INCREASED MALE SEXUAL DISPLAYS CORRELATES WITH VENTRAL POSTERIOR AMYGDALA VOLUME AND CELL VOLUME IN WILD-CAUGHT SIDE-BLOTCHED LIZARDS UTA STANBURIANA
Yu, Hei Yan
Area of Honors:
Bachelor of Science
Lara D La Dage, Thesis Supervisor Dr. Laura Rotunno, Honors Advisor
lizard ventral posterior amygdala sexual behavior predation pressure
Variation in sexual display rate can induce variation in the ventral posterior amygdala (VPA), an area of the brain involved in reproductive behaviors. Specifically, increased sexual displays in the breeding season is correlated with increased VPA attributes. Previous research has demonstrated that higher rates of sexual displays are associated with a larger VPA volume and neuron soma size. However, it remains unclear if individuals residing in different populations reflect results found within the laboratory, as there are likely many more selective pressures in the field with which to contend. Thus, in the current study, we examined variation in VPA attributes of wild-caught side-blotched lizards (Uta stansburiana) from two different states, Oregon and Nevada. In the Nevada population, males have lower display rates than that found in the Oregon population, likely due to increased predation pressures in the Nevada population. Mirroring this, we found that the Nevada population exhibited decreased VPA volume and VPA cell volume suggesting that decreased display rates in the face of predation is associated with downregulated VPA attributes in the field.