Steve Knight

YARD -- The sun was setting on the western horizon when the Chevrolet pickup, with a high rack, pulled out of the barn. It was a mild night and no visible moon when the roof-mounted spotlight blinked on.

This was the beginning of the third and final deer spotlight count at the BigWoods, a final step in acquiring Managed Lands Deer permits for the coming season.

The census line that meanders through the 8,000-acre ranch is just more than 13 miles, but driving at a crawl it can take three to four hours to cover depending on the number of deer spotted along the way.

Stephen Matthews was at the wheel and Heath Burney operated the remote-controlled spotlight. The two had been down this road before on the BigWoods, having logged more than 60 deer on two previous runs in the last month. The route was identified a couple of years earlier by a wildlife biologist who factored in length and the average viewing distance to come up with a rough estimate of the area covered.

It is a slow start tonight, thanks in part to thick woods that make up portions of the BigWoods. When the cover begins to open up, deer numbers slowly begin to build. It starts with a doe and twin fawns, and then another trio. After a few minutes the light again reflects on green-blue eyes, giving away a bachelor a bachelor herd standing in the brush. There are five bucks in the herd. They all look good, but they always do when their antlers are still wrapped in velvet.

When the evening is over the count stands at 56 deer. Twenty-four were bucks, 14 were does, nine were fawns and nine couldn't be clearly identified.

The numbers were up significantly from 2007 when a summer flood on the ranch dispersed the deer in different directions and produced thick vegetation that made spotlighting deer difficult. Last year none of the counts had more than 30 deer, but hunters on the BigWoods still took 40 bucks and 60 does last winter.

Landowners and biologists statewide are currently in the process of getting deer herd estimates by conducting annual spotlight counts. The use of spotlight counts to gather information on a deer population goes back to the 1950s. The use of an airplane and then helicopter soon followed, and are still popular across portions of South and Central Texas. Today biologists are working on the high-tech version of the survey method using multiple cameras placed around a property for prescribed periods of time.

"A spotlight count is just a sampling method. It provides just a range or ballpark of what you think the population is," said Texas Parks and Wildlife Department biologist Jay Whiteside. Stationed in Corsicana, Whiteside is the technical biologist who will crunch the numbers from the BigWoods before determining how many MLD permits the ranch will receive. It is one of about 100 ranches covering more than 150,000 acres he is looking at this summer primarily in the state's Post Oak Savannah region.

Whiteside said the counts don't provide an exact picture of the ranch's deer population or sex ratio. If done right and in combination with incidental sighting reports and harvest data, spotlight counts do provide a window on what is happening within an individual deer population.

To be useful, the biologist said the counts need to be run multiple times on the same course to get a good average. And the course can't go just anywhere for the survey to work.

"There are a lot of variables that play into the accuracy of these counts. Ideally you would run through the different habitat on the ranch and not just through one area with a high population," Whiteside said.

He explained that if a ranch is 75 percent woods and 25 percent open range, ideally the survey route would cover similar habitat.

"It is not a full-proof method, but it seems to work well with most of the ranches I work with in the Post Oak that are 500 or more acres," Whiteside added.

The key to spotlight counts, or any other kind of deer census data, is having several years of information to compare. That way if there is an anomaly like last fall when sightings were down because of high vegetation, it doesn't cause a panic in the management plan.

While the spotlight count provides a herd size estimate and some semblance of a buck-doe ratio, Whiteside said incidental sightings may be a better survey method for actually getting the buck-doe ratio and fawn survival rate. The harvest data, which includes age, weight and antler information, gives the best look at overall herd health.

"You need all the data combined. You can't just pick one over the other, they are all important for different reason. Each gives you a different picture for what you are looking at. Hopefully they point out problems occurring ahead of time whether habitat of overpopulation," Whiteside said.

When it comes to taking the survey numbers and putting them into a harvest plan, it becomes part science and part art.

"When I receive the census data, I have a spread sheet on the computer I enter them into. I work up a population parameter and can manipulate the numbers of how many deer they are harvesting to a point where I am comfortable. The No. 1 goal is to get a sex ratio relatively balanced and the winter population down to where it is not exceeding or maintaining population density," Whiteside noted.

UNDER THE LIGHTS: Spotlight counts give a representative look at a ranch’s deer population and sometimes a little something to get excited about.
(Staff Photo By Steve Knight)