PHOENIX — Animal lovers now have a new piece of good news to go nuts over: a population of endangered red squirrels unique to Arizona is growing slightly.

Wildlife officials found there are 233 Mount Graham red squirrels, which can only be found in the Pinaleño Mountains of southeastern Arizona.

These numbers reflect a sharp boost from the population of 144 squirrels in last year’s survey from the Arizona Game and Fish Department (AZGFD), Coronado National Forest, and the U.S. Fish and Wildlife Service (FWS).

Holly Hicks, AZGFD’s small mammal project coordinator, said this year’s bigger number was a pleasant surprise for all involved.

“We all knew that we were seeing a lot of squirrels and middens during this last survey,” Hicks said in a Thursday news release. “But I don’t think any of us expected such a dramatic increase.”

Endangered red squirrels unique to Arizona bouncing back

This increase is a hopeful sign for conservation efforts, as the species has been struggling for decades.

In the late 1990s, there were around 550 Mount Graham red squirrels, but the 2017 Frye Fire destroyed much of their habitat.

At one point, the animal’s population collapsed to around 35.

Some of the top threats they face are insect infestations, poor pine cone drops due to Arizona’s drought, wildfires and competition with non-native squirrels.

Marit Alanen, the lead Mount Graham squirrel biologist for the FWS, said the latest annual interagency population survey is exciting news.

“We were all extremely concerned for the subspecies after the 2017 Frye Fire caused the squirrel’s population to drop drastically,” Alanen said in the release. “So seeing a number now over 200 is really fantastic news.”

Finding out population of endangered red squirrels populations rose

The partnering agencies who survey the endangered squirrel come to their findings by systematically searching for active middens. That word refers to a large pile of shredded pine cones and nut debris red squirrels create to store their food.

Surveyors can tell a midden is active if there are signs of feeding. Each red squirrel typically has its own midden, so the wildlife officials use these middens to estimate the amount of squirrels are in the survey plots.

Coronado National Forest Supervisor Kervin Dewberry attributed the rising population to a shift in land management practices.

“This survey process allows us to obtain a more accurate picture of the population numbers,” Dewberry said in the release. “We are excited to see that current land management practices being implemented in the Pinaleño mountain range are proving to be beneficial for the Mount Graham red squirrel population.”