Doe, a deer: Local ‘Bambi count’ underway

Program aims to tally, track Sonoma-Napa cervidae population|

It’s never an easy thing, counting a large group of wild animals – especially if those animals are deer.

But that’s exactly what a team of local biologists and wildlife experts are doing in an effort to determine exactly how many bucks, does and fawns call Sonoma and Napa counties home.

“Deer, generally speaking, are very good at not being counted,” says Stacy Martinelli, a biologist with the California Department of Fish and Wildlife.

“People ask us all the time how many deer we have in the area, but we don’t really know,” Martinelli says. “Information about deer is often anecdotal. If you talk to people outside the urban areas, up in the hills, they think deer numbers are down. At the same time, we are hearing about a possible increase of deer in rural and suburban areas – probably because there are fewer predators there, and because people are feeding and watering them.”

Despite such challenges, Martinelli and other local wildlife experts in the department’s Wildlife and Lands Management Program are conducting a two-county study, employing a combination of GPS technology, DNA analysis, and good old-fashioned grunt work to tally the local Bambi numbers. As part of the months-long study – being conducted across Sonoma and Napa, with several target sites in the Sonoma Valley area – a number of deer are being captured and fitted with high-tech GPS collars. Later this spring, the team will go out again and collect fecal samples – literally scooping up deer pellets – then run DNA tests on the much-prized poop that will tell researchers which of the collared deer have deposited which droppings.

“Together, these data-collection methods combined will be able to tell us more accurately how many deer we actually have,” Martinelli says. “Basically, we are trying to get a better estimate, state-wide, of deer population numbers. For this particular study, we’re looking at capturing and collaring 30 deer in Sonoma and Napa, spreading that number around to different parts of the region, a few deer from each area.”

The plan, according to Martinelli, is to capture and collar 15 females and 15 males, with ranges encompassing a combination of private and public lands.

“The collars will stay on for two years,” she says. “Coupled with the fecal DNA studies, the collar information will give us an idea how many deer there are, and what their home ranges are.”

The data will ultimately be used for deer population management and conservation purposes. Also to set hunting tag quotas.

But first, they have to put those collars on all of those deer.

Generally the team uses four distinct capture methods. The first is “free-range darting.” A tranquilizer gun is used to sedate the animal for a short time, during which the GPS collar is put in place.

In other cases, a radio-controlled drop-net is used. The net is suspended from four secure poles and when the team, in hiding nearby, sees that the deer has moved under the net, they send a signal which drops it onto the animal, allowing the team to move in and affix the collar.

The third method, “helicopter capture,” is similar to the net-drop, only much more expensive and a bit more complicated.

“A crew shoots a net from the helicopter, using a special kind of net-shooting gun,” Martinelli says. “We’re doing that on Friday, out at Lake Berryessa. Should be pretty interesting.”

The fourth method is called a “clover trap.”

“It’s basically a box trap,” she says, referring to an actual box, into which a deer is lured with bait, with a door that closes after the deer has entered.

“We’ve had no success with those,” she says. “The deer aren’t falling for it.”

So far, Martinelli admits, her team has only successfully captured and collared two deer out of the planned 30.

“Yes. Just two – so we have 28 more to go,” she says. “Those two deer, by the way, were both does. They were captured near Healdsburg. A doe will generally have a small home range in the winter, but that range could expand in the spring and summer. Right now, our local deer could be hunkering down because of the rains.”

Asked if it’s enjoyable work – tracking wild animals through the mud, collecting their feces and fitting the critters with high-tech accessories – Martinelli laughs.

“Oh, I love it,” she says. “As a wildlife biologist, it feels like exctly what I’m supposed to be doing.”

Email David at david.templeton@sonomanews.com.

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