The Mulchatna caribou herd was once among the largest in Alaska, with a historic range spanning from Dillingham to Bethel to Lake Iliamna. Today, the herd has dwindled to roughly 12,000; the Department of Fish and Game estimates a healthy population would range from 30,000 to 80,000.
Biologist Christi Heun is a representative for the conservation group Defenders of Wildlife. She said an ongoing study, conducted by Fish and Game biologists Nick Demma and Renae Sattler, identified two major contributing factors for the herd’s decline in a presentation last year.
“Habitat quality and disease are the two things that they're like 'smoking guns, this is what's going on,'” she said.
Specifically, the study found low fat ratios in caribou mothers in the herd. Heun said this poor body condition suggests the caribou are competing for a special resource–lichen, which in the past has grown abundantly in the Mulchatna rivershed.
“We know the lichen community in the area is not as good as it used to be,” she said. “There’s encroachment from woody shrubs, as we start getting warmer summers and warmer winters.”
Biologists also recorded epidemic levels of brucellosis - a disease that can result in late-term miscarriages and weak calves. Humans can contract brucellosis by coming into contact with a contaminated animal or by ingesting under-cooked, infected meat.
The study found that brown bears were the primary killer of calves in their first two weeks of life, accounting for 46% of neonatal mortalities. Firearms were reported as the number one killer of cow mortalities, and data on other demographics in the herd were not collected.
This May, Fish and Game undertook a month-long predation control mission, shooting 94 brown bears, five black bears and five wolves in the western subgroup calving area. The work cost approximately $415,000, according to Heun.
Tim Peltier, a regional director at Fish and Game, said the department’s goal was to boost calf survival.
“So this intensive management action - it's a tool that the department can use immediately to try to reverse that declining trend,” Peltier said.
The department said they planned to salvage bear carcasses and offer the meat to surrounding communities that had responded to a previous inquiry made by the department.
Fish and Game’s intensive management plan for the herd estimated approximately 54 to 118 bears in the caribou calving area, which means last month’s measures eliminated the majority. Peltier said the department plans to monitor the effects of these measures.
“We think by targeting one of the two calving areas, we should be able to detect change if predation is a big part of the problem,” he said.
Fish and Game did not report any immediate plans to address the herd’s habitat conditions but did note ongoing research on caribou forage areas across Alaska. There were also no reported disease control measures. Peltier said that brucellosis tends to produce a temporary decline in herd population, not longer-term reduction as seen in the Mulchatna herd.
But biologists like Heun say that removing predators may ultimately further the spread of Brucellosis.
“The predators aren't culling the sick animals, and so they're leaving more sick animals on the ground to infect more animals. So the sickness is spreading,” she said.
Environmental agencies have criticized the state's approach to predators, saying that it compromises healthy populations of wildlife through predator control. Last year, the group Public Employees for Environmental Responsibility requested that the Department of Interior end the use of federal funds for predator control in Alaska. The Department of Interior said the raised concerns did not constitute a misuse of these funds.
Subsistence hunting this season remains closed on caribou for the third year in a row. Caribou is a traditional food resource for many in the region.
Alexander Tallekpalek hunts caribou for subsistence in Levelock, a community north of King Salmon. He said he’s noticed the change in caribou migration.
“They used to go through Levelock, or through the village for a span of three days…There was a pretty big herd back in the ‘90s,” he said.
Tallekpalek said he’s noticed softer ground in the area, too. Now, Tallekpalek said he hunts more moose, whose local population has boomedin recent years.
Meanwhile, the Mulchatna's herd numbers remain low, and the lichen population they eat continues to decline.
This article was updated with the following contextual resources, hyperlinked here. They are also hyperlinked in the text.
Alaska Department of Fish and Game's Operational Plan for Intensive Management 2022 - 2028
Alaska Department of Fish and Game’s Foraging Ecology and Wildlife Nutritional Analysis Lab
Get in touch with the author at christina@kdlg.org or 907-842-2200.
