Impact of artificial light at night on the foraging behaviour of the European Hamster: consequences for the introduction of this species in suburban areas
Résumé
Among the pressures introduced by urbanization, artificial light at night (ALAN) can be problematic,
particularly for nocturnal species. Populations of European hamsters (Cricetus cricetus) have dramatically
decreased in France since 1972 because of habitat loss due to urbanisation and changes in agricultural
methods. The conservation project Life Alister aims to increase the abundance of this species in suburban
areas via hamster release. However, the success of this population-restoration project may be compromised
due to the possible effects of ALAN on the daily and seasonal cycles and behaviour of this nocturnal species.
To understand how hamsters may respond to relocation, we experimentally studied the impact of ALAN on
hamster foraging, a decisive behaviour for survival in natural habitats. This study assessed the behavioural
responses of 18 animals when choosing between two food sources of different palatability in two different
lighting conditions: artificial light (4 or 40 lux) or darkness. Our results show that hamsters avoided lighting
that mimics suburban streetlights, particularly when grooming. Moreover, this study reveals that hamsters
do not avoid street-lit areas when highly palatable food is present, suggesting they would be more susceptible
to predation under these circumstances. Our results suggest that the adverse effects of ALAN on the
behaviour of hamsters released on the outskirts of developed suburban areas could be limited by restricting
the number of street lights, moderating the intensity of street lighting, or switching lights off during the
hours hamsters are most active. We further recommend that wildlife managers avoid planting plants that are
highly palatable to hamsters close to lighting in suburban areas to limit the risk of predation for this species.