A wide range of environmental and physiological factors influence the type and extent of sexual dimorphism found in animals. Influential factors include variable climate, competition for resources and mates, mate choice, and parental investment. In addition, some investigators attribute differences in body size to physiological factors influenced by genetic and...
Pheromones are chemical cues produced by organisms that affect the behavior and/or physiology of conspecifics. The orchestration of reproductive behaviors in many animals depends on the expression of sex pheromones. In insects, intraspecific variation in sex pheromone expression is commonly observed and often influences social interactions between individuals. To what...
Animals respond to stressful situations with increases in plasma levels of
glucocorticoid stress hormones. These hormones originate from the adrenal cortex
in response to stimulation of the hypothalamic-pituitary-adrenal axis.
Glucocorticoids (corticosterone in reptiles) function to mobilize energy and
suppress unnecessary functions until the stress passes. Among these immediately
unnecessary functions...