Wildlife ecologist assists in statewide bobcat study

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Tracy Rittenhouse

After years of hunting and trapping and loss of habitat dwindled their population, Connecticut’s only wildcat appears to be making a comeback. Bobcats were once a rare sight in the state, but residents have glimpsed these predators more frequently in recent years. People across the state have been reporting bobcats in their hometowns to the Department of Energy and Environmental Protection (DEEP). Wildlife experts speculate the animal’s population has been steadily increasing, but lack accurate data about their current numbers.

DEEP started the CT Bobcat Project in September 2017 with the goal of assessing the bobcat population and studying its behaviors in the state. Assistant Professor Tracy Rittenhouse of the Department of Natural Resources and the Environment recently joined the research team. The four-year project will involve data collection over the first two years and then two additional years of analysis and summary.

“Bobcat populations in the entire US were pushed to extremely low numbers,” says Rittenhouse. “In the last few decades, they have been rebounding, especially here in Connecticut. We have confirmed sightings of bobcats in every town. The population data for bobcats we have now is mostly from hunters and trappers from their sightings and accidental trappings on DEEP surveys. One of the main goals of this study is to determine population in the state.”

In addition to a precise population count, the researchers aim to gain knowledge about the preferred prey and food sources for bobcats and where they seek shelter and ascertain the range of the animal to establish activity patterns, including reproduction. This broad ecological study will also help scientists learn more about how these animals compete with other predators or affect populations of their prey.

“This project will help us know more about variances of population density from town to town and the behaviors of bobcats living in urban and exurban regions. We’ll also gather information on the size of their home range, movement rates and the paths they navigate through distinct areas of the state. It’ll be interesting to see the variance in how they navigate different housing densities,” says Rittenhouse.

The bobcat population in Connecticut declined over the last two centuries due to habitat loss, trapping and hunting. Throughout the 1800s, the clearing of land for farming and human settlement greatly reduced habitat and hunting grounds for bobcats.

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Bobcats are being caught and tagged across the state for the project.

Deforestation made bobcats more threatening to farms and livestock, concerning farmers. The view that bobcats were a nuisance led to the implementation of a bounty on the animal in Connecticut from 1935 to 1971. However, the excessive hunting and trapping of bobcats led the state to reassess its position. Fearing potential extirpation, the state made the bobcat a protected furbearer in 1972 and eliminated all hunting and trapping seasons. The regrowth of forests combined with legislative safeguarding has seemingly led to the resurgence of the bobcats in the state. Their expansive diet, which depends largely on the availability and difficulty in catching prey, aided their survival.

“Bobcats are a medium to large size mammalian species and generalist predators, so they eat a wide variety of animals, but they typically target small mammals like squirrels, chipmunks, mice and rabbits. However, bobcats can feed on much larger animals. There are records of attacks on deer and fawns. Our expectation is that bobcat numbers are driven by prey abundance so we anticipate finding more bobcats where there are more prey. It’s also likely we’ll detect a shift in diet for places that are more or less urban,” says Rittenhouse.

The study of diet will also come from another indicator of a surging bobcat population: roadkill. Reports of bobcats struck by vehicles have also risen. Examination of roadkill bobcats gives scientists information about eating habits and other metrics, including age, physical attributes and breeding condition.

Kristen Beattie, a master’s degree student in NRE, has been assisting with necropsies of roadkill bobcats.

“Across Connecticut, we are collecting roadkill bobcats to better understand bobcat ecology,” says Beattie. “We collect a tooth and hair sample from each cat and examine stomach contents for diet analysis.”

Teeth are used to determine the age of the animal and hair samples can reveal what a bobcat has eaten through analysis of stable isotopes of carbon and nitrogen.

“The bobcats that eat only carnivores will have a different carbon-to-nitrogen ratio than bobcats that also feed on herbivores. This analysis will tell us if bobcats are eating the same types of prey or show us that bobcats in urban areas are eating different animals than those in rural areas,” says Rittenhouse.

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Tags are affixed to a bobcat’s ear.

Bobcats are also being live trapped for tagging and collaring. The goal for the first year of the project is to attach an ear tag to every bobcat captured and outfit fifty with GPS collars. GPS collars provide instant location data and can track movement via satellites. DEEP met their current collaring goal in February, says Jason Hawley, a biologist in DEEP’s Wildlife Division and a Ph.D. candidate in NRE. The collars will drop off the animals in the fall and will be attached to fifty new bobcats next year. A video of a bobcat being live trapped for the CT Bobcat Project is available here.

The processing of data from tags and collars can also lend insight into mortality rates. Bobcats can live ten to twelve years in the wild, but biologists assume that many do not live past three or four years.

Other technology will also play a crucial role in helping to study the state’s bobcats.

“We’re working on setting up about eighty wildlife cameras throughout the state to create occupancy models. We created a randomized sample, stratified across an urban gradient, to determine camera placement. Most of our locations are not on state land so that means we’re working directly with private landowners to gain access to properties for camera installation and to collect footage. Landowners have been quite receptive to our work and are always interested in finding out what animals are living and traveling through their backyards,” says Rittenhouse.

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Kristen Beattie meets with a landowner.

Says Beattie, “Over the past two months I have been interacting with landowners across the state. My goal is to recruit participants from various housing densities to set up trail cameras on their properties so we can learn more about the population dynamics of bobcats and their interactions with humans. I’ve received a lot of support, enthusiasm and general interest in the project from home owners, local businesses and town officials.”

Hawley has also been meeting with the public, explaining the scope of the research through presentations on the CT Bobcat Project.

“The response from the public has been overwhelmingly positive. People are excited to get involved and volunteer. One of our more difficult tasks has been finding roles for all of our volunteers,” says Hawley.

Says Rittenhouse, “This is an exciting project that is potentially going to change our perceptions of bobcats. We used to believe bobcats had preferences in their hunting times, usually dawn or dusk, but we’re finding they’re detected equally at all times of day or night. We’re looking forward to what else we learn about these predators and examining how their return is impacting different areas.”

A critical part of the success of the CT Bobcat Project is the continued assistance of the public. If you see a bobcat, please record your observations about the number of animals, the date and location and if an ear tag or collar was visible on the animal. Sighting information can be shared with DEEP through email at deep.ctwildlife@ct.gov or entered using the iNaturalist app and navigating to the CT Bobcat Project page. The app is compatible with both Android and Mac devices.

If you come across a road-killed bobcat, contact the Wildlife Division or Dr. Rittenhouse and, if possible, move the carcass off the road and cover it with branches or other available material.

By Jason M. Sheldon


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