Nocturnal Animal Welfare in Zoos

Nocturnal species in zoos are often housed in day-night reversal exhibits that allow daytime viewing, but managing the welfare of animals whose natural activity cycle is disrupted requires careful attention.

Key Facts

Day-night reversal exhibits use dim red lighting during the day and bright lighting at night to shift activity cycles
Species kept in reversal exhibits include slow loris, pangolins, aardvarks, bats, and various small mammals
Light-sensitive species including slow loris can suffer eye damage from bright lighting
Stress indicators including stereotypic behaviour and elevated cortisol are elevated in some nocturnal species in suboptimal exhibits
Modern nocturnal exhibits use species-appropriate lighting spectra and provide complex, enriched environments

Welfare Considerations

Nocturnal species present unique welfare challenges in zoos. Day-night reversal is a common management tool but must be implemented carefully — light levels during what the animal perceives as night must allow natural activity, and daytime levels must not cause stress or physical harm. Slow loris in particular are highly sensitive to bright light; historical exhibits exposed them to lighting levels that caused eye damage. The welfare of nocturnal species also requires appropriate temperature management, appropriate social grouping, and substrates that support natural movement and hiding behaviour.

What You Can Do

Ask zoos about light management protocols for nocturnal species exhibits
Advocate for species-specific welfare standards to be included in nocturnal exhibit design requirements
Support accreditation standards that require welfare impact assessment for light management in nocturnal exhibits
Donate to zoo conservation programmes with strong nocturnal species welfare records
Engage with the welfare literature on nocturnal animal captive management