New deer population-counting is more high tech, less costly

Tuesday, March 30, 2010 | 12:01 a.m. CDT
Photo from Baskett Conservation Area taken by motion activated cameras. The cameras are part of a conservation study.

Two young deer step into a clearing and head toward a large pile of bright yellow bait corn, their small hooves crunching on crisp snow. They look up quickly with big brown eyes as their motion triggers a click and they are shot — by a digital camera.

The camera, mounted on a steel stake and encased in waterproof housing, is one of 19 set up in August at an MU Wildlife Research area east of Ashland. The Missouri Department of Conservation and the MU Department of Fisheries and Wildlife are using these motion-activated cameras to test a new way of counting deer that has the potential to be more accurate and less expensive than current methods.


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The research has attracted the attention of the Missouri Department of Natural Resources, which is interested in finding more accurate ways to count deer in state parks.

The pictures do more than provide a method for counting deer; they are a window in to the secret life of Missouri’s forests. They show deer eating side by side with raccoons and wild turkeys spreading their wings. Owls swoop down on unwary mice feeding on corn.

Counting deer on a statewide scale is tricky, and counting deer on a local level is expensive and difficult. Yet wildlife managers need this information to make critical decisions — such as how many hunting permits to issue each year and when to conduct managed hunts on state lands.

If deer populations rise too high, property damage, vehicle collisions and impacts on the environment all increase. On the other hand, with too few deer, hunters and wildlife advocates complain.

“The management of deer is dependent on hunting,” said Lonnie Hansen, a deer biologist with the Missouri Department of Conservation. “It’s very handy to know what’s out there. If we know how many deer are out there, then we know how many to shoot.”

One of the earliest methods of counting populations was trapping and tagging live animals. Returning to the field, scientists compared the number of tagged animals they saw the second time with the total number of tagged animals.

This labor-intensive method, which is also hard on the animals, is rarely used today.

The $25,000 camera study financed by the Missouri Department of Conservation is designed to establish an equation that can be used elsewhere to determine the total population based on the number of deer caught by their “camera traps.”

Josh Millspaugh, Professor of Fisheries and Wildlife Sciences at MU, is working on the project at the 2,200 acre Thomas S. Baskett Wildlife Research and Education Area along with Jason Sumners, a deer biologist with the Department of Conservation.

Each camera trap has a pile of dried corn used to bait the deer into camera range.

To test the new approach, the team trapped 71 live deer and attached radio collars along with large white and black numbered tags in their ears.

Then they put out the camera traps.

For each of the 10 days the cameras were set up in August, telemetry was used to determine which of the radio-collared deer were in the area. Meanwhile, the cameras were photographing animals that were attracted to the bait piles, including tagged deer, untagged deer, crows, raccoons, mice and wild turkeys.

With the photography portion of the study over, the team will know the total number captured, the number of tagged deer captured and the number of tagged deer in the area at the time of the experiment. With this information, they have all they need to make an accurate estimate of deer in the area.

Once the baseline research is finished, the method can be replicated elsewhere by setting up camera traps, counting the photographed deer and plugging the data into an equation that will give an estimate of the total number.

Currently, the Department of Conservation biologists estimate the number of deer statewide — between 1.2 and 1.4 million — by using the number of deer killed by hunters and hit by cars each year. Based on these numbers, they estimate how the population is changing year to year.

The Department of Conservation makes estimates of population density in conservation areas  by counting deer from above during flyovers in helicopters and small planes.  The fly-overs can be costly and can only be done in the winter when snow on the ground can provide contrast. The Department of Natural Resources conducts flyover counts in state parks.

The flyovers are expensive, difficult and not always reliable, Sumners said. Counts can only be done in the winter when several inches of snow are on the ground to provide contrast. And aircraft aren’t always available when conditions are right.

Millspaugh and Sumners hope that using cameras to count deer provides a more affordable, practical and accurate measure.

Missouri state parks may be a place to use the technology, according to Ken McCarty, natural resource manager for the Department of Natural Resources Division of State Parks.

“We are going to see if there is some way to use this with our deer program,” McCarty said. “We’re always looking at ways to improve precision and ways that will reduce cost."

McCarty said he has a meeting planned with Millspaugh to learn more about the technique so managers can evaluate whether it is appropriate to use in state parks.

Having accurate population estimates for the parks is important because deer populations can climb in areas like state parks where hunting is not normally allowed. Park managers need accurate population estimates to justify an organized hunt to bring numbers down and to determine if the hunts have reached their targets.

At Rock Bridge Memorial State Park, biologists believe the numbers yielded by recent aerial counts have been lower than the actual population, said Roxie Campbell, the park naturalist.

Ten years ago, in 1999 and 2000, aerial flyovers estimated deer populations in Rock Bridge were up to 53 deer per square mile. A healthy target is 25 deer per square mile, Campbell said.

In 2001, the department conducted a hunt to reduce deer numbers. The next year, flyovers gave an estimate of 22 deer per square mile. The next two years yielded a count of 27 deer per square mile each year. The count in February of 2007 gave a total of 20 deer in the entire park — 6.8 deer per square mile.

“It would be illogical for the count to be as low as numbers indicate,” Campbell said.

The biologists believe that helicopter traffic from a nearby hospital has conditioned the park’s deer to helicopters. The deer are staying hidden under dense cedar trees where the biologist can’t see them from helicopters.

At the same time, deer hit on roads in the park has remained constant and Campbell still sees plenty of tracks and droppings in the park. She is hopeful that a new method of counting deer could help them keep better track of the population.

It will take one to two years before results of the research are published in a peer-reviewed journal.

“I am excited to hear that they are researching this," Campbell said. "We do need a different method."



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