|White-tailed deer bucks seek receptive does during the rut but their strategies are only now becoming clear as a result of new technology to track deer movements. Understanding these movements may benefit both hunters and deer managers.|
In Search of Receptive Does? What Buck Movements Reveal
By Stephen Webb (Biostatistics Specialist, The Samuel Roberts Noble Foundation) and
Ken Gee (Wildlife Research Specialist, The Samuel Roberts Noble Foundation)
In an earlier feature (White-tailed Deer Buck Movements During Rut) of Trophy Points, David Hewitt, B&C Professional Member, discussed preliminary data collected by the Caesar Kleberg Wildlife Research Institute on buck movements in southern Texas using GPS collars. The insights gained by the researchers began to tell a story of the drive that bucks have to breed during rut. As the rut progressed, movements increased, likely as the result of searching for receptive does as well as tending bonds that are formed for ~24 hours when the doe is in heat. Besides the biology gleaned from this study, hunters also should take note of how buck behavior changes during rut to maximize hunting success over a short period when bucks seem to go "crazy!"
From 1998-2005, research conducted by The Samuel Roberts Noble Foundation in southern Oklahoma used GPS collars to determine short-term movement behavior of bucks during reproductive periods. The GPS collars collected 1 location every 15 minutes for ~3 months, allowing researchers to piece together deer movements that previously were unattainable using earlier technology.
During rut, bucks moved an average of 4.6 miles/day. Although this distance was less than the Texas study, movement of bucks during the rut in Oklahoma exhibited the same pattern of increasing movement distance leading up to the rut and then declining during post-rut. Like Hewitt pointed out in his article, there is a lot of individual-to-individual variation…there is also population-to-population variation in movement distance that may stem from the landscapes deer use on each study area as well as population density, sex ratio, age structure, and hunter access.
In another study using the same data as mentioned above, Oklahoma researchers used a new technique called fractal dimension to describe deer movements. Fractal dimension is used to describe the complexity or linearity of the travel paths used by deer. For example, linear paths may be used to traverse larger areas or when searching for resources (and this includes the search for receptive does during rut!) whereas complex paths indicate that a deer is using a smaller area more intensively.
|Deer that shows very intense use of locaized areas with some linear movements to other portions of its home range, including some excursions outside of a 95% kernel home range boundary.||Deer that shows less tortuous movement behavior (relative to deer at left); more linear movements with short-term use of some localized areas and definite travel routes. Deer also makes excursions outside of its 95% kernel home range boundary.|
We know from these studies that bucks move more during rut, but what pattern do they use when searching for does? Movement distance could be the result of many short distance travels in which the deer frequently changes direction, or it could result from long, linear movements in which deer tend to stay on the same path. Therefore, we must use both movement distance and path complexity to fully appreciate the behavior of bucks during rut. During rut, bucks exhibited linear movement paths, which when coupled with increased movement distance, reveals a picture of seeking behavior. This means that deer are travelling longer distances, in straighter lines, to maximize their chances of coming into contact with estrous females. At other times of year, bucks use smaller areas more intensively (for instance, during the early hunting season).
Having this information, hunters now can “arm” themselves with information to help them bag that big buck. During the early part of hunting season, when buck movements are shorter and more confined, hunters may want to pattern bucks and hunt areas bucks are known to frequent (that means, estimate a buck’s home range and get in there and hunt for him). However, once the rut begins and bucks change movement behaviors, patterning bucks will be difficult, so the best bet for success will be to stay in the woods as much as possible and wait for that big buck to make an appearance!
Important points to consider:
- Bucks move less and confine their behavior to smaller areas prior to the rut (meaning, they stay within previously established home ranges).
- Buck movements are greatest during rut. Our data indicate that bucks change movement patterns within previously established home ranges, but other studies have reported bucks wondering outside of normal, pre-rut home ranges.
- Bucks exhibit searching behavior during rut with linear movements resulting in deer using all portions of their home range when in search of does. This is in contrast to other times of the year when deer behavior is concentrated in centralized areas within a smaller portion of their home range.
- After rut, movements decrease as deer return to their normal behaviors, using their home ranges more intensively which may help them recover after the stresses of the rut.
For further reading (available free online):
Webb, S.L., K.L. Gee, B.K. Strickland, S. Demarais, and R.W. DeYoung. 2010. Measuring fine-scale white-tailed deer movements and environmental influences using GPS collars. International Journal of Ecology 2010, Article ID 459610, 12 pages.
Webb, S.L., S.K Riffell, K.L. Gee, and S. Demarais. 2009. Using fractal analyses to characterize movement paths in white-tailed deer and response to spatial scale. Journal of Mammalogy 90:1210-1217.
Stephen Demarais (Mississippi State University), Bronson Strickland (Mississippi State University), and Randy DeYoung (Caesar Kleberg Wildlife Research Institute)
Trophy Points: Big Game Research On Line is complied and edited by David G. Hewitt, a Professional Member of the Boone and Crockett Club and the Stuart W. Stedman Chair for White-tailed Deer Research at the Caesar Kleberg Wildlife Research Institute.