Why squirrels scream

Gray squirrels are the quintessential city squirrel, often seen traveling along power lines and making big fluffy nests in deciduous trees. In my area on the east coast, we also have Red Squirrels who occupy forested regions, while gray squirrels tend to live in the cities.

Red Squirrels are a bit smaller than Gray Squirrels, but the main difference is that Red Squirrels are highly territorial and the same is true for Douglas squirrels on the west coast.

This means you almost never see them mixing with other squirrels except during courtship, mating, and raising the next generation. Do you hear how part of the call is sort of squeaky and high pitched, while another part of the call is much deeper, in a more mid-range or lower end of the sound spectrum? These audible differences help to reveal a lot about the nature of the threat and whether a predator is coming from the air or the ground See research — Red Squirrels produce predator-class specific alarm calls.

Also listen for alarm calls from other animals like birds to help narrow your search and locate the animal. When squirrels alarm at aerial predators, their vocalizations tend to include a lot more higher pitched and squeaky qualities.

High pitched sounds are difficult to locate in the forest, so this is a way for squirrels to sound the alarm, while staying hidden from predator who can follow them in the trees.

Rather than flipping their tail and calling attention to themselves, you might notice squirrels plastering themselves against a tree and being very still. This is a good sign that your squirrel is under pressure from something like a hawk, owl, or eagle, etc.

This confused the heck out of me when I first started studying squirrels because it sounds like a really intense alarm. Notice you start by hearing a series of intense rattles, then as the clip goes on, the squirrel mom gets more and more agitated until she starts calling back.

These are two subtle differences but it can help you make sense of why a squirrel is alarming, and how far away the threat is. Typically in the case of long range alarms, you need to do a bit more investigation and combine your observations of squirrel alarms with bird alarms in order to solve the mystery. So even though the actual noise might sound very similar, the context is completely different!

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Diploma Thesis, Univerzita Karlova, Prague. Frequency-modulated second elements of two-element alarm calls do not enhance discrimination of callers in three eurasian ground squirrels. It's a controlled movement in which the path of the tail tip usually forms a simple arc. A flag is a more conspicuous whipping motion. During a flag see video below , the squirrel's tail tip can move in arcs, figure eights, circles, and various squiggles. View Iframe URL. McRae and Green tested whether these different vocal and visual alarms were associated with particular types of predators.

They studied a wild population of gray squirrels on the University of Miami campus. These squirrels have two main types of predators: aerial predators, such as hawks, and terrestrial predators, particularly domestic cats. The researchers exposed the squirrels to five kinds of potentially threatening stimuli. They simulated a hawk approach by throwing a styrofoam glider painted to look like a hawk in the air.

They simulated a cat attack with a remote-controlled model cat on wheels, driven toward the squirrel. To see if the manner of approach terrestrial versus aerial or physical resemblance to a predator affected the squirrels' alarms, the researchers also presented the squirrels with an object that didn't resemble any predators at all — a red ball — and either rolled it towards the squirrels or threw it overhead like the model hawk.

Overall, McRae and Green found the squirrels have an alarm system with different degrees of specificity. Some, but not all, of the alarm signals were associated with predator type, and combinations of tail signals and vocalizations were more strongly associated with threats than either type of signal alone. Of the three vocalizations and two tail movements, only tail flags and moans were associated strongly with specific predators.

Moans by themselves were specific to the aerially approaching model hawk. Tail flags showed a moderate association with the terrestrially approaching model cat. North American red squirrels respond to predators through three kinds of alarm calls. These are seets, barks, and seet-barks. Seets are high-frequency sounds of low amplitude. Barks are loud alarm calls that have broad overtones.

Seet-barks are an intermediate of the other two sounds. They start like seets, add some harmonics, and end with a bark. The squirrels use seets and seet-barks in response to ravens and other aerial predators. Barks are only used when responding to dogs and people.

Besides being predator-specific, red squirrels also appear to use different alarm calls that reflect varying levels of urgency. For instance, if the squirrel encounters a small bird at the same distance as a large, terrestrial predator, then the level of urgency in the alarm is different. These squirrels communicate through three types of alarm sounds. The first is a soft tooth chatter, the second is a loud chuck, and the third is a short, loud staccato bark.

Palm squirrels use tail signals to communicate as well. Thomas rope squirrels communicate through chucks, whistles, and soft notes.

The chuck sound is short and varies in length. The whistles are loud, whereas the soft notes are comparatively quiet sounds. Fire-footed rope squirrels also have three kinds of alarm sounds. Their chucks are noisier and span across more frequencies as compared to Thomas rope squirrels. They also use double chucks and staccato calls. These squirrels communicate through barks and coos.

Their barks have varying frequencies and are short, broadband calls. Coos, on the other hand, are longer in length.

They are narrowband calls with a descending frequency. The barks are used upon encountering a predator, or in response to loud noises. Coos are used when responding to people. It is inaudible unless you are standing only a few meters away from the squirrel.

It is elicited only in response to people. Bush squirrels communicate through clicks, trills, and alarm barks. Clicks are short and soft broadband calls that are said in repetition. Trills are rapid, narrowband calls, whereas alarm barks are short and loud broadband calls.

Clicks are also used in response to people and predators like snakes and mongooses. Barks are mainly used in response to predators as well. It also communicates through a loud, vocal bark and a loud whining sound. The predator specificity associated with the chuff and bark sounds is unclear.