Bow hunters, like the elk they seek, undergo Metamorphosis in autumn

August 19, 2011 07:49 pm

The scents and sounds of rutting bulls draw the attention of sleek cows in the fall. JIM WARD photo
The scents and sounds of rutting bulls draw the attention of sleek cows in the fall. JIM WARD photo

In autumn, we bowhunters go through an annual metamorphosis. It starts out rather subtle. String fingers begin to twitch, senses become sharper and eery, elk-like calls begin to emit from evening showers. Dedicated hunters start to pour over topo maps and pre-scouting adventures begin. Mere weeks before the season opener, hunters bump up their exercise regimen and start pounding targets with carbon shafts.

Autumn brings changes to the elk herd as well. Good buddies all summer, bulls become irritable with each other. Itchy antlers get a good rub to remove the velvet and sparring matches begin. Soon they’ll become hardened warriors — friends becoming fight-to-the death enemies. Sleek cows become infatuated with the scents and sounds of the rutting bulls and seek their presence.

Gather around your typical bowmen’s campfire and you’ll often hear a plethora of information about elk behavior and their biology, along with the usual drivel about the big one that got away. An often-heard rendering is that weather determines the timing of the elk rut. Hot, dry weather will postpone a cow elk’s estrous cycle and therefore delay the bull’s need to bugle and chase cows. If the bulls aren’t bugling in “your” woods then they must not be in the rut yet.

Not so.

With that line of thinking, a long dry fall would push the conception period back several weeks and the end result would be very late calves the following spring. Late calves go into winter smaller and weaker making them more likely to succumb to the harsh weather. Keep that up and we’re looking at an extinct animal. Ma Nature has a better idea.

Much research has been conducted to better understand the life cycle of elk. One such compilation detailing a vast amount of research was the “Elk of North America” by past U.S. Forest Service Chief Jack Ward Thomas, and wildlife scientist Dale Toweil. Studies revealed that much of an elk’s biological patterns are governed by the amount of light they are subject to throughout the year. Decreasing daylight in the fall triggers the pineal gland, through the eye, and increases hormone levels, preparing the elk for their reproductive cycle. Sunshine, rain, snow, hot or cold — the cows will begin estrous the same time every year and the bulls will respond accordingly.

One such study actually involved putting elk into enclosed buildings with their lighting controlled by timers. The elk were subjected to an intentional shorter light schedule and forced into a condensed rut period —  whenever the light simulated a fall pattern. Bulls grew two sets of antlers in one year. Of course this put a huge drain on their health.

At the Starkey research facility, northwest of La Grande, much has been done to understand other elements of elk biology. Their breeding bull study revealed some interesting facts. Wild elk were surrounded by a 40-mile fence. At the start, only yearling bulls were allowed to participate in the rut. Cows were tested to determine their conception dates. Each year, as the bulls got older, the conception period got shorter and earlier. The yearling bulls took 71 days to finally impregnate all the cows. When they were 5, they only took 41 days. The peak conception date, for the cows, was Sept. 28 when yearling bulls sired the herd. It was Sept. 14 when the 5-year-olds were sires.

According to Bruce Johnson, leader of the study at the time, the Starkey Breeding Bull Study merely confirmed what most biologists already knew. “A higher ratio of older bulls is needed in the elk herds to promote an earlier and more synchronous calving period in the spring,’’ Johnson said.

Shortly after the study, the Oregon Department of Fish and Wildlife began to limit the number of mature bulls harvested by hunters. Johnson pointed out that “much of this effort was already under way as the state’s low bull ratios were becoming socially unacceptable among those concerned about the animal’s well-being.’’

So, what do pineal glands, estrous cycles and synchronous calving periods have to do with hunters? In essence, hunters are predators and the most successful predators, whether they move with two legs or four, are those that learn the particular nuances of their prey.

One on one, elk have a distinct advantage over the hunter. They run faster, have much better senses and know their habitat better. Over the years, hunters have developed tools to close that gap — high-tech bows, range-finders and state-of-the-art clothing. But, all the gadgets in the world won’t guarantee success. The most successful hunters spend a good deal of time in the field — learning their quarry’s habits and habitats. Ample time at the practice range, and becoming intimate with the tools at hand, is all part of a seasoned archer’s tactics.

Become a better woodsman, sprinkle in a little luck and come September you may find yourself in a rut.

Jim Ward lives in La Grande and has hunted elk for more than 50 years. He is a frequent contributor to The Observer and a regular contributor of wildlife photos, for which we thank him immensely.