| 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 |
| 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 |
| 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 |
| 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 |