Current Research
My research focuses on evaluating and analyzing multiple data sets to learn about population and community level processes in birds, with the goal of informing conservation and management actions.
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My current research spans multiple projects related to waterfowl monitoring and management using citizen science data. I am currently part of the NAWMP science support team, advising on new methods to allocate resources for waterfowl management in North America. I have also recently led projects aimed at comparing professionally collected waterfowl count data with eBird Status and Trends products.
Comparing BBS and eBird Trend Estimates
Confidently estimating population trends is of vital importance for a wide range of ecological, conservation, and management applications. North America has two major data sources for estimating population trends of breeding birds—the North American Breeding Bird Survey (BBS) and the global participatory science project eBird. Because the surveys differ in protocols, coverage, and data analysis, their trend estimates are expected to vary in magnitude, direction, and/or precision for at least some species and regions. Here, we compare independently derived estimates of population change between 2012 and 2022 for every combination of species and bird conservation region (BCR) covered by both surveys (n = 5,577 combinations) as well as aggregated across entire ranges or within U.S. or Canada. Uncertainty was substantial for both surveys, though more prevalent for BBS (81% of credibility intervals for estimates included zero) than eBird (34% of confidence intervals overlapped zero). We found agreement of trend directions between the two surveys. Only 1.3% of estimated trends were significant in opposite directions between the two surveys for all species/BCR combinations, with the median difference in trend magnitude being –0.02% (BBS minus eBird trend). Correlations between the two were strongest for estimates that were graded as being high credibility compared to estimates judged to have medium or low credibility. Both surveys were subject to species, taxonomic, and regional effects that influenced agreement. Overall, we show where trend estimates derived from BBS and eBird agree, explore where they diverge, present several comparisons to assist in interpreting results from both surveys, and inform efforts to integrate information from each.
Read the paper here: Same view through a different lens: Comparing population trends for North American birds using eBird and the Breeding Bird Survey
Population Ecology
It is imperative to understand population processes of species of concern if we are to effectively conserve them. Often it is possible to study a population in the field to gain a better understanding of the processes driving the trajectory of its growth or decline. Many times it is not possible to conduct field studies on certain aspects of a species' life history for one reason or another. In these cases simulation models are useful to gain insight into population dynamics. I have used data from field studies and simulation models, to explore population-level processes.
Community Ecology
Populations do not exist in a vacuum; that is, multiple species may be affected by the decline or increase in another, as many species interact. While it is important that we understand population-level processes, knowledge of species interactions can be just as important for conservation. As with my population studies, I have used both simulation modeling approaches and field based studies to examine community dynamics and how conservation efforts may be guided by them.
Conservation
Most of my projects are focused on some aspect of population or community ecology, with conservation being a consistent theme among them. For others, an aspect of conservation is the main focus of the project. To this end, I have added to the quantitative framework by which potential management actions are evaluated and have conducted species-specific conservation studies.