| the fine structure of elongate gametocytes of leucocytozoon ziemanni (laveran). | in an effort to establish comparative data within the genus leucocytozoon, elongate gametocytes of l. ziemanni from naturally infected great horned owls (bubo virginianus) were examined by electron microscopy. micro- and macrogametocytes proved to be easily distinguishable at the electron microscopic level due to dramatic dimorphism at maturity and cytoplasmic and nuclear morphology. the parasite membrane architecture, number and type of cytoplasmic ribosomes of both micro- and macrogametocytes, ... | 1978 | 105117 |
| inclusion body disease (herpesvirus infection) of falcons (ibdf). | inclusion body disease of falcons (ibdf) is caused by a herpesvirus. the clinical course is short, 24 to 72 hours in duration, and is characterized by mild to severe depression and weakness often accompanied by anorexia. the disease is invariably fatal. the virus has a marked affinity for the reticuloendothelial system and hepatocytes,producing focal to diffuse necrosis of infected tissues accompanied by the formation of intranuclear inclusion bodies. the virus is pathogenic for american kestrel ... | 1975 | 163383 |
| normal fasting plasma glucose levels in some birds of prey. | blood samples taken from five great horned owls (bubo virginianus), eight red-tailed hawks (buteo jamaicensis), four marsh hawks (circus cyaneus), two prairie falcons (falco mexicanus), five golden eagles (aquila chrysaetos), and five white leghorn chickens (gallus domesticus) that had been fasted for 24 h were used to determine plasma levels of glucose by the glucose oxidase method. the mean plasma glucose levels were: great horned owls 374.6 mg/100 ml, red-tailed hawks 346.5 mg/00 ml, marsh ha ... | 1978 | 739587 |
| pulmonary oxalosis in association with aspergillus niger infection in a great horned owl (bubo virginianus). | | 1975 | 1156263 |
| the humeroscapular bone of the great horned owl (bubo virginianus) and other raptors. | a small, separate, bony density dorsal to the shoulder joint is radiographically visible in several species of large hawks and owls. gross dissection and histological examination show the bone to lie on the deep surface of the major deltoid muscle in intimate association with the dorsal coracohumeral ligament of the shoulder joint. the tendon of the supracoracoideus muscle passes immediately cranial to the humeroscapular bone. two ligaments distinct from the shoulder joint capsule attach the hum ... | 1992 | 1585989 |
| vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in canadian wildlife. | twenty-six meadow voles (microtus pennsylvanicus), ten woodchucks (marmota monax), thirteen grey squirrels (sciurus carolinensis), thirteen ring-billed gulls (larus delawarensis), six red-tailed hawks (buteo jamaicensis) and eight great horned owls (bubo virginianus) received vaccinia virus recombinant expressing the rabies virus glycoprotein (v-rg) by direct instillation into the oral cavity. each of ten coyotes (canis latrans) received the virus in two vaccine-laden baits. several voles and mo ... | 1990 | 2249183 |
| sarcocystis sp. in mountain goats (oreamnos americanus) in washington: prevalence and search for the definitive host. | during october and november 1986, sarcocystis sp. was detected in 24 of 56 (43%) tongues from hunter-killed mountain goats (oreamnos americanus) in washington (usa). sarcocysts had an unusual sessile polyp-shaped branched wall. mean size of 154 sarcocysts was 71.3 x 37.8 microns (range, 20 to 248 x 10 to 120 microns), and the mean intensity was 2.3 (range, 1 to 28). in an attempt to identify the definitive host, infected tongues were fed to four coyotes (canis latrans), eight domestic dogs, four ... | 1989 | 2509738 |
| comparative morphometric study of the vestibular system of the vertebrata: reptilia, aves, amphibia, and pisces. | morphometric measurements were made from serial sections of the vestibular system in four classes of vertebrates: reptilia, aves, amphibia, and pisces. representative species of reptile studied were the lizard (gekko gecko), the common garter snake (thamnophis sp.), and the common turtle (chelonia sp.). the budgie (melopsittacus undulatas), the common pigeon (columba domestica), the yellow-bellied sapsucker (sphyrapicus varius), and the horned owl (bubo virginianus) were chosen as representative ... | 1986 | 3485883 |
| case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock. | since 1982 when secondary poisoning of a red-tailed hawk (buteo jamaicensis) was documented following the recommended use of famphur applied topically to cattle, the patuxent wildlife research center has tested dead birds of prey for poisoning by famphur and other pour-on organophosphorus (op) insecticides. brain cholinesterase (che) activity was first determined, then if che was depressed greater than or equal to 50%, stomach and/or crop contents were evaluated for anti-che compounds. this repo ... | 1987 | 3586207 |
| yersinia enterocolitica and related species isolated from wildlife in new york state. | fecal specimens for yersinia screening were obtained from a variety of wild mammals, birds, reptiles, fish, and invertebrates throughout new york state. one specimen from each of 1,426 animals was examined. a total of 148 isolates of yersinia enterocolitica and related species were obtained from 133 (9.3%) of the animals. y. enterocolitica was isolated from 100 (7%) of the animals tested, including 81 (10%) of 812 mammals and 19 (3.3%) of 573 birds. y. intermedia, y. frederiksenii, and y. kriste ... | 1986 | 3767355 |
| comparative pharmacokinetics of antifungal drugs in domestic turkeys, red-tailed hawks, broad-winged hawks, and great-horned owls. | the present research was to test in vitro activity of thiabendazole, 5-fluorocytosine, and amphotericin b against 11 isolates of aspergillus fumigatus from avian species. additionally, the plasma concentrations of these drugs were determined in four avian species given a range of dosages by oral, intravenous, and intratracheal routes. thiabendazole inhibited most isolates in vitro at concentrations between 25 and 50 micrograms/ml; however, there were no detectable inhibitory concentrations in th ... | 1985 | 3907612 |
| pharmacokinetics of a long-acting oxytetracycline preparation in ring-necked pheasants, great horned owls, and amazon parrots. | after a single iv or im dose of a long-acting oxytetracycline (otc) preparation, serum concentrations were determined at various times in the ring-necked pheasant, great horned owl, and amazon parrot. pharmacokinetic parameters, including serum half-life (t1/2) and apparent volume of distribution (vd) were calculated from the otc concentration-time curves for each species and route of administration. significant differences (p less than 0.05) were found in the t1/2 and vd parameters between spec ... | 1985 | 4083606 |
| falcon herpesvirus, the etiologic agent of inclusion body disease of falcons. | a viral agent has been isolated from five fatal cases of naturally occurring inclusion body disease in three different falcon species, namely, the prairie falcon (falco mexicanus), the red-headed falcon (f. chiquera), and the peregrine falcon (f. peregrinus). the virus has been shown to possess the physical, chemical, and biological properties of a herpesvirus and has been used to reproduce inclusion body disease in the prairie falcon, merlin (f. columbarius), and american kestrel (f. sparverius ... | 1973 | 4352453 |
| the antibody responses to sheep red blood cells of the red-tailed hawk and great-horned owl. | | 1984 | 6500143 |
| response of great horned owls given the optical isomers of ketamine. | the relative anesthetic effects of the 2 purified isomers and the racemic mixture of ketamine were compared in 6 great horned owls (bubo virginianus), a species in which racemic ketamine is poorly tolerated. other investigators have reported that the l(-) form is only a 3rd as potent as the d(+) form with respect to analgesic action in mammals. accordingly, the racemic and the - forms were given at 2 x and 3 x, respectively, the dose of the + form in an attempt to achieve a potentially equivalen ... | 1984 | 6703445 |
| trichomoniasis in great horned owls. | three cases of trichomonas gallinae infection of deep tissues of the skull or of unusual tissues in great horned owls (bubo virginianus), refractory to recommended doses but responsive to higher doses of dimetridazole, are discussed. trichomonads were isolated from the lesions. | 1980 | 7432340 |
| isolation and serological differentiation of a herpesvirus from bobwhite quail (colinus virginianus, l. 1758). | an infectious agent was isolated from the liver of bobwhite quails (colinus virginianus, l. 1758). the agent was sensitive to chloroform and its multiplication was inhibited by 5-iodine-2-deoxy-uridine. it passed filters with a pore diameter of 220 nm and more but not 100 nm filters. electron microscopic examination revealed numerous nucleocapsids with hollow capsomeres and few enveloped particles in the supernatant fluids of infected cultures. the nucleocapsids were calculated to have 162 capso ... | 1980 | 7447711 |
| prevalence of encysted toxoplasma gondii in raptors from alabama. | little is known about the prevalence of encysted toxoplasma gondii in wild birds. we examined the hearts and breast muscles from 101 raptors for encysted t. gondii. all of the raptors had been submitted for necropsy to the state veterinary diagnostic laboratory, auburn, alabama. tissues were digested in acid-pepsin solution and inoculated into groups of 3-5 laboratory mice. toxoplasma gondii was isolated from 27 of 101 (26.7%) raptors: 8 of 12 (66.7%) red-shouldered hawks (buteo lineatus), 13 of ... | 1993 | 8277379 |
| 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 |
| plasmodium forresteri n. sp., from raptors in florida and southern georgia: its distinction from plasmodium elongatum morphologically within and among host species and by vector susceptibility. | plasmodium forresteri n. sp. naturally infects eastern screech-owls (otus asio), great horned owls (bubo virginianus), barred owls (strix varia), bald eagles (haliaeetus leucocephalus), red-shouldered hawks (buteo lineatus), broad-winged hawks (buteo platypterus), and red-tailed hawks (buteo jamaicensis) in florida and southern georgia. schizonts occur in mature or nearly mature erythrocytes, produce 2-6 merozoites arranged most commonly in fan or cruciform configuration, with mean dimensions am ... | 1997 | 9379302 |
| prevalence of encysted apicomplexans in muscles of raptors. | an acid-pepsin digestion technique was used to examine portions of breast muscle and heart from raptors for encysted protozoans. apicomplexan zoites were present in 52 (45.6%) of the 114 samples examined: 11 of 12 (91.7%) red-shouldered hawks (buteo lineatus), 20 of 34 (58.8%) red-tailed hawks (buteo jamaicensis), two of seven (28.6%) cooper's hawks (accipiter cooperi), three of four (75%) sharp-shinned hawks (accipiter striatus), one (100%) mississippi kites (ictinia misisippiensis), one of two ... | 1999 | 9950339 |
| identification of duck plague virus by polymerase chain reaction. | a polymerase chain reaction (pcr) assay was developed for detecting duck plague virus. a 765-bp ecori fragment cloned from the genome of the duck plague vaccine (dp-vac) virus was sequenced for pcr primer development. the fragment sequence was found by genbank alignment searches to be similar to the 3' ends of an undefined open reading frame and the gene for dna polymerase protein in other herpesviruses. three of four primers sets were found to be specific for the dp-vac virus and 100% (7/7) of ... | 1999 | 10216766 |
| protein electrophoresis as a diagnostic and prognostic tool in raptor medicine. | plasma proteins of 139 healthy adult birds of prey from 10 species were separated by electrophoresis to characterize and document normal reference ranges and species-specific electrophoretic patternsand to evaluate the value of this technique for health screening, disease diagnosis, and prognostic indication. species studied included bald eagle (haliaeetus leucocephalus), red-tailed hawk (buteo jamaicensis), barn owl (tyto alba), great horned owl (bubo virginianus), turkey vulture (cathartes aur ... | 2000 | 11428396 |
| lead poisoning in upland-foraging birds of prey in canada. | we examined the degree of lead exposure, based on tissue-lead concentrations, in 184 raptors of 16 species found dead across canada. the most prevalent species available for examination were red-tailed hawks, great horned owls, and golden eagles (n = 131). the majority of individuals examined had very low lead accumulation, however 3-4% of total mortality in these 3 most commonly encountered species was attributed to lead poisoning. in addition, 1 of 9 bald eagles found dead far from aquatic env ... | 2003 | 12739854 |
| clinical and pathologic features of west nile virus infection in native north american owls (family strigidae). | since the initial report of west nile virus in the northeastern united states in 1999, the virus has spread rapidly westward and southward across the country. in the summer of 2002, several midwestern states reported increased cases of neurologic disease and mortality associated with west nile virus infection in various native north american owl species. this report summarizes the clinical and pathologic findings for 13 captive and free-ranging owls. affected species were all in the family strig ... | 2003 | 14562887 |
| isolation of newcastle disease virus from the great horned owl. | | 1951 | 14850376 |
| noninvasive measures of reproductive function and disturbance in the barred owl, great horned owl, and northern spotted owl. | there is an urgent need for noninvasive methods to study reproduction and environmental stress in at-risk species such as the northern spotted owl (strix occidentalis caurina). two related owl species (barred owl and great horned owl) were used as surrogates to validate hormone assays for fecal metabolites of progesterone, 17beta-estradiol, testosterone, and corticosterone. infusions of radiolabeled hormones showed that the owls excreted most hormone within 6 h. feces and urine contained roughly ... | 2005 | 16055847 |
| pathologic and immunohistochemical findings in goshawks (accipiter gentilis) and great horned owls (bubo virginianus) naturally infected with west nile virus. | the carcasses of 25 great horned owls and 12 goshawks were investigated for west nile virus (wnv) infection by immunohistochemistry (ihc) performed on various organs, including brain, spinal cord, heart, kidney, eye, bone marrow, spleen, liver, lungs, pancreas, intestine, and proventriculus, using a wnv-antigen-specific monoclonal antibody and by wnv-specific reverse transcriptase-polymerase chain reaction (rt-pcr), performed on fresh brain tissue only. wnv infection was diagnosed by ihc in all ... | 2005 | 16094831 |
| serologic evidence of west nile virus infection in three wild raptor populations. | we assayed for west nile virus (wnv) antibodies to determine the presence and prevalence of wnv infection in three raptor populations in southeast wisconsin during 2003-04. this study was conducted in the framework of ongoing population studies that started before wnv was introduced to the study area. for 354 samples, 88% of 42 adult cooper's hawks (accipiter cooperii), 2.1% of 96 nestling cooper's hawks, 9.2% of 141 nestling red-tailed hawks (buteo jamaicensis), and 12% of 73 nestling great hor ... | 2005 | 16252490 |
| experimental rabies in a great horned owl. | a great horned owl (bubo virginianus) was fed the carcass of an experimentally infected rabid skunk. the bird developed antibody titer to rabies, detected by passive haemagglutination, 27 days after oral inoculation by ingestion. the owl suppressed the infection until corticosteroid administration, after which a maximum antibody titer was attained. evidence of active rabies viral infection was seen by fluorescent antibody staining of oral swabs, corneal impression smears and histologic tissue sm ... | 1976 | 16498892 |
| natural and experimental west nile virus infection in five raptor species. | we studied the effects of natural and/or experimental infections of west nile virus (wnv) in five raptor species from july 2002 to march 2004, including american kestrels (falco sparverius), golden eagles (aquila chrysaetos), red-tailed hawks (buteo jamaicensis), barn owls (tyto alba), and great horned owls (bubo virginianus). birds were infected per mosquito bite, per os, or percutaneously by needle. many experimentally infected birds developed mosquito-infectious levels of viremia (>10(5) wnv ... | 2006 | 16699143 |
| west nile virus in raptors from virginia during 2003: clinical, diagnostic, and epidemiologic findings. | sixty-one birds of prey admitted to the wildlife center of virginia (wcv; waynesboro, virginia, usa) from june to november 2003 were tested for west nile virus (wnv) infection. choanal and/or cloacal swabs were obtained and submitted to virginia's division of consolidated laboratory services (richmond, virginia, usa) for analysis with real-time reverse transcriptase polymerase chain reaction (rt-pcr). forty birds of prey were positive for wnv by rt-pcr. five avian families and nine species of ra ... | 2006 | 16870856 |
| raptor mortality due to west nile virus in the united states, 2002. | west nile virus (wnv) has affected many thousands of birds since it was first detected in north america in 1999, but the overall impact on wild bird populations is unknown. in mid-august 2002, wildlife rehabilitators and local wildlife officials from multiple states began reporting increasing numbers of sick and dying raptors, mostly red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus). commonly reported clinical signs were nonspecific and included emaciation, lethargy, ... | 2007 | 17495304 |
| pathology and epidemiology of natural west nile viral infection of raptors in georgia. | carcasses from 346 raptors found between august 2001 and december 2004 were tested for west nile virus (wnv) using virus isolation and immunohistochemistry; 40 were positive for wnv by one or both methods. of these 40 birds, 35 had histologic lesions compatible with wnv infection, one had lesions possibly attributable to wnv, and four had no histologic evidence of wnv. the most common histologic lesions associated with wnv infection were myocardial inflammation, necrosis, and fibrosis; skeletal ... | 2007 | 17495305 |
| risk assessment methodologies for exposure of great horned owls (bubo virginianus) to pcbs on the kalamazoo river, michigan. | dietary exposures of great horned owls (gho; bubo virginianus) to polychlorinated biphenyls (pcbs) in the terrestrial food web at the kalamazoo river, michigan, usa, were examined. average potential daily doses (apdd) in gho diets were 7- to 10-fold and 3-fold greater at the more contaminated location versus a reference location for site-specific exposures quantified as total pcbs and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (teq(who-avian)), respectively. wetland/aquatic prey contributed ... | 2008 | 18260206 |
| gastrointestinal parasites of owls (strigiformes) kept in captivity in the southern region of brazil. | the aim of this research was to study the gastrointestinal parasitism in 12 adult owls kept in captivity in the southern region of brazil. cloacal contents of the species rhinoptynx clamator, tyto alba, athene cunicularia, megascops spp., and bubo virginianus were evaluated. feces and urine were collected and analyzed by the zinc sulfate centrifugal-flotation method and stained by the modified ziehl-neelsen technique. eggs of capillaria spp. and strongylida, oocysts of cryptosporidium spp., eime ... | 2009 | 19005679 |
| [origin and evolution of parasitism in mites of the infraorder eleutherengona (acari: prostigmata). report i. lower raphignathae]. | the evolution of animal parasitism in mites of the infraorder eleutherengona (prostigmata) is discussed. parasitism has arisen independently in numerous phyletic lineages or superfamilies of this infraorder. mites of the family pterygosomatidae are parasites of terrestrial arthropods and lizards, and species of myobiidae are exclusively associated with placental and marsupial mammals. most families of the superfamily cheyletoidea comprise permanent parasites of vertebrates, and mites of the sist ... | 2008 | 19065835 |
| 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 |
| chronic myelogenous leukemia in a great horned owl (bubo virginianus). | a free-ranging adult female great horned owl (bubo virginianus) was presented to the wildlife medical clinic at the university of illinois after being observed with anorexia and decreased activity. a severe leukocytosis (212 400 cells/microl), primarily comprised of mature heterophils, was found at presentation. results of various diagnostic tests including radiographs, chlamydophila serologic testing, measurement of aspergillus antibody and antigen titers, plasma protein electrophoresis, fecal ... | 2009 | 19530405 |
| great horned owl (bubo virginianus) dietary exposure to pcdd/df in the tittabawassee river floodplain in midland, michigan, usa. | soils and sediments in the floodplain of the tittabawassee river downstream of midland, michigan, usa contain elevated concentrations of polychlorinated dibenzofurans (pcdf) and polychlorinated dibenzo-p-dioxins (pcdd). as a long-lived, resident top predator, the great horned owl (bubo virginianus; gho) has the potential to be exposed to bioaccumulative compounds such as pcdd/df. site-specific components of the gho diet were collected along 115 km of the tittabawassee, pine, chippewa, and sagina ... | 2010 | 20872700 |
| isolation and molecular characterization of newcastle disease viruses from raptors. | the present study was undertaken to detect and characterize newcastle disease virus (ndv) in raptors. cloacal and oropharyngeal swab samples were collected from 60 casualty raptors during january to march 2009 in minnesota. inoculation of all these samples (n=120) in 9-day-old embryonated hens' eggs resulted in isolation of haemagglutinating viruses in three samples from two bald eagles and one great horned owl. these three haemagglutinating viruses were confirmed as ndv by reverse transcription ... | 2010 | 21154052 |
| 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 |
| clinical utility of a complete diagnostic protocol for the ocular evaluation of free-living raptors. | objective: to describe a protocol for the examination of free-living raptors and report the ophthalmic examination findings of seven raptor species native to central illinois, namely the barred owl, cooper's hawk, eastern screech owl, great horned owl, american kestrel, red-tailed hawk, and turkey vulture and to determine if the findings relative to visual prognosis affected eligibility for future release. animals studied: seventy-nine free-living raptors. procedures: under manual restraint, ... | 2011 | 22050975 |
| microscopic effects of predator digestion on the surfaces of bones and teeth. | concentrations of small fossil mammals are frequently encountered in cenozoic deposits, but the causes for such accumulations have seldom been determined. in many cases the tooth, jaw, and limb fragments appear to be well-preserved under light microscopy, and it is difficult to differentiate damage due to predator digestion from breakage and abrasion due to physical agents. in order to find more specific evidence of predator digestion, we used a scanning electron microscope (sem) to examine the ... | 2011 | 3201198 |
| fatal pox infection in a rough-legged hawk. | natural pox infection occurred in a free-living rough-legged hawk (buteo lagopus) in northeastern north dakota. gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (buteo jamaicensis) but not in great horned owls (bubo virginianus) following inoculation with case material. death of the rough-legged hawk was attributed to starvation rsulting from inability to capture prey and to blood loss from foot lesions. | 2003 | 167207 |
| knemidokoptes mutans (acari: knemidocoptidae) in a great-horned owl (bubo virginianus). | a routine examination of a captive juvenile great-horned owl (bubo virginianus) revealed bilateral proliferative papillary hyperkeratosis on the feet. microscopic examination of skin scrapings produced numerous mites identified as knemidokoptes mutans. this is the first record of this parasite in a great-horned owl. a single dose of ivermectin (200 micrograms/kg) was effective in treatment of this infection. | 2007 | 2761019 |
| columbid herpesvirus-1 mortality in great horned owls (bubo virginianus) from calgary, alberta. | four cases of columbid herpesvirus-1 infection in great horned owls (bubo virginianus) were identified in calgary, alberta. necropsy findings included severe multifocal hepatic and splenic necrosis, pharyngeal ulceration and necrosis, and gastrointestinal necrosis. occasional eosinophilic intranuclear viral inclusion bodies were associated with the foci of necrosis and polymerase chain reaction (pcr) testing confirmed a diagnosis of herpesvirus-induced disease. the sequence of a pcr amplicon had ... | 2012 | 22942441 |
| identification of a novel renal coccidian (apicomplexa: eimeriidae) from the great-horned owl ( bubo virginianus ), usa. | we diagnosed renal coccidiosis in two of five great-horned owls ( bubo virginianus ) examined in eastern tennessee, us, 2007-13. histopathologic examination of the kidneys revealed multifocal mild-to-moderate dilation and epithelial hyperplasia of collecting ducts. renal collecting duct epithelial cells contained intracytoplasmic microgametocytes, macrogametocytes, and sporulating and sporulated oocysts. renal coccidiosis in affected birds did not result in significant inflammation. sequence ana ... | 2017 | 28139953 |
| extended-spectrum β-lactamase producing escherichia coli isolated from wild birds in saskatoon, canada. | the epidemiology of antimicrobial resistance is extremely complex and involves humans, domestic animals (companion and agricultural) and wildlife. in north america there have been very few investigations targeting antimicrobial-resistant organisms in wildlife. in this study, we characterized the susceptibility of escherichia coli isolated from 75 birds including great horned owls, crows and american robins from the region of saskatoon, canada. the recovery rate of e. coli varied significantly be ... | 2016 | 27214496 |
| serologic evidence of exposure of raptors to influenza a virus. | serum or plasma samples from raptors that prey or scavenge upon aquatic birds were tested by a commercially available blocking enzyme-linked immunosorbent assay for the evidence of antibodies to influenza a virus. samples were taken from birds (n = 616) admitted to two rehabilitation centers in the united states. in addition, samples from 472 migrating peregrine falcons (falco peregrinus) trapped on autumnal and vernal migrations for banding purposes were also tested. only bald eagles were notab ... | 2012 | 22856203 |
| sarcocystis falcatula-associated encephalitis in a free-ranging great horned owl (bubo virginianus). | a great horned owl (bubo virginianus) was admitted to a rehabilitation clinic with severe neurologic signs that were unresponsive to supportive care. the animal was euthanatized because of a poor prognosis. marked granulomatous encephalitis with focal brainstem malacia was detected microscopically. the brainstem was the most severely affected brain location and the only place in which schizonts and merozoites, morphologically compatible with sarcocystis spp., were detected. immunohistochemistry ... | 2009 | 19286517 |
| antibody prevalence and isolation of viable toxoplasma gondii from raptors in the southeastern usa. | raptors are good indicators of the prevalence of toxoplasma gondii in the environment because they prey on small mammals and birds. these prey species are a major source of infection in domestic cats ( felis catus ), which shed the environmentally resistant oocysts. we assessed t. gondii infection in 281 opportunistically available raptors at a rehabilitation facility between 2012 and 2014. antibodies to t. gondii were assayed by a modified agglutination test (cutoff 1:25) and found in serum of ... | 2016 | 27243150 |
| numerical and functional response of predators to a long-term decline in mammalian prey at a semi-arid neotropical site. | occurrence and diet of ten carnivorous predators (four falconiforms, four owls, and two foxes), and population levels of their mammalian prey, were monitored over 45 months at a semi-arid site in north-central chile. early in this period, small mammals irrupted and then declined markedly to a density 7% of that at peak. all four falconiforms (buteo polyosoma, falco sparverius, geranoaetus melanoleucus, parabuteo unicinctus) and one owl (tyto alba) responded numerically to the decline in mammalia ... | 1992 | 28313400 |
| hematologic parameters in raptor species in a rehabilitation setting before release. | to be considered for release, raptors undergoing rehabilitation must have recovered from their initial injury in addition to being clinically healthy. for that purpose, a good understanding of reference hematologic values is important in determining release criteria for raptors in a rehabilitation setting. in this study, retrospective data were tabulated from clinically normal birds within 10 days of release from a rehabilitation facility. hematologic values were compiled from 71 red-tailed hawk ... | 2011 | 22216719 |
| seasonal effects of habitat on sources and rates of snowshoe hare predation in alaskan boreal forests. | survival and predation of snowshoe hares (lepus americanus) has been widely studied, yet there has been little quantification of the changes in vulnerability of hares to specific predators that may result from seasonal changes in vegetation and cover. we investigated survival and causes of mortalities of snowshoe hares during the late increase, peak, and decline of a population in interior alaska. from june 2008 to may 2012, we radio-tagged 288 adult and older juvenile hares in early successiona ... | 2015 | 26717577 |
| resource partitioning among forest owls in the river of no return wilderness, idaho. | we studied resource partitioning among the forest owls in the river of no return wilderness, idaho, during the winter and spring of 1980 and 1981. the owl assemblage consisted of five abundant species: pygmy (glaucidium gnoma), saw-whet (aegolius acadicus), boreal (a. funereus), western screech (otus kennicottii), and great-horned (bubo virginianus). long-eared (asio otus) and flammulated (o. flammeolus) owls were rarely observed. information from the literature supplemented our data to describe ... | 1988 | 28310843 |
| comparison of metabolic substrates in alligators and several birds of prey. | on average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have ... | 2014 | 25043840 |
| 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 |
| laboratory blood analysis in strigiformes-part i: hematologic reference intervals and agreement between manual blood cell counting techniques. | while hematologic reference intervals (ri) are available for multiple raptorial species of the order accipitriformes and falconiformes, there is a lack of valuable hematologic information in strigiformes that can be used for diagnostic and health monitoring purposes. | 2015 | 25627556 |
| comparative physiology of sound localization in four species of owls. | bilateral ear asymmetry is found in some, but not all, species of owls. we investigated the neural basis of sound localization in symmetrical and asymmetrical species, to deduce how ear asymmetry might have evolved from the ancestral condition, by comparing the response properties of neurons in the external nucleus of the inferior colliculus (icx) of the symmetrical burrowing owl and asymmetrical long-eared owl with previous findings in the symmetrical great horned owl and asymmetrical barn owl. ... | 1990 | 2279234 |
| predation by three owl species on northern pocket gophers of different body mass. | we examined the estimated sizes of thomomys talpoides in the diets of bubo virginianus (1,505 g), tyto alba (437 g), and asio otus (245 g) in north-central oregon between 1973 and 1982. the three owl species tended to consume t. talpoides of different size and responded differently to predicted seasonal body mass changes in the t. talpoides population. on an annual basis b. virginianus preyed upon the largest individuals (x = 67.9 g), whereas a. otus preyed upon the smallest (x = 41.0 g). when c ... | 1985 | 28309848 |
| the guild structure of a community of predatory vertebrates in central chile. | the trophic ecology of eleven predator species (falconiforms: buteo polyosoma, elanus leucurus, falco sparverius, geranoaetus melanoleucus, parabuteo unicinctus; strigiforms: athene cunicularia, bubo virginianus, tyto alba; carnivores: dusicyon culpaeus; snakes: philodryas chamissonis, tachymenis peruviana) in two nearby localities of central chile is analyzed. the localities exhibit the typical climate (hot-dry summers, coldrainy winters), and vegetation (chaparral), of mediterranean ecosystems ... | 1981 | 28309444 |
| avian vacuolar myelinopathy outbreaks at a southeastern reservoir. | avian vacuolar myelinopathy (avm) is a neurologic disease of unknown etiology that affects bald eagles (haliaeetus leucocephalus), american coots (fulica americana), and several species of waterfowl. an unidentified neurotoxin is suspected as the cause of avm, which has been documented at several reservoirs in the southeastern united states. we conducted diagnostic and epidemiologic studies annually during october-march from 1998-2004 at clarks hill/strom thurmond lake on the georgia/south carol ... | 2006 | 17092880 |
| partial cloning of cyp2c23a genes and hepatic protein expression in eight representative avian species. | large interspecies differences in avian xenobiotic metabolism have been revealed by microsome-based studies, but specific enzyme isoforms in different bird species have not yet been compared. we have previously shown that cyp2c23 genes are the most induced cyp isoforms in chicken liver. in this study, we collected partial cyp2c23a gene sequences from eight avian species (ostrich, blue-eared pheasant, snowy owl, great-horned owl, chilean flamingo, peregrin falcon, humboldt penguin, and black-crow ... | 2015 | 25229839 |
| helminths in the great horned owl, bubo virginianus, and snowy owl, nyctea scandiaca, of alberta. | | 1978 | 751707 |
| complete genome sequence and evolution analysis of a columbid herpesvirus type 1 from feral pigeon in china. | here, we report the genome sequence of a feral pigeon alphaherpesvirus (columbid herpesvirus type 1, cohv-1), strain hlj, and compare it with other avian alphaherpesviruses. the cohv-1 strain hlj genome is 204,237 bp in length and encodes approximately 130 putative protein-coding genes. phylogenetically, cohv-1 complete genome resides in a monophyletic group with the falconid herpesvirus type 1 (fahv-1) genome, distant from other alphaherpesviruses. interestingly, the evolutionary analysis of pa ... | 2017 | 28316016 |
| seasonally varying predation behavior and climate shifts are predicted to affect predator-prey cycles. | the functional response of some predator species changes from a pattern characteristic for a generalist to that for a specialist according to seasonally varying prey availability. current theory does not address the dynamic consequences of this phenomenon. since season length correlates strongly with altitude and latitude and is predicted to change under future climate scenarios, including this phenomenon in theoretical models seems essential for correct prediction of future ecosystem dynamics. ... | 2016 | 27788349 |
| presumptive keratoglobus in a great horned owl (bubo virginianus). | a juvenile to young adult, male, great horned owl (bubo virginianus,ghow) was presented to the wildlife rehabilitation hospital at lindsay wildlife museum (wrhlwm) due to trauma to the right patagium from barbed wire entanglement. on presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. a severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. the fundus was normal in both eyes (ou). over the course of several days, both corn ... | 2016 | 27477943 |
| pharmacokinetic properties of a single administration of oral gabapentin in the great horned owl (bubo virginianus). | gabapentin (1-[aminomethyl] cyclohexane acetic acid) is a γ-aminobutyric acid analogue that has been shown to be efficacious for neuropathic pain control in humans. plasma gabapentin concentrations >2 μg/ml are considered effective in treating epilepsy in humans and are suggested to provide analgesia for neuropathic pain. this study investigated the pharmacokinetics of a single oral dose of gabapentin suspension (11 mg/kg) in great horned owls ( bubo virginianus ). plasma gabapentin concentratio ... | 2015 | 26352959 |
| pathology in practice. chondro-osseous metaplasia consistent with synovial chondromatosisin a great horned owl. | | 2014 | 25229527 |
| microstructure and cross-sectional shape of limb bones in great horned owls and red-tailed hawks: how do these features relate to differences in flight and hunting behavior? | the red-tailed hawk and great horned owl are two species of raptor that are similar in body size, diet, and habitat. both species use their hindlimbs during hunting, but differ in foot morphology, how they approach and immobilize prey, and the average size of prey captured. they also differ in primary flight style: the red-tailed hawk uses static soaring and the great horned owl uses flap-gliding. the objectives of this study were to characterize the microstructure and cross-sectional shape of l ... | 2014 | 25162595 |
| pharmacokinetics of a single dose of intravenous and oral meloxicam in red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus). | pharmacokinetic data were determined after a single dose of meloxicam in red-tailed hawks (rth; buteo jamaicensis) and great horned owls (gho; bubo virginianus). in a nonrandomized crossover design, individual birds of each species received 1 dose of intravenous meloxicam (0.5 mg/kg i.v.; n = 7 for each species) followed by a 2-week washout period, and then each received 1 dose of oral meloxicam (0.5 mg/kg po; n = 5 for each species). blood samples were collected intermittently after administrat ... | 2013 | 24344511 |
| anticoagulant rodenticides in red-tailed hawks, buteo jamaicensis, and great horned owls, bubo virginianus, from new jersey, usa, 2008-2010. | liver samples from red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus) were analyzed for anticoagulant rodenticides. residues of one or more second generation anticoagulant rodenticides (sgars) were detected in 81 % of red-tailed hawks and 82 % of great horned owls. the most frequently detected sgar was brodifacoum, which was detected in 76 % of red-tailed hawks and 73 % of great horned owls. bromadiolone was detected in 20 % of red-tailed hawks and 27 % of great horned ... | 2014 | 24158357 |
| a technique for evisceration as an alternative to enucleation in birds of prey: 19 cases. | ocular trauma is common in birds of prey presented to wildlife clinics and rehabilitation centers. enucleation is the procedure most commonly described for treatment of end-stage ocular disease or chronically painful eyes in birds; however, there are several disadvantages and risks to this procedure. while evisceration has been suggested as an alternative, it has not been described for multiple cases or with long-term follow-up data in birds of prey. this report details an evisceration technique ... | 2013 | 23971220 |
| presumptive electric cataracts in a great horned owl (bubo virginianus). | this case report describes suspected electrocution in a juvenile female great horned owl (bubo virginianus) with subsequent bilateral cataract formation. the bird flew into a high-voltage power line and was immediately rescued. burn wounds of the head and ataxia with apparent blindness were noted. initial ophthalmic examination 5 days after the incident revealed bilaterally symmetrical anterior subcapsular vacuolar cataracts with absence of intraocular inflammation and a predominantly clear view ... | 2013 | 22432797 |
| second generation anticoagulant rodenticides in predatory birds: probabilistic characterisation of toxic liver concentrations and implications for predatory bird populations in canada. | second-generation anticoagulant rodenticides (sgars) are widely used to control rodent pests but exposure and poisonings occur in non-target species, such as birds of prey. liver residues are often analysed to detect exposure in birds found dead but their use to assess toxicity of sgars is problematic. we analysed published data on hepatic rodenticide residues and associated symptoms of anticoagulant poisoning from 270 birds of prey using logistic regression to estimate the probability of toxico ... | 2011 | 21481471 |
| anticoagulant rodenticide exposure and toxicosis in four species of birds of prey presented to a wildlife clinic in massachusetts, 2006-2010. | mortalities among birds of prey from anticoagulant rodenticide (ar) toxicosis have been documented in several countries. reports on extent of exposure within regions of the united states are limited. this study investigated ar exposure and toxicosis in four species of birds of prey (red-tailed hawks [buteo jamaicensis], barred owls [strix varia], eastern screech owls [megascops asio] and great horned owls [bubo virginianus]) presented to a wildlife clinic in massachusetts. the aims of this study ... | 2011 | 22946375 |
| ecological risk assessment of great horned owls (bubo virginianus) exposed to pcdd/df in the tittabawassee river floodplain in midland, michigan, usa. | soils and sediments downstream of midland, michigan, usa have elevated polychlorinated dibenzofuran (pcdf) and polychlorinated dibenzo-p-dioxin (pcdd) concentrations. to determine if the pcdd/df concentrations have the potential to adversely affect terrestrial avian predators, a site-specific, multiple lines of evidence risk assessment was conducted for the great horned owl (bubo virginianus; gho). as long-lived resident top predators, the gho has the potential to be exposed to relatively great ... | 2010 | 20872699 |
| pulmonary carcinoma in a great horned owl (bubo virginianus). | pulmonary carcinoma was diagnosed in an 18+-year-old captive female great horned owl (bubo virginianus). the owl presented with a history of progressive weakness and sudden onset of frank blood in the droppings. on physical examination, the owl had multiple white to yellow plaques in the oral cavity, decreased air sac sounds on the right side, dyspnea (during manual restraint), and reduced pectoral musculature. whole-body radiographs revealed obliteration of the right-sided air sacs, a soft tiss ... | 2010 | 20722257 |
| retinal structure of birds of prey revealed by ultra-high resolution spectral-domain optical coherence tomography. | to reveal three-dimensional (3-d) information about the retinal structures of birds of prey in vivo. | 2010 | 20554605 |
| anticoagulant rodenticides in three owl species from western canada, 1988-2003. | anticoagulant rodenticides are widely used to control rodent infestations. previous studies have shown that nontarget organisms, such as birds, are at risk for both primary and secondary poisoning. this paper presents rodenticide residue information on the livers from 164 strigiformes which included barn owls (tyto alba), barred owls (strix varia), and great horned owls (bubo virginianus), collected from 1988 to 2003 in the province of british columbia and the yukon territory, canada. livers wer ... | 2010 | 19826750 |
| disseminated lymphoma of presumptive t-cell origin in a great horned owl (bubo virginianus). | a geriatric male great horned owl (bubo virginianus) that was a resident at a raptor center was presented for examination because of stridor and weight loss. results of physical examination, diagnostic imaging, and biopsy were consistent with disseminated lymphoma involving the oropharynx, neck region (including thyroid and parathyroid glands), keel, spleen, and liver. attempts to treat the owl with chlorambucil failed, and the owl was euthanatized 5 months later. neoplastic cells from this owl ... | 2008 | 19014096 |
| pharmacokinetics of butorphanol tartrate in red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus). | to determine the pharmacokinetics of butorphanol tartrate after iv and im single-dose administration in red-tailed hawks (rths) and great horned owls (ghos). | 2008 | 18447789 |
| plasma to egg conversion factor for evaluating polychlorinated biphenyl and ddt exposures in great horned owls and bald eagles. | the benefits of nondestructive sampling techniques, such as plasma sampling, to directly measure contaminant exposure levels in at-risk or protected raptor populations are many. however, such assays are generally inconsistent with the most certain source of toxicity reference values, which are based on feeding studies and quantified as dietary or "in ovo" (egg-based) concentrations. an accurate conversion factor to translate nondestructive plasma-based contaminant concentrations to comparable eg ... | 2007 | 17665679 |
| risk assessment of great horned owls (bubo virginianus) exposed to polychlorinated biphenyls and ddt along the kalamazoo river, michigan, usa. | the great horned owl (gho; bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (pcbs) and p,p'-dichlorodiphenyltrichloroethane (ddt) exposures at the kalamazoo river superfund site (krss), kalamazoo, michigan, usa. the study examined risks from total pcbs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (teqworld health organization [who]-avian toxicity equivalency factor [tef]), and total ddts (sum of ddt, dichlorodiphenyldichloroethylene [dde ... | 2007 | 17665678 |
| a new oligacanthorhynchid acanthocephalan described from the great horned owl, bubo virginianus (strigidae), and red-tailed hawk, buteo jamaicensis (accipitridae), from central arizona, u.s.a. | oligacanthorhynchus nickoli n. sp. (acanthocephala: oligacanthorhynchidae) is described from the great-horned owl, bubo virginianus (gmelin, 1788) (type host), and red-tailed hawk, buteojamaicensis (gmelin, 1788), collected in central arizona. the new species is most similar to oligacanthorhynchus iheringi and oligacanthorhynchus minor, but it differs from all congeners primarily by trunk length, proboscis size and armature, egg size, geographical range, and host species. it is distinguished fro ... | 2007 | 17436950 |
| bilateral phacoemulsification and intraocular lens implantation in a great horned owl. | a great horned owl of estimated age < 1 year that was captured by wildlife rehabilitators was evaluated because of suspected cataracts. | 2007 | 17302557 |
| differential accumulation of polychlorinated biphenyl congeners in the terrestrial food web of the kalamazoo river superfund site, michigan. | a series of field studies was conducted to determine the bioaccumulation of polychlorinated biphenyl (pcb) congeners in the terrestrial food web of the kalamazoo river flood plain. samples included colocated soils, native plants likely to be consumed by wildlife, several taxa of terrestrial invertebrates, small mammals, passerine bird eggs, nestlings, and adults, and great horned owl plasma and eggs. mean concentrations of total pcbs in samples from the former trowbridge impoundment were 6.5 mg/ ... | 2005 | 16173551 |
| proventricular adenocarcinoma in a humboldt penguin (spheniscus humboldti) and a great horned owl (bubo virginianus); identification of origin by mucin histochemistry. | cases of proventricular neoplasm in a humboldt penguin (spheniscus humboldti) and a great horned owl (bubo virginianus) were observed. microscopically, the neoplastic cells formed branching tubules or acini in both cases. galactose oxidase-schiff (gos) staining revealed that the cytoplasm of the normal surface epithelium and surface mucosubstances of the proventriculus adjacent to the neoplasm were positive in both cases. the neoplastic cells in both cases were also classified as gos-positive. t ... | 2004 | 14681071 |
| pharmacokinetics and anesthetic and cardiopulmonary effects of propofol in red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus). | to determine induction doses, anesthetic constant rate infusions (cri), and cardiopulmonary effects of propofol in red-tailed hawks and great horned owls and propofol pharmacokinetics in the owls during cri. | 2003 | 12828251 |
| penetrating keratoplasty for treatment of corneal protrusion in a great horned owl (bubo virginianus). | a young adult great horned owl (bubo virginianus) was examined following presumed trauma. the owl had soft tissue injury to its left wing as well as corneal protrusion, lens subluxation, and iridodialysis of the right eye. the bird's eye was treated surgically with a large, rectangular penetrating keratoplasty. following escape from housing, the bird was found with partial wound dehiscence and iris prolapse 12 days post operation. surgical repair was performed and healing progressed for 14 days, ... | 2002 | 12236872 |
| pharmacokinetics of piperacillan after intramuscular injection in red-tailed hawks (buteo jamaicensis) and great horned owls (bubo virginianus). | this study characterized and compared the pharmacokinetics of piperacillin after single 100 mg/kg i.m. injections in nine red-tailed hawks (buteo jamaicensis) and five great horned owls (bubo virginianus) over 48 hr by a modified agar well diffusion microbial inhibition assay. the mean maximum plasma piperacillin concentrations were 204 microg/ml and 221 microg/ml for the hawks and owls, respectively, and times of maximum concentrations were 15 min and 30 min, respectively. the calculated mean t ... | 2000 | 10884123 |
| poisoning of wildlife with anticoagulant rodenticides in new york. | from 1971 through 1997, we documented 51 cases (55 individual animals) of poisoning of non-target wildlife in new york (plus two cases in adjoining states) (usa) with anticoagulant rodenticides--all but two of these cases occurred in the last 8 yrs. brodifacoum was implicated in 80% of the incidents. diphacinone was identified in four cases, bromadiolone in three cases (once in combination with brodifacoum), and chlorophacinone and coumatetralyl were detected once each in the company of brodifac ... | 1999 | 10231745 |
| synovial chondromatosis in raptors. | fourteen raptors, consisting of 13 great horned owls (bubo virginianus) and one red-tailed hawk (buteo jamaicensis), from central and north central minnesota, western wisconsin, and eastern south dakota (usa) were admitted to a raptor rehabilitation center between june 1992 and june 1995, with perisynovial and synovial chondromatosis affecting multiple joints. birds were severely debilitated primarily due to loss of shoulder motion. the etiology of these lesions in raptors is unknown. | 1999 | 10073365 |
| cutting costs in response to predatory threat by geoffroy's marmosets (callithrix geoffroyi). | ideally, prey should respond to their predators efficiently, without over- or underreacting to the threat. this may be particularly important for small-bodied species for whom metabolic demands are high and predatory risk is great. in the current study, two family groups of callithrix geoffroyi living outside in a rural setting at the center for reproduction of endangered species, san diego wild animal park, were observed before, during, and after ten presentations of a great horned owl model. t ... | 1998 | 9802510 |
| mortality in fledgling great horned owls from black fly hematophaga and leucocytozoonosis. | black fly feeding alone and in concert with leucocytozoon spp. infection caused mortality in fledgling great horned owls (bubo virginianus) in the yukon, canada 1990 to 1991. these mortalities occurred during a year of food shortage corresponding with a decline in the population of snowshoe hare (lepus americanus), the main prey for great horned owls. we hypothesize an interaction between food availability and the consequences of host-parasite interactions. | 1997 | 9249694 |
| glaucoma in a captive-bred great horned owl (bubo virginianus virginianus). | a captive-bred adult great horned owl (bubo virginianus virginianus) behaved as though it was bilaterally blind. an ophthalmological examination showed that it had an increased intraocular pressure in both eyes and gonioscopy showed an abnormality of the iridocorneal angles. retinal changes were also observed. treatment was not attempted and the owl was euthanased. histopathology confirmed the abnormal iridocorneal angles, but the exact aetiology of the primary glaucoma was not identified. | 1997 | 9160532 |
| owl predation on snowshoe hares: consequences of antipredator behaviour. | we show evidence of differential predation on snowshoe hares (lepus americanus) by great horned owls (bubo virginianus) and ask whether predation mortality is related to antipredator behaviour in prey. we predicted higher predation on (1) young and inexperienced hares, (2) hares in open habitats lacking cover to protect from owl predation, and (3) hares in above average condition assuming that rich food patches are under highest risk of predation. information on killed hares was obtained at nest ... | 1996 | 28307843 |
| synovial chondromatosis in a great horned owl (bubo virginianus). | a case of synovial chondromatosis in a great horned owl (bubo virginianus) was found in june 1993. in radiographs of bilateral swelling of the scapulohumeral joint we observed numerous mineralized foci in the soft tissue. the foci were identified by light microscopy as cartilaginous metaplasia. this is the first report of synovial chondromatosis in an owl. | 1996 | 8722282 |
| fine structure of the pecten oculi of the barred owl (strix varia). | the pecten oculi of the barred owl (strix varia) has been examined by light and transmission electron microscopy. the pecten in this species is of the pleated type and is small in comparison to the size of the ocular globe. the pecten consists of 8-10 accordion-like folds that are linked apically by a pigmented tissue bridge. each fold contains numerous capillaries, larger supply and drainage vessels, and abundant pleomorphic melanocytes. most of these capillaries are extremely specialized vesse ... | 1996 | 8720451 |