Commercial fisheries may impact marine ecosystems and affect populations of predators like seabirds. In the Southern Ocean, there is an extensive fishery for Antarctic krill Euphausia superba that is projected to increase further. Comparing distribution and prey selection of fishing operations versus predators is needed to predict fishery-related impacts on krill-dependent predators. In this co...

In many seabird studies, single annual proxies of prey abundance have been used to explain variability in breeding performance, but much more important is probably the timing of prey availability relative to the breeding season when energy demand is at a maximum. Until now, intraseasonal variation in prey availability has been difficult to quantify in seabirds. Using a state-of-the-art ocean dr...

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...

During the breeding season, male green anoles (Anolis carolinensis) court females by extending a red throat fan called a dewlap. Motoneurons controlling this sexually dimorphic behavior are located in two portions of the brain stem: (a) the vagal portion of nucleus ambiguus (AmbX), and (b) the region containing the glossopharyngeal portion of nucleus ambiguus and the ventral motor nucleus of th...

We analyzed carbon isotope ratios (delta13C) of liver and pectoral muscle of Black-throated Blue Warblers (Dendroica caerulescens) to provide a mesoscale perspective on altitudinal tenancy in the Appalachian Mountains, North Carolina, U.S.A. Movements of males are poorly understood, particularly the degree to which yearlings (first breeding season) and older males (second or later breeding seas...

The population of great hornbills (Buceros bicornis) in the United States is rapidly aging, and captive breeding efforts have not met population managers’ expectations for a sustainable captive group. Little is known about the reproductive physiology of these birds. This study reports the first data on the reproductive endocrinology of the great hornbill. The hormone profiles of the only pair o...

In this study, 272 beef heifers were studied from just before their first breeding season (October 15, 2003), through their second breeding season, and until just after they had weaned their first calves in March, 2005. This study was performed concurrently with another study testing the economic effects of an estrous synchronization protocol using PG. Reproductive tract scoring (RTS) by rectal...

Animals restrict breeding to specific times of the year when reproductive success is most likely. In males, the most reliable method of reproductive inhibition is gonadal retrogression to an immature state. Depending on the species, the testes decrease in size by between 10 and 95% in response to environmental cues associated with the non-breeding season. An increased rate of apoptosis can occu...

Thewhite-lipped peccaryTayassu pecari is a social ungulate that forms the largest groups documented for any tropical forest ungulate species. Since the 1950s the species has become increasingly rare in Mesoamerica, and the more frequent reporting of smaller groups may be related to increased hunting pressure. Here we address the conservation status of this species in terms of its group size and...