CURRENT RESEARCH PROJECTS
Population Size, Spatial Patterns, and Genetic Diversity of Black Bears in New York
There are an estimated 6,000-8,000 black bears , but populations have recently undergone range expansions, particularly in the southern part of the state. These numbers are based on reportings and harvest indices. But why are bear populations growing, and how might we expect them to change in the future? Are expansion patterns related to landcover types that bears use? In order to answer these questions, we need rigorous methods of estimating population size and distribution. I use a combination of spatial capture-recapture and occupancy data collection and modeling methods to answer these questions.
My Masters work focused on a region of the Southern Black Bear Range, wherein I conducted a noninvasive genetic spatial capture-recapture study. I collected black bear hair samples from ~200 research sites during the summers of 2011 and 2012. I extracted the DNA and genotyped the samples to identify individuals, which I then used to tabulate which bears I detected, at which research sites I detected them, and on which sampling occasions. From my modeling, I estimated population density (~13.1bears/100km^2), and surprisingly found no pattern between bear density and the amount of forest, agriculture, or human developed landcovers. These results suggest that bears will continue to expand northwards into central New York.
I currently have expanded these sampling methods across the entire Southern Black Bear Range to study similar population patterns in other regions of the state.
Developing an Integrated Population Model of Black Bears in New York
For my PhD work, the main thrust of my work is to estimate population-level patterns of abundance, distribution, and growth in upstate New York. However, there are large parts of the Southern Black Bear Range that remain unsampled even ~200 research sites distributed across the Range. To augment the data, we have started a citizen science project to enlist the help of citizens and volunteers to help collect data on the presence and absence of bears using an app we developed and launched in 2017 called iSeeMammals. Combining this opportunistic data with our systematically collected data from the research sites provides more accurate estimates of population parameters. By collecting data over multiple years, we can also estimate survival, recruitment, and population growth rates.
We developed iSeeMammals as a way to engage the public in collecting black bear data across New York. It collects presence-absence data of bears and bear signs (tracks, scat, hair, and markings) using 3 features: one-off observations, hikes, and trail cameras. The project is accessible by website and smartphone (free Apple + Android app). The project launched in Spring 2017. Check us out on the web and social media!
Phylogeography of Black Bears in New York and the Northeast Region
Black bears in North America expanded out of glacial refugia approximately 21,000 years ago. Since then, bears have experienced range expansion, severe population fragmentation and declines due to loss of habitat and unregulated hunting, and recent population growth in some areas. What genetic signature of these events may still linger in black bears in the Northeast? I am collecting DNA samples from bears across the northeast to identify spatial patterns of the genetic structure of bears. I am using both microsatellite and mitochondrial markers to identify patterns in genetic diversity and structure of black bears across the Northeast US. States agencies have their own bear management plans, but bears do not heed state boundaries. Just as it is important to have baseline knowledge about population size and distribution, genetic patterns provide indication of historical events that may still be affecting current population dynamics.