Full metadata
Title
Avian retinal carotenoid accumulation: ecophysiological constraints and behavioral consequences
Description
The elaborate signals of animals are often costly to produce and maintain, thus communicating reliable information about the quality of an individual to potential mates or competitors. The properties of the sensory systems that receive signals can drive the evolution of these signals and shape their form and function. However, relatively little is known about the ecological and physiological constraints that may influence the development and maintenance of sensory systems. In the house finch (Carpodacus mexicanus) and many other bird species, carotenoid pigments are used to create colorful sexually selected displays, and their expression is limited by health and dietary access to carotenoids. Carotenoids also accumulate in the avian retina, protecting it from photodamage and tuning color vision. Analogous to plumage carotenoid accumulation, I hypothesized that avian vision is subject to environmental and physiological constraints imposed by the acquisition and allocation of carotenoids. To test this hypothesis, I carried out a series of field and captive studies of the house finch to assess natural variation in and correlates of retinal carotenoid accumulation and to experimentally investigate the effects of dietary carotenoid availability, immune activation, and light exposure on retinal carotenoid accumulation. Moreover, through dietary manipulations of retinal carotenoid accumulation, I tested the impacts of carotenoid accumulation on visually mediated foraging and mate choice behaviors. My results indicate that avian retinal carotenoid accumulation is variable and significantly influenced by dietary carotenoid availability and immune system activity. Behavioral studies suggest that retinal carotenoid accumulation influences visual foraging performance and mediates a trade-off between color discrimination and photoreceptor sensitivity under dim-light conditions. Retinal accumulation did not influence female choice for male carotenoid-based coloration, indicating that a direct link between retinal accumulation and sexual selection for coloration is unlikely. However, retinal carotenoid accumulation in males was positively correlated with their plumage coloration. Thus, carotenoid-mediated visual health and performance or may be part of the information encoded in sexually selected coloration.
Date Created
2011
Contributors
- Toomey, Matthew (Author)
- McGraw, Kevin J. (Thesis advisor)
- Deviche, Pierre (Committee member)
- Smith, Brian (Committee member)
- Rutowski, Ronald (Committee member)
- Verrelli, Brian (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
xxxi, 215 p. : ill. (some col.)
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.9326
Statement of Responsibility
by Matthew Toomey
Description Source
Retrieved on Oct. 10, 2012
Level of coding
full
Note
thesis
Partial requirement for: Ph.D., Arizona State University, 2011
bibliography
Includes bibliographical references
Field of study: Biology
System Created
- 2011-08-12 04:54:18
System Modified
- 2021-08-30 01:52:00
- 3 years 2 months ago
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