A preliminary study by the Alaska Department of Fish and Game shows moose numbers may be down on one area of the central Kenai Peninsula.
Poor habitat, predation and vehicle collisions have caused a decline in the moose population of Game Management Unit 15A.
This conclusion comes after wildlife biologist Jeff Selinger and his staff at the Soldotna office of the Alaska Department of Fish and Game conducted an extensive census study in the area north of the Kenai River, east of Nikiski and west of the Kenai Mountains. Selinger said biologists haven't reached the final count, but he has reached the conclusion that the moose population has decreased based on trend studies and a lower percentage of calves in the area. Despite this new information, he said that doesn't necessarily mean hunting in Unit 15A will be negatively impacted.
"With our hunting system down here, (we're now) having a negligible impact on moose," he said. "(Hunters are) only harvesting from a certain segment of the population, mainly bulls."
Biologists conducted their census by aircraft, dividing the area into a grid with rectangles about five and a half to six square miles each. Selinger said the aircraft flies down the center of each rectangle using GPS devices to keep track of the number of moose counted in each unit, classifying each one a high density or low density unit based on the number of animals counted. Once enough units have been counted biologists take a random sample and use statistics and a computer program to come out with an estimate of the overall moose population for the game management unit.
"You can do this type of survey in the fall if you have the right weather conditions," Selinger said. "There has to be relatively fresh snow so you can look for new tracks."
In the fall and winter biologists are able to determine the number of cows, calves and bulls. The bulls are further categorized into yearling bulls or bulls with spike-fork antlers or more than a spike-fork. Selinger said in the spring, when moose lose their antlers, biologists are only able to count cows and calves.
The last census count of moose in Unit 15A was taken in 2001. Selinger said Fish and Game conducts them every five years or so because they are fairly extensive and biologists are able to use them to get a sense of how the overall population is doing.
"The maturation of the habitat isn't there, predation is playing a large role as are auto collisions with moose," he said. "Relatively speaking you have a lower quality habitat in 15A than you had 10 years ago. (And) predator levels are probably relatively consistent."
Fire plays a significant role in the quality of habitat and health of animal populations. Two fires, one in 1947 and another in 1969 in Unit 15A, fertilized the soil and caused plants to release their seeds for new vegetation to grow. Selinger said good quality habitat can sustain healthy animal populations for up to 25 years after a major fire.
"Another fire would definitely help range conditions for moose, grouse and hares," he said. "Not just moose benefit from a fire like that, martin could definitely benefit from that (as well as) some of your avian predators."
Selinger said Unit 15A is one of the best game management units on the Kenai Peninsula to come up with a fairly accurate census count. The mature spruce forests in Unit 7 on the eastern side of the peninsula make it difficult to count moose from the air. Spruce cover in Game Management Unit 15C south of Tustumena Lake and the Kasilof River also inhibits aerial census counting. Selinger calls this dilemma the sightability correction factor and said you can do a count in these areas, but it would reduce the likelihood of having an accurate representation of what the moose population is like in those areas. Despite this, as far as Unit 15 goes, Selinger said 15A has the lowest moose density.
Even though the number of vehicle collisions with moose have decreased, another factor affecting the population in 15A is road kills. Better browse as well as an easier mode of transportation makes highways and plowed roads attractive to moose. But "if you don't have as many animals out there, you're not going to hit as many," Selinger said.
Jessica Cejnar can be reached at firstname.lastname@example.org.