Report on captive hatches of California condors (Gymnogyps californianus): 1983–1990
Abstract 10.1002/zoo.1430100108.abs The California condor (Gymnogyps californianus) recovery plan entails increasing the reproductive rate via replacement-clutch manipulation and artificial incubation of eggs. During the period from 1983 to 1990, 37 eggs have been artificially incubated; 32 of these were known to be fertile and 28 hatched (fertility: 86.5%; hatchability: 87.5%).
Hormones and paternal behavior in vertebrates
This review examines the influence of hormonal stimulation on paternal care in selected species of fish, birds and mammals. Correlational studies of hormonal changes and the occurrence of paternal behavior as well as experimental studies are considered. Understanding the influence of hormones on paternal behavior is complicated by whether the species studied shows maternal, paternal […]
Influence of the rearing system on yolk corticosterone concentration in captive Greater Rheas (Rhea americana)
Many environmental conditions elevate plasma corticosterone in laying birds, leading to elevated hormone accumulation in the egg. We investigated whether maternal yolk corticosterone levels in Greater Rheas differ between fresh eggs collected from an intensive (IRS) and a semi-extensive (SRS) rearing system. After HPLC validation, yolk corticosterone was measured using a corticosterone 125I radio-immunoassay kit. […]