Bumble bees can estimate time intervals

Although many insects show daily and annual rhythms of behavior, the more sophisticated ability to estimate the duration of shorter time intervals had previously been known only in humans and other vertebrates.

The findings are reported by Michael Boisvert and David Sherry of the University of Western Ontario and appear in the August 22nd issue of the journal Current Biology, published by Cell Press.

Bees and other insects make a variety of decisions that appear to require the ability to estimate elapsed durations. Insect pollinators feed on floral nectar that depletes and renews with the passage of time, and insect communication and navigation may also require the ability to estimate the duration of time intervals.

In the new work, the researchers investigated bumble bees' ability to time the interval between successive nectar rewards. Using a specially designed chamber in which bumble bees extended their proboscis to obtain sucrose rewards, the researchers observed that bees adjusted the timing of proboscis extensions so that most were made near the end of the programmed interval between rewards. When nectar was delivered after either of two different intervals, bees could often time both intervals simultaneously. This research shows that the biological foundations of time perception may be found in animals with relatively simple neural systems.