Wildlife management is the science of balancing wildlife populations within the constraints and impacts of a human population.

Biologists use a variety of tools for managing wildlife. Radio and GPS collars are favorites because they allow biologists to monitor animals without impacting animal behavior.

“These collars give us a window into their lives,” said IFW bear biologist Randy Cross, who has collared and tracked thousands of bears in Maine for more than 30 years.

IFW moose biologist Lee Kantar, who is in the midst of a five-year moose survival study designed to assess the health of Maine’s moose population, explains further.

“Radio or GPS collars are arguably one of the best ways to track animals over a long period of time,” said Kantar. “Given that animals are difficult to see and that as observers we do not want to affect how an animal moves or behaves, tracking an animal remotely using radio collars provides unprecedented insight into their lives.”

Radio collars emit a VHF signal that can be monitored by a receiving unit. GPS collars store data to be retrieved at a later date or broadcast data via satellite to a computer or smart phone.

In Maine, radio collars were first used by the bear project in the mid-1970s as IFW biologists sought to learn more about Maine’s expanding bear population.

“The collar allows us to locate bears in the winter. Not only can we count the cubs when they are born, but we can also count how many make it to 1 year old. It gives us answers about productivity, and we can also assess cub survival,” said Cross.

GPS collar data gathered while the bears are not denning is invaluable as well.

“GPS collars identify home ranges, and it also tells us how many bears are crammed in together so we can get bear density estimates in a very powerful way,” said Cross.

“We can get 600 to 800 GPS locations while a bear is outside a den. It helps us analyze what type of habitat bears are using and when.”

The GPS collars on Maine’s moose transmit signals twice a day. If a moose dies, the collar sends a mortality signal, allowing biologists to investigate and determine a cause of death.

“They also allow us to follow the moose over time as they move through the woods. We can see how much space they use in a day, a week, a month or year and gain an understanding of the type of habitats they use as well,” said Kantar. “In addition, we monitor adult cow movements in the spring prior to calving and can detect when and where they are calving.”

But don’t think this technology is limited to large mammals. IFW bird biologist Lindsay Tudor may not be able to use a radio collar on a 3-ounce purple sandpiper, but she can attach a radio transmitting nanotag.

“Nanotags provide us with information on length of stay and local movements,” said Tudor. “We can combine that with existing survey data to determine population trends and status of shorebirds using Maine coastal habitats.”

That data is used for assessing habitat needs and managing protections for migrating shorebirds.

IFW fisheries biologists use radio telemetry as well, including a recent brown trout study on the Shawmut section of the Kennebec River.

“Without radio telemetry, we wouldn’t be able to determine specific movement patterns and behaviors,” said IFW fisheries biologist Jason Seiders. “Radio telemetry gives us real-time information on fish movements and behaviors, and provides a much clearer picture about a fish’s preferred habitat.”

Radio-tagged fish have unlocked secrets concerning spawning areas, and have been instrumental when it comes to regulating water flows on rivers.

“Radio telemetry provides us with data that would otherwise be unavailable,” said Seiders, summing up why biologists tune in to radio and GPS collars.

Mark Latti is a Registered Maine Guide and the outreach coordinator for the Department of Inland Fisheries and Wildlife.

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