Timing of Feline Activity

Key Points
Cats often adapt their activity patterns to the presence of humans. However, experimentally cats show variation in activity pattern and ability to adapt to light conditions, which may be why some individuals exhibit nocturnal activity which is problematic for owners.

Timing of Activity

Cats are commonly described as crepuscular (active primarily during twilight - dawn and dusk), and this pattern of activity has been confirmed in radio-telemetry studies. The cat's crepuscular nature is also supported by the structure and function of the its eye, which has a number of adaptations that improve its function in low light conditions. However, cats have also previously been described as nocturnal and diurnal, based on findings from different studies. Under laboratory conditions in isolation from human contact, cats showed random patterns of activity in continuous light, and free-running circadian rhythms in constant darkness. Food intake was stimulated by simulated starlight and the presence of people. There was also a significant level of idiosyncratic variation in entrainment to different light-dark cycles, indicating that some individuals were more capable than others of adapting to different day length.

Relationship with Human Activity

For many generations domestic cats have been exposed to a different set of selection pressures related to photoperiodicity of behaviour, the availability of prey and the presence of humans. In these altered environmental conditions cats which continued to follow a pattern of entrainment with greater levels of activity during the twilight period might have have been at a survival disadvantage.

The activity of domestic cats is also significantly influenced by human activity. In conditions that more closely resemble an average domestic environment, cats that were more closely involved with their owners showed greater levels of activity during daylight.

Man-made lighting, including light pollution, maintains a constant level of illumination in urban areas that is similar to the crepuscular period. This means that urban cats, and their prey, are exposed to a distorted photoperiod that does not favour proper entrainment. This could lead to alterations of activity patterns, particularly hunting and territorial behaviour. It could also influence prey behaviour and hunting success in urban cats.