Theses and Dissertations

Author

Eric S Michel

Issuing Body

Mississippi State University

Advisor

Demarais, Stephen

Committee Member

Strickland, Bronson K.

Committee Member

Wang, Guiming

Committee Member

Smith, Trent

Date of Degree

1-1-2016

Document Type

Dissertation - Open Access

Degree Name

Doctor of Philosophy

College

College of Forest Resources

Department

Department of Wildlife, Fisheries and Aquaculture

Abstract

Maternal factors have the potential to influence the morphometrics of offspring; however, the magnitude and persistence of those influences are not well known. I investigated the extent to which maternal factors influenced offspring phenotype at the individual and population level for captive white-tailed deer (Odocoileus virginianus) originating from three distinct physiographic regions of Mississippi, USA. First, I tested whether male white-tailed deer displayed improvements in weaponry and body size after two generations of being released from nutritional restrictions. I found that improved nutrition positively influenced all morphometrics; however, we observed variation in magnitude of improvement. Antler size was most responsive to improved nutrition while body mass and skeletal structures were less responsive; potentially indicating an adaptive strategy allowing males to increase yearly reproductive success without jeopardizing lifetime reproductive success. Second, we assessed whether maternal characteristics, early life characteristics or a combination of both persistently influenced morphometrics throughout maturity. I found that late birth date positively influenced offspring body mass through three-years of age; indicating that late-born fawns over-compensated for a late start to life. I also identified an indirect silver-spoon effect as early-, heavy-born fawns were heavy juveniles. In turn, heavy juveniles were also heavy adults. Therefore, male white-tailed deer may gain reproductive opportunities by displaying one of two strategies to increase body mass. Lastly, I estimated heritability for six antler characteristics and quantified the influence of maternal factors such as parturition date and litter size on the predictability of antler size. All antler characteristics were highly heritable. Yearling antler size was a moderate predictor of antler size later in life, but accounting for maternal factors greatly improved predictability. The influence of maternal factors decreased with increasing male age suggesting that compensation for the negative influence of maternal factors may occur after an individual’s first year of life. My results suggest that although antler characteristics are highly heritable, the large influence of maternal factors on predictability indicates that use of yearling antler size as selective harvest criteria may not achieve all management goals.

URI

https://hdl.handle.net/11668/18350

Comments

silver spoon effects||odocoileus virginianus||phenotypic plasticity||maternal effects||heritability||compensatory growth

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