Deer season, forests and gardens

Midweek, at around 9:00 a.m. on a chilly morning, a loud shot breaks the silence of Poor Farm Road. Another follows. The familiar line of trucks is huddled into small pull-offs at the road’s edge. At around 10:30 a.m., another couple of shots ring out.

The annual ritual of deer rifle season is here. Decades ago, when there was an influx of newcomers into the area, some friction occurred between those who traditionally hunted these forested lands and those who had come to build homes in the woods and were unsettled by the concept. Now things seem to have calmed down. In fact, hunters should be welcomed by anyone who cares about conservation or owns a woodlot or working forest.

Deer eat a wide variety of plants (to the tune of 2,000 pounds a year), but they do have favorite foods. Tree buds and tender twigs are targeted because they offer a concentrated package of nutrition, especially buds. A study by the Michigan Department of Natural Resources found that deer preferentially eat the buds of maples, yellow birch, dogwoods, white pine, and white cedar. They readily browse oaks, ash, poplar, and white birch. When deer are desperate, they eat “starvation foods” — beech, red pine, and spruce.

It is noticeable in the woods stretching around Poor Farm Road that there are swaths in which beech saplings are almost the only species growing tall in the understory. Maples and oaks can be found, but only as small, distorted, multi-branched dwarves, due to the incessant browsing of their terminal buds by deer. Stands of hemlocks in the vicinity provide sheltered wintering areas for deer. Winter cold and deep snow restrict the mobility of deer and increase the browse pressure on the immediately adjacent forest.

The browse problem has been numerically quantified, for instance in a study by biologists at Cornell, Ithaca, NY. They found that oak seedlings grew well when protected by wire cages. Lacking such protection, 60% of them were eaten by deer every year. Oaks cannot survive to maturity under this scenario, as it takes about ten years for them to grow tall enough for the tops to escape deer browse.

Maples and oaks are commercially valuable species in the working forest. The same cannot be said of beech. Ever since the arrival of Beech Bark Disease, which was imported about 100 years ago and hit VT in the 1960s, beech trees, never the most-prized timber tree, have declined in health and value. The disease has killed many and does not allow new beeches, that readily grow as suckers from the roots of old beeches, to become large or vigorous. In spite of the disease, beech is staging a takeover of many forests and woodlots as a result of the browse pressure on maples, oaks, etc. Some actual numbers come from New York state where biologists reported that about one-third of forests in NY were compromised by excessive browsing.

There are other changes that are less noticeable to people, but nevertheless very important. This includes severe and long-lasting depletion of native wildflowers, with some species never recovering even when deer were excluded from the area. The early spring availability of nectar and pollen from spring ephemerals is critically important to the health and success of native bees and other pollinators for the rest of the season. In nature, everything is connected.

Birds too, may suffer. The Audubon Society reported that eastern wood pewees, indigo buntings, least flycatchers, yellow-billed cuckoos, and cerulean warblers are negatively impacted when deer populations exceed 20 deer per square mile. Higher deer densities start to drive out ground nesters, including ovenbirds, grouse, woodcock, whippoorwills, and wild turkeys.

The most important deer predator by far is humans. Coyotes are often cited; however the VT Fish and Wildlife Department acknowledges that deer taken by coyotes in winter are already debilitated and destined to starve. Apart from exceptionally severe winters, predation of adult deer by coyotes is minimal. Four-legged predators do not regulate the size of the deer herd.

That responsibility rests with the Department of Fish and Wildlife. They are tasked with the balancing act between pressure to increase the deer herd for hunting and hunting license revenue, the health of forests and agriculture, and perceptions of the general public about deer and hunting. Thus deer herd managers assert that 20 deer per square mile keeps them in balance with their food source, while foresters would prefer the density to be in the order of 5 per square mile.

To give VT F and W credit, they did introduce measures to reduce the herd size beginning in 1979, by allowing antlerless does to be hunted. (Shooting bucks alone does not impact herd size since it only takes one buck to impregnate many tens of does.) At that time, the deer population was estimated at 250,000. In 2021 the population was estimated to be around 130,000, with deer at about 22 per square mile in some places.

While homeowners bemoan the damage that deer inflict on gardens and plantings, they need to recognize their role in the problem. Gardens, lawns, and clearing edges offer a very nutritious diet to deer, allowing them to breed more successfully (twin fawns from a pregnancy.)

House lots encroaching on woods put entire areas off-limits to hunting, the only means of deer control. Likewise, posting blocks of land has the effect of making hunting impracticable across a wider landscape by interrupting continuity. By inadvertently feeding deer and deterring hunting, suburban creep into forests contributes to increasing the deer population.