At Maine Audubon we field many tales recounted to us over the phone and, of course, via email. From all these conversations and messages, psychological studies could be done around observer biases, much in the way you hear about the same problem with eyewitness accounts of crimes.

To help break down a scenario, we’ll often ask our own questions to try to remove any biases from the answers. For example, I might ask: “Where was the white on the wing?” rather than “was the white at the base of the primaries?” to all the people who think they’ve seen a golden eagle in Maine. The best-case scenario is when we get detailed notes, and, my favorite, drawings or sketches to go along with an observation.

This leads us to a question from a Brunswick resident who wrote recently regarding backyard squirrels. Over the past few weeks, the squirrels have been showing tail injuries. The letter was complete with drawings of the distinct tails – a masterpiece of naturalist inquisition and observation.

Injuries to a squirrel’s tail can come from a variety of sources, including predators or accidents. It is actually common to see gray squirrels with some visible injury, usually presenting as stripped hair or a nipped tail tip. These injuries are never life threatening, as the tail is not vital for survival, but they can make their lives a bit more challenging. Their tails are used for many purposes, especially balance and warmth, and also for communication. You’ve probably seen (and heard) an agitated squirrel flicking its tail, a common signal that something is amiss.

If you really want to get into squirrel signaling, there is a fascinating paper in the journal Behavior, by McRae and Green, that looked at the “joint tail and vocal alarm signals of gray squirrels” from 2014. Essentially, the combination of unique vocalizations and tail movements are used to indicate distinct approaching stimuli, with combinations for aerial versus terrestrial predators, and based on how high of a threat the stimuli is perceived to be. Knowing these many uses, it is easy to see how having a functioning tail is preferred, though not required, for a squirrel.

In the injuries reported (and drawn) from Brunswick, several had the distal 4 inches and then new hair growing back at that point; one had a bare spot right at that 4-inch point, another had no hair at all after the 4-inch point with just “black” skin visible; and one was bloody at that point. The most interesting thing to me is that they are consistent. There is variation in the degree of injury, from apparently broken to just altered hair, but given the similarity in location, all about 4 inches along the tail, I think it is safe to assume they are all from the same, or similar, offenders.

I would be surprised to see such consistency coming from a natural predator. That would take a lot of luck for the squirrels – or bad luck for the predators (think hawks or foxes) – to have six or seven squirrels in one backyard all showing the same near-miss injury. We occasionally get reports from people who have squirrels (and sometimes birds) get their tails (or limbs) stuck in the crux of a bird feeder pole or fence. That seems a bit more reasonable as a possible cause of these injuries; I can imagine each of these squirrels trying to reach a feeder and perhaps not having great balance on a narrow pole, causing them to lose balance at a consistent point.

My other guess as a cause for these injuries would be from a trap, albeit one for something smaller than a gray squirrel. Again I’m mostly basing this on the consistency across these adult squirrels, but it seems reasonable that if they were going into a trap (think Havahart) with a closing door that was too small for a large gray squirrel, that door closing on their tails could result in similar injuries.

I may also be biased in this thinking because this is the time of the year that we get a lot of inquiries from folks who want to trap and translocate squirrels and other wildlife. By late summer, we’re seeing lots of young mammals on the landscape starting to venture out on their own, and unfortunately find themselves in some unwanted locations. We should always remember that those animals are just doing what they do naturally, and we should find ways to reduce the conflicts – excluding them from gardens with fences, adding baffles around bird feeders, etc. As a reminder, translocation of animals is often a death sentence for them. Gray squirrels are one of the most commonly translocated species and a study by the Humane Society of the United States found that 97% of squirrels died or disappeared (mostly from predation) within 88 days of being released.

When I was growing up, we’d always joke that the squirrels with tail injuries were the ones that didn’t know to raise their tails while crossing the road. While we may never know the exact cause of the tail damage for the Brunswick squirrels, it holds as a good reminder about how fascinating and vulnerable and hopefully resilient these backyard critters are. It’s also a nice tale of how careful observation leads us to interesting questions about the world around us.

Have you got a nature question of your own? Email questions to ask@maineaudubon.org and visit www.maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 7 to 9 am, at the Gilsland Farm Audubon Sanctuary in Falmouth.

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