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Ecological perspectives
In recent history, ecologists and psychologists have been interested in whether and how time is perceived by non-human animals, as well as which functional purposes are served by the ability to perceive time. Studies have demonstrated that many species of animals, including both vertebrates and invertebrates, have cognitive abilities that allow them to estimate and compare time intervals and durations in a similar way to humans.

There is empirical evidence that metabolic rate has an impact on animals' ability to perceive time. In general, it is true within and across taxa that animals of smaller size (such as flies), which have a fast metabolic rate, experience time more slowly than animals of larger size, which have a slow metabolic rate. Researchers suppose that this could be the reason why small-bodied animals are generally better at perceiving time on a small scale, and why they are more agile than larger animals.

Examples in fish
In a lab experiment, goldfish were conditioned to receive a light stimulus followed shortly by an aversive electric shock, with a constant time interval between the two stimuli. Test subjects showed an increase in general activity around the time of the electric shock. This response persisted in further trials in which the light stimulus was kept but the electric shock was removed. This suggests that goldfish are able to perceive time intervals and to initiate an avoidance response at the time when they expect the distressing stimulus to happen.

In two separate studies, golden shiners and dwarf inangas demonstrated the ability to associate the availability of food sources to specific locations and times of day, called time-place learning. In contrast, when tested for time-place learning based on predation risk, inangas were unable to associate spatiotemporal patterns to the presence or absence of predators.

Examples in birds
When presented with the choice between obtaining food at regular intervals (with a fixed delay between feedings) or at stochastic intervals (with a variable delay between feedings), starlings can discriminate between the two types of intervals and consistently prefer getting food at variable intervals. This is true whether the total amount of food is the same for both options or if the total amount of food is unpredictable in the variable option. This suggests that starlings have an inclination for risk-prone behavior.

Pigeons are able to discriminate between different times of day and show time-place learning. After training, lab subjects were successfully able to peck specific keys at different times of day (morning or afternoon) in exchange for food, even after their sleep/wake cycle was artificially shifted. This suggests that to discriminate between different times of day, pigeons can use a internal timer (or circadian timer) that is independent of external cues. However, a more recent study on time-place learning in pigeons suggests that for a similar task, test subjects will switch to a non-circadian timing mechanism when possible to save energy resources. Experimental tests revealed that pigeons are also able to discriminate between cues of various durations (on the order of seconds), but that they are less accurate when timing auditory cues than when timing visual cues.

Examples in mammals
A study on privately owned dogs revealed that dogs are able to perceive durations ranging from minutes to several hours differently. Dogs reacted with increasing intensity to the return of their owners when they were left alone for longer durations, regardless of the owners' behavior.

After being trained with food reinforcement, female wild boars are able to correctly estimate time intervals of days by asking for food at the end of each interval, but they are unable to accurately estimate time intervals of minutes with the same training method.

When trained with positive reinforcement, rats can learn to respond to a signal of a certain duration, but not to signals of shorter or longer durations, which demonstrates that they can discriminate between different durations. . Rats have demonstrated time-place learning, and can also learn to infer correct timing for a specific task by following an order of events, suggesting that they might be able to use an ordinal timing mechanism. Like pigeons, rats are thought to have the ability to use a circadian timing mechanism for discriminating time of day.

Time perception in invertebrates
When returning to the hive with nectar, forager honey bees need to know the current ratio of nectar-collecting to nectar-processing rates in the colony. To do so, they estimate the time it takes them to find a food-storer bee, which will unload the forage and store it. The longer it takes them to find one, the busier the food-storer bees are; and therefore the higher the nectar-collecting rate of the colony. Forager bees also assess the quality of nectar by comparing the length of time it takes to unload the forage: a longer unloading time indicates higher quality nectar. They compare their own unloading time to the unloading time of other foragers present in the hive, and adjust their recruiting behavior accordingly. For instance, honey bees reduce the duration of their waggle dance if they judge their own yield to be inferior. Scientists have demonstrated that anesthesia disrupts the circadian clock and impairs the time perception of honey bees, as observed in humans. Experiments revealed that a 6 hour-long general anesthesia significantly delayed the start of the foraging behaviour of honeybees if induced during daytime, but not if induced during nighttime.

Bumble bees can be successfully trained to respond to a stimulus after a certain time interval has elapsed (usually several seconds after the start signal). Studies have shown that they can also learn to simultaneously time multiple interval durations.

In a single study, colonies from three species of ants from the genus Myrmica were trained to associate feeding sessions with different times. The trainings lasted several days, where each day the feeding time was delayed by 20 minutes compared to the previous day. In all three species, at the end of the training, most individuals were present at the feeding spot at the correct expected times, suggesting that ants are able to estimate the time running, keep in memory the expected feeding time and to act anticipatively.