Rut; Love Crazy vs. Zombie Deer
November in Texas, and love is in the air. November is pretty much right in the middle of rut season, or breeding time, for white-tailed deer. The rut season can start as early as the end of September and may last all the way through the winter months.
There are an estimated four million white-tailed deer living in Texas. Deer do not migrate, but they remain in an area around one square kilometer in size (which is less than ½ a square mile). They are often solitary animals but can be found in herds ranging in various sizes, although males and females generally stay separate for much of the year. However, bucks are likely to travel around much more during the rut season as they search for does. Rutting behavior typically begins around the time that velvet is shed from the antlers (which also coincides with the seasonal decrease in day length and increasing testosterone levels in the bucks) and ends when bucks’ antlers are shed (coinciding with declining testosterone levels). Sparring and marking behaviors will be seen when rut begins; the bucks naturally rub against trees to remove the velvet from their antlers. This behavior continues with rubbing and scraping, and each buck leaves his scent on the trees he rubs on (this is from a scent gland located between the buck’s eyes, just below the antlers). This is a way to mark territory, and to announce to other bucks and does “who” is in the area looking for love. This continuous rubbing on trees, as well as the increased amounts of testosterone, causes the bucks’ necks to swell. During most of the year, bucks tend to avoid each other, but sometimes in the early spring and summer some sparring will break out to establish dominance prior to rut. If this dominance has not been established prior to rut season, then fighting between bucks may occur if a challenger approaches a more dominant, buck. The dominant buck will often posture, which includes their back hair standing up, approaching each other at a sideways angle, ears back, and walking stiff legged. If this display of dominance doesn’t dissuade the challenger, then a fight will generally break out. At this point, heads will be lowered, and the bucks will head butt each other and use their antlers to fight. Usually, one buck overpowers the other and the challenger is driven off. Since the rut season can last for several months, the continuous fighting can be very hard on the bucks and can cause some to die. The bucks that survive and establish their dominance are the ones that will breed with the does; at this point, vocalizing and lip curling can be observed, which usually means that a receptive doe has been observed by the buck. Because bucks are more aggressive and territorial during rut, this is also a time of year when they can be more dangerous to people and domestic animals. Their hormones are raging, and they can just be downright cranky. For some bucks, their urge to mate is so intense and they are so preoccupied with establishing their dominance that many bucks may not even eat much during rut (so does that mean they may be “hangry” too? Could be!). Extra vigilance is always a good idea during rut season because bucks are continuously on the move. Even if not provoked, hormonal, hungry, all hyped up is never a good combination, so bucks might attack a person or other animal they perceive as a rival, and their sharp hooves, powerful kicks, and sharp antlers can extremely dangerous.
In Southeast Texas, rut typically runs from about mid-October to mid-November. Once their testosterone levels drop and the bucks shed their antlers, the rut season comes to an end. After rut, deer may remain together in herds for the remainder of the winter months. Gestation for the does is about 200 days, so in late spring/early summer, the herds break up again, with bucks going their separate ways and does going off on their own to give birth to their fawns.
All the above attributes constitute normal behavior for white-tailed deer, even when they might act a little “crazy” during rut. However, “zombie deer” (a term being used a lot lately) addresses a completely different issue. Zombie deer is a real thing, referring to deer suffering from Chronic Wasting Disease, or CWD. Chronic Wasting Disease is a neurological disease in deer, elk, moose, and other members of the deer family, known as cervids. This disease was first recognized in 1967 in captive mule deer in Colorado (in a deer-breeding facility) and it has since been documented in captive and free-ranging deer in many U.S. states as well as two Canadian Provinces and South Korea. The first case of CWD in Texas was discovered in 2012 in free-ranging mule deer in an isolated area of far west Texas. CWD has been found in mule deer and white-tailed deer in captive breeding facilities throughout the State of Texas as well as free-range mule and white-tailed deer in far west Texas and the panhandle. To see specific cases documented throughout Texas since 2012, you can go to this link on the website of Texas Parks and Wildlife: https://tpwd.texas.gov/huntwild/wild/diseases/cwd/tracking.
Chronic Wasting Disease is contagious; it can be transmitted freely within and among cervid populations. No treatments or vaccines are currently available. Chronic wasting disease is of great concern to wildlife managers. Chronic Wasting Disease is not known at this time to infect livestock or humans. This disease is transmitted directly through animal-to-animal contact, and indirectly through contact with objects or environment contaminated with infectious material (including saliva, urine, feces, and carcasses of CWD-infected animals). It also seems that does can transmit CWD to fawns in utero. Chronic Wasting Disease (CWD) has a long incubation period, averaging 18–24 months between infection and the onset of noticeable symptoms. During the incubation period, animals look and act normal. The term “zombie deer” comes from the way deer affected with CWD behave when symptoms appear. Once the disease is active, the most obvious sign of CWD is progressive weight loss. Numerous behavioral changes also have been reported, including decreased social interaction, loss of awareness, drooling, drooping ears, excessive thirst and urination, and loss of fear of humans. Unfortunately, all CWD symptoms can have other causes and could lead to misdiagnosis of the condition if the animal is not specifically tested for CWD. If you have concerns about a particular deer, please contact your local game warden or TPWD biologist, or call the Texas Parks & Wildlife Information number at 800-792-1112. Wildlife rehabilitation centers or individual rehabilitators are no longer allowed to intervene or assist with any adult deer in Texas due to concerns over CWD; rehabbers are only allowed to care for spotted fawns.
To learn more about what we do and view pictures of many of the animals we assist, please visit our Facebook page at www.facebook.com/SavingTexasWildlife. Details and specifies-specific flowcharts regarding how to help found animals can be found on our website www.ftwl.org (click on “Help and Advice”).
These charts are extremely helpful to determine if an animal truly needs rescuing or not. If you need assistance with a wildlife animal you may have found, please call us at 281-259-0039 or
email us at [email protected]. We offer many educational programs (including camps, birthday parties, educational presentations, and Second Saturdays). Our educational visitor’s center is open the second Saturday of each month from 10 a.m. to 2 p.m., located at 29816 Dobbin Hufsmith Road, Magnolia, Texas, so the next date is Saturday, November 13 ($5 per person, kids 3 and under are free).