CWHC Rebranded Day 2: Health Issues affecting the Gray Jay

Photo credit: Dan Strickland

The CWHC has received very few Gray Jay submissions to our diagnostic labs over the years. Is it their remarkable resilience? Perhaps it is their preference for remote areas of the boreal forest, where carcasses are quickly scavenged and not likely to be discovered by people.

The Gray Jay is not a threatened species, and populations are stable across most of their range; nevertheless, there are a few health issues affecting these birds. Climate change is well documented to cause range shifts in various species and the distribution of Gray Jays has undergone a contraction in the southernmost reaches of their range. An example of such a range reduction has been documented in Algonquin Park, Ontario, where researchers have been studying Gray Jays for several decades. These researchers suggest that declines are due to reduced preservation of food caches in warmer winter temperatures.

West Nile Virus is another health issue affecting Gray Jays. Many birds carry this virus with seemingly no ill effects, but Gray Jays and other members of the Corvidae family are particularly susceptible and tend to die quickly once infected. The virus has not caused noticeable population declines over much of their range, but researchers in Colorado have reported significant Gray Jay population decreases in years of particularly high West Nile virus activity.

Because of their tendency to eat carrion, Gray Jays are also susceptible to accidental death caused by human activities. Inadvertent poisonings relating to pest or predator control activities are one example as are incidental trappings due to Gray Jays feeding on baited traps set for fur bearing species.

Interestingly, Gray Jays may play a positive role in another important wildlife health issue: winter tick. Gray Jays, as well as their Raven relatives, have been documented feeding on winter ticks, and there are anecdotal reports of them picking ticks off the backs of moose. As winter tick is a serious issue in moose that can result in severe hair loss, leading to starvation and death, this gives us one more reason to appreciate the Gray Jay!

Click here for a downloadable version: Gray Jay Campaign Day 2