Deer hunters know that bucks fight during the mating season, using their antlers as weapons, throwing their body weight behind them.

And for a long time, it was commonly believed that the biggest buck in an area sired the majority of fawns.

We know now, through DNA research involving those big bucks, and the annual crop of fawns, that isn’t the case. Often “lesser” bucks with smaller racks and bodies sire a number of fawns. That makes sense, especially if the buck-to-doe ratio is very high on the doe side.

Let’s imagine a scenario occurring during the peak days of November. Mr. Big Buck is dogging a doe, who is about to be ready to breed. He’ll stay with her, fending off all challengers, until the time is right. She can be bred for 48 hours. So for at least one day before she is ready, and for the two days she is ready, Mr. Big Buck is her constant companion.

And meanwhile, a number of other does have entered the “ready to breed” stage. Since Mr. Big Buck is tied up at the moment, the door to those other does is open to Buck Junior and his kind. But do the mature does actually prefer the bigger bucks? Are they made starry eyed (as we are) by the sight of a large set of antlers?

“While attractive to hunters, the antlers as ornament theory has never been proven,” said Duane Diefenbach, U.S. Geological Survey, Cooperative Fish & Wildlife Research Unit. Researchers from the USGS, the Department of Natural Resources/Bureau of Forestry, Penn State University and the Pennsylvania Game Commission are working together on a Deer-Forest study, capturing deer and applying radio collars and ear tags. The study area includes Rothrock, Bald Eagle and Susquehanna state parks. “We know bucks use antlers to compete with other males, and sure, it makes sense that those large bony protuberances might signal to a female that a male with bigger antlers has better genes.”

But proving that females actually choose males with larger antlers seemed to be an impossible task. The bucks with larger antlers have bigger bodies, so where females choosing large antlers or larger body size? And maybe there was no choice involved – the doe simply winds up with a larger male because he wins all the fights. In a blog, the Pennsylvania researchers shared information about a recent study in Mississippi.

Researchers at Mississippi State University’s Deer Lab set up an experiment to answer those questions about large antlers. In order to prove a theory – that the female deer made a choice – they had to come up with some game-changer ideas.

First, they gave males replaceable headgear. Hardened antlers are simply bone with no nerves, so they sawed off their antlers but left a projection above the burr of several inches. This became the base for interchangeable antlers of various sizes.

With this setup the researchers could mix and match antlers at will, on bucks of similar size. They set up 3 experimental pens in a row, with the female’s pen in between the two male pens. They put a female in heat (estrus) in the middle pen and similar body-size males on either side. The difference between males was simply their interchangeable headgear. Then they set up cameras to record how much time a female spent near the pen of either buck.

What did they find out? They repeated the experiment 25 times, and 20 times the females spent more time next to the pen with the larger antlered males.

“So are we finished studying mate selection in white-tailed deer? Hardly,” Diefenbach said. “There are other factors that likely influence mate choice, such as age, body size, and pheromones.”

How do those factors apply to the size of antlers to influence female mate selection?

“The never-ending curse of research,” Diefenbach said. “Answers simply beget more questions.”