tree_ghost,
Years ago, I set up and ran a study on my place looking at the number and location of rubs on the property each year. The study was run by creating a series of "survey lines" across the property. These were developed by generating random starting locations, as well as travel directions and distances. I permanently marked these survey lines with stakes and flagging tape so we could use the same lines year after year. Each year, well after the season and rut were over (usually mid-February), we would walk these survey lines and measure and record every rub we found that was within 10 meters of the survey line. We would record a number of characteristics of each rub, such as the diameter of the rubbed tree, species of tree, height of the top and bottom of the rub, and the habitat and terrain the rub was in. Basically, these survey lines and the area 10 meters either side became long, narrow sample surveys of rubs on the property. From this, we could calculate rub densities by habitat type and terrain type, as well as the average rub density for the entire property for each year of the survey.
At first, I was comparing these annual rub density numbers to herd dynamics data generated from hunter observation data, but not long into the study I was able to compare against more accurate photo census generated herd dynamics numbers. As a general rule, differences in rub densities from year to year could be attributed to changes in annual herd dynamics. However, there were a couple of "fluke" years that just didn't match that pattern. It was only later, when playing around with the data, that I realized acorn crops were also playing a big role. In essence, when comparing years with similar acorn crops, herd dynamics differences would explain differences in rub densities. But when comparing years where the herd dynamics were the same, it was acorn crops that were driving differences in rub densities. In fact, extreme differences in acorn crops produced extreme variations in rub densities, even more so than herd dynamics.
So the take-away from this study was, yes herd dynamics are a strong player in buck rubbing activity, but extreme variations in acorn crops can be a much bigger player in rubbing behavior than herd dynamics.
