The influences of age (4 to 12 wk), sexual maturity status, and sex on hypothalamic-pituitary-adrenal (HPA) axis responsiveness were investigated by measuring changes in peripheral basal levels of corticosterone (B) and responses to 10 min of physical restraint in a crush cage or injection of 1-24 adrenocorticotropic hormone (ACTH) in 2 genotypes of Japanese quail divergently selected for long ...

Size and age estimates at sexual maturity were determined for 162 male and 273 female little skates Leucoraja erinacea collected from the western Gulf of Maine. Maturity ogives suggest that 50% maturity in females occurs at age 9.5 years and 480 mm total length (LT), whereas 50% maturity in males occurs at a slightly younger age of 7.7 years and smaller size of 460 mm LT. Age estimates were mad...

Single Comb White Leghorn pullets were used to determine the effects of 6-methoxy-2-benzoxazolinone (6-MBOA) and photoperiod on sexual maturity and egg production. Pullets were maintained on a constant 11L:13D photoperiod until 18 weeks of age and then were divided into two light-controlled chambers. Half the pullets in each chamber received a standard layer mash and the other half received the...

Previously recognized color and pattern variants of adult Cichla temensis in Amazon flood pulse river environments reflect the cycling of individuals through seasonal sexual maturity and spawning. Individuals also vary in shape from blocky to fusiform. To determine if shape differences are related to patterns of fat reserve deposition and utilization, and to quantify the relationship of shape w...

Determining the fitness consequences of sibling interactions is pivotal for understanding the evolution of family living, but studies investigating them across lifetime are lacking. We used a large demographic dataset on preindustrial humans from Finland to study the effect of elder siblings on key life-history traits. The presence of elder siblings improved the chances of younger siblings surv...

A newly developed Semantic Misattribution Procedure (SMP), a semantic variant of the Affect Misattribution Procedure (AMP), was used in three studies as an indirect measure of sexual interest. Using a known-group approach, homosexual men (Study 1 & 2), heterosexual men (Study 1 to 3) and heterosexual women (Study 3) were asked to guess the meaning of briefly presented Chinese ideographs as “sex...