Climate Crisis Deepens for America’s Moose
“The state’s moose population has been in decline for years but never at the precipitous rate documented this winter,” said Tom Landwehr, DNR commissioner. “This is further and definitive evidence the population is not healthy. It reaffirms the conservation community’s need to better understand why this iconic species of the north is disappearing from our state.”
The state’s annual hunting season isn’t a cause for the moose’s decline. Researchers last month began an ambitious research project to figure out what’s killing them off. Calves are dying at higher rates than normal and, more significantly, adult moose in their prime are dropping dead.
What was once a healthy population sustainable enough to allow hunting is now in rapid decline. The population in northeast Minnesota has been declining for years, from 8,840 in 2006 down to only about 2,760 counted in January 2013. While just 46 bull moose were harvested in 2012, the population plunged by nearly 1,500 moose from 2012 to 2013. Minnesota’s other population of about 4,000 moose in northwest Minnesota virtually disappeared over 20 years, with fewer than 100 remaining by the mid-2000s.
What’s Driving the Decline?
“This is a tragic collapse, but it isn’t a surprise,” says Dr. Doug Inkley, a wildlife biologist and the National Wildlife Federation’s senior scientist. “There are probably several factors affecting the population, but we know moose have trouble coping with hot weather, which has been on the rise in Minnesota. Stress factors, such as rising temperatures, can cause moose health to decline, making them more vulnerable to disease and predators.”
The National Wildlife Federation highlighted the climate crisis’ impact on Minnesota moose just last week with the release of a new report, Wildlife in a Warming World:
Biologists attribute most of this decline to increasing temperatures: when it gets too warm moose typically seek shelter rather than foraging for nutritious foods needed to keep them healthy. They become more vulnerable to tick infestations, which have proliferated as the region has warmed. Ticks leave moose weakened from blood loss and with hairless patches where they tried to rub off the ticks. Without protective hair, these animals can die from cold exposure in the winter. Individual moose infested with 50,000 to 70,000 ticks—ten to twenty times more than normal—have been documented.
Signs of Struggle
Nationwide, it’s harder to get an exact gauge on the impact of climate change since moose have only recently returned to their historical range in some areas. Moose were once found as far south as Pennsylvania before over-hunting and habitat destruction wiped them out from much of the eastern United States. Populations in places like Massachusetts are still re-establishing a foothold.
But in New Hampshire, the impact of warmer temperatures on moose are clear and dire. Researchers say New Hampshire moose are literally being eaten alive by ticks. Moose there have to deal with 30,000 ticks at a time in a normal year, but in recent warm years, moose carry as many as 150,000 ticks. The moose die of anemia, a lack of healthy red blood cells. After the unseasonably warm winter in 2011, they think that it’s likely that all calves born the previous year were killed along with 40 percent of adults.
And then 2012 was America’s hottest year on record. In Michigan, where a moose have returned to the Upper Peninsula, efforts to count the population have been hampered by warm temperatures – without a covering of white snow, researchers can’t spot the brown moose from the air.
Time to Confront Climate Change
The climate crisis is already changing the playing field for wildlife and urgent action is needed to preserve America’s conservation legacy. Species that have spent thousands of years or more adapting to their ecosystems are now watching their homes transformed before their eyes. We must act now to cut carbon pollution, speed our transition to clean energy, and safeguard America’s ecosystems and communities.
Congress hasn’t shown much interest in tackling the climate crisis, but the Obama Administration can take a number of steps, like using Clean Air Act authority to limit carbon pollution from new and existing power plants, rejecting the dirty Keystone XL tar sands pipeline, and ensuring the budget fights ahead do not slash critical investments in clean energy.