Animals can maximize fitness by optimizing energy acquisition through the selection of favorable foraging habitats, but trade-offs exist between time spent in preferred feeding habitats, energetic costs of travel, and reproductive constraints. For pelagic seabirds, geographic distribution of suitable breeding islands can restrict access to marine prey resources and influence foraging strategies...

Although the starling has the capacity for explosive population growth, its population in Britain has declined by two-thirds over the last 40 years. Here we summarize a major study (Crick et al., 2002) which investigates the reasons for this. The starling is commonest in urban and farmland habitats, though density in the latter is much lower; the total breeding population is estimated at 9 mill...

Visual predators tend not to hunt during periods when efficiency is compromised by low light levels. Yet common murres, a species considered a diurnal visual predator, frequently dive at night. To study foraging of murres under different light conditions, we used a combination of archival tagging methods and astronomical models to assess relationships between diving behaviour and light availabi...

Reproductive performance has an important effect on economic efficiency in dairy farms with short yearly periods of breeding. The individual factors affecting the outcome of an artificial insemination have been extensively researched in many univariate models. In this study, these factors are analysed in combination to create a comprehensive multivariate model of conception in Irish dairy cows....

ABSTRAC7: -Olive-winged bulbul (Pycnonotus plumosus) and cream-vented bulbul (P. simplex) were found to be sedentary non-territorial species with home range sizes of 0.29-7.23 ha during the breeding season. Range sizes were not significantly different between species. Indices of available food sources (or food plants) within the home ranges of both species were also not significantly different....

During the summer of 2002, an epidemic of West Nile meningoencephalitis occurred in southern Louisiana. Following the outbreak, blood samples were collected from 1,692 captive rhesus monkeys (Macaca mulatta), pigtail macaques (M. nemestrina), and baboons (Papio spp.) that were permanently housed outdoors at a nonhuman primate breeding facility in St. Tammany Parish, Louisiana. The serum samples...

Selective breeding of rohu, Labeo rohita to Aeromonas hydrophila infection requires a challenge model to obtain LD50 dose and study of bacterial persistence in survivors’ tissues. Fish were bath challenged with various routes viz., only immersion, after scale removal (with and without high stocking), after skin abrasion (with and without high stocking), under only high stocking density and afte...

The period of parental care can be a demanding life-history stage because parents need to find sufficient resources to feed themselves and their offspring. Often, this is reflected by elevated baseline levels of glucocorticoids—hormones that regulate metabolism and energy allocation. During 10 breeding seasons, we studied plasma corticosterone (the major avian glucocorticoid) concentrations as ...

Subfertility problems are encountered frequently in the cattle and buffalo bulls commercially maintained for semen production in dairy farms and under field conditions for natural insemination. Reports are scarce on the incidence of subfertility in breeding bulls, especially in India. The objective of the present study was to assess the incidence of the male reproductive anomalies leading to di...

Longevity and lifetime productivity are important factors influencing profitability for the cow-calf producer. Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning. Longevity data were collected on 2,195 heifers from producers in ...