Publications

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survey of leucocytozoon in in south carolina.an extensive survey of birds for leucocytozoon in south carolina during the summer of 1972 revealed that blue jays, purple grackles and domestic chickens were commonly infected. no alternate hosts were found for leucocytozoon smithi of turkeys.1976819913
arbovirus surveillance in florida: wild vertebrate studies 1965-1974.wildlife species from 38 of florida's 67 counties were surveyed over a 10 year period for the presence of antibody to the five major arboviruses circulating in the state. the routine screening of 7891 sera from wild birds and mammals via the hemagglutination-inhibition (h1) test with selected reactors subjected to serum neutralization testing has 1) provided information regarding geographic distribution and seasonality of circulation of these viruses 2) identified enzootic foci of infection and ...19751152173
community ecology of helminth parasitism in an insular passerine avifauna.three hundred and thirty specimens of 7 species of passerine birds from south bass island, ottawa county, ohio, were examined for helminth parasites. the total number of helminth specimens collected was 4,333. forty-one helminth taxa were identified. ten species of helminths were identified as having foci of infection on the island. an index of association for these 10 species is presented. the low association revealed between helminth species utilizing common species of intermediate hosts indic ...19761255354
fat of the wild avian filarial nematode chandlerella quiscali (onchocercidae: filarioidea) in the domestic chicken.chandlerella quiscali is a filarial nematode parasitizing the brain of the common grackle (quiscalus quiscula versicolor), blue jay (cyanocitta cristata bromia), brown-headed cowbird (molothrus ater ater), and starling (sturnus vulgaris). filarial infections of many wild bird species are common but natural infections of domestic fowl are rare. the habits of many wild birds commonly bring them in close association with domestic poultry. because of the high prevalence of c. quiscali in grackles (9 ...19807393850
eastern equine encephalomyelitis virus in relation to the avian community of a coastal cedar swamp.eastern equine encephalomyelitis virus (eeev) is perpetuated in eastern north america in a mosquito-wild bird maintenance cycle that involves culiseta melanura (coquillett) as the principal enzootic vector and passerine birds as the primary amplifying hosts. we examined the role of birds in the eeev cycle at a site in southern new jersey where eeev cycles annually at high levels. birds and mosquitoes were sampled during three epiornitics and one season of limited virus activity. we examined anti ...19947966175
ixodes dammini (acari: ixodidae) infestation on medium-sized mammals and blue jays in northwestern illinois.high prevalence of infestation of five species of medium-sized mammals and blue jays, cyanocitta cristata (l.), by immature ixodes dammini spielman, clifford, piesman and corwin was found in castle rock state park in northwestern illinois during may-august 1991. raccoons, procyon lotor l., and opossums, didelphis virginiana kerr, were infested with the highest larval densities and were trapped primarily in bottomland forest and ecotone habitats. all species had similar nymphal densities, except ...19938254647
spring migratory birds (aves) extend the northern occurrence of blacklegged tick (acari:ixodidae).birds that had migrated northward across lake superior were captured upon reaching landfall at thunder cape (48 degrees 18' n, 88 degrees 56' w) at the southwestern tip of the sibley peninsula, northwestern ontario, from 9 may to 9 june 1995. twenty-one of 530 birds examined (6 of 55 species) had a total of 34 ticks; 1 blue jay, cyanocitta cristata, had a northern fowl mite, ornithonyssus sylviarum (canestrini & fanzago). four blacklegged tick, ixodes scapularis say, larvae were found on an amer ...19968699451
molecular epidemiologic investigations of mycoplasma gallisepticum conjunctivitis in songbirds by random amplified polymorphic dna analyses.an ongoing outbreak of conjunctivitis in free-ranging house finches (carpodacus mexicanus) began in 1994 in the eastern united states. bacterial organisms identified as mycoplasma gallisepticum (mg) were isolated from lesions of infected birds. mg was also isolated from a blue jay (cyanocitta cristata) that contracted conjunctivitis after being housed in a cage previously occupied by house finches with conjunctivitis, and from free-ranging american goldfinches (carduelis tristis) in north caroli ...19979284386
mycoplasma sturni from blue jays and northern mockingbirds with conjunctivitis in florida.northern mockingbirds (mimus polyglottos) and blue jays (cyanocitta cristata) in a florida (usa) wildlife care facility developed clinical signs and gross lesions suggestive of the ongoing outbreak of mycoplasma gallisepticum (mg) conjunctivitis in house finches (carpodacus mexicanus) and american goldfinches (carduelis tristis). mycoplasmal organisms were cultured from conjunctival/corneal swabs of birds with sinusitis, conjunctivitis, and/or epiphora. all of the isolates tested were identified ...19989577796
concomitant mycotic and verminous pneumonia in a blue jay from georgia.an emaciated, moribund, male blue jay (cyanocitta cristata) was collected in georgia (usa) and died shortly after capture. necropsy revealed nine large nematodes identified as diplotriaena tricuspis in the thoracic and abdominal air sacs and within the pericardial sac. multiple mycotic granulomas also were observed in the lungs and air sacs, and fungal culture of these lesions yielded pure growth of aspergillus fumigatus. histologic examination of the lungs revealed disseminated granulomatous in ...19989706574
the effect of background cuing on prey detection.studies of prey detection have typically focused on how search image affects the capture of cryptic items. this study also considers how background vegetation influences cryptic prey detection. blue jays, cyanocitta cristata, searched digitized images for two catocala moths: c. ilia, which is cryptic on oak, and c. relicta, which is cryptic on birch. some images contained moths while others did not. the ability of blue jays to detect prey during repeated presentations of one prey type within a s ...19989790707
mycoplasmosis in captive crows and robins from minnesota.mycoplasma sturni is a recently described organism previously associated with conjunctivitis in european starlings (sturnus vulgaris), northern mockingbirds (mimus polyglottos) and blue jays (cyanocitta cristata). herein we describe the isolation of m. sturni from an american crow (corvus brachyrhynchos) presenting with conjunctivitis. a nested-pcr was designed for identification of m. sturni in clinical specimens and the sensitivity of the reaction was found to be 10 colony-changing units. the ...200111504228
experimental infection of north american birds with the new york 1999 strain of west nile virus.to evaluate transmission dynamics, we exposed 25 bird species to west nile virus (wnv) by infectious mosquito bite. we monitored viremia titers, clinical outcome, wnv shedding (cloacal and oral), seroconversion, virus persistence in organs, and susceptibility to oral and contact transmission. passeriform and charadriiform birds were more reservoir competent (a derivation of viremia data) than other species tested. the five most competent species were passerines: blue jay (cyanocitta cristata), c ...200312643825
epizootiology of haemoproteus danilewskyi (haemosporina: haemoproteidae) in blue jays (cyanocitta cristata) in southcentral florida.prevalence and density of haemoproteus danilewskyi was studied in a population of free-ranging blue jays (cyanocitta cristata) in southcentral florida (usa) from may 1992 to december 1995. prevalence of infection was 27% for data combined over years, seasons, ages, and sexes. prevalence did not vary between sexes or among years, but increased with age and varied with season, being highest in june-july and lowest in november-january. parasite density did not vary between sexes or among seasons, b ...200312685063
ecology of culicoides (diptera: ceratopogonidae) in southcentral florida and experimental culicoides vectors of the avian hematozoan haemoproteus danilewskyi kruse.to determine the vectors of haemoproteus danilewskyi in blue jays (cyanocitta cristata) in southcentral florida (usa), we conducted a 2 yr study from january 1993 to december 1995 of the presence and seasonal abundance of culicoides spp. of the 14 species of culicoides captured in centers for disease control light traps, 10 were ornithophilic. of these, c. edeni, c. knowltoni, c. stellifer, c. beckae, and c. arboricola were most abundant, representing 46% of the total collection and 99% of the o ...200312685081
initiating arbovirus surveillance in arkansas, 2001.migratory birds could introduce west nile (wn) virus to arkansas. the purpose of this study was to establish a cooperative arbovirus surveillance program to monitor mosquitoes and birds in arkansas for arboviruses. our objectives were to: 1) perform routine, multicounty collections of mosquitoes and test them for eastern equine encephalitis, st. louis encephalitis, and wn viruses; and 2) conduct passive surveillance by testing dead wild birds for wn virus. arbovirus surveillance was organized by ...200312693852
arbovirus surveillance in rhode island: assessing potential ecologic and climatic correlates.during 1995-2000, mosquitoes were collected from sites throughout rhode island and tested for the presence of arboviruses. mosquito trapping was done weekly from june to october with co2-baited light traps. in all, 186,537 mosquitoes belonging to 7 different genera were collected, of which coquillettidia perturbans was most abundant. a total of 6,434 pools were processed for arbovirus isolation, from which 193 arboviral isolations were made. these included 109 highlands j, 71 eastern equine ence ...200314524538
rapid antigen-capture assay to detect west nile virus in dead corvids.the utility of the vectest antigen-capture assay to detect west nile virus (wnv) in field-collected dead corvids was evaluated in manitoba and ontario, canada, in 2001 and 2002. swabs were taken from the oropharynx, cloaca, or both of 109 american crows, 31 blue jays, 6 common ravens, and 4 black-billed magpies from manitoba, and 255 american crows and 28 blue jays from ontario. the sensitivity and specificity of the antigen-capture assay were greatest for samples from american crows; oropharyng ...200314718083
arboviral infection in two species of wild jays (aves: corvidae): evidence for population impacts.we examined the prevalence of antibodies to three mosquito-borne arboviruses in blue jays, cyanocitta cristata, and florida scrub-jays, aphelocoma coerulescens, to identify the effects on host survival, the influence of sex and age on infection, and the temporal patterns of antibody prevalence. blood samples from 306 blue jays and 219 florida scrub-jays were collected at archbold biological station (lake placid, fl) from april 1994 through december 1995. sera were analyzed for hemagglutination-i ...200415061281
patterns of west nile virus infection in ohio blue jays: implications for initiation of the annual cycle.west nile virus (wnv) was first detected in north america in new york city in 1999 and rapidly moved westward. understanding the mechanisms by which the amplification cycle is reinitiated each year increases our ability to predict epizootics and geographic expansion of the disease. such understanding is enhanced by knowledge of the patterns of infection in the vertebrate reservoir hosts. blue jays (cyanocitta cristata) may serve as reservoir hosts for wnv. we examined the influence of age and da ...200415155993
mosquito and arbovirus activity during 1997-2002 in a wetland in northeastern mississippi.the species composition and population dynamics of adult mosquitoes in a wetland near iuka, ms, were analyzed over a 6-yr period (1997-2002) and reverse transcription-polymerase chain reaction (pcr) detection rates of arboviruses determined during five of those years. blood meals of three likely vector species were identified using a pcr-based method that allows identification of the host to species. culex erraticus (dyar & knab) composed 51.9% of the population during the 6-yr period with 295 f ...200415185956
experimental west nile virus infection in blue jays (cyanocitta cristata) and crows (corvus brachyrhynchos).ten crows (corvus brachyrhynchos) and three blue jays (cyanocitta cristata), species indigenous to north america, were intravenously inoculated with 10(3) pfu of west nile virus (wnv) strain ny99 for production of positive tissues for canadian surveillance. both species developed clinical signs 4 days postinoculation (dpi). virus was detected in blood, cloacal and tracheal swabs, and in a number of organs by reverse transcriptase-polymerase chain reaction (rt-pcr) and virus isolation (titers rea ...200415232136
rapid detection of west nile virus in birds using the vectest wnv antigen assay.to determine if the vectest west nile virus antigen assay (for testing mosquitoes) could be adapted to detect west nile virus (wnv) rapidly and accurately in birds for screening purposes.200415559727
vectest as diagnostic and surveillance tool for west nile virus in dead birds.the vectest antigen-capture assay for west nile virus was performed on oral and tissue swabs from dead birds in new york state from april 2003 through july 2004. results were compared with those from real-time reverse transcriptase-polymerase chain reaction of kidney or brain. oral vectest sensitivity is adequate for surveillance in american crows (corvus brachyrhynchos) (87%), blue jays (cyanocitta cristata) (80%), and house sparrows (passer domesticus) (76%). oral vectest performed well for sm ...200415663856
west nile virus detection in the organs of naturally infected blue jays (cyanocitta cristata).blue jays (cyanocitta cristata) are an effective indicator species for west nile virus (wnv) and may be regionally important in surveillance efforts. the sites of wnv replication and sensitivity of virus detection techniques are undefined for blue jays. the objectives of this study were to describe the gross and microscopic pathology associated with natural wnv infection in blue jays, as well as determine the most appropriate tissues to be used for virus isolation, reverse transcription-nested p ...200516107670
patterns of avian nest predators and a brood parasite among restored riparian habitats in agricultural watersheds.in fragmented edge-dominated landscapes, nest predation and brood parasitism may reduce avian reproductive success and, ultimately, populations of some passerine species. in the fragmented agroecosystem of northwest mississippi, placement of drop-pipe structures has been used as a restoration technique for abating gully erosion along stream banks. these actions have formed small herbaceous and woody habitat extensions into former agricultural lands. we quantified species relative abundances, spe ...200516160783
west nile virus detection in kidney, cloacal, and nasopharyngeal specimens.we compared kidney tissue samples and cloacal and nasopharyngeal swab samples from field-collected dead crows and blue jays for west nile virus surveillance. compared to tissue samples, 35% more swab samples were false negative. swab samples were usually positive only when the corresponding tissue sample was strongly positive.200516229775
avian hosts for west nile virus in st. tammany parish, louisiana, 2002.west nile virus (wnv) infections in free-ranging birds were studied in slidell, st. tammany parish, louisiana, after a human encephalitis outbreak peaked there in july 2002. seroprevalence in resident, free-ranging wild birds in one suburban site was 25% and 24% in august and october, respectively, indicating that most transmission had ceased by early august. mortality rates, seroprevalence rates, host competence, and crude population estimates were used in mathematical models to predict actual ...200516354808
west nile virus surveillance in east baton rouge parish, louisiana.west nile virus (wnv) was detected for the first time in louisiana in the fall of 2001. surveillance data collected from east baton rouge parish in 2002 were examined to establish baseline data on wnv activity, to support the current design of disease surveillance programs, and to target vector control efforts in the parish. the first indications of wnv activity were from a dead northern cardinal collected in february and from a live male cardinal sampled on 14 march. in mosquito pools, wnv was ...200717536365
host feeding pattern of culex quinquefasciatus (diptera: culicidae) and its role in transmission of west nile virus in harris county, texas.the vertebrate hosts of 672 blood-engorged culex quinquefasciatus say, collected in harris county, texas, during 2005, were identified by nucleotide sequencing pcr products of the cytochrome b gene. analysis revealed that 39.1% had acquired blood from birds, 52.5% from mammals, and 8.3% were mixed avian and mammalian blood meals. most frequent vertebrate hosts were dog (41.0%), mourning dove (18.3%), domestic cat (8.8%), white-winged dove (4.3%), house sparrow (3.2%), house finch (3.0%), gray ca ...200717620633
defensive spray of a phasmid insect.the walkingstick, anisomorpha buprestoides, has two defensive glands in its thorax from which it ejects an aimed spray when disturbed. contact stimulation is the usual trigger for the discharge, but birds may elicit the spray by merely approaching the insect. the secretion proved effectively deterrent to ants, predaceous beetles, mice, and blue jays, but not to an opossum.196517751052
associations between two mosquito populations and west nile virus in harris county, texas, 2003-06.associations between culex quinquefasciatus, aedes albopictus and west nile virus (wnv) activity, temperature, and rainfall in harris county, texas 2003-06 are discussed. human cases were highly correlated to cx. quinquefasciatus (r = 0.87) and ae. albopictus (r = 0.78) pools, blue jays (r = 0.83), and ae. albopictus collected (r = 0.71), but not cx. quinquefasciatus collected (r = 0.45). human cases were associated with temperature (r = 0.71), not rainfall (r = 0.29), whereas temperature correl ...200717939505
complete genome analysis and virulence characteristics of the louisiana west nile virus strain lsu-ar01.west nile virus (wnv) is a member of the flaviriridae family, which can cause significant morbidity and mortality in birds, horses, and humans. the wnv-lsu-ar01 strain was isolated from a dead blue jay in louisiana in 2001. phylogenetic analysis using 75 full wnv genomes revealed that the lsu-ar01 strain belongs to a distinct subclade among the north american strains. the lsu-ar01 strain differed from the ny-99 prototypic strain by 26 nucleotides causing six amino acid changes. an asparagine-to- ...200919130199
"anting" in blue jays: evidence in support of a food-preparatory function.anting, the plumage-dipping behavior to which ants (mostly formicines) are commonly subjected by birds (mostly passerines), is shown in tests with hand-raised blue jays (cyanocitta cristata) and the ant formica exsectoides to be instinctive: the birds displayed typical renditions of the behavior on the first occasion that they encountered ants. evidence is presented supportive of the view that anting is a strategy by which birds render ants fit for ingestion. formicine ants are ordinarily protec ...200819169379
host selection by culex pipiens mosquitoes and west nile virus amplification.recent field studies have suggested that the dynamics of west nile virus (wnv) transmission are influenced strongly by a few key super spreader bird species that function both as primary blood hosts of the vector mosquitoes (in particular culex pipiens) and as reservoir-competent virus hosts. it has been hypothesized that human cases result from a shift in mosquito feeding from these key bird species to humans after abundance of the key birds species decreases. to test this paradigm, we performe ...200919190226
the risk of west nile virus infection is associated with combined sewer overflow streams in urban atlanta, georgia, usa.at present, the factors favoring transmission and amplification of west nile virus (wnv) within urban environments are poorly understood. in urban atlanta, georgia, the highly polluted waters of streams affected by combined sewer overflow (cso) represent significant habitats for the wnv mosquito vector culex quinquefasciatus. however, their contribution to the risk of wnv infection in humans and birds remains unclear.201020529765
temporal and spatial patterns of west nile virus transmission in saginaw county, michigan, 2003-2006.the dynamics of west nile virus (family flaviviridae, genus flavivirus, wnv) infection in mosquitoes, sentinel pheasants, and wild dead birds were evaluated during 2003-2006 in saginaw co., mi. mosquitoes were collected by new jersey light traps at 22 sites during may-september, pooled by species and sample location, and tested for presence of wnv rna by using a real-time reverse transcription-polymerase chain reaction assay. oral swabs from wild dead birds submitted by the public were tested by ...201121936324
the culex pipiens complex in the mississippi river basin: identification, distribution, and bloodmeal hosts.members of the culex pipiens complex are the primary vectors of st. louis encephalitis virus and west nile virus in the mississippi river basin (mrb). the cx. pipiens complex in the mrb is composed of 4 taxa: cx. p. pipiens form pipiens, cx. p. quinquefasciatus, hybrids between cx. p. pipiens f. pipiens and cx. p. quinquefasciatus, and cx. p. pipiens form molestus. three studies on bloodmeal hosts with large sample sizes have been conducted on members of the cx. pipiens complex in the mrb includ ...201223401948
comprehensive mapping of common immunodominant epitopes in the west nile virus nonstructural protein 1 recognized by avian antibody responses.west nile virus (wnv) is a mosquito-borne flavivirus that primarily infects birds but occasionally infects humans and horses. certain species of birds, including crows, house sparrows, geese, blue jays and ravens, are considered highly susceptible hosts to wnv. the nonstructural protein 1 (ns1) of wnv can elicit protective immune responses, including ns1-reactive antibodies, during infection of animals. the antigenicity of ns1 suggests that ns1-reactive antibodies could provide a basis for serol ...201222347477
geography and timing of cases of eastern equine encephalitis in new york state from 1992 to 2012.in new york state (nys), eastern equine encephalitis (eee) was first reported in a human in 1971, in horses in 1970, and in pheasants in 1952.201626901637
house finch (haemorhous mexicanus) conjunctivitis, and mycoplasma spp. isolated from north american wild birds, 1994-2015.sampling wild birds for mycoplasma culture has been key to the study of house finch (haemorhous mexicanus) conjunctivitis, yielding isolates of mycoplasma gallisepticum spanning the temporal and geographic ranges of disease from emergence to endemicity. faced with the challenges and costs of sample collection over time and from remote locations for submission to our laboratory for mycoplasma culture, protocols evolved to achieve a practical optimum. herein we report making m. gallisepticum isola ...201627285414
supersuppression: reservoir competency and timing of mosquito host shifts combine to reduce spillover of west nile virus.in the eastern united states, human cases of west nile virus (wnv) result from spillover from urban epizootic transmission between passerine birds and culex mosquitoes. in atlanta, ga, substantial wnv presence in hosts and vectors has not resulted in the human disease burden observed in cities with similar infection pressure. our study goal was to investigate extrinsic ecological conditions that potentially contribute to these reduced transmission rates. we conducted wnv surveillance among hosts ...201627503511
effects of vasoactive intestinal peptide on prolactin secretion in three species of passerine birds.previous work on domesticated species has indicated that vasoactive intestinal peptide (vip) is an important prolactin-releasing factor in these birds, but no comparative work in passerine birds has been reported. this study showed that iv injections of vip (50-100 microg/kg body mass) result in a dramatic, but transitory, rise in plasma prolactin in mexican jays (aphelocoma ultramarina). significant increases in prolactin were also observed following vip injection in blue jays (cyanocitta crist ...19999882553
plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,danaus plexippus l. reared on milkweed plants in california: 2.asclepias speciosa.the pattern of variation in gross cardenolide concentration of 111asclepias speciosa plants collected in six different areas of california is a positively skewed distribution which ranges from 19 to 344 μg of cardenolide per 0.1 g dry weight with a mean of 90 μg per 0.1 g. butterflies reared individually on these plants in their native habitats ranged from 41 to 547 μg of cardenolide per 0.1 g dry weight with a mean of 179 μg. total cardenolide per butterfly ranged from 54 to 1279 μg with a mean ...198424318600
automatic recognition of harmonic bird sounds using a frequency track extraction algorithm.this paper demonstrates automatic recognition of vocalizations of four common bird species (herring gull [larus argentatus], blue jay [cyanocitta cristata], canada goose [branta canadensis], and american crow [corvus brachyrhynchos]) using an algorithm that extracts frequency track sets using track properties of importance and harmonic correlation. the main result is that a complex harmonic vocalization is rendered into a set of related tracks that is easily applied to statistical models of the ...200819045673
putative audio recordings of the ivory-billed woodpecker (campephilus principalis).putative audio recordings of the ivory-billed woodpecker (campephilus principalis) are presented along with discussions of the videos from which they were extracted and the observations that were made when these data were obtained. on two occasions, high-pitched calls were heard coming from the direction of a bird that was identified in the field as an ivory-billed woodpecker. these calls seem to match the description of an alarm call that was reported in the 1930s. one of the videos captured a ...201121428525
new harpirhynchinae dubinin (acariformes: harpirhynchidae)--intracutaneous and feather-base parasites of birds.seven new species of intracutaneous parasites of the subfamily harpirhynchinae dubinin (acariformes: cheyletoidea: harpirhynchidae) are described: anharpyrhynchus elizae sp. nov. from cyanocitta cristata (type host), cyanocitta stelleri (passeriformes: corvidae), and colaptes auratus (piciformes: picidae) from the usa; anharpyrhynchus apodus sp. nov. from lichmera indistincta (type host) and phylidonyris novaehollandiae (passeriformes: meliphagidae) from australia; anharpyrhynchus lukoschusi sp. ...201425283209
chemical defense in the plant bug lopidea robiniae (uhler).secretions from the metathoracic glands (mtg) of the black locust bug, lopidea robiniae (uhler) (heteroptera: miridae) contained six major compounds, including (e)-2-hexenal, (e)-2-hexen-1-ol, (e)-2-octenal, (e)-2-octen-1-ol (e)-2-heptenal, and (z)-3-octen-1-ol. males and females did not differ significantly in the relative compositions of identified compounds. in feeding trials, six bird species [robin (turdus migratorious), blue jay (cyanocitta cristata), brown thrasher (toxostoma rufum), kill ...200211944836
effects of climate and exurban development on nest predation and predator presence in the southern appalachian mountains (usa).in the eastern united states, land-use and climate change have likely contributed to declines in the abundance of neotropical migrant birds that occupy forest interiors, but the mechanisms are not well understood. we conducted a nest-predation experiment in southern appalachian mountain forests (north carolina, u.s.a.) during the 2009 and 2010 breeding seasons to determine the effects of exurban development and temperature on predator presence and the average number of days until eggs in an arti ...201222624665
power lines, roads, and avian nest survival: effects on predator identity and predation intensity.1 anthropogenic alteration of landscapes can affect avian nest success by influencing the abundance, distribution, and behavior of predators. understanding avian nest predation risk necessitates understanding how landscapes affect predator distribution and behavior. 2 from a sample of 463 nests of 17 songbird species, we evaluated how landscape features (distance to forest edge, unpaved roads, and power lines) influenced daily nest survival. we also used video cameras to identify nest predators ...201424967077
visual search and attention in blue jays (cyanocitta cristata): associative cuing and sequential priming.visual search for complex natural targets requires focal attention, either cued by predictive stimulus associations or primed by a representation of the most recently detected target. because both processes can focus visual attention, cuing and priming were compared in an operant search task to evaluate their relative impacts on performance and to determine the nature of their interaction in combined treatments. blue jays were trained to search for pairs of alternative targets among distractors. ...201424893217
differences in relative hippocampus volume and number of hippocampus neurons among five corvid species.the relative size of the avian hippocampus (hp) has been shown to be related to spatial memory and food storing in two avian families, the parids and corvids. basil et al. [brain behav evol 1996;47:156-164] examined north american food-storing birds in the corvid family and found that clark's nutcrackers had a larger relative hp than pinyon jays and western scrub jays. these results correlated with the nutcracker's better performance on most spatial memory tasks and their strong reliance on stor ...201323364270
butterfly wing markings are more advantageous during handling than during the initial strike of an avian predator.the "false head" hypothesis states that due to the posterior ventral wing markings of certain butterflies which resemble a "false head," visually hunting predators, such as birds, are deceived into attacking the hind wing area rather than the true head of the butterfly. in the laboratory, six groups of artificially marked dead cabbage butterflies, pieris rapae, were presented to blue jays, cyanocitta cristata. of the six "false head" markings, only the eyespot significantly influenced the point ...198528561349
a natural toxic defense system: cardenolides in butterflies versus birds.we have verified that wild birds can become conditioned to reject naturally toxic insects either visually (experiment 1) or by taste (experiment 2). we have also verified, however, that unconditioned taste rejection of noxious chemicals by wild birds also occurs (experiment 3). such unconditioned responses to the aposematic visual and taste cues of many insects, in fact, often appear to be as important as, or more important than, conditioned responses. in a large number of laboratory feeding exp ...19853860070
intersexual comparison of mimetic protection in the black swallowtail butterfly, papilio polyxenes: experiments with captive blue jay predators.the black swallowtail butterfly (papilio polyxenes asterius stoll), is commonly assumed to exhibit female-limited batesian mimicry of the aposematic pipevine swallowtail (battus philenor [l.]), since the dorsal wing surfaces of p. polyxenes females, but not males, resemble those of the model. however, the ventral wing surface is monomorphic and closely resembles that of the model in both sexes. thus both sexes of p. polyxenes should benefit from mimicry during periods of ventral surface exposure ...198928568560
blue jay mania. 19938518987
the blue jay cached the nut. 193917833347
what did the blue jay do with the nut? 193917732503
beech range extension and vegetation history: pollen stratigraphy of two wisconsin lakes.the pollen stratigraphy of two small lakes in eastern wisconsin (radtke lake, washington county, and gass lake, manitowoc county) records the holocene (past 10 000 yr) spread of beech (fagus grandifolia: fagaceae). radiocarbon dates were obtained for the oldest stratigraphic levels at which beech pollen appeared consistently in amounts > 0.5% of terrestrial pollen. a spatially continuous pattern of beech expansion from the north was ruled out, because beech trees grew in wisconsin by 6000 bp, 20 ...198729357137
feeding success and host selection by culex quinquefasciatus say mosquitoes in experimental trials.arthropod vector feeding preferences are defined as an overutilization of a particular host species given its abundance in relationship to other species in the community. numerous methods exist to quantify vector feeding preferences; however, controlled host choice experiments are generally an underutilized approach. in this report, we present results from controlled vector host choice experiments using culex quinquefasciatus say (diptera: culicidae) mosquitoes and wild avian hosts identified as ...201930964426
forage ratio analysis of the southern house mosquito in college station, texas.culex quinquefasciatus is the principal vector of west nile virus (wnv) in the south central united states, yet limited data on host utilization are available. we evaluated host utilization over a 3-month period in 2013 in a residential landscape in college station, texas. pcr sequencing of the mitochondrial cytochrome oxidase 1 gene permitted molecular identification of vertebrate bloodmeals to the species level. forage ratio analysis identified bird species that were overutilized and underutil ...201829920164
smaller on the left? flexible association between space and magnitude in pigeons (columba livia) and blue jays (cyanocitta cristata).humans and other apes represent magnitudes spatially, demonstrated by their responding faster and more accurately to one side of space when presented with small quantities and to the other side of space when presented with large quantities. this representation is flexible and shows substantial variability between cultural groups in humans and between and within individuals in great apes. in contrast, recent findings suggest that chicks show a spatial representation of magnitude that is highly la ...202031328952
dietary circumvention of acorn tannins by blue jays : implications for oak demography.blue jays consume large quantities of acorns to fuel energy-demanding caching flights in the fall. yet blue jays possess no known physiological adaptation to counter the negative effects of a high tannin diet on protein digestion. dietary experiments were conducted to determine if blue jays could subsist on an acorn-only diet, and if they could not, to determine whether supplements of acorn weevil larvae (curculio), present inside acorns, enabled them to maintain their mass. comparative tannin a ...199328314027
discounting and reciprocity in an iterated prisoner's dilemma.the iterated prisoner's dilemma (ipd) is a central paradigm in the study of animal cooperation. according to the ipd framework, repeated play (repetition) and reciprocity combine to maintain a cooperative equilibrium. however, experimental studies with animals suggest that cooperative behavior in ipds is unstable, and some have suggested that strong preferences for immediate benefits (that is, temporal discounting) might explain the fragility of cooperative equilibria. we studied the effects of ...200212481142
tracking a changing environment: optimal sampling, adaptive memory and overnight effects.foraging in a variable environment presents a classic problem of decision making with incomplete information. animals must track the changing environment, remember the best options and make choices accordingly. while several experimental studies have explored the idea that sampling behavior reflects the amount of environmental change, we take the next logical step in asking how change influences memory. we explore the hypothesis that memory length should be tied to the ecological relevance and t ...201222024660
optimal short-sighted rules.the aim of this paper is to assess the relevance of methodological transfers from behavioral ecology to experimental economics with respect to the elicitation of intertemporal preferences. more precisely our discussion will stem from the analysis of stephens and anderson's (2001) seminal article. in their study with blue jays they document that foraging behavior typically implements short-sighted choice rules which are beneficial in the long run. such long-term profitability of short-sighted beh ...201222973188
genetic sequence data reveals widespread sharing of leucocytozoon lineages in corvids.leucocytozoon, a widespread hemosporidian blood parasite that infects a broad group of avian families, has been studied in corvids (family: corvidae) for over a century. current taxonomic classification indicates that leucocytozoon sakharoffi infects crows and related corvus spp., while leucocytozoon berestneffi infects magpies (pica spp.) and blue jays (cyanocitta sp.). this intrafamily host specificity was based on the experimental transmissibility of the parasites, as well as slight differenc ...201627189064
brain cholinesterase inhibition in songbirds from pecan groves sprayed with phosalone and disulfoton.brain cholinesterase (che) activities of songbirds collected in pecan groves 6 to 7 hr after separate applications of the organophosphorus pesticides, phosalone and disulfoton, were compared to mean che activities of controls (normals) as a measure of insecticide exposure. in general, reduction of brain che activity greater than or equal to 2 standard deviations below the control mean indicates exposure to an anticholinesterase compound. phosalone had little effect on brain che activity of birds ...19902304190
plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,danaus plexippus reared on the milkweed,asclepias eriocarpa in california.this paper is the first in a series on cardenolide fingerprinting of the monarch butterfly. new methodologies are presented which allow both qualitative and quantitative descriptions of the constituent cardenolides which these insects derive in the wild from specificasclepias foodplants. analyses of thin-layer chromatographic profiles ofasclepias eriocarpa cardenolides in 85 individual plant-butterfly pairs collected at six widely separate localities in california indicate a relatively invariant ...198224415043
the pathology of capillariasis in the blue jay. 19715156481
metazoan parasites of the blue jay, cyanocitta cristata l. 195613332505
tool-making and tool-using in the northern blue jay.laboratory-raised northeirn blue jays (cyanocitta cristata) have been observed tearing pieces from pages of newspaper and utilizing them as tools to rake in food pellets which were otherwise out of reach. the frequency of this behavior was dependenit upon the motivational state of the jay and the presence of food pellets.197317806587
the helminth parasites of the blue jay, cyanocitta cristata bromia, from south bass island, ohio. 19744434280
visual detection of cryptic prey by blue jays (cyanocitta cristata).blue jays learned to respond differentially to the presence or absence of catocala moths in slides. this detection of the moths by the jays was affected by the background upon which the moth was placed and its body orientation, thus providing an objective measure of crypticity. these procedures are useful for the study of visual detection of prey.197717732294
search image formation in the blue jay (cyanocitta cristata).blue jays trained to detect catocala moths in slides were exposed to two types of slide series containing these moths: series of one species and series of two species intermixed. in one-species series, detection ability increased with successive encounters with one prey type. no similar effect occurred in two-species series. these results are a direct demonstration of a specific search image.197917813172
acorn dispersal by the blue jay (cyanocitta cristata).blue jays transported and cached 133,000 acorns from a stand of quercus palustris trees in blacksburg, virginia, representing 54% of the total mast crop. a further 20% (49,000) of the mast crop was eaten by jays at the collecting site. a large proportion of the nuts remaining beneath the collecting trees was parasitized by curculionid larvae. the number of nuts transported per caching trip ranged from 1-5 with a mean of 2.2. mean distance between seed trees and caches was 1.1 km (range: 100 m-1. ...198128311093
aversion/attraction of blue jays to microwave irradiation.aversion/attraction experiments were conducted to determine whether birds can perceive the presence of 2.45 ghz continuous wave microwave irradiation by observing whether blue jays (cyanocitta cristata) exhibit an attraction or an aversion to the field when exposed to 25 and 50 mw/cm2. at power densities of 25 and 50 mw/cm2 blue jays exhibit an aversion to microwave irradiation.19846522499
effects of weevil larvae on acorn use by blue jays.blue jays (cyanocitta cristata l.) are important consumers and dispersers of the nuts of oaks and other fagaceous trees in eastern north america. acorns compose much of the jay diet, especially during the autumn when jays may consume or cache a significant portion of an acorn crop. however, jays do not appear to possess physiological adaptations for countering the protein-binding properties of secondary compounds (tannins) found in acorns. we offered captive blue jays a mixture of infested and u ...199728307995
visual predators select for crypticity and polymorphism in virtual prey.cryptically coloured animals commonly occur in several distinct pattern variants. such phenotypic diversity may be promoted by frequency-dependent predation, in which more abundant variants are attacked disproportionately often, but the hypothesis has never been explicitly tested. here we report the first controlled experiment on the effects of visual predators on prey crypticity and phenotypic variance, in which blue jays (cyanocitta cristata) searched for digital moths on computer monitors. mo ...200211832937
pathogenicity of haemoproteus danilewskyi, kruse, 1890, in blue jays (cyanocitta cristata).although the impact of blood parasite infections on passerine birds is potentially great, little is known of their pathologic effects. we studied haemoproteus danilewskyi in experimentally infected captive and naturally infected free-ranging blue jays (cyanocitta cristata) to determine patterns of infection and examine the pathologic effects of the parasite on the host. physiologic changes, such as elevated numbers of lymphocytes, heterophils, basophils, eosinophils, and monocytes and decreased ...200312685080
effects of temporal clumping and payoff accumulation on impulsiveness and cooperation.animals show impulsiveness when they prefer a smaller more immediate option, even though a larger more delayed option produces a higher intake rate. this impulsive behavior has implications for several behavioral problems including social cooperation. this paper presents two experiments using captive blue jays (cyanocitta cristata) that consider the effects of payoff accumulation and temporal clumping on impulsiveness and cooperation. payoff accumulation refers to a situation where the benefits ...200616226849
spatial heterogeneity, predator cognition, and the evolution of color polymorphism in virtual prey.cryptically colored prey species are often polymorphic, occurring in multiple distinctive pattern variants. visual predators promote such phenotypic variation through apostatic selection, in which they attack more abundant prey types disproportionately often. in heterogeneous environments, disruptive selection to match the coloration of disparate habitat patches could also produce polymorphism, but how apostatic and disruptive selection interact in these circumstances is unknown. here we report ...200616481615
hormone levels and infection of haemoproteus danilewskyi in free-ranging blue jays (cyanocitta cristata).annual spring relapse of blood parasite infections in birds is believed to be the result of hormonal changes associated with breeding. as part of a larger study on the epizootiology of haemoproteus danilewskyi in blue jays in south-central florida, we studied the relationship between h. danilewskyi infections and levels of luteinizing hormone, prolactin, progesterone, testosterone, estradiol, and corticosterone. we found a positive association between intensity of h. danilewskyi infection and co ...200616884020
eavesdropping squirrels reduce their future value of food under the perceived presence of cache robbers.caching behavior frequently occurs within a social context that may include heterospecific cache pilferers. all else equal, the value of cacheable food should decline as the probability of cache recovering declines. we manipulated gray squirrels' (sciurus carolinensis) estimate of the probability of cache recovery using experimental playbacks of the vocalizations of a potential cache robber, the blue jay (cyanocitta cristata). we used giving-up densities (guds) to quantify relative changes in sq ...200818220481
does multiple seed loading in blue jays result in selective dispersal of smaller acorns?studies from both tropical and temperate systems show that scatter-hoarding rodents selectively disperse larger seeds farther from their source than smaller seeds, potentially increasing seedling establishment in larger-seeded plants. size-biased dispersal is evident in many oaks (quercus) and is true both across and within species. here, we predict that intraspecifc variation in seed size also influences acorn dispersal by the blue jay (cyanocitta cristata linnaeus), but in an opposite manner. ...201121910843
why not lie? costs enforce honesty in an experimental signalling game.communication depends on reliability. yet, the existence of stable honest signalling presents an evolutionary puzzle. why should animals signal honestly in the face of a conflict of interest? while students of animal signalling have offered several theoretical answers to this puzzle, the most widely studied model, commonly called the 'handicap principle', postulates that the costs of signals stabilize honesty. this model is the motivating force behind an enormous research enterprise that explore ...201424225460
the not-so-blue jays.watching birds is great entertainment, and there's fascinating physics behind how some get their colours, says chanda prescod-weinstein.202032501351
courtship behavior and coloration influence conspicuousness of wolf spiders (schizocosa ocreata (hentz)) to avian predators.signalers must balance the benefits of detection by intended receivers with the costs of detection by eavesdroppers. this trade-off is exemplified by sexual signaling systems, in which signalers experience sexual selection for conspicuousness to mates as well as natural selection for crypsis to predators. in this study, we examined how courtship behavior and body coloration influenced the conspicuousness of males to avian predators in the well-studied brush-legged wolf spider system (schizocosa ...201930650339
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