Parental Investment and Male Ornamentation in the Eastern Bluebird (Sialis Sialis)

Bright plumage coloration in most birds is thought to be a product of sexual selection. Brighter, more-ornamented males are preferred by females because their plumage conveys information regarding the quality of the individual. One measure of male quality is willingness to invest in offspring. In birds, investment is usually measured as the rate at which nestlings are provisioned. However there are other forms of parental investment. The purpose of this study is to quantify the relationship between two measures of parental investment and their association with structural plumage coloration in male Eastern Bluebirds (Sialia sialis). I found there was no correlation between nestling provisioning and nest defense for males or females. Males with brighter UVblue plumage tend to provision nestlings at higher rates and more-ornamented males tend to defend the nest from a predator at lower rates. This study suggests that structural coloration is an indicator of the ability of a male to invest in its young. However, because nestling provisioning and nest defense (the two main male parental investments) were not correlated, I suggest that nestling provisioning and nest defense are not equivalent measures of parental investment, and condition-dependent traits have different relationships to different measures of parental investment.

Name thesis:degree_name

Master of Science in Biology (M.S.)

Level thesis:degree_level

Thesis (open access)

Discipline thesis:degree_discipline

Department of Biology

Year dc:date.available

2006

Author dc:creator

• Wetzel, Daniel Paul

Contributors dc:contributor

• Steve Vives
• Daniel Gleason

• ETD
• Parental investment
• Sexual selection
• Structural coloration
• Nest defense
• Eastern Bluebird
• Sialia sialis 2
• Birds

Repository record dc:identifier

https://digitalcommons.georgiasouthern.edu/etd/711

OAI identifier oai:identifier

oai:digitalcommons.georgiasouthern.edu:etd-1711