by Dr. Sarah Treanor Bois, PhD
Director of Research & Education at the Linda Loring Nature Foundation
There is a crispness in the air now as fall begins to settle in. Among the changing leaves and cooler temperatures, another change is happening. For our whitetailed deer population, fall is the most romantic time of the year: the rut.
The rut is the magical season when deer are breeding and more active than any other time of the year. Bucks have shed the velvet from their newly grown antlers and get aggressive with each other fighting for territory and female attention. The females go into estrus and everyone is “twitterpated.”
Because the hunting season coincides with the rut, the whitetail deer rut is one of the most studied breeding cycles, so you’d think we’d have had it all figured out by now. And while we do know a lot about the rut, there is still some debate about what causes peaks and duration.
The rut can range from several months in southern states like Florida to a short window of time in the fall in the Northeast. For white-tailed deer in Massachusetts, the rut lasts for about three weeks (but is still variable) generally starting late October. The exact timing of the rut varies by photoperiod. Contrary to popular opinion, the rut is not influenced by moon phase, weather changes, or planetary alignments. Bucks are ready as soon as their antlers shed the velvet in September, but the females come into estrus later. Photoperiod (amount of daylight each day) is what triggers females to come into estrus, and the does dictate rutting activity. The peak of the rut is about the middle of that three-week period. In Massachusetts, peak rut activity takes place between November 6 and November 20 each year.
You may notice some signs as you walk through conservation lands around the island that bucks are getting ready for the rut. The first thing you may notice are rubs: trees or thick shrubs where bucks have rubbed their antlers against the wood. They do this to build their neck muscles for fighting and start to scent-mark their territories. I have even found rubs on the wooden 4×4 posts at the Linda Loring Nature Foundation where we mark the trails. Apparently, any wood will do.
Another thing that is less obvious to a non-hunter/outdoors-person are scrapes. Scrapes are also created before the rut and will be noticed as small clearings on the ground. The bucks use their hooves to scrape away leaves and expose a patch of fresh soil. They then mark the area with their scent glands and with urine. Bucks almost always position their scrapes under overhanging tree branches. The males scent-mark the branch by licking it and rubbing their orbital gland (near their eyes) on it. These scrapes are a form of scent communication among deer. Other does and bucks may be attracted to these areas and will urinate on the scrape to leave their own scent. From these scents, a buck can determine the sex and reproductive status of other animals in the area. Scrapes are seen along swamp or field edges and sometimes clearings among trees.
As does come into estrus and the rut truly begins, all the deer are more active. Bucks chase does and “harass” them until ready to breed. Because of this, it is also the time when more deer are hit by cars than any other time of year. During the rut, bucks can lose up to 20% of their body mass since they are so focused on breeding. Once the rut tapers off, the bucks will go back to eating and regaining the weight they had lost.
Generally, white-tailed deer are herbivores and consume a wide variety of herbaceous and woody plants (including my garden, I might add). As we go from fall into winter, the deer diet begins to change with the season. In fall, and early winter, hard mast such as acorns and beech nuts as well as soft fruits such as apples are a major part of their diet. With the onset of winter, the deer begin to feed on hard browse (twigs, shoots, hardy leaves, and buds) and can spend time in evergreen and conifer cover to seek shelter from the wind and snow. Deer also physically prepare for winter by better insulating their bodies. In the fall, deer gradually trade their summer hair coat for a thicker, longer coat and darker hairs called guard hairs, while also growing in a much thicker undercoat.
As the deer change behavior with the seasons, so do our local hunters and wildlife observers. People begin to track deer patterns looking for signs of the start of the rut. Deer hunting season on Nantucket (zone 14) starts in October. Hunting on Nantucket has become a popular activity, especially bow (or archery) hunting. Nantucket has one of the highest deer densities in the Commonwealth of Massachusetts. Based on the last few years of hunts, among other studies, Nantucket and Martha’s Vineyard have estimated deer densities of more than 50 per square mile, according to the Division of Fisheries and Wildlife. As a benchmark, a study from Pennsylvania found that the threshold density where deer begin to have serious negative impacts on forest vegetation is at more than 20 deer per square mile. For Nantucket, we have more than double that threshold level leading to serious negative impacts to vegetation.
New England blazing-star (Liatris novae-angliae), a state listed plant species, is a favorite deer snack as is the state-endangered Lions’s Foot (Nabalis serpentaria). The latter species almost exclusively reproduces in the grasslands inside the airport fence—a natural deer exclosure. Just outside of said fence, the flowering stalks of the Lion’s Foot are munched even before setting seed.
Another major conservation concern is the impact white tail deer populations have on non-native invasive plants. Since deer mainly prefer the native flora they are accustomed to, they preferentially eat the native plants, giving the non-natives an even greater competitive advantage. This has been documented with garlic mustard (Alliaria petiolata) among other species.
Many notable ecologists and conservationists suggest that to be a true plant conservationist, you must support appropriate, ethical deer herd reductions. Deer hunting is a time-honored tradition and a great way to get some sustainable protein in the freezer for the winter. Hunting is also a necessary management tool used by land managers across the island. While you may not be a hunter, you may be able to enjoy the spoils as I do. More simply put: Save a plant, eat a deer.
For the Nantucket Conservation Foundation, the island’s largest land owner, hunting is an important part of responsible land stewardship for many of their properties. As they say, “We encourage all visitors to our (NCF) properties at this time of year to be respectful of hunters, keep pets leashed, and wear brightly colored, highly visible clothing, especially during the two-week shotgun season window. Hunters should be alert and courteous to pedestrians, bicyclists, dog walkers and their pets, and other non-hunters who are out enjoying Nantucket’s open conservation lands.” For details on NCF’s hunting policies and which properties are open to hunting, visit nantucketconservation.org/properties/hunting. Massachusetts Hunting Calendar: mass.gov/info-details/deer-hunting-regulations
Youth hunt day is October 2nd. Archery season goes from October 4 through November 27th. Shotgun season is November 29th to December 11th and primitive firearms is from December 13 to the 31st. Hunting hours begin ½ hour before sunrise and end ½ hour after sunset. Hunting is prohibited on Sundays.