Date of Award

3-15-2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

School of Biological Sciences

First Advisor

Scott K Sakaluk

Second Advisor

Charles F Thompson

Abstract

In recent years, temperatures have increased globally, and by different amounts locally. As local climates change and temperatures increase, nestlings from a variety of bird species are exposed to the threat of increased oxidative stress, producing adverse effects on growth and survival of offspring. One defence against oxidative stress is to increase the dietary intake of antioxidants. I tested the hypothesis that experimental heating of house wren nests during the incubation period leads to increased oxidative stress in offspring. I predicted that experimental heating of nests would lead to decreased growth and survival of young, but that these negative effects would be ameliorated by dietary supplements of the anti-oxidant vitamin E, found naturally in the invertebrate prey with which parents provision their young. I employed a split-brood design in which I experimentally manipulated nest temperature of entire broods, while simultaneously providing dietary supplements of vitamin E to half of the nestlings within broods. To control for the possibility that experimental heating of nests might also influence maternal incubation behavior, thereby potentially confounding any treatment effects, I also recorded female incubation effort. There was a significant interaction between nestbox heating treatment and vitamin E treatment in their effect on nestling mass, a trait that is positively correlated with survival and future reproductive success. Vitamin E supplementation promoted increased nestling mass in heated nests, whereas it had the opposite effect in control nests, but these effects were weak. Heating significantly affected female incubation behaviour, with females in heated nestboxes investing less in incubation than those in unheated boxes. These results suggest that within specific limits, effects of climate change on nestling development in cavity-nesting birds can be mitigated by adjustments in female incubation behaviour.

Comments

Imported from Farchmin_ilstu_0092N_12131.pdf

DOI

https://doi.org/10.30707/ETD2022.20220705065050752613.999998

Page Count

50

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