duration of alphavirus neutralizing antibody in naturally infected birds.native birds, mostly passerine species, ecologically associated with culiseta melanura, the enzootic vector of eastern equine encephalomyelitis and highlands j viruses in the eastern united states, were examined over a 12-year period in southeastern massachusetts. these studies concentrated on those individual birds known, by banding returns, to be residents of large wooded swamps where both eastern equine encephalomyelitis and highlands j viruses were known to be enzootic. of 8,417 birds sample ...19882829638
incompetence of catbirds as reservoirs for the lyme disease spirochete (borrelia burgdorferi).we compared the relative infectivity to vector ticks of gray catbirds (dumetella carolinensis) and white-footed mice (peromyscus leucopus) for the lyme disease spirochete (borrelia burgdorferi). of 28 catbirds captured in a site enzootic for this agent, 18 were infested by immature ixodes dammini, the tick vector. by comparison, each of 32 mice sampled concurrently from the same site was infested, and by about 10 times as many ticks as were found infesting the 3 most commonly netted bird species ...19892918445
tick infestations of birds in coastal georgia and alabama.mist-netted birds were examined for ticks on jekyll island, glynn co., georgia (32 bird species) in 1996-1998, and at fort morgan, baldwin co., alabama (36 species) in 1998 during fall migration. sixty-two (14.7%) of 423 birds from jekyll island and 22 (13.3%) of 165 birds from fort morgan were infested with ticks. the mean number of ticks per infested bird was 2.0 on jekyll island and 6.3 at fort morgan. ten species of birds were infested with ticks on jekyl1 island where 87% of all ticks were ...200010780541
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
reservoir competence of native north american birds for the lyme disease spirochete, borrelia burgdorfieri.reservoir competence for the lyme disease spirochete, borrelia burgdorferi, was tested for six species of native north american birds: american robin, gray catbird, brown thrasher, eastern towhee, song sparrow, and northern cardinal. wild birds collected by mist netting on fire island, ny, were held in a field laboratory in cages over water and locally collected larval ticks were placed on the birds, harvested from the water after engorgement, and tested for infection by direct fluorescentantibo ...200515962798
identification of avian- and mammalian-derived bloodmeals in aedes vexans and culiseta melanura (diptera: culicidae) and its implication for west nile virus transmission in connecticut, evaluate the host-feeding patterns of aedes vexans (meigen) and culiseta melanura (coquillett) as secondary vectors of west nile virus (family flaviviridae, genus flavivirus, wnv) in northeastern united states, we identified the source of vertebrate bloodmeals by sequencing portions of the cytochrome b gene of mitochondrial dna. analysis of polymerase chain reaction products from a total of 119 ae. vexans revealed that 92.4% of individuals acquired blood solely from mammalian and 2.5% from av ...200617017250
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
mosquito landing rates on nesting american robins (turdus migratorius).we measured mosquito landing rates on adult and nestling american robins at nests with infrared cameras in washington, d.c., and maryland, united states. mosquitoes landed on nesting robins almost exclusively between dusk and dawn. the mean number of mosquito landings per night was higher for adults (123.3 +/- se 32.8) than nestlings (37.26 +/- 14.8). the fraction of mosquitoes landing at a nest on nestlings increased with decreases in adult brooding. oral swabs from nestlings at these and 13 ot ...200717767414
epidemiology of west nile virus: a silent epiornitic in northern delaware in 2007 without associated human cases.abstract. we performed a 2-year longitudinal study (2006-2007) of west nile virus (wnv) infections in wild birds, mosquitoes, and sentinel chickens at 6 wnv-endemic sites in northern delaware. we determined virus infection rates of culex pipiens and other mosquito vectors as well as seroprevalence and antibody titers of amplifying hosts. endemicity status varied widely among the 6 sites based on 3 criteria-mosquito infections, sentinel chicken seropositivity, and wild bird seropositivity. a high ...201021033054
Field investigation of innate immunity in passerine birds in suburban Chicago, Illinois, USA.The innate immune system is the first line of defense against pathogens, and it plays a fundamental role in coordinating a protective immune response in birds. Although many studies have evaluated avian immune responses in the laboratory, many fewer studies to date have done so in a field setting. To gain insight into interspecific differences in immune function in wild birds, we used a field-deployed in vitro microbicidal assay to measure constitutive innate immunity of whole blood collected fr ...201121719824
short-chain carboxylic acids from gray catbird (dumetella carolinensis) uropygial secretions vary with testosterone levels and photoperiod.the uropygial gland of birds produces secretions that are important in maintaining the health and structural integrity of feathers. non-volatile components of uropygial secretions are believed to serve a number of functions including waterproofing and conditioning the feathers. volatile components have been characterized in fewer species, but are particularly interesting because of their potential importance in olfactory interactions within and across species. we used solid-phase microextraction ...201020346408
volatile and semivolatile compounds in gray catbird uropygial secretions vary with age and between breeding and wintering grounds.the uropygial secretions of some bird species contain volatile and semivolatile compounds that are hypothesized to serve as chemical signals. the abundance of secretion components varies with age and season, although these effects have not been investigated in many species. we used solid-phase microextraction headspace sampling and solvent extraction coupled with gas chromatography-mass spectrometry to detect and identify volatile and semivolatile chemical compounds in uropygial secretions of gr ...201121424249
new species of the feather mite family proctophyllodidae (acariformes: astigmata) from two species of mockingbirds (passeriformes: mimidae) in eastern north america.four new species of the feather mite family proctophyllodidae are described from two species of the family mimidae (passeriformes): proctophyllodes apanaskevichi sp. n. (proctophyllodinae) and amerodectes dumetellae sp. n. (pterodectinae) from the gray catbird, dumetella carolinensis (l., 1766), and proctophyllodes gallowayi sp. n. (proctophyllodinae) and metapterodectes toxostomae sp. n. (pterodectinae) from the brown thrasher, toxostoma rufum (l., 1758). a. dumetellae and m. toxostomae represe ...201424897846
living with aliens: effects of invasive shrub honeysuckles on avian nesting.invasive species have come to the forefront of conservation biology as a major threat to native biodiversity. habitats dominated by shrub honeysuckles (lonicera spp.) in the united states have been characterized as "ecological traps" by ecologists. here we tested this hypothesis by investigating the effects of shrub honeysuckles on the nesting ecology of native birds in seven study sites in central pennsylvania, usa. we examined how the abundance of shrub honeysuckles influenced the selection of ...201425229633
annual life-stage regulation of lipid metabolism and storage and association with ppars in a migrant species: the gray catbird (dumetella carolinensis).the annual cycle of a migrating bird involves metabolically distinct stages of substantial fatty acid storage and periods of increased fatty acid mobilization and utilization, and thus requires a great deal of phenotypic flexibility. specific mechanisms directing stage transitions of lipid metabolism in migrants are largely unknown. this study characterized the role of the ppars (peroxisome proliferator-activated receptors) in regulating migratory adiposity of the gray catbird (dumetella carolin ...201627591312
an integrated population model for bird monitoring in north america.integrated population models (ipms) provide a unified framework for simultaneously analyzing data sets of different types to estimate vital rates, population size, and dynamics; assess contributions of demographic parameters to population changes; and assess population viability. strengths of an ipm include the ability to estimate latent parameters and improve the precision of parameter estimates. we present a hierarchical ipm that combines two broad-scale avian monitoring data sets: count data ...201728036137
linking breeding and wintering grounds of neotropical migrant songbirds using stable hydrogen isotopic analysis of feathers.recent studies have shown that stable hydrogen isotope ratios (δd) in the tissues of animals often correlate with δd of local precipitation. here we examined the relationship between δd in feathers and growing season precipitation for neotropical migrant songbirds breeding over a continent-wide isotopic gradient. δd values were determined on feathers of 140 individuals of 6 species of wild insectivorous forest songbirds (setophaga ruticilla, empidonax minimus, vermivora peregrinus, catharus ustu ...199628307604
quantitative magnetic resonance analysis and a morphometric predictive model reveal lean body mass changes in migrating nearctic-neotropical passerines.most studies of lean mass dynamics in free-living passerine birds have focused on old world species at geographical barriers where they are challenged to make the longest non-stop flight of their migration. we examined lean mass variation in new world passerines in an area where the distribution of stopover habitat does not require flights to exceed more than a few hours and most migrants stop flying well before fat stores near exhaustion. we used either quantitative magnetic resonance (qmr) ana ...201121079970
leukocyte response to eastern equine encephalomyelitis virus in a wild passerine bird.leukocyte counts are frequently used to assess the immunologic status of animals; however, few studies have directly looked at the predictive value of leukocyte counts and an animal's ability to respond to an infection with a pathogen. understanding how an animal's leukocyte profile is altered by an active infection can assist with interpretation of leukocyte profiles in animals for which infection status is not known. in this study we examine the leukocyte counts of gray catbirds (dumetella car ...201324597116
anaplasma phagocytophilum infection in american robins and gray catbirds: an assessment of reservoir competence and disease in captive wildlife.anaplasma phagocytophilum (dumler et al.) is the bacterial agent of human granulocytic anaplasmosis, an emerging infectious disease. the main vector of a. phagocytophilum in the united states is the blacklegged tick (ixodes scapularis (say)) and various small and medium-sized mammals are reservoirs. previous studies indicate that birds are exposed to a. phagocytophilum; however, because no studies have directly investigated avian susceptibility, reservoir competence, and morbidity for a. phagocy ...201323427666
Molting success of Ixodes scapularis varies among individual blood meal hosts and species.The blacklegged tick (Ixodes scapularis) is an important vector of emerging human pathogens. It has three blood-feeding stages, as follows: larva, nymph, and adult. Owing to inefficient transovarial transmission, at least for the Lyme disease agent (Borrelia burgdorferi), larval ticks rarely hatch infected, but they can acquire infection during their larval blood meal. Nymphal ticks are primarily responsible for transmitting pathogens to hosts, including humans. The transition from uninfected ho ...201121845946
test of recrudescence hypothesis for overwintering of eastern equine encephalomyelitis virus in gray catbirds.eastern equine encephalitis virus (eeev; family togaviridae, genus alphavirus) epizootics are infrequent, but they can lead to high mortality in infected horses and humans. despite the importance of eeev to human and animal health, little is known about how the virus overwinters and reinitiates transmission each spring, particularly in temperate regions where infected adult mosquitoes are unlikely to survive through the winter. one hypothesis to explain the mechanism by which this virus persists ...201121845951
highly variable acquisition rates of ixodes scapularis (acari: ixodidae) by birds on an atlantic barrier island.acquisition of ticks by bird hosts is a central process in the transmission cycles of many tick-borne zoonoses, but tick recruitment by birds has received little direct study. we documented acquisition of ixodes scapularis say on birds at fire island, ny, by removing ticks from mist-netted birds, and recording the number of ticks on birds recaptured within 4 d of release. eight bird species acquired at least 0.8 ticks bird(-1) day(-1) during the seasonal peak for at least one age class of i. sca ...201021175049
host-seeking activity and avian host preferences of mosquitoes associated with west nile virus transmission in the northeastern u.s.a.mosquito host-seeking activity was studied using a custom-designed trap to explore: (1) at which time interval of the night adult mosquito abatement would be most effective, and (2) if there exists an avian-specific host-seeking preference. overnight trials using traps baited with dry ice showed that aedes taeniorhynchus (wiedemann) was most active at dusk and was then captured throughout the night. in contrast, culex spp. (cx. pipiens (linnaeus) and cx. restuans (theobald) delayed most activity ...201020618650
test of recrudescence hypothesis for overwintering of west nile virus in gray catbirds.west nile virus is a pathogen of concern for both human and wildlife health. although many aspects of the ecology of west nile virus are well understood, the mechanisms by which this and similar mosquito-borne viruses overwinter and become reinitiated each spring in temperate regions is not known. a thorough understanding of this mechanism is crucial to risk assessment and development of control strategies. one of the hypotheses to explain the mechanism by which this virus persists from year to ...201020496593
prevalence of west nile virus in migratory birds during spring and fall investigate the role of migratory birds in the dissemination of west nile virus (wnv), we measured the prevalence of infectious wnv and specific wnv neutralizing antibodies in birds, principally passeriformes, during spring and fall migrations in the atlantic and mississippi flyways from 2001-2003. blood samples were obtained from 13,403 birds, representing 133 species. specific wnv neutralizing antibody was detected in 254 resident and migratory birds, representing 39 species, and was most c ...200919996451
west nile virus antibodies in avian species of georgia, usa: 2000-2004.west nile virus (wnv) was first isolated in the state of georgia in the summer of 2001. as amplifying hosts of wnv, avian species play an important role in the distribution and epidemiology of the virus. the objective of this study was to identify avian species that are locally involved as potential amplifying hosts of wnv and can serve as indicators of wnv transmission over the physiographic and land use variation present in the southeastern united states. avian serum samples (n=14,077) from 83 ...200616584328
antibody response of wild birds to natural infection with alphaviruses.from 1986 to 1990, we conducted our second longitudinal study in the central (upstate) new york (cny) area on the wild avian hosts of eastern equine encephalomyelitis (eee) virus. field-collecting methods mirrored a study conducted from 1978 to 1980 at the same endemic focus. over the 5-yr study period, we captured 6,296 birds representing 99 species and took 4,174 blood samples from representatives of 83 species. gray catbirds, song sparrows, and veerys were the three dominant species captured ...200415605649
seroprevalence of eastern equine encephalomyelitis virus in birds and larval survey of culiseta melanura coquillett during an interepizootic period in central ohio.from june through august in 1999 and 2000, we conducted an avian serosurvey for eastern equine encephalomyelitis (eee) virus at killbuck marsh wildlife area (kmwa), a focus of infection in central ohio. we also monitored abundance of the suspected enzootic vector, culiseta melanura coquillett, in brown's lake bog, an adjacent wetland. of the 363 birds of 30 species sampled in 1999, three gray catbirds (dumetella carolinensis) were positive for antibodies to eee virus, representing 1.2% of the av ...200415266743
abundance and temporal distribution of ornithonyssus sylviarum canestrini and fanzago (acarina: mesostigmata) in gray catbird (dumatella carolinensis) nests.the northern fowl mite, ornithonyssus sylviarum canestrini and fanzago, is a common ectoparasite of wild birds. despite its ability to transmit eastern equine encephalitis (eee) virus under laboratory conditions and potential for involvement in the natural eee virus cycle, we know little about its abundance or temporal distribution in nature. from june to august 2000, we studied the abundance of o. sylviarum in the nests of gray catbirds (dumatella carolinensis), a reservoir host for eee virus, ...200415266741
impact of selective herbicide right-of-way vegetation treatment on birds.power line rights-of-way provide a major portion of the shrub habitat in new york. since this habitat type is on the decline, many of the birds dependent on shrub habitat are also declining. the methods used to control right-of-way vegetation could therefore have serious impacts on several birds of conservation concern. since new york is increasingly using selective herbicide treatments in vegetation management, we sought to investigate the potential impacts of these treatments on nesting birds. ...200212402095
avian and mammalian hosts for spirochete-infected ticks and insects in a lyme disease focus in connecticut.spirochetes and their vectors and reservoirs were studied in a lyme disease focus in east haddam, connecticut, from mid-may through september 1983. ixodes dammini subadults were comparable in number on white-footed mice (peromyscus leucopus) (means = 2.9 +/- 3.6 sd) to those on 27 different species of birds (means = 2.3 +/- 4.2 sd) representing 11 families within the order passeriformes. less commonly found ticks on birds (means less than or equal to 0.1) were immature ixodes dentatus and haemap ...19846516460
testing the role of sensory systems in the migratory heading of a songbird.the identification of the sensory cues and mechanisms by which migratory birds are able to reach the same breeding and wintering grounds year after year has eluded biologists despite more than 50 years of intensive study. while a number of environmental cues have been proposed to play a role in the navigation of birds, arguments still persist about which cues are essential for the experience based navigation shown by adult migrants. to date, few studies have tested the sensory basis of navigatio ...200919946085
stress, metabolism, and antioxidants in two wild passerine bird species.antioxidants protect against free-radical damage, and free radicals, in turn, are thought to underlie aging. thus, measuring antioxidants may aid field ecologists in understanding the physiological mechanisms that underlie life-history trade-offs. antioxidant levels are known to vary markedly in response to the stress of capture in many birds. these changes in antioxidants could result from regulation (e.g., by stress-related hormones) or consumption (e.g., by an increase in free radicals due to ...201318518772
stable isotopes in breath, blood, feces and feathers can indicate intra-individual changes in the diet of migratory songbirds.we used stable isotopes of c in breath, blood, feces and feathers to identify intra-individual changes in diet and the timescale of diet changes in free-living songbirds at a stopover site. because accurate interpretation of differences between the delta13c of breath, plasma, and red blood cells (rbcs) relative to diet requires knowing the turnover rate of c within them, we determined the rate of change of c in breath, plasma and rbcs for yellow-rumped warblers (dendroica coronata). half-lives o ...200515586297
relic behaviours, coevolution and the retention versus loss of host defences after episodes of avian brood parasitism.most previous studies of brood parasitism have stressed that host defences, such as egg recognition, are lost in the absence of parasitism. such losses could result in coevolutionary cycles in which parasites shift away from well-defended hosts only to switch back to them later at a time when these hosts have lost much or all of their defences and the parasite's current hosts have built up effective defences. however, the alternative 'single trajectory' model predicts that parasites rarely switc ...200111170700
magnetic information calibrates celestial cues during migration.migratory birds use celestial and geomagnetic directional information to orient on their way between breeding and wintering areas. cue-conflict experiments involving these two orientation cue systems have shown that directional information can be transferred from one system to the other by calibration. we designed experiments with four species of north american songbirds to: (1) examine whether these species calibrate orientation information from one system to the other; and (2) determine whethe ...200011032648
motor stereotypy and diversity in songs of mimic thrushes.the relationship between the motor and acoustic similarity of song was examined in brown thrashers (toxostoma rufum) and grey catbirds (dumetella carolinensis) (family mimidae), which have very large song repertoires and sometimes mimic other species. motor similarity was assessed by cross correlation of syringeal airflows and air sac pressures that accompany sound production. although most syllables were sung only once in the song analyzed, some were repeated, either immediately forming a coupl ...19968738752
motor dynamics of song production by mimic brown thrashers (toxostoma rufum) and grey catbirds (dumetella carolinensis) neither side of the syrinx has a consistently dominant role in song production. during song, the two sides operate independently, but in close cooperation with each other and with the respiratory muscles which are capable of adjusting expiratory effort to maintain a constant rate of syringeal airflow despite sudden changes in syringeal resistance. phonation is frequently switched from one side of the syrinx to the ot ...19947964705
amblyomma auricularium (ixodida: ixodidae) in florida: new hosts and distribution records.previous published evidence for the occurrence of an exotic armadillo tick, amblyomma auricularium (conil), in florida is scant, but we found it is fully established and integrated into the state's tick fauna. we collected 11,192 specimens of this tick from naturalized nine-banded armadillos, dasypus novemcinctus l., and 14 other species of wild native mammals and birds in florida, while sampling statewide during 2004 through 2007. in all, we document its specific presence only in 14 contiguous ...201728082640
vector-host interactions of culex pipiens complex in northeastern and southwestern usa.studies on the vector-host interactions of culex pipiens complex mosquitoes by sequencing portions of mitochondrial cytochrome b gene indicate that cx. p. pipiens f. pipiens predominantly feed on avian hosts (93.1%), and focus feeding activity on several key bird species, in particular the american robin, the gray catbird, and the house sparrow in connecticut. however, cx. p. quinquefasciatus indiscriminately feed on both birds and mammals. culex p. quinquefasciatus in harris county - texas and ...201223401953
longitudinal studies of west nile virus infection in avians, yucatán state, méxico.following the introduction of west nile virus (wnv) into north america in 1999, surveillance for evidence of infection with this virus in migratory and resident birds was established in yucatán state, méxico in march 2000. overall, 8611 birds representing 182 species and 14 orders were captured and assayed for antibodies to wnv. of these, 5066 (59%) birds were residents and 3545 (41%) birds were migrants. twenty-one (0.24%) birds exhibited evidence of flavivirus infection. of these, 8 birds had ...200415018768
catbirds are the new chickens: high sensitivity to a dioxin-like compound in a wildlife species.dioxins and dioxin-like compounds (dlcs) are highly toxic and persistent global pollutants with extremely large differences in sensitivity across taxonomic groups. the chicken has long been considered uniquely sensitive to dlcs among avian species; but dlc toxicity in nondomesticated birds is largely untested, and the relevance of the chicken as an ecological model is uncertain. new approaches that use genotyping of the ahr1 ligand binding domain to screen for dlc sensitivity among avian species ...201728379684
the ecological-evolutionary interplay: density-dependent sexual selection in a migratory songbird.little is understood about how environmental heterogeneity influences the spatial dynamics of sexual selection. within human-dominated systems, habitat modification creates environmental heterogeneity that could influence the adaptive value of individual phenotypes. here, we used the gray catbird to examine if the ecological conditions experienced in the suburban matrix (sm) and embedded suburban parks (sp) influence reproductive strategies and the strength of sexual selection. our results show ...201222837842
organophosphate pesticide method development and presence of chlorpyrifos in the feet of nearctic-neotropical migratory songbirds from canada that over-winter in central america agricultural areas.recent modeling analysis suggests that numerous birds may be at risk of acute poisoning in insecticide-treated fields. although the majority of avian field studies on pesticides have focused on treated seed, granule, insect or vegetation (oral exposure) ingestion, dermal exposure is an important exposure route when birds come into contact with deposited pesticides on foliage and other surfaces. some nearctic-neotropical migratory songbirds are likely exposed to pesticides on their non-breeding h ...201626421621
the influence of study species selection on estimates of pesticide exposure in free-ranging birds.field studies of pesticide effects on birds often utilize indicator species with the purpose of extrapolating to other avian taxa. little guidance exists for choosing indicator species to monitor the presence and/or effects of contaminants that are labile in the environment or body, but are acutely toxic, such as anticholinesterase (anti-che) insecticides. use of an indicator species that does not represent maximum exposure and/or effects could lead to inaccurate risk estimates. our objective wa ...201424174132
the presence and impact of environmental lead in passerine birds along an urban to rural land use gradient.contamination of wetlands by lead shot and lead fishing weights has generated a tremendous amount of research into the impact of lead poisoning on wildlife. less well known are the potential threats to wildlife posed by lead contaminants still prevalent in urban environments. despite a u.s. federal ban on lead-based paint and gasoline in 1978 and 1986, respectively, lead residue is still prevalent at hazardous levels in urban and suburban environments and may present a health concern for people ...200717549547
patterns of haemoproteus beckeri parasitism in the gray catbird (dumatella carolinensis) during the breeding season.we determined the prevalence and intensity of blood parasites in breeding gray catbirds (dumatella carolinensis) at killbuck wildlife area in wayne and holmes counties, ohio (usa) from june through august 2000. of 98 catbirds sampled, 40 (40.8%) had detectable infections of haemoproteus beckeri. overall prevalence of h. beckeri in this population is high relative to that reported in earlier blood parasite surveys of both breeding and migrant catbirds. mean intensity of h. beckeri infection did n ...200314567219
neural pathways for bilateral vocal control in songbirds.ipsilateral and contralateral projections of nucleus robustus archistriatalis (ra), a telencephalic vocal premotor nucleus, to respiratory-vocal nuclei in the brainstem were defined in adult male wasserschlager canaries, grey catbirds, and zebra finches, three songbird species that appear to differ in the degree of lateralized syringeal dominance. in all three species, ipsilateral projections of ra to the medulla included the tracheosyringeal part of the hypoglossal nucleus (xiits), that innerva ...200010870082
song development by grey catbirdswhat are the relative roles of imitation, improvisation and invention in the development of large song repertoires in species of the songbird family mimidae? this question was addressed in a laboratory study of the vocal development of young grey catbirds, dumetella carolinensiscollected from western massachusetts. two groups heard a repeated 10-s, tape-tutored segment of catbird song, two other groups heard a repeated 16-min segment and a fifth group heard no tape-tutored songs. one male select ...19979268478
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