| The Piping Plover (Charadrius melodus) is a rare shorebird currently restricted to three isolated nesting populations in the Great Lakes, Great Plains, and Atlantic Coast of North America; the Great Lakes population is federally endangered, numbering only 17 breeding pairs when listed in 1986. Once a population is already small, as most endangered populations are, random events such as severe weather or loss of genetic diversity caused by mating between closely related individuals can have a pronounced effect on population persistence. To reverse small population size, researchers must focus on determining the original and ongoing causes of population decline as well as developing an understanding of how small size influences existing population dynamics. In my dissertation, I assess the degree to which external factors have contributed to the currently small size of the Great Lakes population by identifying sources of mortality for adult Piping Plovers throughout the annual cycle (Chapters 1 & 2). In addition, I examine the influence of traits resulting from the small size of the Great Lakes population and may reinforce its imperiled status, including the degree of inbreeding depression (Chapter 3) as well as age-dependent survival and reproduction (Chapter 4). Finally, I assess the effectiveness of a conservation technique used to augment Great Lakes population size: the salvage and captive-rearing of abandoned eggs (Chapter 5). The questions posed in my dissertation are ones commonly asked by professionals responsible for the conservation of Piping Plovers. The answers to these questions are intellectually interesting, but far greater value comes from the fact that they are relevant to on-the-ground conservation efforts. Implementing informed conservation strategies will not only support population growth in the Great Lakes, but is also widely applicable to shorebird species throughout North America. |
