We investigated levels of DNA damage in blood cells of barn swallows (Hirundo rustica) inhabiting the Chernobyl region to evaluate whether chronic exposure to low-level radioactive contamination continues to induce genetic damage in free-living populations of animals. Blood samples were obtained from barn swallows collected at sites with different background levels of radiation, including a rel...

Sexual trait divergence has been shown to play a role in the evolution of reproductive isolation. While variation in multiple sexual signals is common among closely related species, little is known about the role of these different axes of phenotype variation with respect to the evolution of behavioral reproductive isolation. Here we study a unique population of barn swallows (Hirundo rustica t...

Phenotypic differences among individuals are often linked to differential survival and mating success. Quantifying the relative influence of genetic and environmental variation on phenotype allows evolutionary biologists to make predictions about the potential for a given trait to respond to selection and various aspects of environmental variation. In particular, the environment individuals exp...

1997. The relation among gonadal steroids, immunocompetence, body mass, and behavior in young Black-headed Gulls (Larus ridibundus). American Naturalist 150:201–219. SAINO, N., A. P. MøLLER, AND A. M. BOLZERN. 1995. Testosterone effects on the immune system and parasite infestations in the Barn Swallow (Hirundo rustica): An experimental test of the immunocompetence hypothesis. Behavioral Ecolog...

Ecologically similar sympatric species, subject to typical environmental conditions, may be expected to exhibit synchronous temporal fluctuations in demographic parameters, while populations of dissimilar species might be expected to show less synchrony. Previous studies have tested for synchrony in different populations of single species, and those including data from more than one species hav...

According to life-history theory, the allocation of limiting resources to one trait has negative consequences for other traits requiring the same resource, resulting in trade-offs among life-history traits, such as reproduction and survival. In vertebrates, oxidative stress is increasingly being considered among the physiological mechanisms forming the currency of life-history trade-offs. In th...

At the beginning of the breeding season, the outermost tail feathers of 31 male Barn Swallows Hirundo rustica were either shortened by 20 mm, elongated by 20 mm or left unmanipulated. In first broods, the number of feeding bouts (per nestling per hour) by males and females did not differ significantly among experimental groups. However, in second broods, males with elongated tails fed their nes...

city parks play an important role in the welfare of metropolitan people. higher species richness of birds can be considered as a reflection of the health of the park and may satisfy visitors to a higher extent being in a more natural environment. we studied the influence of area and shape of city parks on bird species richness and diversity. 13 parks from among the 35 main city parks in isfahan...