Two experiments, one examining oestrus and ovarian activity in 5 genotypes of young ewes exposed continuously to teaser rams and the other examining the onset of the breeding season in 4 separate strains of young Merino ewes, were carried out at Hamilton. In each experiment there were genetic differences in the duration of the non-breeding season. In experiment 1, Merinos and Comebacks had a sh...

With the goal of characterizing the type and degree of injuries and blemishes incurred by horses living under natural social conditions, all members of a semi-feral herd of ponies were inspected on 4 occasions over a period of 28 months. Two occasions were during breeding/foaling season and 2 during non–breeding/foaling season months. On each occasion, each animal was examined (N = 47–65) and a...

The nature of seasonal breeding in both domestic and wild mammals has been known for centuries but only recently have we gained some insight into the mechanisms involved. Environment, encompassing climatic, nutritional, and biotic factors, plays a major role in synchronizing reproductive rhythms. Examples of the effect of environmental factors upon reproductive activity are discussed within the...

—We developed and tested a 10-min call-broadcast survey protocol using conspecific vocalizations to assess Peregrine Falcon (Falco peregrinus) territory occupancy in the Mojave Desert of southern Nevada and northwestern Arizona from 2008–10. Response rate of peregrines, when adults were confirmed present immediately prior to broadcasting, averaged 83% during the breeding season and peaked at 10...

Overabundant white-tailed deer (Odocoileus virginianus) pose risks to property, health, and safety of human beings. Public concerns about lethal management can impair efforts to address these issues, particularly in urban settings. Several techniques developed for reducing reproductive output of deer have limited utility because they require repeated dosing to achieve permanent effect and face ...

It is known that breeding success in birds declines with an advance in the laying date. In this paper, breeding success diminished with laying date in a house sparrow (Passer domesticus) population breeding in captivity. The principal cause of the cline in breeding success with date was a decrease in the female feeding rate. The parental effort in females decreased with the advance of the layin...

Arabian babblers (Turdoides squamiceps; mean adult body mass=72.5 g) inhabit extreme deserts of Israel. Previous studies have shown that their daily field metabolic rates are similar in winter and summer and that there is an increase during the breeding season. We hypothesized that the difference in seasonal daily field metabolic rate would be a consequence of differences in daytime metabolic r...

no published information are available on the reproductive indices of local abadeh does reared innorthern fars province, southern iran. this study was conducted to determine the duration of the breedingseason, and the length and duration of the oestrous cycle. twenty single parity 2-year-old does from abadeh(weighing 19–26 kg) were purchased and transferred to the school of veterinary medicine ...

Achieving a consistently successful A.I.-breeding program in a cow-calf operation requires attention to those heifers and cows not having normal estrous cycles (cycling) at the beginning of the breeding season. Because so many factors contribute to whether breeding females are cycling, including weather patterns, nutrition (availability of native forages or stored feeds), age or days since calv...

1. While the reasons for group-living have been studied for decades, little is known about why individuals become solitary. 2. Several previous experimental studies could demonstrate that group-living can arises as a consequence of ecological constraints. 3. It has been argued that reproductive competition between group members leads to significant costs of group-living, being a main reason of ...