| aerobic bacterial flora of addled raptor eggs in saskatchewan. | in south-central saskatchewan, canada, in 1986, 1987 and 1989, the aerobic bacterial flora was evaluated from 75 unhatched raptor eggs of three species: 42 of the swainson's hawk (buteo swainsoni), 21 of the ferruginous hawk (buteo regalis), and 12 of the great horned owl (bubo virginianus). in addled swainson's hawk eggs, the most common bacterial genera were enterobacter (18 eggs), escherichia (12), and streptococcus (10). seven great horned owl eggs and six ferruginous hawk eggs also containe ... | 1997 | 9131569 |
| buteo nesting ecology: evaluating nesting of swainson's hawks in the northern great plains. | swainson's hawks (buteo swainsoni) are long-distance migratory raptors that nest primarily in isolated trees located in areas of high grassland density. in recent years, anthropogenic conversion of grassland habitat has raised concerns about the status of the breeding population in the northern great plains. in 2013, we initiated a study to investigate the influence of extrinsic factors influencing swainson's hawk nesting ecology in north-central south dakota and south-central north dakota. usin ... | 2015 | 26327440 |
| raptors lack lower-field myopia. | the presence of lower-field myopia (described in chickens, pigeons, quail and amphibians) allows these animals to keep the ground in focus while performing other visual tasks. a relationship has also been reported between the eye height and the degree of myopia observed. all of the animals reported in the literature to date are ground-foraging species. using infrared neutralizing video retinoscopy and static photoretinoscopy we found a lower-field myopia to be absent in the barn owl (tyto alba), ... | 1995 | 7610576 |
| ground squirrel shooting and potential lead exposure in breeding avian scavengers. | recreational ground squirrel shooting is a popular activity throughout the western united states and serves as a tool for managing ground squirrel populations in agricultural regions. belding's ground squirrels (spermophilus beldingi) are routinely shot in california, nevada, and oregon across habitats that overlap with breeding avian scavengers. ground squirrels shot with lead (pb)-based bullets may pose a risk to avian scavengers if they consume carcasses containing pb fragments. to assess the ... | 2016 | 27942006 |
| External parasites of raptors (Falconiformes and Strigiformes): identification in an ex situ population from Mexico. | Raptorial birds harbor a variety of ectoparasites and the mayority of them are host specific. The aim of this study was to identify the ectoparasites of captive birds of prey from Mexico, as well as to verify their impact in the health of infested birds. Raptorial birds were confiscated and kept in captivity at the Centro de Investigación y Conservación de Vida Silvestre (CIVS) in Los Reyes La Paz, Mexico State. Seventy-four birds of prey (66 Falconiformes and eigth Strigiformes) of 15 species w ... | 2011 | 22017130 |
| serological and parasitological prevalence of toxoplasma gondii in wild birds from colorado. | ground-feeding birds are considered important in the epidemiology of toxoplasma gondii because they serve as indicators of soil contamination by oocysts, and birds of prey are indicators of t. gondii prevalence in rodents and other small mammals. cats excrete environmentally resistant oocysts after consuming tissues of t. gondii -infected birds. in the present study, sera and tissues from 382 wild birds from colorado were tested for t. gondii infection. antibodies to t. gondii were found in 38 b ... | 2010 | 20950101 |
| molecular and morphological divergence in a pair of bird species and their ectoparasites. | in an evolutionary context, parasites tend to be morphologically conservative relative to their hosts. however, the rate of neutral molecular evolution across many parasite lineages is faster than in their hosts. although this relationship is apparent at the macroevolutionary scale, insight into the processes underpinning it may be gained through investigations at the microevolutionary scale. birds and their ectoparasitic lice have served as important natural experiments in co-evolution. here, w ... | 2009 | 19655998 |
| clinical evaluation and outcomes of naturally acquired west nile virus infection in raptors. | west nile virus (wnv) infection and associated disease and mortality have been documented in numerous north american raptor species. information regarding clinical presentations and long-term outcomes of wnv-infected raptors is important in the clinic for the diagnosis, treatment, and assessment of prognosis, as well as for understanding potential population level effects on raptor species. raptors of 22 species admitted to a rehabilitation clinic were tested, from 2002 to 2005, for previous and ... | 2009 | 19368240 |
| first detection of bacillus anthracis in feces of free-ranging raptors from central argentina. | prevalence of anthrax spores in feces of raptors was determined from samples collected in november-december 2000 and april-may 2001 in an agricultural region of santa fé province, argentina. feces were tested from 48 birds of six raptor species. one of 14 chimango caracaras (milvago chimango) and one of eight road-side hawks (buteo magnirostris) tested positive. the prevalence of bacillus anthracis spores in feces for the six species was 4% (n=48). the prevalence was 7% (n=14) for chimango carac ... | 2007 | 17347404 |
| phylogeography of the galápagos hawk (buteo galapagoensis): a recent arrival to the galápagos islands. | galápagos hawks (buteo galapagoensis) are one of the most inbred bird species in the world, living in small, isolated island populations. we used mitochondrial sequence and nuclear minisatellite data to describe relationships among galápagos hawk populations and their colonization history. we sampled 10 populations (encompassing the entire current species range of nine islands and one extirpated population), as well as the galápagos hawk's closest mainland relative, the swainson's hawk (b. swain ... | 2006 | 16376110 |
| nutritional condition and serum biochemistry for free-living swainson's hawks wintering in central argentina. | we assessed the nutritional condition and established reference values for serum chemistry parameters in a long distance migrant bird of prey, the swainson's hawk (buteo swainsoni), wintering in central argentina. we analyzed serum concentration of urea, uric acid, cholesterol, and triglycerides and assessed age and sex related differences in these parameters. a body condition index was obtained from the resultant residuals of the regression of body mass and a morphometric measure. no statistica ... | 2004 | 15123177 |
| atypical chlamydiaceae in wild populations of hawks ( buteo spp.) in california. | chlamydiaceae bacteria infect many vertebrate hosts, and previous reports based on polymerase chain reaction (pcr) assays and serologic assays that are prone to cross-reaction among chlamydial organisms have been used to describe the prevalence of either dna fragments or antibodies to chlamydia spp. in wild raptorial populations. this study reports the pcr-based prevalence of chlamydiaceae dna that does not 100% match any avian or mammalian chlamydiaceae in wild populations of hawks in californi ... | 2018 | 29517435 |
| plumage polymorphism and fitness in swainson's hawks. | we examine the maintenance of a plumage polymorphism, variation in plumages among the same age and sex class within a population, in a population of swainson's hawks. we take advantage of 32 years of data to examine two prevalent hypotheses used to explain the persistence of morphs: apostatic selection and heterozygous advantage. we investigate differences in fitness among three morph classes of a melanistic trait in swainson's hawks: light (7% of the local breeding population), intermediate (57 ... | 2011 | 21767320 |
| habituation of responses of quail (colinus virginianus) to a hawk (buteo swainsoni): measurement through an 'innate suppression' technique. | | 1969 | 5392638 |
| ddt and hexachlorobenzene residues in southeastern washington swainson's hawks (buteo swainsoni). | | 1981 | 7195752 |
| organochlorine and mercury residues in swainson's and ferruginous hawk eggs collected in north and south dakota, 1974-79. | residues of organochlorine pesticides, polychlorinated biphenyls (pcbs), and mercury were measured in eggs of swainson's hawks (buteo swainsoni) and ferruginous hawks (b. regalis) collected in north and south dakota during 1974-79. dde was the most common compound detected in the eggs, but residues were below levels known to have adverse effects on reproduction. other organochlorine compounds and mercury were found at low levels. eggs of ferruginous hawks tended to contain more compounds with hi ... | 1988 | 24248525 |
| knemidokoptes in a swainson's hawk, buteo swainsoni. | a male swainson's hawk (buteo swainsoni) at a rehabilitation facility in colorado was presented with severe crusting of the skin on the medial thighs and caudal ventral body. male and female knemidokoptes mites were found on a cellophane tape preparation of the affected area. the hawk's clinical signs resolved with treatment with ivermectin administered at 200 microg/kg, i.m., every 10 days for three treatments. | 2004 | 15526899 |
| hailstorms as a cause of mass mortality of swainson's hawks in their wintering grounds. | we describe a mass mortality event of wintering swainson's hawks (sh, buteo swainsoni) in central argentina during november 2003. one hundred thirteen sh were found dead as a consequence of a single hailstorm. in addition, 14 hawks with severe injuries were recovered alive, but only 10 of these survived 1 wk later. another 45 dead birds of 11 species were collected in the area. interviews with local land-owners conducted in other areas of the sh wintering grounds provided further evidence of pas ... | 2005 | 16244079 |
| migration patterns, use of stopover areas, and austral summer movements of swainson's hawks. | from 1995-1998, we tracked movements of adult swainson's hawks (buteo swainsoni) using satellite telemetry to characterize migration, important stopover areas, and austral summer movements. we tagged 46 hawks from july - september on their nesting grounds in seven u.s. states and two canadian provinces. swainson's hawks basically followed three routes south on a broad front, converged along the east coast of central mexico, and followed a concentrated corridor to a communal austral summer area i ... | 2017 | 26380528 |
| soaring migratory birds avoid wind farm in the isthmus of tehuantepec, southern mexico. | the number of wind farms operating in the isthmus of tehuantepec, southern mexico, has rapidly increased in recent years; yet, this region serves as a major migration route for various soaring birds, including turkey vultures (cathartes aura) and swainson's hawks (buteo swainsoni). we analyzed the flight trajectories of soaring migrant birds passing the la venta ii wind farm during the two migratory seasons of 2011, to determine whether an avoidance pattern existed or not. we recorded three pola ... | 2014 | 24647442 |
| polymelia and syndactyly in a swainson's hawk (buteo swainsoni). | a hatch-year swainson's hawk (buteo swainsoni) recovered from modoc county, california, us, on 12 august 2012 had malformations of the rear limbs consisting of bilateral polymelia and syndactyly. we describe the malformations and evaluate potential causes. postmortem examination revealed varus rotation of both femurs and abnormal appendages originating from the distal medial surface of the tibiotarsi with two nonfunctional digits on the right leg and one digit on the left leg. there was syndacty ... | 2016 | 26555107 |
| reduced mhc and neutral variation in the galápagos hawk, an island endemic. | genes at the major histocompatibility complex (mhc) are known for high levels of polymorphism maintained by balancing selection. in small or bottlenecked populations, however, genetic drift may be strong enough to overwhelm the effect of balancing selection, resulting in reduced mhc variability. in this study we investigated mhc evolution in two recently diverged bird species: the endemic galápagos hawk (buteo galapagoensis), which occurs in small, isolated island populations, and its widespread ... | 2011 | 21612651 |
| prioritizing avian species for their risk of population-level consequences from wind energy development. | recent growth in the wind energy industry has increased concerns about its impacts on wildlife populations. direct impacts of wind energy include bird and bat collisions with turbines whereas indirect impacts include changes in wildlife habitat and behavior. although many species may withstand these effects, species that are long-lived with low rates of reproduction, have specialized habitat preferences, or are attracted to turbines may be more prone to declines in population abundance. we devel ... | 2016 | 26963254 |
| tonometry of normal eyes in raptors. | an applanation tonometer was used to estimate intraocular pressure in normal eyes of several species of raptors. no bird had active injury or illness, though some were nonreleasable to the wild because of previous injury. mean (+/- sd) intraocular pressure was 20.6 (+/- 3.4) mm of hg in red-tailed hawks (buteo jamaicensis, n = 10), 20.8 (+/- 2.3) mm of hg in swainson's hawks (buteo swainsoni, n = 6), 21.5 (+/- 3.0) mm of hg in golden eagles (aquila chrysaetos, n = 7), 20.6 (+/- 2.0) mm of hg in ... | 1994 | 8017692 |
| permanent genetic resources added to molecular ecology resources database 1 february 2012 - 31 march 2012. | this article documents the addition of 171 microsatellite marker loci and 27 pairs of single nucleotide polymorphism (snp) sequencing primers to the molecular ecology resources database. loci were developed for the following species: bombus pauloensis, cephalorhynchus heavisidii, cercospora sojina, harpyhaliaetus coronatus, hordeum vulgare, lachnolaimus maximus, oceanodroma monteiroi, puccinia striiformis f. sp. tritici, rhea americana, salmo salar, salmo trutta, schistocephalus solidus, sousa p ... | 2012 | 22642264 |
| health of an ex situ population of raptors (falconiformes and strigiformes) in mexico: diagnosis of internal parasites. | successful programs for ex situ and in situ conservation and management of raptors require detailed knowledge about their pathogens. the purpose of this study was to identify the internal parasites of some captive raptors in mexico, as well as to verify their impact in the health status of infected birds. birds of prey were confiscated and kept in captivity at the centro de investigación y conservación de vida silvestre (civs) in los reyes la paz, mexico state. for this, fecal and blood samples ... | 2011 | 22017131 |
| pilot study: correlation of the surface skin temperature between the leg and foot using thermographic imaging in captive hawks. | the purpose of this study was to determine whether the thermal image temperatures of the tibiotarsal scaled region of the raptor leg and the plantar surface of ipsilateral foot while perching were correlated. the correlation between leg and foot temperature was sought to determine whether remote imaging of the legs can be used as a reliable predictor of foot temperature. the right and left tarsometatarsal region (leg) and metatarsal pad (foot) of 10 captive hawks, including 8 red-tailed hawks (b ... | 2020 | 32702956 |
| pyric-carnivory: raptor use of prescribed fires. | fire is a process that shaped and maintained most terrestrial ecosystems worldwide. changes in land use and patterns of human settlement have altered fire regimes and led to fire suppression resulting in numerous undesirable consequences spanning individual species and entire ecosystems. many obvious and direct consequences of fire suppression have been well studied, but several, albeit less obvious, costs of alteration to fire regimes on wildlife are unknown. one such phenomenon is the response ... | 2017 | 29152203 |
| early life conditions and immune defense in nestling swainson's hawks. | the quality of perinatal conditions directly influences the physical and immunological development of nestlings, yet it is inherently variable across space and time. long-term breeding data for a population of swainson's hawks (buteo swainsoni) in northern california show a continuum of territory occupancy and productivity values of individual territories and nests. here we explore effects of variation among territories on immune system development. we hypothesize that nestlings benefitting from ... | 2019 | 31180801 |