How birds are harmed by light pollution

This is what the researchers explained in the study X,Y, and Z: A bird's eye view on light pollution, published in the Ecology and evolution.

by Lorenzo Ciotti
How birds are harmed by light pollution

"The global increase in light pollution is being viewed with growing concern, as it has been reported to have negative effects ranging from the individual to the ecosystem level. Unlike movement on the ground, flying and swimming allows vertical motion.

Here, we demonstrate that flight altitude change is crucial to the perception and susceptibility of artificial light at night of air-borne organisms. Because air-borne species can propagate through the airspace and easily across ecotones, effects might not be small-scale.

Therefore, we propose including airspace as a vital habitat in the concept of ecological light pollution. The interplay between flight altitude and the effects of light pollution may not only be crucial for understanding flying species but may also provide valuable insights into the mechanisms of responses to artificial light at night in general." This is what the researchers explained in the study X,Y, and Z: A bird's eye view on light pollution, published in the Ecology and evolution.

Among the environmental damages caused by light pollution, there is difficulty or loss of orientation in various animal species, alteration of the photoperiod in some plants, alteration of the circadian rhythms in plants, animals and microorganisms, stunted growth of the periphyton.

In 2001, a new retinal photoreceptor was discovered in the eye which does not contribute to the mechanism of vision, but regulates our biological clock. The peak sensitivity of this sensor is in the blue part of the visible spectrum and for this reason, lamps with a strong blue cast are the ones that can most alter our circadian rhythms.

While the lamps that cause less damage, from this point of view, since they have a dominant red color of the visible spectrum, are the high pressure sodium ones, and even less harmful, the low pressure ones. The main cultural damage is due to the "disappearance of the starry sky" in the most polluted countries and areas.

The starry sky has always been a main source of inspiration for religion, philosophy, science and culture in general. But the light pollution that is reflected in the atmosphere produces a veiled glare with a wide surface field, which blocks the vision of stars and celestial objects, normally visible to the naked eye.

Among the sciences most damaged by the disappearance of the starry sky there is undoubtedly both amateur and professional astronomy; a sky that is too bright in fact greatly limits the efficiency of optical telescopes which must increasingly be positioned away from this form of pollution.