نتایج جستجو برای: metastatic nest
تعداد نتایج: 100669 فیلتر نتایج به سال:
Avian nest success often varies seasonally and because predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of snakes that are nest predators has lent some support to the link between snake activit...
-Patterns of nest placement and its relationship to nest success in the Eastern Kingbird (T_JJT~Y~Y~US tyrannus) were studied in populations breeding in New York and Kansas. Data were augmented with information on nest placement in other open-nesting tyrannids in order to examine the hypothesis that these flycatchers place their nests chiefly so as to conceal them from predators. Nesting succes...
—Nest placement of open-nesting bird species may affect risk of nest predation, nest microclimate, and reproductive success. In populations that breed in multiple habitat types and over long seasons, nest placement should vary seasonally and by habitat to compensate for seasonally changing and habitat specific environmental conditions that might affect the relationship between nest placement an...
—We studied the consequences of nest-site choice on nesting success under differing disturbance levels for the Rufous-bellied Thrush (Turdus rufiventris). We compared nest-site choice and nest success between a disturbed site and an undisturbed site in a montane subtropical forest in northwestern Argentina. We found no overall difference in daily predation rate (DPR) between the disturbed and u...
Across the brains of different bird species, the cerebellum varies greatly in the amount of surface folding (foliation). The degree of cerebellar foliation is thought to correlate positively with the processing capacity of the cerebellum, supporting complex motor abilities, particularly manipulative skills. Here, we tested this hypothesis by investigating the relationship between cerebellar fol...
Nest box choice experiments were carried out outside the breeding season on adult silver and blue fox vixens with no previous permanent nest box experience. Nest boxes were varied in height of placement, number of rooms, presence of entrance room or platform and light conditions. Only one parameter was varied in any one experiment. Both fox species clearly preferred an elevated multi-room nest ...
Current statistical methods for estimating nest survival rates assume that nests are identical in their propensity to succeed. However, there are several biological reasons to question this assumption. For example, experience of the nest builder, number of nest helpers, genetic fitness of individuals, and site effects may contribute to an inherent disparity between nests with respect to their d...
The habitat, but also the nest hole of a hole-nesting species, will degrade the song during transmission. We investigated how the sounds degrade in a sound transmission experiment with the song of the Pied Flycatcher Ficedula hypoleuca (Muscicapidae). Ten different song elements were transmitted to microphones placed inside and outside a nest box. On average, song degradation was much greater i...
Laying hens are strongly motivated to use nests for egg laying, and alternative production systems (e.g., aviaries) provide artificial sites to meet this need and ensure efficient collection of clean, undamaged eggs. However, nests are typically not provided to allow simultaneous use by all hens; therefore, competition or mislaid eggs can result. To understand the influence of strain on laying ...
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