Most baleen whales are capital breeders that use stored energy acquired on foraging grounds to finance the costs of migration and reproduction breeding grounds. Body condition reflects past success can act as a proxy for individual fitness. Hence, monitoring seasonal gain in body while inform how marine mammals support migration, growth, reproduction, well nutritional health overall population....

Pocket gophers were collected from irrigated alfalfa fields (IRR) and non-irrigated fallow fields (NIRR) in Davis, California, for 2 years. Reproduction was continuous in IRR fields with very little seasonal variation in reproductive activity. In contrast, reproduction in NIRR fields occurred primarily during the rainy season (winter and spring). Females in IRR fields produced approximately twi...

BACKGROUND Season of birth has been reported to affect later reproduction in samples of pre-modern women and contemporary men. METHODS To examine whether the effect of birth date is also valid in contemporary women, we investigated the association between birth month and measures of reproductive performance (number of live-born children, % childless individuals) in a representative sample of ...

Small-bodied, nocturnal mouse lemurs (Microcebus) are widespread across diverse forest habitats in Madagascar. They are strict seasonal breeders and can, depending on the habitat and species, undergo daily or prolonged torpor to minimize energy expenditure during periods of food and water scarcity. Duration of reproduction, number of litters per season and timing of births vary across individua...

Fluctuations in food availability are a major challenge faced by primates living in seasonal climates. Variation in food availability can be especially challenging for females, because of the high energetic costs of reproduction. Therefore, females must adapt the particular demands of the different reproductive stages to the seasonal availability of resources. Madagascar has a highly seasonal c...

The control of seasonal reproductive activity in sheep and goats in open sheds, needs extra-light (E) during the photosensitive phase (equivalent to long days, LD), followed by treatment with melatonin (equivalent to short days, SD). In autumn-born Ile-de-France or Lacaune ram lambs, 2 months of E followed by decreasing daylength for 90 days, advanced onset of the first breeding season by allow...

Annual cycles in life-history traits often are interpreted as adaptations. The Mt. Graham red squirrel (Tamiasciurus hudsonicus grahamensis) is an endangered species isolated in the Pinaleno Mountains of Arizona (United States) at the southernmost range terminus where the ecology is poorly known. I monitored annual cycles of reproduction and body mass in male and female Mt. Graham red squirrels...

Ž . Our understanding of insulin-like growth factor-I IGF-I in cervids has been limited mostly to its effects on antler Ž . Ž . Ž . Ž development in red deer Cer us elaphus , roe deer Capreolus capreolus , fallow deer Dama dama , and pudu Pudu . puda . Although IGF-I has been found to play a critical role in reproductive function of other mammals, its role in reproduction of deer is unknown. Th...

Because parental care is costly, a sexual conflict between parents over parental investment is expected to arise. Parental care behavior is an adaptive decision, involving trade-offs between remating, and consequently desertion of the brood, and continuing parental effort. If the main advantage of desertion is remating, then this will be a time constraint, because the deserting individual will ...

the objectives of this study were to 1) describe the risk factors, incidence, production and reproduction consequences of retained placenta in dairy cows, and 2) estimate the financial losses associated with retained placenta. calving records from march 2008 to december 2013 comprising 59,341 calving were included in the data set. the effects of risk factors on retained placenta incidence were ...