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Growing deer population taking a toll on forests

CASTILE – Naturalists at Letchworth State Park call it the “Deer Zone.”

It starts about 6 inches at ground level and extends upward to about 6 feet. That’s where new shoots of native trees and shrubs should be growing in the forest understory at the southern end of “the Grand Canyon of the East.” But no young saplings are to be found.

That’s because of hungry deer.

“The deer just munch, munch, munch,” said Douglas K. Bassett, Letchworth’s naturalist.

Vast empty areas – not only in Letchworth but throughout the region – will continue with growing deer herds, fewer predators and decreased deer harvests by hunters.

Just this month, the state Department of Environmental Conservation released figures showing hunters took 1,100 fewer deer across the eight counties of Western New York than the year before. Statewide, nearly 5,000 fewer deer were killed during last fall’s hunting season.

It’s only a 2 percent drop, but it was still discouraging news for those at Letchworth, naturalists like Bassett and local farmers afflicted by ever-proliferating deer herds.

“The only way to get things into balance is to have less deer,” Bassett said.

Letchworth is a microcosm of what is happening across the state, as state biologists eye the growing deer herds and their effect on forests.

“White-tailed deer are the number one culprit that are implicated in all of this,” said H. Brian Underwood, a research wildlife biologist with the U.S. Geological Survey. He is stationed and serves as an adjunct associate professor at the State University of New York College of Environmental Science and Forestry.

Underwood estimates that nearly 40 percent of all female deer in the state need to be culled annually just to maintain current population numbers of about 1 million deer. And, if their numbers continue growing as fewer hunters take to the forest, it’s going to create “a major problem someday,” he said.

“It can’t be the only solution,” Underwood said of deer hunting, “because we’ll be in big trouble.”

Food and shelter

In reality, today’s forest is based on the ecosystem of a century ago.

What a forest looks like a century from now is largely dependent on what happens there today.

So, when the lives of the century-old trees – which began as seedlings in the early 20th century and comprise the upper canopy of today’s forest – come to an end, the next generation of saplings that should grow to take their place simply won’t be there to do it.

It could happen at Letchworth, around the Niagara Frontier and across the Northeast where deer populations are running wild.

“That’s not overstating it,” said Martin Dovciak, an assistant professor and Roosevelt Forest ecologist at ESF in Syracuse. “That’s a real, real concern.”

When agriculture shrank in New York State about 100 years ago, it spelled a comeback for forests, but that was when it was under much less pressure from deer.

It’s not to say the future landscape of upstate New York won’t have trees, but concentration and composition of future forest areas could look a lot different than today.

For instance, researchers found deer eat myriad trees and shrubs but seem to prefer sweet sugar maple saplings to species like beech.

More beech trees, and the nuts that fall from them could promote other wildlife. But imagine the impact on the hardwood industry or New York’s maple producers.

And not just trees are affected. Besides an understory devoid of young saplings, some plant species like the flowering bloodroot and trillium plants also are dwindling away at Letchworth.

Nature finds its own delicate balance, and the current deer population is disrupting that.

“Deer really have a more dramatic effect on the regeneration of the forest than climate change,” Dovciak said. “It affects the sustainable resources of the forest of New York State.”

Too many deer

Ecologists say 12 to 15 deer per square mile is the maximum threshold the ecosystem can sustain without damage.

In many areas where the damage is most apparent, deer concentrations can be upward of 100 or more per square mile.

The state Department of Environmental Conservation has a five-year plan for deer management that acknowledges high deer concentrations “are capable of dramatically altering the structure and composition of their forest habitat.”

Unchecked deer herds can have significant effects on the entire forest.

Fewer trees mean fewer song birds, which in turn means fewer predators and so on up the food chain. It also means reduced diversity of plant species, changes to the soil composition and more erosion.

“It affects more than just the deer,” said Jorie M. Favreau, an associate professor of wildlife biology at Paul Smith’s College in the Adirondacks. “It goes far beyond just the deer and the plants, it’s the whole ecosystem.”

What happened in Yellowstone National Park over the past two decades is a case in point.

After reintroducing gray wolves at Yellowstone in the mid-1990s, scientists found wolves cut the population of plant-eating elk in half.

Culling the elk and other ungulates in the park meant fewer saplings and other native brush being eaten.

“Woody trees like willow, aspen and cottonwood experienced a dramatic recovery,” according to a recent BBC report. All those rooted plants that are now thriving are also lessening erosion on riverbanks and streams. That means deeper, cleaner and more naturally flowing water channels, and with it, the possibility of an improved diversity of fish, birds and wildlife in the ecosystem.

No one is suggesting wolves be returned to New York, but what happened at Yellowstone illustrates the devastating influence that large herbivores can wreak on a forest ecosystem.

There are some natural predators to deer returning to New York’s forest like coyotes and black bear.

But, scientific studies show there is a long way to go before the ecosystem returns to that coveted balance.

Looking for solutions

If natural predators aren’t an immediate answer, the most effective deer killers remain the hunters. But even then, hunters are not as skilled as other predators.

In all, state DEC figures show hunters took 238,670 deer statewide during the 2014 hunting season.

About 22 percent of the harvest came from Western New York, including 7,511 deer taken from Erie County.

Weather, like the double lake-effect snowstorm last November, explains why some 1,100 fewer deer were killed by hunters last year.

“It was 100 percent on the weather,” said Rich Davenport, a big game co-chairman with the New York State Conservation Committee.

“It was the first week of the season,” Davenport said of the double snowstorms. “There were some guys who couldn’t get out. There were certainly plenty of deer.”

Hunters are not as efficient or motivated as other predators.

“They have food in the freezer at home, and they can go back home without food. It’s not life or death for them,” said Bassett, the Letchworth naturalist. “We cannot replace the lack of predators by hunting.”

So the herds grow.

Of the estimated 800,000 to 1 million deer statewide, about a quarter are taken each year during hunting season. Another roughly 70,000 are killed in collisions with motor vehicles. Countless others die of starvation.

So what is the solution?

Forced sterilization programs are impractical, mainly because of the expense, experts say.

But researchers are now putting some once-theoretical concepts to the test, including naturally herding deer herds into certain areas by altering the landscape where they browse.

The idea is to corral large numbers of deer into a certain area by promoting vegetation deer like in hopes it lures them out of the areas where large herds aren’t wanted, namely Letchworth State Park and other prime forested areas.

Another solution, ecologists say, could be allowing commercial hunting for deer to create a market for venison. A lot of the excess harvested deer meat is now provided to prison populations and the poor, but some envision making the transition from game meat to a product available at the meat counter of your neighborhood supermarket.