Mother Deer Protect Their Future Dominant Males While They Are Still In The Womb
March 7, 2013

Mother Deer Protect Their Future Dominant Males While They Are Still In The Womb

Michael Harper for — Your Universe Online

A new Brigham Young University (BYU) study has delved into the longstanding debate of “Nature versus Nurture,” proving that dominant male deer are often the result of a mother´s extra special care.

According to the study, led by BYU student Eric Freeman, and published in the latest issue of PLoS ONE, a mother deer knows when her male offspring will be a great leader of deer, even as the male is still in the womb. This extra attention gives the male deer an extra hoof up on the competition, helping him take his place at the top of the herd.

“Our research demonstrates clearly that a mother´s investment in her offspring was evident during adulthood, even though offspring live independently of their mothers from a very young age,” explained Brock McMillan, the associate professor of wildlife ecology at BYU.

McMillan also claims that the mother´s intuition about their unborn male begins while the baby deer is still in the womb. While pregnant, the mother will ensure her best health for the benefit of her new baby deer. Once the male deer is born, the mother will continue her healthy habits to provide more nourishing milk for her son. She´ll also hunt out the best places for her family to live, safe from predators and other dangers.

McMillan also says that while a mother´s care is key to determining which male deer will emerge as the “Great Prince of the Forest,” there are other factors at play, namely the human effect.

Deforestation and other human behaviors have slowly dwindled away the natural habitats of many species. With tightening spaces in which to live, these deer are often brought into close quarters with their predators, such as wolves.

According to Freeman and McMillan, these factors also play a part in determining which deer will become the dominate male. Yet, even with these factors in place, the first few years spent with the mother can prepare a male deer for even the harshest of environments and habitats.

“Male deer and elk live independently of their mothers for several years in highly variable environments,” said McMillan. “They live through severe winters with deep snow and little to eat, dry summers with poor quality food and years of injuries and ailments associated with everyday life. Even with many years of exposure to the environment, the maternal effect was still evident.”

To study the mother´s effect on male deer, the BYU researchers studied species from Colorado, Montana, Nevada, New Mexico, Utah and Wyoming. Specifically, these students studied the antlers of deer which had been hunted from these areas. The research team did not take part in hunting any of the deer themselves.

Analyzing the antlers, the BYU team was specifically looking at the size of the antlers to determine sexual selection and male dominance. The team then compared this data with climate data from the year the deer was born. Combining these data points, the team concluded that those deer which received better nurturing were more likely to become dominate males.

“In this case,” write the authors in the study, “antler size is the maternally-influenced trait, indicating that the offspring of females in good condition will likely have larger antlers, a sexually selected trait.”

In closing, Freeman says points learned in this study can also be observed in humans.

“For those unconcerned about deer or elk, this research can be a reminder that similar research exists for humans,” he said. “Conditions experienced in utero affect offspring throughout their life even in long-lived species.”