The Cougar (Puma concolor) in its habitat selection avoids the glare of areas with strong artificial lighting associated with human settlements more than the light reflected from them in the sky or the illumination of the moon, according to an international study led by the Complutense University of Madrid ( UCM). Made in California.
Other variables found in previous studies to influence cougar space use, such as distance from roads or land use, had a much smaller influence than the influence of glare from nearby lights.
“This avoidance is likely due to the fact that animals associate these human settlements with them Risk areas for them” suggests Rafael BarrientosResearcher in the Department of Biodiversity, Ecology and Evolution at UCM.
The work, published in Philosophical Transactions of the Royal Societycombines for the first time the study of sky brightness with nearby light pollution generated by cities on the horizon and the natural light of the moon.
GPS geolocation collars
To carry out the study, in which the American universities of California and Texas are also involved, 102 pumas were tracked between 2002 and 2022 and equipped with a GPS collar for geolocation.
The researchers were able to show that the puma’s choice of habitat varied between day and night and that areas that were heavily contaminated at night due to nearby artificial light were also avoided during the day.
The cougar’s choice of habitat varied between day and night. Areas heavily contaminated by artificial light were also avoided during the day
Artificial light, which is constantly increasing worldwide, affects the sensory systems, orientation and distribution of animalsand has the potential to cause ecological and evolutionary harm. Beyond the general pattern of avoiding glare from nearby lights, each of the 102 cougars showed a more or less intense response, suggesting that future studies should also consider individual variability in responses.
“The results suggest that even in generalist animals like the puma, artificial night light can change their quality of life.” Habitat selection patterns. Therefore, it is a source of pollution that we should reduce,” concludes Barrientos.
Bibliographical note:
Barrientos R. et al. “Nearby nighttime illumination, rather than sky glow, is associated with habitat selection by a top predator in human-dominated landscapes. Philosophical Transactions of the Royal Society (2023).