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Old 12-26-2009 | 08:41 PM
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glew22
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This is some research I found that backs up my theory (not saying that my theory is true, just that this material supports it). It examined stress that develops in an overpopoulated deer herd. The reasearch was done by Ozoga and colleagues, and Jason Snavely wrote an article on the findings; this article can be found on the qdma website "Social stresses of an overpopulated deer herd." I will post exerpts, and my commentary will appear within brackets.

"What would happen if a deer herd (either fenced or unfenced) was provided with unlimited, high quality feed and allowed to grow unimpeded? Could deer be stockpiled like livestock at extremely high densities without detrimental effects? A landmark study conducted in Michigan nearly 20 years ago provided some answers to this very question. More on this study later.
While the impacts of nutritional stress associated with overpopulated deer herds have been well documented, the impacts of social stress in overpopulated herds is relatively poorly understood.

Well–established social positions minimize unnecessary energy expenditure and help maintain social order. For example, when food is scarce, the dominant doe will eat before subordinate does and yearling bucks [could be similar to a mature buck gaurding and defending a doe while a subordinate buck watches].

A study to explore the effects of high density on social stress in white–tailed deer was conducted in Upper Michigan by researchers John J. Ozoga and Louis J. Verme. These researchers supplementally fed an enclosed deer herd until it resembled a wild herd that exceeded the carrying capacity of the land. They provided unlimited feed and allowed it grow to 10 times the acceptable carrying capacity, over 100 deer per square mile.
Interestingly, the researchers found that as deer density increased the survival rate of fawns decreased. In other words, while there were more does to raise offspring, fewer were successful at rearing young due to density–related stress. Keep in mind that access to high quality feed was unlimited.

In the Michigan study, increasing deer density also affected antler development. When the deer density was low, yearling bucks did not exhibit short spikes. However, at higher densities, 22 percent of the yearling bucks grew short spikes as their first set of antlers. Keep in mind that proper nutrition was available even as densities increased to 10 times that which the natural habitat conditions could sustain. Ozoga and Verme concluded that, “Socially stressed male fawns experienced a physiological setback and probable sex hormone imbalance that impaired antler pedicle development.” ...Ozoga states the obvious that, “Undersized pedicles resulted in smaller–than– normal antlers.” While it is well documented that a lack of adequate nutrition will prevent a buck from reaching its full genetic potential, it is apparent that density related stress can produce similar effects. Biologists now believe that social stress may be affecting antler growth and fawn recruitment in some herds.

What are the management implications of this research? First, the study demonstrated that even with unlimited access to high quality feeds, social stress caused by overpopulation can have profound negative effects on a deer herd. At very high densities, the resulting social disorder increases competition for available food, increases energy expenditure, decreases fawn survival, decreases antler growth in bucks, and reduces the overall health of the herd."
Maybe I shouls have titled the thread "Effect of stress"

Last edited by glew22; 12-26-2009 at 08:44 PM.
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