ticks (acari: ixodidae) infesting wild birds (aves) and white-footed mice in lyme, ct. | birds were captured and recaptured (20.8% of 5,297) with japanese mist nets, and white-footed mice, peromyscus leucopus (rafinesque), were caught and recaught (69.1% of 355) with sherman box traps during the late spring, summer, and early fall from july 1989 through october 1991 to study tick-host relationships in lyme, ct. ixodes scapularis say, a vector of lyme disease spirochetes, borrelia burgdorferi sensu stricto johnson, schmid, hye, steigerwalt & brenner, infested 803 birds (15.2%) in 36 ... | 1995 | 7650706 |
long-term vocal recognition in the northern fur seal. | the ability to recognize and remember individual identities for long periods of time has important implications for the evolution of animal social behaviour, particularly complex interactions such as cooperation or mate choice. despite this importance, there is only a single example of long-term individual recognition in nature, the 8-month retention of neighbour's song among male hooded warblers, wilsonia citrina, and there is none for a non-human mammal. associations between individuals spanni ... | 2000 | 10935635 |
estimating the effects of habitat and biological interactions in an avian community. | we used repeated sightings of individual birds encountered in community-level surveys to investigate the relative roles of habitat and biological interactions in determining the distribution and abundance of each species. to analyze these data, we developed a multispecies n-mixture model that allowed estimation of both positive and negative correlations between abundances of different species while also estimating the effects of habitat and the effects of errors in detection of each species. usi ... | 2015 | 26287671 |
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 ... | 1996 | 28307604 |
binational climate change vulnerability assessment of migratory birds in the great lakes basins: tools and impediments. | climate change is a global concern, requiring international strategies to reduce emissions, however, climate change vulnerability assessments are often local in scope with assessment areas restricted to jurisdictional boundaries. in our study we explored tools and impediments to understanding and responding to the effects of climate change on vulnerability of migratory birds from a binational perspective. we apply and assess the utility of a climate change vulnerability index on 3 focal species ... | 2017 | 28225817 |
factors affecting aural detections of songbirds. | many factors affect the number of birds detected on point count surveys of breeding songbirds. the magnitude and importance of these factors are not well understood. we used a bird song simulation system to quantify the effects of detection distance, singing rate, species differences, and observer differences on detection probabilities of birds detected by ear. we simulated 40 point counts consisting of 10 birds per count for five primary species (black-and-white warbler mniotilta varia, black-t ... | 2007 | 17494409 |
stopover and fat deposition by north american wood-warblers (parulinae) following spring migration over the gulf of mexico. | length of stopover and rate of weight gain (fat deposition) were studied in several species of passerine birds that stopped in southwestern louisiana along the northern coast of the gulf of mexico after a trans-gulf flight. fatdepleted birds were more common among the birds that arrived at our study site in southwest louisiana, though variability characterized our samples. migrants that landed after encountering opposing winds or rain over the northern gulf of mexico were, on average, fatter tha ... | 1987 | 28310413 |
demographic costs associated with differences in habitat space occupancy. | delimiting the habitat characteristics describing the environmental conditions required by a species has become a critical tool for predicting organismal responses to environmental change. grinnell emphasized the effects of environmental factors on the ability of a population to maintain a positive growth rate, yet few studies have included demographic or reproductive data in analyses of the grinnellian niche. identifying differences in habitat exploitation patterns in response to structural var ... | 2016 | 27851742 |
extraterritorial forays and male parental care in hooded warblers. | extrapair paternity is common among many songbird species yet few studies have quantified male extraterritorial foray (etf) effort and examined potential trade-offs. one potentially important constraint for males is the need to provide parental care. current models of male extrapair mating tactics propose that males reduce extraterritorial foray effort later in the breeding season because they face a trade-off between feeding nestlings versus pursuing extrapair matings. however, detailed field s ... | 2000 | 10877906 |
extra-pair mating effort of male hooded warblers, wilsonia citrina | few researchers have been able to quantify the time or effort expended by male birds in seeking extra-pair copulations with neighbouring females. in this study, we radio-tracked male hooded warblers, to determine the frequency and duration of intrusions onto neighbouring territories. extra-pair fertilizations are common in hooded warblers, with 35% of females producing extra-pair young. males intruded onto territories where females were nest building more often than expected by chance and approa ... | 1998 | 9514671 |
development of the corticosterone stress response differs among passerine species. | glucocorticoids are steroid hormones which increase dramatically in response to a physical or perceived stressor. however, developing young of altricial species typically have a damped glucocorticoid stress response. the developmental hypothesis posits that the physiological stress response should develop concurrently with an individual's ability to respond to a challenge. the dampened response may benefit an organism, as chronic exposure to glucocorticoids can have short- and long-term detrimen ... | 2020 | 32027877 |