Date of Completion


Degree Type

Honors Thesis - Campus Access


Biology (BIOL)

First Advisor

Heather Watts


Nest building is a critical component in reproduction for numerous avian species. In pine siskins (Spinus pinus) it has been observed that females are primarily responsible for nest construction. This study investigates nesting behavior in captive pine siskins in order to examine the relationship between nesting behavior and changes in reproductive physiology, as well as to evaluate a simple method for quantifying this behavior in captivity. Captive male and female pine siskins were paired and monitored as they came into breeding condition from March to July of 2012. Nest behavior was periodically tested by presenting nesting material to each pair and observing behavior via video recording for ten-minute intervals. The amount of time spent within one body length of the material as well number of strands that were picked up in the beak was then quantified. Intensity of nesting behavior (i.e. contact with the nesting material or time spent within one body length) was then compared to changes in reproductive physiology, including defeathering of the brood patch and increases in circulating levels of very low-density lipoprotein (VLDL), a yolk precursor that indicates follicular development. Results showed a significant relationship between nesting behavior and time of the breeding season as well with circulating levels of VLDL. This method shows promise for quantifying nesting behavior in captive pine siskins.