by Braiden Quinlan, FWCB Class of 2017
This past summer I had an amazing opportunity to work on an urban/suburban black bear study in Asheville, NC. This project was in its third and final field season under the direction of Nick Gould (PhD student, FWCB) and is a joint effort between North Carolina State University and the North Carolina Wildlife Resources Commission. This five-year study is designed to examine the population ecology of an urban/s
uburban bear population. The study largely examines the spatial ecology of black bears in urban habitats and hopes to investigate questions such as whether or not the city of Asheville functions as a source or sink for American black bears; and whether these urban/suburban bears are vulnerable to the legal harvest.
During my time on this project, I served as a volunteer research technician. There were multiple responsibilities that had to be completed on a day-to-day basis. Twice per day, bear traps had to be checked – once in the morning and again in the evening. During my time on the project, we had a maximum of 12 traps set in and around the city limits of Asheville. While checking traps, I would use an assortment of locally donated pastries, cakes, donuts, and frosting as bait to lure the bears into the traps. As the bait was not specific solely to bears, we captured some bycatch such as raccoons and opossums. In the case of either raccoon or opossum captures, the protocol was to immediately release the animals unharmed.
When we were fortunate enough to capture a bear in one of our culvert traps, we would visually assess their weight to anesthetize them with a drug combination of telazol, ketamine, and xylazine. This drug combination is very forgiving, meaning that it is difficult to administer too much drug to cause ill effects. Typically we had approximately 60 minutes to complete the workup.
Once immobilized, we monitor the bears’ vital signs (heart rate, pulse, temperature) throughout the process to ensure a stable condition for the animal.
Because this is a movement-based ecology study, the bears must be able to be tracked (i.e., followed through time and space) as well as individually identified. To accomplish this, we fit Vectronic GPS collars on the bears that would transmit the bears’ location every hour while the bear was outside the city limits of Asheville, and every fifteen minutes when the bear was inside the city limits. Once the GPS collar and identifying marks (i.e., matching ear tags, lip tattoo, and PIT (Passive Integrated Transponder tag) were attached to the bear, we took morphometric measurements and collected multiple biological samples. Some of the measurements included: weight (lbs), total length (tip of nose to base of tail), front/hind paw width and length, canine length and width, and numerous others, if time permitted. Biological samples included tissue
(ear punches), fecal collection, rectal and nasal swabs, tick collection, blood, and a premolar tooth that is used to age the bear. Over time bears either lose their collars, or we retrieve intentionally detonated collars, making it important to have other means for identifying individuals were they to be captured again or show up as a mortality in the future.
My other (office/data) responsibilities included entering various data ranging from trap site locations and the type of bait used to examining the most recent GPS locations for all the actively collared bears to assess/determine movements out of the study area as well as to identify any potentially missing bears. The rule of thumb was that if a bear had not sent data in three days one of the crew would have to locate the bear, or its collar.
There were typically three reasons why a collar would not send data: an emergency/low battery mode indicating battery failure, a mortality mode (collar was stationary for more than 12 hours) indicating either a deceased bear or a “dropped” collar, or the bear was in a location that had poor ability to communicate with the iridium satellites. Regardless of the cause, it was up to me to locate the bear/collar and determine the reason for the unsuccessful transmission of data.
While tracking a bear, I would begin by looking at the animals most recent locations on a google earth map and beginning my vehicle search as close to that location as possible. The GPS collars emit a VHF radio signal (each collar has its own frequency), and I was equipped with a telemetry receiver and an omnidirectional antenna mounted on the roof of the work truck. As the truck got closer to the collar, the signal would become louder indicating I was closing in on the bears’ location. If the collar was in a low battery mode, or in mortality, I would try to retrieve it on foot. To determine the direction the signal was coming from on foot, I would use a Yagi antennae.
On several occasions, I spent hours tracking a bear that had a collar that was in low battery mode, attempting to get close enough to use a separate receiver that allowed us to “detonate” or to remotely release the collar from the bear. Various other jobs that I had during my “down” time was cleaning the immobilizing darts used to tranquilize the bears, categorizing and processing the samples, sorting through photos from camera traps set at different trap locations, and occasionally collecting a vehicle-killed bear.
My experience taught me about the scientific process in a hands-on way, and I learned more about field work and acquired many useful skills associated with it than I thought would be possible in just one month. While I was there, I was part of at least twelve new bear captures and was involved in many recaptures. The days were some of the longest days I have ever had (generally 13 hour days), but they were also some of the most memorable – in the best way. Overall, my experiences in Asheville were some of the best of my life.