Saturday, August 29, 2009

New Study Says Every Buck Has A Shot

from the Outdoor Wire:

FEATURE
New Study Says Every Buck Has A Shot
For those of us who were never the alpha male of our crowds, reason to take heart. It seems that even in white-tailed deer, long thought to be reflections of the dominant buck due to the domination of does, that ain't necessarily so.

As a study from the Journal of Mammology was headlined "Every buck has a shot".

The study, conducted in Texas, Oklahoma and Mississippi, used DNA sampling rather than empirical observations of herds to determine genetic paternity. And, when it comes to mating patterns, a the study http://allenpress.com/system/files/pdfs/emails/2009/08/mamm-90-04-946-953.pdf finds that among white-tailed deer, every buck has a shot at contributing to the next generation.

Previous studies of the mating habits of deer have focused on behavioral observations, and it appeared that a few dominant, mature bucks obtained most of the matings and therefore likely sired most of the offspring each year. But the new study using genetic paternity tests (rather than observations) produced unexpected results.

This study finds there is a wider distribution of age and physical maturity among fathers of white-tailed deer.

The study, published in the August 2009 issue of the Journal of Mammalogy, bucks long-standing assumptions about white-tailed deer mating patterns.

Studies characterizing male reproductive success as highly skewed with a small number of mature dominant males monopolizing breeding are criticized for depending too heavily on behavioral observations and circumstantial evidence. This study, however, found that physically immature males1.5 to 2.5 years of age fathered 30 to 33 percent of offspring in the populations examined, even where larger, mature males were present (spare me the "babies having babies" comment, OK).

Dominating the social organization might not guarantee reproductive success. Other factors, among them ecological and behavioral variables may limit the ability of individual males to control access to females.

Young or subdominant males may be successful in fertilization by using alternative strategies that do not rely on dominance. In fact, those alternative strategies sound a lot like trolling the bar scene or cruisin for Cougars in humans.

The immature males think nothing about roaming - widely- in search of females in heat.

They also "pay proper attention" to a doe -the study says those younger males may spend 24 hours "tending" to a receptive female.

They also take advantage of something else uncovered in the study: evidence of female promiscuity that makes it easier for male deer of any age to find a mate.

Sound familiar?

The study sampled 1,219 deer from those three scattered populations. Total DNA was taken from either blood or ear-tissue samples, but antler material was also gathered and processed.

Three "captive populations" were studied from the Noxubee National Wildlife Refuge in Mississippi, the King Ranch in Texas, and the Noble Foundation Wildlife Unit in Oklahoma. Researchers say they provided different demographic makeups due to long-term differences in harvest and herd management. One location allowed public hunting, while another was more restrictive, using herd thinning as a management technique. Those differences made for a more diverse demographic, giving the research a better foundation. That made it easier to evaluate adult sex ration and male age structure on reproductive success.

Apparently, we share some common traits with our friends the white-tail.

EDITORS NOTE: The full text of the research article, "Molecular Evaluation of the White-Tailed Deer (Odocoileus Virginianus) Mating System" (Journal of Mammalogy, Vol. 90, No. 4, August 2009, published by Allen Press), is available at http://allenpress.com/system/files/pdfs/emails/2009/08/mamm-90-04-946-953.pdf. To learn more about the American Socity of Mammalogists, visit http:www.mammalsociety.org

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