Jerkasourous of the non-typical kind
Loc: Nashville, TN
This is a topic I've wanted to discuss for some time, but didn't really have the data to prove my point. However, as more detailed GPS-collar data is becoming available, I think I can post this with some conviction.|
What should be used as a measure of QDM success for a given property? In the traditional sense, herd health indicators, especially deer body weights by age and buck antler development by age has been used, as well as fawn recruitment numbers, buck age structure numbers, sex ratio numbers, etc.
However, all of this is based on the idea that you are looking at the same group of deer that live on a given property from year to year. Now this very well may be the case on very large properties, say of several thousand acres. But what about the small properties, such as those of 1,000 acres or less? And more importantly, what about properties of a square mile (640 acres) or less? How many individual deer are you actually "raising" from birth to death on a property of 640 acres or less? I'll bet the answer is very, very few.
From what I've been seeing of the more detailed long-term GPS-collar information that is becoming available, there appears to be a lot more "shifting" of ranges from birth to death than was originally assumed. This is especially true of bucks. When you consider the Yearling Buck Dispersal (YBD) process, shifting seasonal ranges, and highly variable rut-season ranges for individual bucks, how many of the mature bucks that might be photographed on a 640 acre or smaller property in a given fall season were actually born on that property? I'll bet the answer is near zero. The vast, vast majority of those bucks come from "somewhere else." If that is the case, does the condition of those bucks mean anything about the management of the property? Nope, at least not health-wise.
And although does are more "home-bodies" than bucks, often living their entire lives in their birth range, on smaller properties that have implemented intense doe harvests, from year to year how many of the does seen and harvested from the property have actually lived their entire lives on that property? When small properties hit the doe population hard, reproduction does increase, but if does are not being hit hard on surrounding properties, doe groups from those surrounding properties will shift their range into the managed property to take advantage of the "gaps" in habitat utilization produced by the doe harvests. This means you do have "resident" does born on the managed property, but you also have a considerable number of "immigrant" does that have shifted into the property from surrounding properties as adults. So health conditions of the immigrant does do not provide a measure of herd health from the managed property, and there is no way to tell the difference between a resident doe and an immigrant doe.
So now we have this established "paradigm" of QDM success based on improvements in herd structure and health that may simply not be true on smaller properties. The deer using a particular smaller property during the hunting season--especially the mature deer of both sexes--may not be the product of the local habitat. Many of those deer spent at least some of their life, if not the majority, "somewhere else."
If this is the case, what should be used as a measure of success on smaller properties?
"Know where you stand, and stand there" --Jesuit Father Daniel Berrigan
"There is no reasoning someone out of a position he has not reasoned himself into." --Clive James