The number of moose in northeastern Minnesota continues to fall, according to aerial survey results released by the Minnesota Department of Natural Resources.
Based on the survey, wildlife researchers currently estimate that 4,900 moose populate northeastern Minnesota. Last year the agency estimated the population was 5,500 animals. Moose numbers are estimated using an aerial survey of the northeastern Minnesota moose range.
Since 2005, the downward trend in moose numbers has been statistically significant. In addition to the decline in the calf-to-cow ratio, the bull-to-cow ratio also continued to decline, with an estimated 64 bulls per 100 cows, according to the survey.
Survey results revealed lower moose numbers and the proportion of cows accompanied by calves continued a 14-year decline, dropping to a record low of 24 calves per 100 cows. The proportion of cows accompanied by twin calves was at the lowest level since 1999, which contributed to the record-low calf-to-cow ratio.
Data from the survey can be examined HERE.
“These indices along with results from research using radio-collared moose all indicate that the population has been declining in recent years,” Dr. Mark Lenarz, DNR forest wildlife group leader, said in a DNR media release.
Aerial surveys, conducted each year since 1960 in the northeast, are based on flying transects in 40 randomly selected plots spread across the Arrowhead region of Minnesota.
A study of radio-collared moose in northeastern Minnesota between 2002 and 2008 determined that non-hunting mortality was substantially higher than in moose populations outside of Minnesota. Combined with the reduced number of calves, the high mortality has resulted in a population with a downward trend.
The causes of moose mortality are not well understood. Of 150 adult moose radio-collared since 2002 in Minnesota, 114 have subsequently died, most from unknown causes thought to be diseases or parasites. Ten moose died as a result of highway vehicle accidents. Two were killed by trains. Nine deaths were clearly the result of wolf predation.