Scientists study nutrition in moose

Posted: Friday, April 29, 2005

PALMER — It's a sight that has caught more than one passer-by off guard: five moose in a pen at the University of Alaska's experiment farm, including four calves wearing halters and a 3-year-old cow with a dish-sized rubber plug stuck in her side.

It's not a new Mat-Su zoo or some high school prank gone awry.

Rather, the moose are being kept in the 12-acre pen as part of a nutrition study being conducted by Palmer-based state wildlife biologist Bill Collins and University of Alaska Anchorage professor Don Spalinger.

The two hope the work, started last year, will answer some basic questions about moose dietary needs. But it could also help solve a mystery that has puzzled biologists for years — why aren't there more moose in the Nelchina Basin?

Moose in the popular caribou and moose hunting area off the Glenn Highway have relatively low calving rates, low rates of twin births and tend to give birth for the first time at an older age, Collins said.

Predators are thought to be part of the problem. It's one of a handful of places where state officials have authorized aerial shooting of wolves in hopes of boosting moose populations.

But what Collins and Spalinger are trying to figure out is whether a lack of good food, not sharp-toothed enemies, is also playing a role. Specifically, they wonder if the willow, aspen and other plants in the area, while abundant, lack enough usable nitrogen to support a larger moose population. Moose need nitrogen to survive like humans need protein, Collins said.

It requires some unique work to find not only how much nitrogen is in the plant, but how much the moose is absorbing, Collins said.

In one of the more interesting experiments, Collins grinds up bits of willow, fireweed and other moose browse, stuffs it in nylon tea bags, then sticks the tea bags directly into the cow's gut through the plug in its side.

After an appropriate amount of time, he removes the tea bags by pulling on an attached string, dries them out and measures what's left. The difference between the starting and finishing weight tells him how quickly the moose is digesting the food, he said.

In another test, the moose are confined to a stall and fed specific diets.

Collins and Spalinger then measure the nitrogen levels in the moose droppings and urine, which are collected in grates and traps below the stall. That tells them how much nitrogen the moose are absorbing.

It's not exactly glamorous work, admits Collins.

But it is unique research, said boss Earl Becker, a state fish and game official who oversees studies for the wildlife conservation division's Southcentral region.

Few biologists have looked in-depth at nutritional requirements for moose, Becker said. The most obvious reason is a lack of subjects. Tame moose are hard to come by, he said.

The tedious nature of the work is also a factor.

Collins spent three weeks last fall handpicking willow leaves to feed the moose. He and Spalinger also gathered fireweed, aspen and willow twigs, all of which had to be picked by hand, freeze-dried and put into cold storage in Anchorage.

The work is also a perfect fit for Collins, said Becker, who described the biologist as a ''MacGyver with a Ph.D.''

Collins, 56, has spent much of his life studying wild animals, including mule deer and moose, he said. It's a subject he can talk about at length, so much so that his wife warns visitors not to ask questions about his work, he said.

''My biggest problem is knowing when to shut up,'' he said.

He clearly enjoys working with the moose. All were orphans that were hand-raised, he said. During a recent tour, they followed Collins around like ducklings and eagerly crowded him looking for treats.

One key to understanding his research, he said, is how different moose are from humans, not just in what they eat but how they process food, he said.

Humans digest the food they eat to break down the protein and other key nutrients.

Moose, on the other hand, build proteins inside their stomachs, using nitrogen from plants they eat. Like a mini-factory, they ferment the plants, pulling the nitrogen out, which feeds bacteria that live in their gut. The moose then digest the bacteria, which contain the protein they need to survive, Collins said.

Too little nitrogen and the animal starves, which is why moose can die with a full stomach, he said.

Collins, thrifty by nature, is doing the work on a shoestring, Becker said. The department has $18,000 in federal funds budgeted for the study, but Collins may not use that much.

He and Spalinger built the pen themselves using 8-foot-high fence tied to steel posts. They used borrowed equipment from the experiment farm, and the fencing came from the state Department of Corrections, which had used it to keep reindeer at the Point MacKenzie prison, Collins said.

The total cost including the stalls was about $2,000, Collins said.

The work isn't far enough along to yield any conclusive results. Spalinger said they hope to know more by next year.

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