By Matt Kroschel

SUMMIT COUNTY, Colo. (CBS4) – Ticks seem to be unusually bad this year, and a particularly nasty little bug is taking aim at Colorado’s moose populations in Summit County.

Summer is providing much needed relief for moose populations in Colorado who are now under siege from blood-sucking ticks.

The winter tick, a common parasite throughout North America, has grown in both numbers and impact over the last several years — and it has started to take a toll on Colorado’s moose.

The ticks infest moose at a time of year when the animal is at its weakest and over the course of several months it can drain them to the point of mortality, according to state wildlife biologists.

The clearest sign of a moose affected by ticks are patches of hair missing from its dark brown coat, exposing the animal’s bare skin, according to Jeromy Huntington with Colorado Parks and Wildlife.

Moose are most prevalent in parts of Canada and the northern New England states. Herds there have seen high mortality rates due to the winter ticks. It now appears Colorado herds are facing an uptick in ticks.

Despite its name, the winter tick does not take to frigid climates. The elevation of Colorado’s Western Slope, and its associated temperatures, has kept the pest from being the growing problem, until now. Even with more moose being spotted with the ticks, so far populations have not been impacted.

Matt Kroschel covers news throughout Colorado working from the CBS4 Mountain Newsroom. Send story ideas to mrkroschel@cbs.com and connect with him on Twitter @Matt_Kroschel.