Publication Date

2008-07-28

Availability

Open access

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Biology (Arts and Sciences)

Date of Defense

2008-04-25

First Committee Member

Michael Gaines - Committee Member

Second Committee Member

William Searcy - Committee Member

Third Committee Member

Theodore H. Fleming - Mentor

Fourth Committee Member

Gerald Wilkinson - Outside Committee Member

Abstract

The buffy flower bat (Erophylla sezekorni) is a neotropical leaf-nosed bat (Phyllostomidae) that is endemic to the Greater Antilles. Although this species is one of the most common and abundant species of mammals in the West Indies, very little is known about its ecology and evolution. To address this deficiency, I studied the genetic structure and mating system of the buffy flower bat on several islands throughout its range, focusing a more intensive study on the island of Exuma, Bahamas. I first studied the effects of ocean barriers on genetic diversification within Erophylla and two related endemic genera of endemic West Indian bats, Brachphylla, Phyllonycteris (Chapter II). I found evidence that ocean barriers inhibit gene flow and promote speciation within these genera. Focusing on genus Erophylla (Chapter III), I found that ocean channels usually act as barriers to gene flow among island populations within species. However, relatively shallow and narrow ocean channels formed semi-permeable barriers allowing gene flow between some island populations. Within the buffy flower bat, Erophylla sezekorni (Chapter IV), genetic diversity of mitochondrial DNA fragments was positively correlated with island size, with small islands having reduced genetic diversity. However, genetic diversity at several nuclear microsatellite loci was not correlated with island area and levels of genetic diversity were high for most island populations. In addition, island populations within the Great Bahamas Bank and Little Bahamas Bank showed high levels of gene flow between islands and showed no evidence of genetic bottlenecks. Populations of E. sezekorni on Exuma (Chapters IV and V) exhibited a polygynous mating system that included vigorous visual, acoustic, and olfactory male display behaviors. However, the social structure that I observed had a negligible effect on genetic diversity and genetic structure within these populations. Overall, the buffy flower bat exhibits very few of the genetic symptoms of island life, such as reduced genetic diversity and increased genetic isolation, and is evolutionarily adapted to persist on small oceanic islands.

Keywords

West Indies; Island Biogeography; Glossophaginae; Chiroptera; Caribbean

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