Undergraduate Honors Theses

Thesis Defended

Spring 2017

Document Type


Type of Thesis

Departmental Honors


Ecology and Evolutionary Biology

First Advisor

Dr. Rebecca J. Safran

Second Advisor

Dr. Pieter Johnson

Third Advisor

Dr. Sharon Kay Collinge


Avian incubation behavior involves a complex set of decisions to balance off-bouts of self-maintenance and on-bouts of egg temperature regulation. Nest ectoparasites may indirectly affect offspring fitness by directly altering the lengths and frequencies of parental on and off-bouts during incubation. Although parasites are known to impact parental care when nestlings are present, whether parental incubation behavior changes in response to nest ectoparasites is not well understood. To assess whether nest ectoparasites influence incubation behavior, I manipulated northern fowl mites (Ornithonyssus sylviarum) in barn swallow (Hirundo rustica erythrogaster) nests at the start of incubation. I compared disinfected and parasitized nests using model eggs with temperature data loggers to measure incubation rhythms and temperatures. The four main questions were 1) do parasites influence the duration of the incubation period 2) do parasites influence incubation rhythms 3) do parasites influence egg temperature and 4) does incubation behavior change across the incubation period. All variables of interest exhibited high variation across all three phases of incubation regardless of clutch size or treatment, indicating incubation is a highly flexible parental behavior. These results suggest parasites do not directly affect incubation behavior, however clutch size increases time on nest during the early stages of incubation. This suggests incubation is a dynamic behavior possibly constrained by parental fitness and other environmental factors, rather than nest ectoparasite intensity. Although ectoparasites are known to influence barn swallow territory choice and nestling provisioning, my results demonstrate that the presence of this ectoparasite does not influence incubation behavior.