GF&P begins bobcat kitten survival study
SPEARFISH — The South Dakota Game, Fish, and Parks has begun a study on bobcat kitten survival, marking the first time that the department has fitted radio collars on the kittens only weeks old.
Brady Neiles, a resource biologist for the GF&P, successfully captured and collared two kittens Tuesday morning.
“Ultimately, we’re looking for a population growth rate for bobcats in the Black Hills of South Dakota,” Neiles said.
For the past three years, GF&P staff members have trapped adult bobcats in live traps – cages that close when the bobcats step on a plate triggering the door closure. The bobcats are then tranquilized and fitted with collars that send radio signals that can be tracked by biologists.
Currently, 32 bobcats are collared in the Black Hills. About half are females. Neiles said the wildlife officials then target the females using telemetry signals to locate den sites.
Collaring kittens this small required a new type of collar. Neiles worked with an engineer with B9Creations in Rapid City to design new collars.
Traditional collars used with tracking young animals, such as deer, use an elastic collar that degrades over time and will eventually be ripped off the fawn’s head when it snags on something such as brush.
“We needed a very durable collar,” Neiles said. “Kittens chew on each other and the collar. … We needed an expandable collar.”
The collars still are elastic that will break down in ultraviolet light and will come off in about a year, but the collars are covered with plastic. “They are going to be biting on these things trying to pull them off,” he said. “They have paws with claws.”
Another collar design uses the elasticity in the spiral collar itself to expand and eventually fall off.
Neiles said kittens this young have never been collared.
“This really hasn’t been done before with collars because we couldn’t really figure out a great system to collar something that small of an individual,” Neiles said. “Six months is the youngest studied collared individual.” Traditionally, kittens have radio transmitters surgically implanted into their bodies.
“Even though surgery goes pretty quickly, it is something we didn’t want to do,” he said.
Monday, Neiles found a den occupied with a female and two kittens by her side.
“It’s weird I got a photo with her in the den,” he said.
Typically, the females will leave as the researches approach. This was the case Tuesday when he returned to the tight den with a dirt floor and a overhanging rock. Inside he found two kittens weighing about 1.4 pounds each. Within five minutes, the kittens were collared, and Neiles departed the site, listening to the transponder receiver for chirps identifying the location of the female, ensuring she returned to the den.
Neiles said the study on the kittens would continue for the next two years, with capturing the animals occurring in the spring. The study on bobcats will continue for the next five or 10 years.
Adult female bobcats grow to about 20 pounds, while males weigh about 30. He said by the time kittens are 1 year old, the expected life of the collar, they will weigh 13-17 pounds.
Neiles said the two he recently captured will be the only two collared this year as this is the pilot study year. Eventually kittens will be captured throughout the Black Hills.
So far, Neiles said, the biologists are seeing a 67% survival rate for a year from previous studies, which he said was pretty good.
Mortality in the Black Hills, he said, was mixed fairly evenly between hunter or trapper harvest, vehicles strikes, and starvation.
While there have been instances of mountain lions killing bobcats, they traditionally do not live in the same terrain, he said.
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