نتایج جستجو برای: sparrows
تعداد نتایج: 1328 فیلتر نتایج به سال:
Dispersal plays a key role in the response of populations to climate change and habitat fragmentation. Here, we use data from a long-term metapopulation study of a non-migratory bird, the house sparrow (Passer domesticus), to examine the influence of increasing spring temperature and density-dependence on natal dispersal rates and how these relationships depend on spatial variation in habitat q...
West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006-2008,...
Sparrows in the nine-primaried oscine family Passerellidae represent an attractive model for studying avian diversification across North and South America. However, the lack of phylogenetic resolution at the base of the New World sparrow tree has hampered the use of the existing sparrow phylogeny to test questions about the evolution of sparrow traits. We generated phylogenomic data from 1,063 ...
Although people with autism spectrum disorders (ASD) often have severe problems with pragmatic aspects of language, little is known about their pragmatic reasoning. We carried out a behavioral study on high-functioning adults with autistic disorder (n = 11) and Asperger syndrome (n = 17) and matched controls (n = 28) to investigate whether they are capable of deriving scalar implicatures, which...
T he pineal gland of house sparrows was one of the first biological clocks believed to act as a circadian pacemaker. This view came from brilliant experimental studies by Menaker and coworkers (1, 2) demonstrating that removal of the pineal gland caused arrhythmic behavior and transplantation of pineal glands into pinealectomized arrhythmic birds restored locomotor rhythms. Takahashi and Menake...
During the latter-half of the nineteenth century, the utility of the house sparrow (Passer domesticus) to humankind was a contentious topic. In Britain, numerous actors from various backgrounds including natural history, acclimatisation, agriculture and economic ornithology converged on the bird, as contemporaries sought to calculate its economic cost and benefit to growers. Periodicals and new...
Many species of songbirds exhibit dramatic seasonal variation in song output. Recent evidence suggests that seasonal changes in auditory processing are coincident with seasonal variation in vocal output. Here, we show, for the first time, that frequency selectivity and temporal resolution of the songbird auditory periphery change seasonally and in a sex-specific manner. Male and female house sp...
The story told in this lecture starts with an innocuous little geometry problem (one that Erdős would have liked), posed in a September 2006 blog entry by R. Nandakumar, an engineer from Calcutta, India: “Can you cut every polygon into a prescribed number of convex pieces that have equal area and equal perimeter?” This little problem is a “sparrow”, tantalizing, not as easy as one could perhaps...
In behavior reminiscent of the responsiveness of human infants to speech, young songbirds innately recognize and prefer to learn the songs of their own species. The acoustic and physiological bases for innate recognition were investigated in fledgling white-crowned sparrows lacking song experience. A behavioral test revealed that the complete conspecific song was not essential for innate recogn...
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