Sunday, October 9, 2011

Missouri Black Bear Project, Part I

This summer I lived and worked in the Ozarks as part of a field crew studying the population dynamics, resource selection, and movements of black bears (Ursus americanus) in Missouri.  The project is being run by Clay Wilton, a master's student in the Carnivore Ecology lab at the University of Mississippi (http://fwrc.msstate.edu/carnivore/students.asp).  The study spans the south central and southeast part of the state and is divided into two seasons, the first having been this summer and covering approximately 20,000 square km. Black bears were extirpated from the state in the 1940's due to excessive and unregulated hunting, loss of forest habitat, and urbanization. Since the 1960's, however, bears have slowly returned to the state, most likely from a combination of better forest management and a successful bear reintroduction project in Arkansas in the 60's. Clay's project, however, will be the first study of its kind on bears in the state, as the population is unknown. Knowing bear numbers and understanding their movements and habitat preferences will be key in future bear management, encouraging expansion, and encouraging positive human-wildlife interaction.

 A bear census is not the same as a human census. One cannot simply walk up to a bear den and ask "how many are you?" A bear census, however, still takes a lot of work, and efficiency is key.  Non-invasive techniques are tools in wildlife research that biologists can employ to save time and gather information on elusive and hard to reach species (or minimize stress on animals). These tools can usually be in the field when we cannot, ie all night and all day, and in several places at once. The methods used in Clay's study includes infrared camera traps and baited, barbed wire hair snares. Camera traps can "capture" and "recapture" animals on film as a means to detect presence and movements of individual animals. Individuals can be identified based on photos, as these cameras are triggered by movement to shoot film and video. In the case of this project, we set up more than one hundred cameras across the study site at hair snare locations. Barbed wire hair snares are a means to collect hair samples from animals for DNA assessment, species identification, and other laboratory tests.  Barbed wire wrapped around trees surrounds a bait pile, usually covered in scent lures or food, to entice an animal to enter the corral and hopefully leave a hair sample in the process.  This method is not painful to animals, as thick fur coats protect the skin from scratching. This summer, we created and managed more than three hundred hair snares.
 
In order to set these snares and cameras, we covered both public and private property in search of probable bear habitat. It took our team four weeks to set all of the snares, and the remaining two months of the study to bait and to check for samples.  Additionally, our field crew was able to attend the radiocollaring of black bears, since the study assesses the movements of individual animals as well.  The GPS collars provide animal locations every ten minutes, so Clay is able to download the collar data via satellite and create maps of animal movements (which is totally cool, because you can watch a bear walk a twenty mile trail and literally pass within feet from your snares and not enter one, or you can imagine that a bear is reading a good book because he/she sat in the same patch of woods for eight hours). Because bears are crafty, we also had to venture out on occasion to retrieve a dropped, or slipped, GPS collar.

Due to the size of this summer's study site, our field crew split up and lived in two different field houses, with Clay traveling between the two each week to cover snare locations.  My field house was on Caney Mountain, an awesome conservation area outside of Gainesville and home to everything imaginable, from wild hogs to bats to skunks. On days off, we often traveled to the North Fork river for kayak trips and fishing, or into town to use the internet, as we had no cable access out in the boonies. We also formed a front porch mountain band comprising of guitars, harmonica, a mandolin, and beer. As the only female on this study, I often reminded myself that although we shared one bathroom, we more importantly shared an interest in carnivore ecology...

Please visit the Missouri Black Bear Project's website for more information and cool photos (look for the hair snare crew!) as I compose Parts II and III of the study: http://www.fwrc.msstate.edu/carnivore/mo_bear/index.asp