Meeting Abstract

9.2  Sunday, Jan. 4  Slight changes in incubation temperature affect early growth and stress endocrinology in wood duck (Aix sponsa) ducklings DURANT, Sarah E*; HEPP, Gary R; MOORE, Ignacio T; HOPKINS, Brittney C; HOPKINS, William A; Virginia Tech, Blacksburg; Auburn Univ, Auburn; Virginia Tech, Blacksburg; Virginia Tech, Blacksburg; Virginia Tech, Blacksburg sdurant@vt.edu

Although the effects of incubation temperature on phenotype of avian hatchlings are poorly understood, recent research suggests that subtle changes in incubation conditions can influence hatchling characteristics including body size and condition. We explored the effects of incubation temperature on hatching success, survival to 9-d post hatch, growth, and the hypothalamo-pituitary-adrenal (HPA) axis in wood duck (Aix sponsa) ducklings. Wild wood duck eggs were experimentally incubated at temperatures that encompass the range of temperatures of naturally-incubated wood duck nests (35.0, 35.9, and 37.0C). Survival and growth were monitored in ducklings fed ad lib for 9-d post hatch. In addition, baseline and stress-induced plasma corticosterone concentrations were measured in 2- and 9-d old wood ducklings. Hatching success and post hatch survival was greatest in ducks incubated at the intermediate temperature. Ducklings incubated at both 35.9 and 37.0C had 43% higher growth rates than ducklings incubated at 35.0C. In addition, ducklings incubated at the lowest temperature had higher baseline (17-50%) and stress-induced (32-84%) corticosterone concentrations than ducklings incubated at 35.9 and 37.0C at 2- and 9-d post hatch. We also found a significant negative correlation between body size and plasma corticosterone concentrations (baseline and stress-induced) in 9-d old ducklings. To our knowledge, this is the first study to demonstrate that thermal conditions during embryonic development can influence the HPA axis of young birds. Our results demonstrate that subtle changes (<1.0C) in the incubation environment can have important consequences for physiological traits important to fitness.