One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed...

Predation risk can inflict profound effects on prey by influencing prey behavior and other traits. Prey are often subjected to a diversity of predators, which can exert differential predation pressures on prey life-history strategies. In birds, breeding adults and offspring (as eggs, nestlings, and fledglings) are susceptible to different types of predators, and life-history theory predicts tha...

The physico-biochemical properties of follicles and its plausible effect on quality and maturational competency of oocytes during the different breeding periods of the year was studied in buffaloes (Bubalus bubalis). Ovaries were collected from sexually mature buffaloes slaughtered at abattoir during high breeding (DecemberFebruary; HB) and low breeding (April-July; LB) periods of the year. The...

The reproductive performance of pigs is one of the main determinants of the profit farmers make from pig production. This study was undertaken to describe whether periods of high environmental temperature have an effect on the farrowing rate, litter sizes and number of stillbirths in commercial breeding units in South Africa. Data were collected weekly from four commercial breeding units with g...

Unlike terrestrial birds, many species of seabirds forage far from their breeding sites. Alternating nest attendance by the two parents allows for long distance foraging trips during lengthy incubation periods. Even so, limited food availability or poor weather can sometimes delay birds in their return to the nest. Thus, egg temperatures may drop to ambient levels for periods of a day or more (...

in rabbits, especially in some races, limb movement disorder called splay legs, are mostly unilateral or bilateral in front or hind legs at an early age. the severity ranges from mild to severe in this case. in breeding colony of albino dutch laboratory rabbits, the splay leg disorder has been observed over the years permanently.within the scope of this research, 1.5-2.5% of 700-750 number of c...

Members of the order Psittaciformes (parrots and cockatoos) are among the most long-lived and endangered avian species. Comprehensive data on lifespan and breeding are critical to setting conservation priorities, parameterizing population viability models, and managing captive and wild populations. To meet these needs, we analyzed 83, 212 life history records of captive birds from the Internati...

The diet of the brown skua (Catharacta skua loÈnnbergi) was studied at Mayes Island, Kerguelen archipelago, by collection of prey remains on 11 territories during the complete breeding cycle of the species there. In nine territories, collections were daily or every two days for a quantitative investigation of the diet. The blue petrel (Halobaena caerulea) and thin-billed prion (Pachyptila belch...

Timing of reproduction can influence individual fitness whereby early breeders tend to have higher reproductive success than late breeders. However, the fitness consequences of timing of breeding may also be influenced by environmental conditions after the commencement of breeding. We tested whether ambient temperatures during the incubation and early nestling periods modulated the effect of la...