NSF Postdoctoral Fellowship in Biology: Importance of monsoon rains for songbird migration and stopover refueling in the American desert southwest

Griego, Michael, Bernalillo NM

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Each fall, billions of migratory birds cross through the Sonoran, Mojave, and Chihuahuan deserts during their southward migration to their wintering grounds in Mexico and Central America. These habitats are drastically different from their summer breeding grounds in temperate northern latitudes of Canada and Alaska. The heat and aridity presents new challenges to birds as they stop to refuel in the desert southwest prior to continuing their journey south. The Fellow will investigate how seasonal monsoon rains in the desert southwest can assist songbirds passing through the region each fall. The annual monsoons have the potential to provide birds with cooler temperatures, greater availability of surface water, and an abundance of insects and seeds for food. These resources are critical for refueling migratory birds as they prepare to fly nonstop over thousands of kilometers of arid lands prior to reaching central and southern Mexico. The best current climate change models for the desert southwest all indicate that total monsoon rainfall will be reduced, and the timing of the storms will become more erratic over the coming century. Understanding precisely how wildlife currently utilize monsoon resources is essential to predict how these changing weather systems can impact species in the future. Additionally, this award will support the Fellow in developing a broadly accessible training workshop directed at diverse applicants wishing to pursue academic postdoctoral fellowships which will be presented at the National Diversity in STEM conference. The central goal of this research is to determine if monsoon weather events assist songbird recovery at stopover sites in the Chihuahuan desert. The Fellow will quantify the contributions that periodic monsoon rains have endogenous water reserves of migrants and determine if whole-animal performance is constrained by water balance in songbirds at arid land stopover sites. Quantifying the contribution of monsoon rainfall to animals’ water reserves depends on being able to measure a nuanced exchange of oxygen neutrons in a complex biogeochemical system. The research will use an isotopic assay which allows for the reliable detection of the monsoon rain pulse in the tissues of animals. This method will be a revolutionary tool for ecologists, and the Fellow will be one of the first to apply this technique in the field. Additionally, the Fellow will measure whole-animal metabolic performance using standard respirometry, and refueling performance by analyzing plasma metabolites using minimally invasive techniques on free-living birds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.