To examine relationships between highly pathogenic avian influenza prevalence and migration patterns of Pacific common eiders (Somateria mollissima v-nigrum) nesting in Northwest Alaska, we marked 25 adult Pacific common eiders (24 females and 1 male) from the Cape Espenberg breeding area (28 June-7 July 2007) with satellite transmitters and sampled individuals for highly pathogenic avian influ...

BACKGROUND Predation may potentially lead to negative effects on both prey (directly via predators) and predators (indirectly via human persecution). Predation pressure studies are, therefore, of major interest in the fields of theoretical knowledge and conservation of prey or predator species, with wide ramifications and profound implications in human-wildlife conflicts. However, detailed work...

The influence of season on the plasma progesterone concentrations and morphometric values of corpus luteum and ovary was studied through ultrasonography in spring (n=10) and dry hot (n=10) seasons on alternate days during the estrous cycle regardless of estrous phases in Nili-Ravi buffaloes. The mean morphometric values of length and width of ovary and the diameter and area of corpus luteum wer...

Carotenoid-based plumage coloration plays a critical role for both inter- and intrasexual communication. Habitat and diet during molt can have important consequences for the development of the ornamental signals used in these contexts. When molt occurs away from the breeding grounds (e.g., pre-alternate molt on the wintering grounds, or stopover molt), discerning the influence of habitat and di...

knowledge of traits associated with drought tolerance would be useful for developing breeding materials fortarget environments. to study these traits, 119 spring durum wheat breeding lines (bls) from the international maize and wheat improvement center (cimmyt) were evaluated along with local checks (one modern cultivar and three landraces) in three experiments under terminal and non-terminal d...

Difference equations provide an important framework for analysis of dynamical phenomena in biology, ecology, economics, and so forth. For example, in population dynamics discrete systems adequately describe organisms for which births occur in regular, usually short, breeding seasons. Recently the problem of oscillation and nonoscillation of solutions for nonlinear delay difference equations has...

Global climate change is driving species' distributions towards the poles and mountain tops during both non-breeding breeding seasons, leading to changes in composition of natural communities. However, degree season differences climate-driven community shifts has not been thoroughly investigated at large spatial scales. We compared rates winter (non-breeding season) summer (breeding) their rela...

The search for ways to select for improved beef cow efficiency has become the holy grail of the beef cattle seedstock industry. Increases in beef production have often been possible due to enhancements in the reproduction indexes (e.g. calving frequency, age at first calving, calving interval), nutrition concepts (e.g. strategic supplementation, type of forage as well as quantity and quality), ...

The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (Apr...