Leo Tolstoy once stated that the most important advice he could give would be to “stop a moment, cease your work, look around you.” It’s doubtful Tolstoy had white-tailed deer in mind when he said this, but surely this advice applies to cervids, especially those living near areas that attract walkers, joggers, and cyclists.
Over the past year, a team of biology students from Mitchell Community College have used trail cameras to monitor deer activity throughout greenway patches in Statesville, NC. These cameras have been used to estimate deer population, but researchers have also used them to compare deer activity in different areas. Two groups of cameras were used. Cameras in group A were placed deep in the woods away from human-made recreational trails and group B cameras were placed less than 25 m from the actual greenway trails. The researchers were interested in knowing if deer activity differs as the deer get closer to human used trails. During a 3 month period in the fall 2016, the cameras collected 139 pictures of deer on trails or less than 25 m from the trails and 522 pictures of deer in the deep forest. The pictures were then analyzed. Figure 1 shows the results.
Deer activity around trails peaks around 8:00 a.m., then drops off significantly. Activity is pretty much nonexistent around trails from 10:00 a.m. to 5:00 p.m. The deer don’t start using the trails again until after 6:00 p.m. On the other hand, deer activity in the deep woods peaks close to 9:00 a.m. and does not hit a low point until 11:00 a.m. During the day, deer activity in the deep woods stays consistently higher than activity along trails. White-tails tend to rest during the day in areas of highly dense vegetation. However, they are not resting for long periods of time. They are alternating between moving, eating, and resting. Our data suggests that this cycle occurs in the deep woods during the daytime hours. Is it simply because that’s where the vegetation is or do human-made trails have something to do with it?
Notice that right around 8:00 p.m., deer activity along the trails becomes higher than activity in the deep woods. It stays like this the entire night. There may be some simple explanations. It could be that the trails provide easier travel for the deer during the night. Maybe the deer are avoiding coyotes, especially when they have fawns to protect. The trails could also provide the deer easier access to the corn and bean fields nearby. Finally, maybe the deer know when people will not be out on the trails, and they purposely chose those times. Is it possible that the presence of people is what actually impacts the deer behavior on a daily basis?
While there is really no way to answer these questions from our small data set, there have been other studies over longer periods of time with more cameras that have looked at some of the same questions regarding this behavior.
Lashley et al. (2014) showed that female white-tailed deer, at baited sites, were 46% more vigilant when fawns were present. They also showed that does and bucks spent more time feeding as the size of the group increased, implying that there is safety in numbers for deer.
Parsons et al. (2016) found that prey species like deer avoided potential predators like dogs, humans, and coyotes in time, but not in space. The deer in this study did not greatly increase vigilance. The researchers concluded that dogs that are on the recreational trails with their human owners have a lesser impact on prey vigilance than free-ranging dogs.
More related to our study, Schuttler et al. (2016) analyzed the head posture of deer in over 3400 pictures to determine if deer are more vigilant in areas with both high human hunting and high coyote activity. What they found was not what they expected. They found that deer vigilance was actually lower in areas with high human recreation. This result is interesting because it may indicate that deer become habituated to human presence in areas such as our greenway spaces.
More than likely, there are a combination of factors that cause deer at this greenway patch to use the trails more during the overnight hours. In the future, more cameras will be used over a longer period of time to attempt to understand how these urban deer stay safe.