Tick infestations can drain the blood supply of moose and can lead to malnutrition and death. In a year with average weather conditions, a moose will probably carry 30,000 ticks by late fall. In years with a late first snow fall, a moose could carry 160,000 ticks. Photo: Patrick Lafreniere. Download.
The average moose in New Hampshire stands about six feet tall at the shoulder and weighs about 1,000 pounds. Yet a creature smaller than the eraser on a pencil is a big threat to these massive animals, popular with both wildlife watchers and hunters.
The creatures posing the threat are winter ticks – Dermacentor albipictus. A New Hampshire Fish and Game Department study that began in 2001 collared and tracked moose and found winter ticks accounted for 41 percent of all moose deaths in the state over a five-year period. That was nearly the same percentage of collared moose killed by hunting and moose-vehicle collisions combined. Virtually all the calf deaths during the study were due to winter ticks.
New Hampshire Fish and Game Department researchers will spend the next several years studying the best way to accurately determine the numbers of ticks on moose and how that relates to mortality rates, as well as the changing climate.
According to a report from the Union of Concerned Scientists, “rising temperatures over the past few decades have caused snow to become wetter and decreased the average number of snow-covered days across the state.” In looking toward the future, the report says climate change could see New Hampshire’s snow season shrink by almost 50 percent by mid-century.