|
|
The Minnesota Department of Natural Resources (DNR) 2022 annual Aerial Moose survey results are in and what it shows is that for the 11th straight year, there is little change in the moose population.
According to the report, there are 4,700 moose in northeastern Minnesota, the highest moose estimate since 2011. Still, that’s statistically unchanged from the previous 11 years.
Each year the population estimate is compared to 2006 because the state’s highest moose population peaked at 8,840 and then started on a drastic population drop.
In a bit of good news, the 2022 cow to calf ratio was 45 calves to 100 cows, the highest count since 2005. Calves are also estimated to be 19 percent of population. The report noted that both factors “are indicators of potential improvement in reproductive success, which has a positive impact on population numbers.”
The survey spanned almost four million acres, covering 436 survey plots over northeastern Minnesota.
Every five years, all survey plots are re-stratified as low, medium, or high moose density based on past survey observations of moose, locations of recently harvested moose, and past survey observations by researchers and moose managers.
Two helicopters, a 1Bell Jet Ranger (OH-58) and 1 MD500E, were used to conduct the flights. Flights were conducted from January 6 to January 14, 2022. Based on optimal allocation analyses, 15 low, 18 medium and ten high-density plots and ten habitat pots were surveyed.
In his 2022 survey report, Dr. Glenn DelGiudice, Forest Wildlife Population and Research Group said, “This year 373 moose were observed on 40 (75 percent) of the 53 plots surveyed, which is more than the 308 moose observed on 39 of 52 plots during the 2020 survey.”
Of the moose counted, 151 were bulls, 154 cows, and 62 calves, with six unclassified adults.
DNR aerial moose surveys have taken place since 1960. In 2005 adjustments made the study more accurate and annual results more comparable.
The annual population survey is the most critical aspect of DNR moose management. Tracking moose numbers and determining the gender and age makeup of the population allows the DNR to monitor the health and well-being of moose.
In 2012, the DNR made nine forested areas a permanent part of the moose survey. These areas include different types of forests, including forests disturbed by events such as wildfires, blow-downs, and timber harvests.
According to the 2022 report, the primary objective of the moose study is to estimate how many moose there are, the percent of calves, and calf/cow and bull/cow ratios.
This year’s calf/cow ratio of .45 “is notably greater than the 16-year average since 2005,” states the report. Calves were 17 percent of the moose observed and represent 19 percent of the estimated 2022 population.
Demographic data helps the DNR best determine and understand the population’s long-term trend and the composition and spatial distribution of the moose population. From this data, harvest quotas for subsequent State hunting seasons can be set (when applicable) and, with these findings, improve the researchers understanding of moose ecology. The study also helps developed future management strategies.
Last year, due to COVID-19, the annual survey wasn’t conducted.
“Past aerial survey and research results have indicated that the long-term trend of the population in northeastern Minnesota has been declining since 2006. However, recent data suggest the population has at least stabilized and may even be increasing slightly, corroborated by a piecewise polynomial curve. This year’s population is only 47 percent less than in 2020 when the survey was last conducted. Although the long-term declining linear trend remains statistically significant, the overall strength of the decline has been weakened by recent estimates,” sums up the study.
Is the moose population finally stabilizing? The report makes clear, “But regardless of the method, we caution that current population trends do not necessarily predict future trends because underlying demographic factors affecting population abundance can change over time.”
The survey was a partnership with the Divisos of Enforcement, Fish and Wildlife and Forestry, the Fond du Lac Band of Lake Superior Chippewa, and the 1854 Treaty Authority.
Leave a Reply