Date of Submission
Open Access Senior Thesis
Bachelor of Arts
© 2022 Madeline Galbraith
Long-distance animal migration plays a large role in the spread of infectious disease, potentially causing an increase or a decrease in infection. These outcomes can be serious, as infection has the ability to induce a variety of effects on the host, all which may impact their overall health. The consequences of infection on a host can be measured using body condition. Changes to an individual’s body condition are central to the mechanisms involved in migration’s ability to both increase (ex: susceptibility) and decrease infection (ex: migratory culling). Therefore, when assessing potential migratory effects, it is important to consider relationships between infection and body condition. To determine migration’s role in infection-body condition dynamics, we studied measures of coccidia infection and body condition in a migratory species, White-crowned Sparrows (WCSPs), and controlled for migration using a non-migratory species, CA Towhees. Data was collected in Claremont, CA twice per year for each species, once after WCSP migration in the fall and once before their migration in the spring. We analyzed two data sets, one with both condition and parasite data, and one much larger data set that lacked infection data. Overall, we found significant differences in body condition across species, but only in the subset of individuals with infection data did we see significant seasonal variations and a significant interaction effect of season and species on body condition. Additionally, infection status significantly differed across species, and infected birds were found to be in greater condition than those uninfected. Future research needs to address any potential biases found in the data set with infection data, in addition to increasing sample sizes, to truly understand migration’s role in the relationships between infection and body condition.
Galbraith, Madeline, "The Relationship Between Parasite Infection, Body Condition, and Migration in White-Crowned Sparrows and California Towhees" (2023). CMC Senior Theses. 3107.