Meeting Abstract
Developmental environment can have a strong influence on offspring phenotype. In oviparous species, incubation temperature is known to influence sex, physiology, and survival. In birds, incubation temperature varies daily and among nests; however, little is known about how fluctuating incubation temperatures influence offspring, particularly its long-term effects on fitness-related measures. Beak color is a secondary sex characteristic that indicates health status and influences successful mating for both male and female zebra finches (Taeniopygia guttata). We assessed whether periodic cooling during embryonic development 1) has a persistent effect on beak coloration into adulthood and 2) alters coping behavior, which was tested by a handling bag test. Embryos were incubated at one of the three temperatures: constantly low (36.4°C), periodic cooling (average 36.4°C), and control (37.4°C) temperatures. A year later, females underwent a handling bag test to measure activity levels and potential changes in beak color due to repeated handling and restraint. Birds in the periodic treatment had significantly darker and duller beak color compared to the controls, while no effect on hue or saturation was observed. Incubation temperature did not influence coping behavior, and repeated handling and restraint did not have any significant effects on any parameters of beak color. Since value (brightness) was not affected by treatments at 95 days post-hatch but was significant 300 days post-hatch, the periodic cooling treatment appears to have a latent effect on beak color after sexual maturity.
