Chad Wilhite
Graduate student
Department of Natural Resources and Environmental Management
University of Hawaii at Manoa.
Email: cwilhite (at) hawaii.edu
Effective conservation of Earth’s ecosystems stems from an understanding of individual parts and their connections within the system. I am interested in describing and understanding how these parts, individuals and species, interact with each other and their habitat in the context of species conservation.
My work represents a diverse background exploring spatial ecology and species conservation in various systems. I have spent time working in sytems ranging from Eastern Box Turtles in a New York pine barrens system to North American Porcupines in a California coastal dune system. As an avid birder I am particularly interested in the application of this research to avian conservation.
Working under the guidance of Dr. Price I will have the opportunity to further my career studying the spatial ecology and conservation of avifauna by exploring habitat use and breeding biology of Pueo, or Hawaiian Short-eared Owls (Asio flammeus sandwichensis). After earning a B.S. in Wildlife Management with a minor in Applied Statistics from Humboldt State University I am looking forward to pursuing my studies further in Hawaii.
Thesis Research
Species may exhibit different spatial ecological strategies throughout their distribution as a mechanism to persist in spatially heterogeneous environments. Thus, studies of spatial ecology should incorporate movement data from across a species’ distribution. Short-eared owls (Asio flammeus) are a globally distributed, and declining, species inhabiting continental and island systems spanning polar and tropical climates. In the first chapter of my thesis I aim to describe global movement patterns of short-eared owls and to infer potential conservation implications. I reviewed 20 publications and will utilize citizen science collected data from the global birding platform, eBird, to analyze and characterize annual migration patterns. I expect short-eared owls exhibit a spectrum of annual movement patterns ranging from extremely vagrant and migratory to non-migratory. Migratory and vagrant annual movement patterns are expected at high latitudes and are strongest in polar breeding populations. Non-migratory populations are expected in tropical and subtropical island systems. I suggest that vagrancy in short-eared owls at high latitudes is likely driven by strong association with grassland systems where prey resources are patchily distributed and dynamic, especially at high latitudes. In contrast, I postulate that non-migratory populations have more flexible diets and more diverse habitat preferences, allowing them to persist in one location without migrating.
In Hawai‘i the endemic short-eared owl subspecies, the pueo (Hawaiian short-eared owl: Asio flammeus sandwichensis) inhabits an ecosystem composed of isolated tropical islands and are expected to use habitat differently than their continental counterparts. Given limited seasonality, minimal interspecific competition, and limited island landscapes. I aimed to describe habitat use patterns of pueo in Hawai‘i, where I hypothesized that pueo exhibit higher site fidelity, fewer nomadic movements, and utilize a broader range of habitat types than their continental counterparts. In this study I deployed VHF transmitters on four pueo captured on leeward O‘ahu. Transmitters lasted for 3-months with one harness failing prematurely and one mortality, likely due to collision with a communications tower, leaving two with greater than 50 relocations. Throughout the duration of the study pueo did not exhibit migratory behavior and maintained stable home ranges averaging 482 acres. Pueo were found roosting almost exclusively in patches of forest and foraging in mowed fields with some observations of foraging near human structures. These results suggest that pueo are less vagrant and utilize a broader range of habitats than their continental counterparts. The non-migratory status of pueo indicate that conservation of habitat at scales of about 500 acres are appropriate and habitat use results suggest the importance of forested and open habitat. These findings will help guide conservation actions that will allow pueo populations to thrive across the Hawaiian Islands once again.
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