Pastoralists on the Tibetan alpine rangeland suffered great economic loss in cold season, due to serious live-weight loss of domestic livestock under traditional grazing management. This study aimed to evaluate the effect of dietary types (crude protein levels) on feed intakes, growth performance and economic returns of local Tibetan sheep and yaks during cold season. Twenty-four yearling Tibet...

Reproductive failure is a major source of economic loss in the beef industry. The majority of this loss occurs because cows do not become pregnant during a defined breeding season. Therefore, the goal of any breeding program is to maximize the number of females that become pregnant. This means that fertility plays a major role in the success of any breeding program. This review will focus on th...

Outbreaks of avian influenza in North American poultry have been linked to wild waterfowl. A first step towards understanding where and when avian influenza viruses might emerge from North American waterfowl is to identify environmental and demographic determinants of infection in their populations. Laboratory studies indicate water temperature as one determinant of environmental viral persiste...

—Studies on breeding biology in Neotropical birds are crucial for understanding different aspects of their life histories and also for their conservation. We describe the nesting biology of the Red-crested Cardinal (Paroaria coronata) in central Argentina, a common suboscine that inhabits south temperate forests. We monitored 367 nests from October to February 2005–2008. Nest initiation followe...

The occurrence of antibody of myxoma virus in wild rabbits following epizootics is highest in the semi-arid north-west of Victoria and lowest in temperate southern Victoria. Occurrence ranges up to about 90% in the north-west and to about 70% in the south except on the Western Plains where epizootics are rare and antibody occurrence seldom exceeds 30%. The establishment of the European rabbit f...

The social organisation of a population of Microtus agrestis was studied by trapping and radiotracking in southern England. There was no significant variation in male home-range size during the breeding season or between years but there was significant variation in core areas between years but not during the breeding season. There was no significant relationship with male density and core area ...

Understanding latitudinal variation in avian life-history traits has been a focus of many demographic studies around the world. However, we still know little about annual or intra-annual demographic variation within tropical regions or about how factors such as breeding season and precipitation influence demographic rates. In this study, we estimated intra-annual apparent survival of the White-...

Seasonal changes in ovulatory activity, assessed by the measurement of plasma progesterone and plasma prolactin concentrations were monitored in 10 Spanish ibex females captured in the National Wildlife Reserve of Sierra Nevada (South Spain, 37 degrees N). Five of the 10 female ibex showed ovulatory activity with a mean (+/- s.e.m.) duration of the oestrous cycle of 19.4 +/- 1 days (range: 17-2...

Despite the fact that migration occurs in a wide variety of taxa worldwide, little is known about the conditions under which migration is expected to evolve from an ancestral resident population. We develop a model that focuses on ecological factors affecting the evolution of migration in a seasonal environment within a genetically explicit framework. We model the evolution of migration for two...

Production records from 291 Boer-Spanish and Spanish does, collected between 1994 and 2004 in the Edwards Plateau region of West Texas, were examined to compare Boer-Spanish and Spanish does for body weights, fertility, prolificacy, and number of kids weaned. Traits were analyzed using single-trait mixed models. Boer-Spanish does were heavier at birth than Spanish does (2.79 vs. 2.67 kg, P = 0....