Duck nesting success was studied on South Dakota Game Production Areas in 1985 and 1986. Mayfield success rates for all species combined were 28.0 and 28.4 percent, respectively. Predators were responsible for nearly 90 percent of nest failures. Results from lake Albert Island and Hogsback served to demonstrate potential for intensive management to increase duck nesting success.

SANDERCOCK, B.K., and PEDERSEN, H.C. 1994. The effect of renesting ability and nesting attempt on egg-size variation in willow ptarmigan. Can. J. Zool . 72: 2252 2255. Interclutch variation in the size of free-living willow ptarmigan (Lagopus lagopus alexandrae) eggs was examined at Chilkat Pass, British Columbia. Egg volume (19.9 f 0.1 cm3; mean f 1 SE) fell within the range reported for other...

Species that occupy the same area and use the same resources must either compete with each other or find ways to minimize competition. For rodents, 1 important resource is nesting sites. In this study I present data from direct behavioral observations in the succulent karoo of South Africa that show aggressive interactions between bush karoo rats (Otomys unisulcatus) and striped mice (Rhabdomys...

Grande Riviere Beach in Trinidad and Tobago is an important nesting site in the Caribbean for the Critically Endangered leatherback sea turtle, Dermochelys coriacea. Community members were concerned that beach erosion and seasonal river flooding were destroying many of the nests deposited annually and thought that a hatchery was a possible solution. Over the 2001 turtle nesting season, the Inst...

In socially unstable groups of male laboratory mice, individuals may experience a chronic stress situation. Previous experiments have shown that the transfer of specific olfactory cues during cage cleaning, and the provision of nesting material decrease aggression and stress in group-housed male mice. In this study, the combined effect of these husbandry procedures were tested for their long-te...

—Habitat loss and pollution have been linked to declines of numerous freshwater turtle species, which are among the most endangered vertebrates in the world. We examined characteristics of nest sites of Common Snapping Turtles (Chelydra serpentina) located in a system modified by agricultural and industrial land use. We compared characteristics of 150 turtle nests and patterns of nest depredati...

Under temperature-dependent sex determination (TSD), temperatures experienced by embryos during development determine the sex of the offspring. Consequently, populations of organisms with TSD have the potential to be strongly impacted by climatic warming that could bias offspring sex ratio, a fundamental demographic parameter involved in population dynamics. Moreover, many taxa with TSD are imp...

Species that display temperature-dependent sex determination are at risk as a result of increasing global temperatures. For marine turtles, high incubation temperatures can skew sex ratios towards females. There are concerns that temperature increases may result in highly female-biased offspring sex ratios, which would drive a future sex ratio skew. Studying the sex ratios of adults in the ocea...