A day-long pattern of behaviour that tends to be repeated day after day. Environmental changes between night and day affect animals both directly and indirectly. Thus there may be changes in food availability and in numbers of predators, which are brought about by changes in light intensity, temperature, etc. In adjusting to the differences between night and day, the animal adopts a daily routine that is made up of many different aspects of behaviour fitted together to form a pattern that tends to be repeated day after day.
When individual activities are studied, they tend to follow a circadian rhythm, which is partly due to the fact that the activity must fit in with other aspects of the daily routine, and partly due to the influence of the biological clock.
Daily routines enable animals to make the best use of their time and to exploit opportunities. Thus the European kestrel (Falco tinnunculus) is a diurnal predator that specializes in preying upon small mammals. They catch prey throughout the day, but do not immediately eat what they catch. They tend to cache surplus prey throughout the day, and retrieve them at dusk. This routine enables the kestrel to make the most of available prey throughout the daylight hours without spending too much time eating the prey.
Subjects: Zoology and Animal Sciences.