By Matt Soniak
More than a few pet parents claim that their animals know, with startling accuracy, when it’s time for dinner or a walk or when one of their humans are due to arrive home. Are dogs just very good at guessing, or do they really understand and keep track of time?
“I’m not sure anyone has studied this in detail in dogs, but having a general sense of time of day is something that every animal species that’s been studied seems to have,” says Dr. Clive Wynne, a psychologist who studies canine behavior and cognition at Arizona State University.
Indeed, a review of research on the subject by psychologist William Roberts from the University of Western Ontario found ample evidence that many different animals are sensitive to time. “They can learn to go to a particular place for food at a particular time of day,” he wrote. “And they can learn to precisely time short intervals upon the presentation of an external stimulus.” For example, oystercatcher birds feed on shellfish that are only available for a short period each day during low tide, and scientists have observed them returning to shellfish beds at exactly the right time each day. Other researchers, meanwhile, found that pigeons flocked to certain parts of a college campus every day right around lunchtime so they could pick at the scraps.
Meanwhile, domestic animals have shown they can track time, too. As petMD has reported before, cats trained to eat from one of two bowls based on how long they were held in a cage before being released to eat could tell the difference between intervals of 5, 8, 10, and 20 seconds, which implies to researchers that cats have “an internal clock that is responsible for assessing the duration of events.” In another study, researchers showed that dogs left home alone greeted their owners more intensely—displaying more tail wagging, attentive behavior, and overall energy—after an absence of two hours than they did when the owner was only gone half an hour.
How Do Dogs Keep Track of Time?
Dogs don’t have watches or keep day planners, so how do they track the passing of time? Scientists have a few ideas. First, animals and other organisms have an internal clock of sorts called a circadian rhythm, a roughly 24-hour cycle in their physiological processes that responds to cues like the cycle of light and darkness. Instead of knowing what hour meals are served or ticking off units of time in their heads, dogs may be keeping track of time using this rhythm, responding to a physiological state they reach at a particular time of day, and associating it with a particular event, like dinner.
Alternatively, “animals might use markers in their daily life to keep track of time, such as position to the sun in the sky,” Roberts tells petMD. Wynne suggests that dogs may also simply pick up on social cues that tell them something is about to happen. Dogs are “watching everything you do for some clue that something is going to happen that’s going to matter to them,” he says. These cues don’t necessarily indicate to them what time it is but are predictors that an important event is close at hand.
Then there’s an interesting idea suggested by dog cognition researcher Alexandra Horowitz in her recent book Being a Dog. Horowitz thinks that dogs might be able to smell time, in a way. As scents come and go and move around the house during the day, dogs may use the presence, absence, or strength of a particular scent to track time and figure out how long ago something happened or how close they are to a future event. If you feed your dog on a regular schedule or leave for work at the same time every day, your dog may anticipate the next meal or your arrival home based on the strength of the food scent remaining in their bowl or your scent lingering by the front door.
When it comes to keeping track of longer lengths of time, dogs and other animals may have more trouble. Just as they might use certain daily cues to mark time during a single day, Roberts thinks they could use daily cycles to keep track of more extended time. “However, humans remember important events by assigning dates and times of day to them,” he says. “Without our time technology devices, it’s hard to see how animals could do this.”
Dogs might be able to figure out what time dinner is, then, but don’t expect them to know when Christmas or their birthday is coming up.