Chipmunk Clucks Revisited

Written by Lang Elliott on March 22, 2011 · 5 Comments

Sometimes one’s memory is not so good. After telling a friend that I only had three solid observations of chipmunks responding to aerial predators by giving cluck calls, I went back to my original published study from 1978 and discovered that I had actually recorded a whopping seventeen (17) instances of this behavior, not just three as I had remembered. And come to think of it, I’ve observed at least three additional examples since my study, bringing the total to around twenty! Not bad, even from a scientific point of view.

Concerning my monograph on chipmunk behavior published in 1978, I am pleased to announce that you can now download a hi-resolution PDF copy, thanks to Smithsonian Institution. I had no idea they had made it available online (click on the graphic to access the PDF):

Reference: Elliott, Lang. 1978. Social Behavior and Foraging Ecology of the Eastern Chipmunk (Tamias striatus) in the Adirondack Mountains, Smithsonian Contributions to Zoology, Number 265, Smithsonian Institution Press, Washington, D.C.

Just so we’re all up to speed on this matter, be sure to check out my two previous blog posts: The Clucking Munk and The Chipping Munk. Below is a summary recording featuring the chipmunk’s aerial predator alarm call, cluck, cluck, cluck, cluck … (ending with a chip-trill), followed by high-pitched chipping, chip, chip, chip, chip …, the latter most often given in the presence of ground predators (at least that’s my educated guess):

An Eastern Chipmunk giving 'cluck' calls followed by another individual giving 'chip' calls. Recordings by Lang Elliott made in the Adirdondack Mountains of upstate New York.0:00 / 0:00

One friend tells me he has heard chipmunks clucking in the presence of house cats, and it appeared to him that the cats were stalking the chipmunks and that the chipmunks were responding with the clucks. I would be the first to admit that clucks might be given in response to ground predators, even though my experience has been otherwise. Given that chipmunks may cluck for five or ten minutes after a hawk has flown away, it is quite possible that a cat would walk by during that refractory period, leading an observer to believe the cat is responsible. On the other hand, maybe they do cluck in response to cats. I certainly have no observations to the contrary.

To my blog followers: Let me know if any of you have something relevant to add to this discussion. Have you noticed the clucking yourself? And have you ever nailed down an event (aerial predator fly-by, ground predator walk-by, etc.) that you think actually instigated a clucking bout? Have you ever heard chipmunks cluck in response to cats nearby?

The Chipping Munk

Written by Lang Elliott on March 3, 2011 · 10 Comments

With regard to yesterday’s Clucking Munk post, which featured a recording of the Eastern Chipmunk’s “aerial predator alarm call,” some folks asked me to provide an example of its counterpart: the “ground predator alarm call.” So I’ve decided to do just that, as well as briefly describe the differences.

The ground predator alarm is a loud, high-pitched, staccato “chip,” given in a measured series (as you might guess, the chipmunk is named for this call). The energy of the call, frequency-wise, is mostly well above 3000 Hz. Here is an example:

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In contrast, the aerial predator alarm call is characterized by a loud, hollow cluck at around 1200 Hz that is accompanied by a much softer high frequency aspect (clucks can be heard several hundred feet away):

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It is true that you may come across a chipmunk giving calls that seem intermediate, but for the most part the two call types are distinct (at least that is my belief). In general, if the low clucking aspect of the call is present and dominant, the chipmunk is most likely responding to an aerial predator, although he might be giving the call because he hears neighboring chipmunks giving the call (clucking is contagious in this respect—if one chipmunk sees a hawk and starts clucking, a neighbor might soon join-in, even though he might not have seen the hawk).

A BRILLIANT IDEA: Why don’t we name this animal based on what sound he’s making? If we come across an individual who is chipping, we will call him a Chip-munk. But if we come across an individual who is clucking, maybe we should call him a Cluck-munk. I rather like that … Cluckmunk! And if he isn’t making any sound? How about Stripemunk!

There is yet another vocalization type made by chipmunks. It is called the “chip-trill” and is given by chipmunks who are diving for cover. I believe that chipmunks give this call no matter what the disturbance (a diving hawk, a fox or dog on the charge, or a human suddenly appearing). Almost always, if you hear this call, the chipmunk is rushing into a burrow, a tree hollow, or other shelter, although in my best recording he gives a chip-trill in the middle of a chip series:

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If you’re interested, you can download a hi-resolution PDF of my original study, provided online by Smithsonian Institution:

Elliott, Lang. 1978. Social Behavior and Foraging Ecology of the Eastern Chipmunk (Tamias striatus) in the Adirondack Mountains, Smithsonian Contributions to Zoology, Number 265, Smithsonian Institution Press, Washington, D.C.

The Clucking Munk

Written by Lang Elliott on March 2, 2011 · 11 Comments

Oh my, what praytell shall I post this evening? It’s been a long, busy day, so whatever I do can’t take too much effort. Let me see what I have sitting here on my desktop (computer desktop, that is). Hmmmm … how about a recording of … a couple of Eastern Chipmunks giving “aerial predator alarm calls” in response to a Broad-winged Hawk perched in a nearby tree, the hawk giving its penetrating alarm whistle because it could see me sitting there with my headphones on, a few hundred feet away? (FYI, I had set my microphone close to the hawk’s nest just to get his alarm screams; the two chipmunks that started calling off to one side were a complete surprise.)

Will this be exciting enough for everyone, or have I pampered you so much that it won’t impress at all? Well, whatever, here it is:

Eastern Chipmunks giving aerial predator alarm calls in the presence of a Broad-winged Hawk that is also calling. 9am, 27 June 1995, in hardwood forest near Ithaca, New York. Recording © Lang Elliott.0:00 / 0:00

This is quite an instructive recording. The “clucking” of the Eastern Chipmunk is, in fact, given in the presence of aerial predators such as hawks or day-hunting owls. Guess who discovered this? Yep, ME, yours truly. Way back in the mid-1970s, for my masters degree in Animal Behavior and Ecology at the University of Maryland, I studied the social behavior of a population of chipmunks in the Adirondack Mountains of upstate New York. I made lots of interesting discoveries and described many aspects of their social life that nobody else had witnessed, but figuring out that the hollow cluck-calls are given in the presence of aerial predators was perhaps my most important contribution to their natural history.

At first I had no idea what it was about. I’d hear one chipmunk start clucking, then another, then another, as a “clucking bout” seemed to spread through the forest along a path. It wasn’t until autumn and spring, when the leaves were no longer on the trees, that I was able to put it all together. Seventeen times altogether I was lucky enough to see hawks fly by—mostly Broad-winged Hawks, but also Cooper’s Hawks and even a Goshawk—and in every instance clucking gradually erupted along the flight path of the hawk. When chipmunks gave these calls they became alert, and often sat still on a log, rock, or stump. As you might suspect, an alert chipmunk does not make good prey. If a hawk were to swoop at one, the perched chippie would see it coming and dash to safety.

Why do chipmunks give these calls when they see an aerial predator? Well, I’m not totally sure, but it might have something to do with altruism and genetics, with the “relatedness” of neighbors in the forest habitat. Biologists theorize that if neighbors are related, then it’s a good idea to alert your neighbor of danger, as long as it’s not too dangerous to do so. From an evolutionary perspective, this means that the calling chipmunk is helping pass on its genes, by helping neighbors that share genes . . . or something like that. In addition to the relatedness hypothesis, it is also possible that the sound simply tells the hawk that it has been spotted, that it won’t fare well here, and that it might as well move on down the road.

If you’re interested, you can download a hi-resolution PDF of my original study, provided online by Smithsonian Institution: