CHEYENNE - A research project designed to provide wildlife managers with information on migration, habitat use and reproduction rates of moose in western Wyoming is yielding some valuable information that is giving biologists a better understanding of the Sublette moose herd unit.
The Sublette moose herd is one of the largest populations of the Shiras moose sub-species in North America. The herd was declining in the early 2000s but since 2006 has stabilized and may be slightly increasing. In 2010 the WyomingGame and Fish Department along with the University of Wyoming and the Wyoming Cooperative Wildlife Research Unit initiated research with the help of the Governor’s Office, U.S. Forest Service and private individuals. The study involves the capturing and subsequent radio collaring of moose allowing biologists to track movements andrecapture animals to gather additional information. Capture of moose began in 2011 and is focusing on the moose population on the eastern slope of the Wyoming Range.
During the study there have been up to 64 moose wearing radio collars at any one time. As the collared animals are recaptured, biologists are able to check on pregnancy and body condition and the presence of the arterial worm parasite elaeophora (ay-lee-off-er-a).
“We know that body condition of the moose that have died over the past four years has played a major role of their ability to survive the winter,” said Star Valley area Game and Fish biologist Gary Fralick. “We also believe that body condition is playing a significant role in reduced pregnancy rates.”
Fralick said that the pregnancy rate of the segment of the herd that spends the winter along the east slope of the Wyoming Range has averaged about 70 percent. While that figure is lower than originally thought, a positive is thatonce the calves are born the survival is around 90 percent through the first six weeks of life.
Another bonus of the radio collars is the information provided on migration. Collars have enabled biologists to accumulate data showing that some segments of the population are completely migratory, some are mostly sedentaryand another segment is conditionally migratory meaning that some moose may or may not migrate depending on body condition or if they produced a calf in the past spring. It was found that some cows with calves may stay in the area where they were born or may stay in one place until the calves are big enough to travel.
Fralick said that the study has provided wildlife managers with valuable insights on how moose move through their habitats from private land winter ranges to summer ranges on the national forest. “The migration factors alone are an understanding we didn’t have several years ago,” Fralick said. “It has opened up a whole new spectrum of the way we understand the Sublette moose herd.”
(Contact: Al Langston (307) 777-4540)