Batrachotoxins are neurotoxic steroidal alkaloids first isolated from a Colombian poison-dart frog and later found in certain passerine birds of New Guinea. Neither vertebrate group is thought to produce the toxins de novo, but instead they likely sequester them from dietary sources. Here we describe the presence of high levels of batrachotoxins in a little-studied group of beetles, genus Chore...

Migration remains one of the great mysteries of animal life. Small migratory birds rely on refuelling stopovers after crossing ecological barriers such as deserts or seas. Previous studies have suggested that fuel reserves may determine stopover duration but this hypothesis could not be tested because of methodological limitations. Here, we provide evidence that subcutaneous fat stores determin...

The discovery of Hongshanornis longicresta, a small ornithuromorph bird with unusually long hindlimb proportions, was followed by the discovery of two closely related species, Longicrusavis houi and Parahongshanornis chaoyangensis. Together forming the Hongshanornithidae, these species reveal important information about the early diversity and morphological specialization of ornithuromorphs, th...

Abstract In the present study we performed a comparative dietary analysis of two predatory birds, Long-eared Owl (Asio otus) and Common Kestrel (Falco tinnunculus) in district Lviv city. We found that are typical small mammal specialists within urban ecosystem. Considering abundance biomass prey, mammals comprise 98.4% Owl’s diet. The species composition coincides almost 50% food intake compari...

Distribution, management anD ProDuctivity of Poultry genotyPes in most developing countries, there are two parallel poultry industries: one using high-performing commercial layer or broiler genotypes; and the other based on lower-performing, dual-purpose indigenous breeds. the proportions in these two categories vary widely among countries, but in lower-income countries, indigenous stock compri...

The anterior commissure (AC) and the much smaller hippocampal commissure constitute the only interhemispheric pathways at the telencephalic level in birds. Since the degeneration study from Zeier and Karten (), no detailed description of the topographic organization of the AC has been performed. This information is not only necessary for a better understanding of interhemispheric transfer in bi...

The ability to takeoff quickly and accelerate away from predators is crucial to bird survival. Crude oil can disrupt the fine structure and function of feathers, and here we tested for the first time how small amounts of oil on the trailing edges of the wings and tail of Western sandpipers (Calidris mauri) affected takeoff flight performance. In oiled birds, the distance travelled during the fi...

We have examined Na(+),K(+)-ATPase molecular activity and membrane fatty acid composition in the heart of six mammalian and eight avian species ranging in size from 30 g in mice to 280 kg in cattle and 13 g in zebra finches to 35 kg in emus, respectively. Na(+),K(+)-ATPase activity scaled negatively with body mass in both mammals and birds. In small mammals, the elevated enzyme activity was rel...

The avian hippocampal formation (Hf) plays an important role in spatial memory for food storing. Here we examined the effects of excitotoxic lesions of the Hf and subsequent neural transplantation on a one-trial associative memory task in zebra finches. The results showed (1) that small ibotenic acid lesions of the dorsal Hf of zebra finches produced significant spatial memory impairments compa...

background: several regulatory proteins are involved in salmonella invasion. the key regulator of spi-1 (salmonella pathogenicity island 1 ) is hila, a transcriptional activator encoded on spi-1 that regulates the expression of the spi-1 secretion system. objectives: importance of hila mutation on s. enteritidis colonization and shedding in layer hens was evaluated in a long-term experiment. me...