Seasonally-breeding animals use the photoperiod as a blunt cue that the breeding season is approaching. Other cues in the environment that predict the emergence of breeding resources allow animals to fine-tune their season to maximize success. It’s already known that supplementary environmental cues (cues other than photoperiod) can affect how the breeding season progresses in birds. Using female European starlings, I tested whether supplementary cues would alter sexually-motivated behaviors that proceed breeding and brain regions that control these behaviors.
I manipulated female starling access to nesting cavities (which are required for breeding in this species) and the presence of spring-like cues in outdoor aviaries. Birds either were given standard lab housing, standard lab housing plus a nest cavity, or a semi-natural environment (pictured right) complete with ivy, flowering plants, nest cavities, flowing water, and preferred food items (such as insects and berries). We tested the effects of this manipulation on mRNA expression in the medial preoptic area, ventromedial nucleus of the hypothalamus and the ventral tegmental area — currently, I’m working on writing to communicate what we found (to be continued).