TACOMA — Squirrels seem to be a common mammal encountered throughout daily life. If they’re not in your yard, they’re perched on trees or scurrying across roadways. But one species of squirrel is in danger in Washington state: the western gray squirrel.
A new review of the animal’s protective status by the Washington State Department of Fish and Wildlife recommends changing the western gray squirrel from “threatened” to “endangered” in the state. The western gray squirrel is one of three native tree squirrels in Washington state, and it has been in decline since the late 19th century, according to the status review.
Threats to western gray squirrels
The WDFW has three classifications for native animals it identifies as being in danger or requiring special care:
• Sensitive: A species vulnerable or declining. They’re likely to become threatened or endangered in a significant portion of its range if the state doesn’t take action to remove threats. Examples of animals in the category include the gray whale, common loon, larch mountain salamander and various species of insects.
• Threatened: A species that’s likely to be endangered in the near future in a significant portion of its range if the state doesn’t act to remove threats. Examples include the sea otter, mazama pocket gopher, American white pelican, green sea turtle and various fish and mollusks.
• Endangered: A species that is seriously in danger of extinction throughout most of its range or within the entire state. Many species of mammals, birds, reptiles, fish and birds are categorized here.
The primary factors endangering the western gray squirrel are habitat loss and fragmentation, Taylor Cotten, the department’s assessment section manager, stated in the release. Other phenomena like wildfires, highway mortality and disease threaten their survival.
Another factor significantly impacting the squirrel’s safety is climate change. According to the WDFW, the western gray squirrel is exposed to climate change at a moderate level and its sensitivity is at a moderate-high level. For example, climate change has shifted the impact wildfires have on habitats. These fires continue to kill the squirrels and destroy a large amount of their habitat.
The squirrel species is also sensitive to disease outbreaks like mange and the western equine encephalitis virus. Scientists predict climate change will make these outbreaks more frequent because of warmer temperatures. This trend is relevant to humans, too. One study from August 2022 found that climate hazards aggravated more than half of the 375 infectious diseases that infect humans.
Currently, WDFW classifies the tree squirrel as a Species of Greatest Conservation Need. These are wildlife that require the most conservation attention, according to Mary Linders, a biologist with WDFW and co-author of the squirrel’s status review report. Linders said in an interview with The News Tribune that the department is actively taking steps to protect the western gray squirrel in several ways:
• Monitor its population
• Assess its habitat
• Manage the forests on WDFW-managed land to allow trees to grow larger, which supply the squirrel with one of its food sources
• Coordinate with several parties such as federal landowners, private landowners and land trusts to protect habitats and limit the amount of trees being cut down
Washington state’s western gray squirrel
The western gray squirrel is one of several species of native tree squirrels in Washington state. The others are the Douglas squirrel, red squirrel and northern flying squirrel. The Western gray squirrel is the largest tree squirrel in the state, Linders said.
The gray squirrel is mainly isolated to three parts of the state: the northern Cascade region, the Klickitat region around the Columbia River, and an area called southern Puget Trough, essentially Pierce and Thurston counties. They inhabit forested areas that contain large trees such as conifers, Oregon white oaks and Ponderosa pine.
Linders said the department doesn’t have a concrete estimate on the amount of western gray squirrels in the state but said there are probably less than a few thousand statewide.
The species plays a special role in its local ecosystem, Linders said. Aside from seeds and nuts — which the squirrels get from trees, about 50 percent of the gray mammal’s diet consists of truffles, which contain fungi and spores that are beneficial to trees. When the squirrel eats and then defecates the mushroom, it spreads the spores and fungi around, helping trees to grow larger.
Public comment period on squirrels
Linders said the department is seeking input from the public to help her team assess whether they should reclassify the western gray squirrel as endangered. WDFW also asks the public for input so people can point out if the status review has any potential holes in the data. In addition, anyone can provide data that the department either didn’t have or hadn’t considered.
You can download the document on WDFW’s website and add written comments on it. Submit them to Taylor Cotten at her email, TandEpubliccom@dfw.wa.gov, or mail in your observations to the department’s P.O. box: 43141, Olympia, WA 98504-3200.