Undergraduate Honors Thesis

Abstract

• Many species of animals, particularly birds, provide parental care as offspring grow and develop. Bi-parental care, wherein both parents contribute to care, increases the quality of care while partially offsetting physical costs. Effective bi-parental care requires coordination between parents; therefore, it is expected that pairs with stronger bonds can coordinate care more successfully. While some research has been performed on the relationship between pair bonds and reproductive success, these studies typically rely on divorce as a measure of pair bond strength or experimental manipulation in captivity. Divorce, however, can be influenced by several factors beyond pair bond strength. Therefore, there is a need for methods of measuring pair bond strength that can be performed within a single breeding season for short-lived birds in the wild. In this study, I aim to determine whether pair bond strength is correlated with increased reproductive success using a novel form of determining pair bond strength on a wild population of rural barn swallows (Hirundo rustica erythrogaster). I measured pair bond strength as the amount of time pairs spent together during egg incubation. I sought to determine whether this measure of pair bond strength is correlated with 1) the number of days it takes for that pair to relay a replacement clutch, 2) the mean amount of time between nest visits near the end of the nestling stage, and 3) the number of successful fledglings produced by that pair. I found that pair bond strength as defined by time spent together during incubation has a significant effect on relaying timing, with pairs who relayed faster also spending more time together during incubation and stronger pair bonds. There was no effect on the mean time between nest visits or number of successful fledglings. These results indicate that there is potential evolutionary pressure on pair-bond behavior, particularly during the incubation period, and that time spent together during incubation is a practical, effective way of measuring pair bond strength for a short-lived songbird in the wild. Future research should be done to apply this new measure of pair bond strength across other systems to explore variation in pair bond strength and reproductive success.

Creator

• Murdoch, Grace

Date Awarded

• 2024-04-03

Academic Affiliation

• Ecology and Evolutionary Biology

Advisor

• Safran, Rebecca J

Committee Member

• Demmig-Adams, Barbara
• Renfrow, Stephanie
• Safran, Rebecca J
• Doak, Daniel F.

Granting Institution

• University of Colorado Boulder

Contributors

• Kenny-Duddela, Heather

Subject

• reproductive success
• barn swallows
• parental care
• Hirundo rustica
• Pair bond
• incubation
• relaying time
• songbirds
• parental coordination

Last Modified

• 2024-04-16

Resource Type

• Undergraduate Honors Thesis

Rights Statement

• In Copyright

Language

• English [eng]

Relationships

In Collection:

• Arts and Sciences Honors Program

Items

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	THE_EFFECTS_OF_PAIR_BOND_STRENGTH_ON_REPRODUCTIVE_SUCCESS_IN_NORTH_AMERICAN_BARN_SWALLOWS__HIRUNDO_RUSTICA_ERYTHROGASTER__BY_GRACE_MURDOCH.pdf	2024-04-16	Public	Download