Study: Warmer summers worsen tick infestations for US moose
TRAVERSE CITY, Mich. – It’s a ghastly sight: ticks by tens of thousands burrowed into a moose’s broad body, sucking its lifeblood as the agonized host rubs against trees so vigorously that much of its fur wears away.
Winter tick infestation is common with moose across the northern U.S. – usually survivable for adults but less so for calves, and miserable either way. And climate change might make it worse, scientists reported Monday.
Data collected over 19 years at Michigan’s Isle Royale National Park showed moose have more ticks during winters following particularly warm summers, according to a study published in the peer-reviewed journal Frontiers in Ecology and Evolution.
That’s presumably because higher temperatures quicken the development of tick eggs, boosting the number surviving to hatch, said author Sarah Hoy, a research assistant professor of animal ecology at Michigan Technological University. “We usually think about winter having a big impact on moose, but growing evidence suggests summer might be even more important,” Hoy said.
In addition to the partial loss of their bristly winter coats, tick infestation makes moose anemic and less able to reproduce, she said. It’s a leading cause of recent population declines in the Northeast, where summer temperatures have been surging more than in the Upper Midwest.