NSF Award
1407040
Higher temperatures associated with climate change can cause changes in marine food webs, resulting in a diminished food supply for top consumers. In response, these consumer species must change strategies and behaviors in order to adapt. One change that has been observed in numerous species is an increase in cannibalism. Another is the timing of reproductive activities. Such changes can in turn lead to a cascade of changes throughout an ecosystem, affecting survival of individual species and the well-being of the entire system. El Niño events mimic some features of long-term climate change on short time scales, allowing for tests of some climate-related hypotheses in marine systems. This project will examine the impact of climate-change-related food shortages on organisms both theoretically, using mathematical models, and empirically, at a large colony of seabirds that function as an important indicator species. The work will provide cross-disciplinary training in mathematical biology for undergraduate, masters, and Ph.D. students. The project emphasizes training undergraduates and members from underrepresented groups. Undergraduate students will be involved at every stage of the research process, from data collection and analysis to joint authorship of peer-reviewed publications. The investigators engage the general public and wildlife managers through public lectures and interviews, and by working with biologists and managers from the U.S. Fish and Wildlife Service. The results of this work have important implications for the management of natural populations responding to climate change.<br/><br/>In previous work the investigators demonstrated (1) a strong positive association between rising sea surface temperatures (SSTs) and increased egg cannibalism in glaucous-winged gulls (Larus glaucescens), which are important indicators of marine environmental quality; and (2) the existence of every-other-day ovulation synchrony in glaucous-winged gulls, with the degree of synchronization proportional to colony density. Proof-of-concept mathematical models suggest that the two traits may be co-adaptive, and that, in general, rising SSTs may initiate a cascade of changes in life history strategies in colonial seabirds. The objectives of this study are to (1) develop and analyze general mathematical models for exploring the interaction of SSTs, reduced environmental food availability, cannibalism, and reproductive synchrony in terms of population and adaptive dynamic responses to changes in food availability; (2) field test, in a specific system, predictions associated with two general hypotheses suggested by the mathematical models, namely, that cannibalism is an adaptive response to decreased food supply, which can be a consequence of increased SST, and that reproductive synchrony is an adaptive response to cannibalism; and (3) train undergraduate, master's, and Ph.D. students in interdisciplinary STEM research involving mathematical modeling and field research, intentionally emphasizing the training of underrepresented groups.
