Latest moose death adds to ongoing study

By Lauren Yates, Adirondack Daily Enterprise

ONCHIOTA — A young moose found dead in Franklin County earlier this month likely died of a parasitic worm known to affect the Adirondacks’ limited moose population, a necropsy by the state Department of Environmental Conservation has determined.

The necropsy found that Fascioloides magna, or giant liver fluke — a parasitic flatworm that can cause illness and death in deer and moose — was the probable cause of death for a less than 1-year-old moose that was recovered from the woods of Onchiota on April 6, DEC Big Game Biologist James Stickles said last week. The DEC was able to locate the moose because it was fitted with a GPS collar this past January as part of the DEC’s Adirondack Moose Research Project, a multi-year project that launched in January 2022 to assess moose health and population in the park. The moose’s collar alerted the DEC that the animal had died.

DEC Wildlife employees and Environmental Conservation Police Officers Nathan Favreau and Jeremy Fadden recovered the moose’s body from a “heavily forested” area in Onchiota while the ground was still covered in 2 to 3 feet of snow. The DEC employees traveled by snowmobiles and UTV, then hiked another 500 yards to reach the moose carcass. The group then loaded its body onto a sled and pulled it back to the snowmobiles. The necropsy was later performed in the DEC’s wildlife pathology lab in Delmar.

This is the fifth young moose of 33 collared in the DEC’s Adirondack Moose Research Project to have died from giant liver fluke, according to Stickles.

RELATED: The Adirondacks’ moose population is stagnant. Researchers want to know why.

Moose were thought to be entirely absent from New York state for around 120 years. Extensive logging and hunting are believed to have wiped out the state’s moose population from the 1860s until the 1980s, when moose are believed to have reentered the state. The Adirondack Moose Research Project is one of the DEC’s most recent efforts to track the animals’ populations, habitats and challenges since their reemergence.

By tracking moose, the DEC hopes to unveil why moose populations in New York have stayed relatively small — with a little more than 700 moose across the state, according to the DEC’s most recent count in 2018 — compared to moose populations in neighboring northeastern states like Vermont, where the moose population is in the 2,000-3,000 range. The largest moose population in the contiguous 48 states is in Maine, where there are an estimated 60,000 to 70,000 moose.

Illnesses like giant liver fluke, as well as sickness caused by winter ticks, deer brain worm, tapeworms and Neospora are known to threaten New York’s moose population, according to Cornell University’s Wildlife Health Lab, which partners with the DEC to examine and test moose samples. Deer scat and snails are carriers of giant liver fluke, the latter of which moose unintentionally ingest when they eat greens that have infected snails attached. In a DEC and Cornell University-led study of 100 moose mortalities between 2000 and 2014, researchers found that 21% of those deaths were caused by liver flukes.

The Adirondack Moose Research Project tracks moose from their first year of life to learn how extensively these diseases are limiting moose populations and to identify other challenges Adirondack moose face as they grow to adulthood. The DEC has collared 33 moose calves since the project’s inception. Seven of those have since died, with five of the seven dying of giant liver fluke, according to Stickles. The other two died of “mortal injuries,” Stickles said — when moose sustain injuries, they often don’t recover due to their size. Besides parasites and injuries, other threats to moose mortality in the Adirondacks include vehicle collisions and, for moose calves less than 9 weeks old, black bears, according to the DEC.

The DEC is currently monitoring a total of 24 moose for the Adirondack Moose Research Project. One moose dropped a collar, according to Stickles, and another collar malfunctioned and hasn’t reported a location since November 2022.

The Adirondack Moose Project is a partnered effort between the DEC, New York Cooperative Fish and Wildlife Research Unit and the College of Veterinary Medicine at Cornell University, the State University of New York College of Environmental Science and Forestry, and Native Range Capture Services.