منابع مشابه
Swallows track human moves
Most studies of the impact of humans on other species tend to be negative as more and more habitats are destroyed or degraded, so a new study provides a surprising contrast. It adds weight to the view that one of the northern hemisphere's best-loved summer visitors has vastly increased in range and numbers as a result of human activity. The barn swallow is found across North America, Europe and...
متن کاملRoosts and migrations of swallows
— Swallows of the north temperate zone display a wide variety of territorial behaviour during the breeding season, but as soon as breeding is over, they all appear to adopt a pattern of independent diurnal foraging interleaved with aggregation every night in dense roosts. Swallows generally migrate during the day, feeding on the wing. On many stretches of their annual journeys, their migrations...
متن کاملSexually dimorphic swallows have higher extinction risk
The effect of sexual selection on extinction risk remains unclear. In theory, sexual selection can lead to both increase and decrease extinction probability depending on the ecology of the study system. Thus, combining different groups might obscure patterns that can be found in groups that share similar ecological features. Using phylogenetic comparative analysis, we studied sexual plumage dim...
متن کاملConvergent evolution in social swallows (Aves: Hirundinidae)
Behavioral shifts can initiate morphological evolution by pushing lineages into new adaptive zones. This has primarily been examined in ecological behaviors, such as foraging, but social behaviors may also alter morphology. Swallows and martins (Hirundinidae) are aerial insectivores that exhibit a range of social behaviors, from solitary to colonial breeding and foraging. Using a well-resolved ...
متن کاملSome Observations of Sunbathing in Swallows
--Tree Swallows (Tachycineta bicolor), Violet-green Swallows (T. thalassina) and Barn Swallows (ttirundo rustica) were observed sunbathing under conditions that produced apparent hyperthermia as evidenced by gaping, posture and timing of exposure. Sunbathing was observed only on days having air temperatures above 30 C, medium to high humidities and low wind velocities. Duration of sunning behav...
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ژورنال
عنوان ژورنال: Nature
سال: 1880
ISSN: 0028-0836,1476-4687
DOI: 10.1038/022029b0