On this May evening, many American pikas were making "long calls" in an amphitheater-shaped talus slope. Their combined calls filled the talus slopes with a grand concert.
Apparently, male American pikas perform this long-call song during the breeding season presumably to attract females. Some researchers assume this "long call" is made almost exclusively by male pikas to define and signal their territory, or they may make this call if another pika has violated a territory boundary. Some researchers believe females may also make this same call later in the season. The long call song may last 30 seconds or longer.
The long-call song is composed of a series of short and staccato individual calls. My analysis reveals a triplet of sounds which make up each blast of the long call (when viewed as a waveform or spectral frequency display). Sometimes, the last few bark calls in this long-call song have a slight downward inflection.
Researchers continue to decipher the mystery of the pika's calls. Subtle differences and similarities in the vocal utterances can be a challenge for humans to understand. Through extended observation, persistence, and collaboration, humans make general assumptions regarding the meaning of pika calls. In the published book: (Rabbits: The Animal Answer Guide; Susan Lumpkin) there is a claim that American pika's vocal repertoire consists of eight different calls. It appears as if calls of pikas provide listeners with information about intention, and objects and events in the environment.
Some American pikas will make a single call before heading out to gather food. Are they bragging to their neighbors, keeping count of their food-gathering runs, or just letting others know "I'm heading out for some vegetation"?
When pikas appear to be afraid or running for cover, they often make a "rumbled" version of the short call. This "I'm afraid", or "I'm running away", or "danger, danger" call often has a shaky tone with a downward spiral variation.
A young pika (juvenile) makes a call with a higher frequency as compared to an adult.
A single "eek" call that has a flat or guttural sound, is sometimes made by a pika if there is a predator (bird, weasel, marten, snake, other) nearby. Sometimes, a pika will mistake a squirrel or chipmunk for a predator, and make this same flat call. I personally have observed pika making a short call when the short or long-tailed weasel enters their neighborhood. Based on my observation, the calls are made from pikas that are far from the potential predator.
Some young pikas (juvenile) will make a squeaking sound combined with what sounds like a cat purring. I have only observed this unique sound on the Beartooth plateau in Montana and Wyoming. May this call signal "territorial" communication between the juvenile and a parent?
The American Pika will (attempt) call with vegetation wedged in their mouth. The call often sounds muffled and sounds different from a single call.
There are geographic variations in pika calls (and sounds) and variations within a single pika colony. Calls differ in many ways including call frequency, the number of calls, call duration, call inflection, and call volume.
Sound spectrograms help humans visualize and illustrate animal calls and sounds - including the sounds made by pika. The sound-spectrograms reveals a series of horizontal lines - almost like a bar code. These bars stacked on top of each other are composed of the fundamental frequency which is the bar at the base, and the harmonics or overtones which are the rest of the bars above the fundamental frequency.
Talus slopes and rock piles are home to a number of animals, including the yellow-bellied marmot. On occasion, their warning whistle proceeds that of the pika's warning call.
Some pikas living in the La Sal mountains near Moab produce high-decibel calls. These La Sal pika have the loudest calls I've personally heard. Some of their short call consists of two tones that have the utterance of "Pie-Kuh".
Strong winds can muffle the sound of the pika's call. On the Beartooth Plateau, for example, during late summer and autumn, sustained winds of 20 MPH (and gusts of 40 MPH or more) are common. Even with the strong winds pikas gather plants and communicate with one another. Like other creatures on this planet, their Dialects may vary geographically.
Interspecies communication implies the sharing and understanding of information from two or more species. Researchers in Canada studied calls made by collared pika (Ochotona collaris) and rodents. Using playback experiments, they tested how pikas attended to and distinguished between alarm calls of sympatric alpine mammals (marmot, squirrel, etc.).
Animal acoustic communication and animal vocalizations are complicated. Pika's unique language may be so complex that they have a different "call" or "word" they use to identify the type of predator in their neighborhood. They may even have a call that lets others know " "humans are in the neighborhood" ?
Mr. Jere Folgert
Bozeman, MT (USA)