The causes and consequences of individual variation in survival and fecundity of Great Lakes piping plovers (Charadrius melodus)

Abstract

The piping plover (Charadrius melodus) is a small shorebird endemic to North America and restricted to three breeding populations: Atlantic Coast, Great Plains, and Great Lakes. Listed as federally endangered in 1986, the Great Lakes population has numbered from 17 to 71 known breeding pairs. Despite recovery efforts, the population is far from the federal recovery goal of 150 breeding pairs. The purpose of my dissertation research is to understand the causes and consequences of individual variation in survival and fecundity during key breeding stages through four distinct methods of investigation: life-history theory, quantitative genetic analysis, population demography, and behavioral assessment. Effective conservation of small wildlife populations requires the intersection of many scientific disciplines and I seek to achieve this unification through the four chapters of my dissertation. First, I investigate how age and parental experience with breeding, a mate, and a nesting location influence reproductive success (Chapter 1). In chapter 2, I investigate the heritabilities of three fitness-related traits (chick body mass, natal dispersal distance, and female timing of breeding) to determine which are strongly environmentally-determined and thus susceptible to impacts of global climate change. In chapter 3, I tease apart the relative influences of various developmental and environmental factors at pre-fledging, post-fledging, and adult stages to more precisely inform population recovery actions. In my final chapter, I test the hypothesis that captive-reared chicks have lower survival rates than those reared in the wild because of a lack of threat recognition. The insights gained from my research not only pertain to this small shorebird breeding in the Great Lakes, but also provide a more comprehensive framework for analyzing data on marked individuals with the goal of shaping conservation actions for an entire population. Further, the new analytical methods applied to ecologically complex data will be important to any study that uses long-term marking. Avian populations are predicted to become more threatened in the future, so it is increasingly critical to understand factors driving vital rates and to develop approaches to alleviate threats to population persistence.