Cute critter faces uphill battle for survival

Southern Arizona is home to a unique subspecies of red squirrel— the Mt. Graham red squirrel. They've evolved in isolation from other red squirrels in the conifer forests of the Pinaleño Mountains. A small habitat range and small population—even when thriving—means these squirrels are more vulnerable to threats. 

Mt. Graham red squirrels are on the small side, around 8 inches long and weighing in at 8 ounces. Their fur is gray to brown, although it can have a reddish appearance. Photo by Joel Sartore, National Geographic.

In 1987, with a proposed observatory threatening critical habitat, they were listed as an endangered species. The squirrels became somewhat famous as environmentalists and Apache fought against the development of the University of Arizona observatory. The University won and the observatory was constructed, but this does have one big positive for the squirrels, which is that in order to develop the land, an agreement was made in which population is surveyed quarterly, recreation is limited and habitat is, to an extent, preserved.  

When the squirrels were listed as endangered 1,750 acres were designated as "Mount Graham Red Squirrel Refugium" in the area where squirrels were most observed. Since then, though, squirrels have been found primarily outside this area, and a 2011 report stated that only 277 acres of the original refugium boundary currently provides habitat.  

The squirrels live in high elevation areas, over 8,000 ft, with conifer trees that provide them with food, some protection from birds of prey and places to nest. Their main food source is conifer seeds, and fluctuations in food supply has a direct relationship to population changes. Unfortunately, insects and fires have destroyed many of the trees the squirrels depend on.  

The small red patch in the mountains southwest of Safford represents critical habitat. Map by U.S. Fish and Wildlife.

Another threat to the Mt. Graham red squirrel are competition with the Abert's squirrel, which Fish and Wildlife introduced in the 1940s and occupies a similar role in the ecosystem. But the number one threat to the Mt. Graham red squirrels is climate. Rising temperatures means more wildfires, more insect outbreaks and more drought, all of which will and does directly affect critical habitat.  

In 2017 the Frye Fire burned 48,000 acres on the Pinaleños. Afterwards, the red squirrel population was down to from 252 to only 35. A recent survey has the population up to 67, as of fall 2018. 

  

Population change over time. Graph from the Conservation Research Laboratory at the University of Arizona.

 Biologist John Koprowski who studies the squirrels says that they're important to the local ecosystem as seedeaters and dispersers. Their middens (large stashes of pinecones for winter eating) are used for habitat by other animals. He also points out that the more we learn about an individual species like the squirrels, the more we learn about the ecosystem they're a part of.  

In the most recent press release AZGFD said that squirrel research, long-term strategies to care for fire-damaged areas, and a breeding program are some of the conservation methods they’re interested in using. In the recovery plan they specifically list: 

• restricting vehicle speed 
• planting trees 
• monitoring insect infestations 
• eliminate or control Abert's squirrel population 
• reduce predation 
• investigate impact of summer homes and a Bible camp  
• partner with other organizations 

For the last three decades measures have been taken to research and protect the Mt. Graham red squirrels, yet their population has tended to decline. While their recently increased numbers are hopeful, it seems very possible that their threats outweigh their protections, and saving them is going to be an uphill battle.  

Sources:  

2011 US Fish and Wildlife Service Recovery Plan  https://ecos.fws.gov/docs/recovery_plan/FR00000388%20Draft%20Mount%20Graham%20Red%20Squirrel%20Recovery%20Plan%20First%20Revision%20Final.pdf 

Mount Graham International Observatory: Mount Graham Red Squirrel https://mgio.arizona.edu/mount-graham-red-squirrel 

Population Trends of the Mount Graham Red Squirrel  

https://cals.arizona.edu/research/redsquirrel/mgrs-data.html 

Q&A: UA biologist talks Mount Graham red squirrel conservation 

http://arizonasonoranewsservice.com/qa-ua-biologist-talks-mount-graham-red-squirrel-conservation/ 

The Real Red Squirrel Peril, New York Times, 1990 https://www.nytimes.com/1990/05/29/opinion/the-real-red-squirrel-peril.html 

US Fish and Wildlife Service Environmental Conservation Online System https://ecos.fws.gov/ecp0/profile/speciesProfile?spcode=A09O