY males) vs. males that began breeding ≥2 years of age (ASY males) in an effort to elucidate what renders breeding of SY males rare. Of the 732 males of known age whose breeding we studied over 32 years (1980–2011) 13 (2%) were SY and 719 (98%) were ASY During this period, the incidence of breeding of SY males changed markedly, as 12 of the instances of breeding of SY males were recorded in the first half of our study, only 1 in the latter half. We suggest that SY males could acquire nest sites more readily in the first half of the study when the breeding population of ASY males was apparently lower. Males breeding in their second year were on average similar in size to ASY males but were molting more extensively than were ASY males. ASY males lived ...

We examined banding encounter records from 1920 to 2006 for three raptors that are commonly banded in North America: American Kestrel (Falco sparverius, 4707 encounters), Sharp-shinned Hawk (Accipiter striatus; 5256), and Cooper's Hawk (A. cooperii; 3848). We selected birds banded during summer or autumn migration and encountered during winter to investigate movement distances and winter latitudes by sex, age, year banded, banding latitude, and flyway. Female American Kestrels migrated farther than males, but travel distances did not vary by age. Distance moved to wintering sites declined with encounter year for American Kestrels, suggesting that migratory short-stopping may be occurring across North America. Movements of the three species typically showed a chain migration pattern; however, female American Kestrels from the most northern latitudes demonstrated a leapfrog pattern, moving beyond mid-latitude birds to more southerly wintering latitudes. Female American Kestrels and Cooper's Hawks m...

Cooper's Hawks (Accipiter cooperii) have recently colonized many urban landscapes across North America, but data on breeding densities and trends in densities of these populations are lacking. We surveyed for woodland raptors throughout approximately 1000 km2 in the metropolitan Milwaukee, Wisconsin, area over a 21-yr period, 1988–2008. We documented the natural colonization of this urban landscape by a pioneer Cooper's Hawk population and its subsequent growth from 1993–2008 (4 to 41 laying pairs, 4 to 55 occupied sites). Nearest-nest distances decreased and the number of Cooper's Hawk laying pairs increased while nesting surveys remained consistent temporally and spatially, indicating that density of breeding pairs was increasing in the metropolitan Milwaukee area. Approximately 15 yr after initial colonization, the breeding density of Cooper's Hawks in some localized areas averaged one laying pair per 330 ha (range: 68–587 ha). From 1996–2008, as breeding density increased, average annual prod...

REGISTRO DE ACCIPITER COOPERII, BUTEO SWAINSONI Y BUTEO BRACHYURUS EN CUBA Reporto informacion sobre la migracion otonal de Accipiter cooperii, Buteo swainsoni y Buteo brachyurus hacia Cuba. Las observaciones las realice entre el 21 de julio y el 1 de octubre del 2007 en el Cabo de San Antonio, extremo occidental de Cuba. No obtuve evidencias de que las tres especies cruzaran el Estrecho del Yucatan, y todos los individuos que llegaron al Cabo de San Antonio revirtieron su ruta migratoria hacia el este. Los avistamientos realizados sugieren que las especies A. cooperii, B. swainsoni y B. brachyurus son visitantes invernales casuales en Cuba. [Traduccion del equipo editorial]

The associations among corticosterone levels, energy stores, and stress are highly relevant to bird migration physiology. Many birds maintain elevated baseline corticosterone levels during migration, yet they frequently modulate additional glucocorticoid secretion, probably to protect their flight muscles from catabolism. We report on the adrenocortical response to capture and handling stress in three Accipiter species, the Sharp-shinned Hawk (Accipiter striatus), the Cooper's Hawk (A. cooperii), and the Northern Goshawk (A. gentilis) during fall migration. We found mean baseline corticosterone levels to be similar in Sharp-shinned Hawks and Northern Goshawks, but significantly higher in Cooper's Hawks. Likewise, mean baseline levels of corticosterone did not differ in hatch-year and after-hatch-year male and female Sharp-shinned Hawks and Northern Goshawks, but they were higher in adult male Cooper's Hawks than adult females. Mean corticosterone levels did not increase significantly after 30 min...

Few studies at a broad geographical scale have characterized intraspecific variation in morphology of woodland hawks in the genus Accipiter. From 1999 to 2007 we investigated morphological variation in large samples of live Cooper's Hawks (A. cooperii) nesting in four study areas: coniferous woodland around Victoria, British Columbia, Canada, isolated deciduous woodlands in short-grass prairies of northwestern North Dakota, towns and rural deciduous woodlands along the border of North Dakota and Minnesota, and urban and rural mixed deciduous and coniferous landscapes of Wisconsin. These sites span 2660 km across the northern part of the species' breeding range. We measured body mass (i.e., size), wing chord, tail length, tarsus diameter, hallux length, and culmen length of breeding adults, finding significant and clinal variation in body mass (or size). The smallest and most similar-sized birds occurred in British Columbia and western North Dakota, larger birds along the border between North Dak...

Accurate identification of sex is important for many raptor studies, but may be difficult to determine in the field for some species. Because of size differences between males and females, morphological measurements have often been used to sex raptors. However, few investigators have examined the accuracy of using measurements of individuals made at one location to sex individuals of the same species at another location. Our objective was to develop more accurate region-specific methods for determining the sex of Red-tailed Hawks (Buteo jamaicensis), Red-shouldered Hawks (B. lineatus), and Cooper's Hawks (Accipiter cooperii) migrating through and wintering in California. We determined sex using a polymerase chain reaction (PCR)-based genetic test and grouped individuals based on sex, age, and geographic area. We did not combine groups due to differences in measurements between age classes and geographic areas. We then compared a suite of morphological measurements between males and females of each combination, and developed both a discriminant function and a flowchart to determine the sex of Red-tailed and Red-shouldered hawks in the field. The flowcharts were more accurate than the functions for both species. We also confirmed the accuracy of the current flowchart used to determine the sex of Cooper's Hawks migrating along the California coast. These region-specific methods for Red-tailed and Cooper's hawks were generally more accurate than published methods, possibly indicating different populations of these species and highlighting the importance of validating sexing methods when using them in different locations.

ANALISIS GENETICOS CONFIRMAN EL PRIMER REGISTRO DE POLIGINIA EN ACCIPITER COOPERII Analisis geneticos confirmaron las observaciones de comportamiento que sugirieron el primer registro de poliginia en Accipiter cooperii, en el cual un unico macho adulto y dos hembras adultas con sus nidos urbanos distanciados por 313 m en un cementerio en Grand Forks, North Dakota, criaron exitosamente pichones durante 2006. La poliginia puede haber comprometido la produccion reproductiva de cada una de las hembras, ya que su produccion de tres pichones por nido estuvo por debajo de la media general de 3.8 pichones criados en otros 12 nidos exitosos en Grand Forks durante 2006. La produccion colectiva de seis pichones por parte del macho poligino, igualo la maxima produccion anual conocida para un nido para esta especie, y fue mayor que la media de 3.6 pichones criados por nido exitoso considerando todos los nidos individuales (N = 32) en el area de Grand Forks entre 2004 y 2006. El macho poligino fue un reproductor expe...

ENDOGAMIA Y OBSERVACIONES RELACIONADAS EN ACCIPITER COOPERII Dos parejas hermano-hermana de Accipiter cooperii se reprodujeron a 2.7 y 3.9 km, respectivamente, de sus nidos natales en la Isla de Vancouver, en Columbia Britanica, Canada. La primera pareja emplumo exitosamente cuatro polluelos, pero el intento de reproduccion de la segunda pareja fracaso. Ademas, cuatro halcones se reprodujeron o intentaron reproducirse en sus territorios natales, lo que podria aumentar la probabilidad de endogamia. Especulamos que la endogamia podria ser mas frecuente en esta poblacion insular que en las poblaciones del continente debido a que la geografia de la isla podria limitar las distancias de dispersion natal. [Traduccion del equipo editorial]

COMPORTAMIENTO DE DEPREDACION Y DIETA DE MACHOS DE ACCIPITER COOPERII DURANTE EL PERIODO DE INVERNADA EN UN HABITAT RURAL El comportamiento durante el invierno de los halcones del genero Accipiter no ha sido muy estudiado. En este estudio exploramos el comportamiento de caza y la dieta de machos de A. cooperii en un habitat rural (oeste de Indiana, Estados Unidos) durante los inviernos de 2001 a 2004. Seguimos a 11 halcones utilizando radio-telemetria y registramos la identidad de las especies atacadas y depredadas. En este estudio, el halcon A. cooperii capturo presas con un amplio rango de tamano, desde palomas de la especie Columba livia hasta aves mas pequenas como Junco hyemalis. El tipo de presas capturadas se sobrepuso ampliamente con las presas capturadas por A. striatus en un estudio previo, pero se diferencio marcadamente de las presas capturadas por las hembras de A. cooperii en zonas urbanas. Sin embargo, la estrategia de caza de los machos rurales de A. cooperii fue similar a la de sus contra...

SOSPECHAS DE DEPREDACION POR ACCIPITER SOBRE INDIVIDUOS SEGUIDOS CON TELEMETRIA DE FALCO SPARVERIUS EN EL ESTE DE PENSILVANIA, EUA Estudiamos 19 individuos marcados con radio collares de Falco sparverius en un mosaico de fincas y pequenos fragmentos de bosque en el este de Pensilvania, EUA, durante los inviernos de 1996–1997, 1997–1998 y 1998–1999. Seguimos a once hembras y a ocho machos por un promedio de 121 dias (DE = 59; rango 28–208). Ocho (42%) de las aves fueron halladas muertas o se presumio que estaban muertas basandonos en sus restos y en la recuperacion de los radio transmisores. Debido a que las tasas de mortalidad invernal no fueron estadisticamente diferentes entre los anos, combinamos los datos y calculamos una tasa promedio de mortalidad invernal que fue de 0.39. Cinco muertes fueron directamente atribuibles a aves depredadoras de aves, presumiblemente del genero Accipiter. Se observo la presencia de Accipiter cooperii en las areas de invernada del 68% de las aves con radio collares y es...

RELACION ENTRE LOS SITIOS DE ASENTAMIENTO TEMPORALES Y LOS SITIOS DE LA PRIMERA ANIDACION EN ACCIPITER COOPERII En las aves territoriales, los transeuntes son individuos no reproductivos que se encuentran en fase de dispersion y pueden entrar en una poblacion reproductiva cuando un territorio de cria se hace disponible. Existe poca informacion sobre el movimiento de estos individuos transeuntes con relacion al sitio donde eventualmente anidan por primera vez. Examine la relacion espacial entre las areas de vida de individuos de Accipiter cooperii no reproductivos en su primer ano de vida y las areas en que anidaron mas tarde. De nueve halcones que establecieron areas de vida en su primer invierno, seis adquirieron sitios de cria (y uno fue encontrado muerto) entre 2 a 8 anos despues, los cuales se localizaron en o cerca de las areas de vida que establecieron durante su primer invierno. [Traduccion del equipo editorial]

DEPREDACION DE NIDOS DE COLINUS VIRGINIANUS POR AVES RAPACES Colinus virginianus es una especie que anida en el suelo y tipicamente presenta una tasa de perdida de nidos alta. Hasta hace poco tiempo, la determinacion de las causas de perdida de los nidos se basaba en senales diagnosticas poco confiables registradas en los nidos depredados. Como parte de un estudio exhaustivo sobre la dinamica depredador-presa en C. virginianus (2000–2004), utilizamos monitoreos mediante camaras de video con infrarrojo durante las 24 horas para determinar las causas especificas de la depredacion de nidos. Colocamos camaras de video en 672 nidos de C. virginianus y registramos 249 eventos de depredacion. Las depredaciones fueron hechas por mamiferos (40.2%), serpientes (31.7%), hormigas (11.6%), aves rapaces (1.2%) y por otras causas y por razones desconocidas (15.3%). Durante este estudio registramos tres especies diferentes de aves rapaces depredando nidos de C. virginianus o comiendo sus huevos: un individuo de la especi...

MAYR, E. 1963. Animal species and evolution. Harvard University Press, Cambridge, Massachusetts. MCVAUGH, W., JR. 1972. The development of four North American herons. Living Bird 11:155-172. MCVAUGH, W., JR. 1975. The development of four North American herons. Living Bird 14:163-183. PALMER, R. S. 1962. Handbook of North American birds, vol. 1, loons through flamingos. Yale University Press, New Haven, Connecticut. PETERSON, R. A. 1995. The South Dakota breeding bird atlas. Northern State University Press, Aberdeen, South Dakota. PHILLIPS, A., J. MARSHALL, AND G. MONSON. 1964. The birds of Arizona. University of Arizona Press, Tucson. RoDGERS, JR., J. A. 1977. Breeding displays of the Louisiana Heron. Wilson Bulletin 89:266-285. SCHMIDT, R. 1979. First nesting record of a Louisiana Heron in North Dakota. Prairie Naturalist 11:9395. SKADSEN, M. 1986. First South Dakota Tricolored Heron nest. South Dakota Bird Notes 38:95-96. SOUTH DAKOTA ORNITHOLOGISTS' UNION. 1991. The birds of South Dakota, 2nd ed. Northern State University Press, Aberdeen, South Dakota. SPRUNT, A., JR. 1954. A hybrid between the Little Blue Heron and the Snowy Egret. Auk 71:314315.

First Detection of Lyme Disease Spirochete Borrelia burgdorferi in Ticks Collected from a Raptor in Canada During a pan-Canadian tick-host study, we detected the spirochetal bacterium, Borrelia burgdorferi sensu lato, which causes Lyme disease, in ticks collected from a raptor. Lyme disease is one of a number of zoonotic, tick-borne diseases causing morbidity and mortality worldwide. Larvae of the avian coastal tick, Ixodes auritulus, were collected by wildlife rehabilitators from a Cooper’s hawk, Accipiter cooperii, on Vancouver Island, British Columbia. Using PCR amplification of the linear plasmid ospA gene of B. burgdorferi, 4 (18%) of 22 larvae were positive.

Hemograms were determined for 26 Cooper's (Accipiter cooperii) and 55 sharp-shinned hawks (Accipiter striatus) captured during spring migration (27 March to 12 May 1987) on the south shore of Lake Ontario, New York (USA). No significant differences were noted in packed cell volume and estimated total solids between the species. However, Cooper's hawks had significantly higher total white blood cells counts and higher concentrations of heterophils, monocytes, and eosinophils. Proportionally, lymphocytes made up a smaller percentage of the differential count in the Cooper's hawk. Eosinophil concentrations and percentages of the differential count were significantly higher in the females of both species. Both species had a high prevalence of Leucocytozoon toddi and Haemoproteus spp. infection. Haemoproteus nisi and H. elani were identified in both hawks. Trypanosoma avium was identified in a single Cooper's hawk and Plasmodium circumflexum was identified in a sharp-shinned hawk. Prevalence of Leucocytozoon toddi and Haemoproteus spp. infections were significantly higher in the birds caught late in the spring as compared to those caught earlier in the spring; this was evidence for a spring recrudescence of patent parasite infections.

Based on histories and gross and histologic findings, snakebite was diagnosed in three dead raptors submitted for post-mortem examination from northern Florida and southern Georgia (USA). Two immature red-tailed hawks (Buteo jamaicensis) were found next to dead and partially eaten venomous snakes. An adult Cooper's hawk (Accipiter cooperii) was found adjacent to a den containing a cotton-mouth (Agkistrodon piscivorus) and an eastern diamondback rattlesnake (Crotalus adamanteus). Gross findings in all birds consisted of hemorrhage and gangrenous necrosis of one limb. Severe muscular degeneration was seen histologically.

Prior analyses and reviews of diet in the Cooper's Hawk (Accipiter cooperii) have suggested that avian prey usually provides a majority of items and biomass, but this interpretation may be compromised by methodological problems. In Wisconsin, we found that indirect collection of prey remains near nests (92% birds) overestimated the proportion of avian items in comparison to direct observation of prey deliveries to nestlings (51-68% birds). Previous studies using indirect methods may have overstated the frequency of birds in the diet. Also, most avian items brought to nestlings in Wisconsin, as elsewhere, were young birds. Some prior studies relying on indirect methods and using prey species' adult mass to calculate avian biomass have probably accentuated the methodological bias toward birds among prey remains. In Wisconsin, birds provided a minority of prey biomass (4046%) in two of our three sampling pools. Proportions of avian items and biomass are highly variable in the small set of other direct dietary studies of the Cooper's Hawk, all from the breeding season. Because of methodological, seasonal, geographic, and other limitations, existing data do not warrant an assumption that birds prevail in the diet. Because vulnerable ground foraging animals (as well as young birds) appear to constitute most of the breeding season diet, we also question the assumption-based mainly on breeding season studiesthat Cooper's Hawks feed principally on prey of high "agility," as proposed in some theories of reversed sexual size dimorphism.

BARTONEK, J. C., AND C. W. DANE. 1964. Numbered nasal discs for waterfowl. J. Wildl. Manage. 28: 688-692. BISHOP, R. A., D. D. HUMBURG, AND R. D. ANDREWS. 1978. Survival and homing of female mallards. J. Wildl. Manage. 42:192-196. BLOHM, R. J. 1978. Migrational homing of male Gadwalls to breeding grounds. Auk 95:763-766. COULTER, M. W., AND W. R. MILLER. 1968. Nesting biology of black ducks and mallards in northern New England. Vermont Fish Game Dep. Bull. 682. p. 73. DWYER, T. J., S. R. DERRICKSON, AND D. S. GILMER. 1973. Migrational homing by a pair of Mallards. Auk 90:687. EVRARD, J. 0. 1990. Male philopatry in Mallards. Condor 92:247-248. GREENWOOD, P. S. 1980. Mating systems, philopatry and dispersal in birds and mammals. Anim. Behav. 28:1140-1167. LESSELS, C. M. 1985. Natal and breeding dispersal of Canada Geese (Branta canadensis). Ibis 127:3141.

Author(s): Slater, Arthur J. | Abstract: Information concerning 19 species of birds associated with 28 buildings on the University of California at Berkeley campus has been collected for 25 years. Sixteen species are included under three minor associations (temporary roosters, building invaders, and species that nest on (or in) buildings in small numbers). Barn owls and ravens have caused intense, though localized problems. Two additional species (cliff swallows and feral pigeons) have caused major problems. Feral pigeons have caused the most difficult problems to resolve. Case histories are used to describe problems associated with these birds, and control strategies for them. Cooper’s hawks have nested in central campus locations for the last four years and their contributions to pigeon control, interactions with campus buildings, and adjustments to their presence are discussed.

During a routine examination of a female Cooper's hawk (Accipiter cooperii) nematodes were found in the thoracic air sacs. A total of 12 females and nine males were recovered and identified as Serratospiculoides amaculata. This is the first record of this parasite found in a raptor, other than a falcon, in North America.