Effects of Maternal Stress on Performance Behavior of Lizard Offspring

Open Access
Author:
Heppner, Jennifer Joan
Area of Honors:
Wildlife and Fisheries Science
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Tracy Lee Langkilde, Thesis Supervisor
  • Margaret C Brittingham, Honors Advisor
Keywords:
  • maternal stress effects
  • maternally-derived stress
  • prenatal stress
  • phenotypic plasticity
  • developmental plasticity
  • glucocorticoids
  • corticosterone
  • stress hormones
  • offspring
  • eastern fence lizard
  • Sceloporus undulatus
  • performance behavior
  • fitness-relevant traits
  • locomotion
  • sprint speed
  • righting ability
Abstract:
Optimal functioning of the hypothalamic-pituitary-adrenal (HPA) axis, and resulting production of glucocorticoids (GCs), can significantly impact how individuals cope with environmental challenges. Elevation in maternal GCs, including corticosterone (CORT), impact offspring phenotype, performance, and fitness. While many of these programed developmental changes in offspring phenotype have been perceived as negative, it is hypothesized that these maternal GCs may be plastically enacting an adaptive response in offspring phenotype that can increase fitness. However, little is known of how this maternally-derived stress (MDS) adaptively effects offspring phenotype and prepares offspring to better survive in their post-natal environments. In order to investigate the adaptive potential of maternal stress, we first must quantify effects on fitness-relevant traits. I tested the hypothesis that maternal stress will alter fitness-relevant behavior of offspring expressed early in life. I manipulated CORT of gravid female Eastern Fence Lizards (Sceloporus undulatus) by dosing them daily with ecologically-relevant concentrations of CORT, to mimic those resulting from attack by fire ants (Solenopsis invicta). I measured righting ability and sprint speed of the resulting offspring soon after hatching and found no effect of maternal CORT on these performance behaviors. In contrast to previous results of elevated maternal CORT having outcomes on offspring, our results do not show an effect of maternal GCs on offspring phenotype. Future studies should examine the plastic potential of maternal CORT on other offspring phenotypes to discover the full effects of maternal stress on offspring fitness.