Many wild species exhibit seasonal cycles of testicular and adrenal functions suggesting important interrelationships between the two. However, data on desert rodents are very scarce. We investigated the pituitary adrenal (PA) axis activity of the Libyan jird from the Sahara desert, during the breeding and the non-breeding seasons. We explored, during the breeding season, the effects induced by...

This study reports the gender and seasonal specificity of hormonal, behavioral, and coloration responses displayed by "resident" male lizards (Sceloporus undulatus) exposed to male or female "intruders" during staged encounters in outdoor enclosures. Resident males were engaged in staged encounters with males or females for 1 h per day on 9 consecutive days during the breeding and postbreeding ...

In birds, parents adjust their feeding behaviour according to breeding duties, which ultimately may lead to seasonal adjustments in nutritional physiology and hematology over the breeding season. Although avian physiology has been widely investigated in captivity, few studies have integrated individual changes in feeding and physiological ecology throughout the breeding season in wild birds. To...

The house mouse has adapted well to the cereal crops of south-eastern Australia where populations show aperiodic outbreaks over large areas. A 20-year population study has provided a wealth of information on breeding ecology, demographic changes, spatial behaviour and epidemiology. The breeding season can be as short as 4.5 months and as long as 10 months with litter size changing seasonally fr...

In order to attribute the behaviour of an animal to its personality it is important to study whether certain behavioural traits show up consistently across a variety of contexts. The aim of this study was to investigate whether breeding state males of the two-spotted goby, Gobiusculus flavescens, showed consistent degree of boldness when tested in four different behaviour assays. We also wanted...

The habitat suitability index, which reflects spatial variability in species occurrence probability, has been shown to exhibit various contrasting relationships with local demographic performances (survival, productivity) in several species. One proposed explanation for these discrepancies is that the link between the habitat suitability index and demography is influenced by density-dependent, ...

We studied the reproductive ecology of the Ringed Warbling-Finch Poospiza torquata and the Cinnamon Warbling-Finch P. ornata during four breeding seasons in the Reserve of Ñacuñán, western Argentina. We described the breeding biology of both species, examined temporal variation in reproductive parameters under contrasting weather conditions, and compared reproductive traits of these sympatric P...

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...

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...