Date of Award

Fall 12-1-2015

Degree Type

Masters Thesis

Degree Name

Master of Science (MS)


Biological Sciences

Committee Chair

Frank Moore

Committee Chair Department

Biological Sciences

Committee Member 2

Jodie Jawor

Committee Member 2 Department

Biological Sciences

Committee Member 3

David Echevarria

Committee Member 3 Department



This thesis examines the use of defensive strategies in relation to territories year round in the northern cardinal (Cardinalis cardinalis). Responses to recorded neighbor song and stranger song playback from the middle of a focal male’s territory were measured. This allowed for an estimation of aggression in both the winter and spring seasons. Each focal male was subjected to both treatments (stranger song and neighbor song). Males were more responsive over-all to neighbor song playback, however in the winter months, persistence of response to neighbor song playback increased. It was also shown that southeastern United States cardinals show year-round territory occupancy and more importantly the tendency to defend that territory during the entire year. Blood collected from a small number of birds during a neighbor STI trial shows that circulating testosterone does not significantly change from baselines or birds being challenged with a strange song playback.