Light pollution causes grasshoppers to chirp during the day and can disrupt reproductive processes

Light pollution causes grasshoppers to chirp during the day and can disrupt reproductive processes

Cricket. Credit: Keren Levy

A joint study conducted by researchers from Tel Aviv University and the Open University of Israel revealed that exposing male chickens to artificial light at night (ALAN) can impair their activity cycles. According to the researchers, nocturnal chirping is the male’s way of calling females to come and mate with him, and the disturbance of it can disrupt the reproductive processes and even endanger the entire species. Previous studies around the world have shown that light pollution is harmful to many species of animals and plants. The researchers call for reducing ALAN as much as possible to enable coexistence in the night environment.

The study was led by Prof. Amir Ayali and Keren Levy from the School of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University and Prof. Anat Barnea from the Department of Natural and Life Sciences at the Open University. Yoav Wegrzyn from Prof. Ayali’s laboratory and Ronny Efronny also participated in the study. The newspaper was published in Proceedings of the Royal Society B, and also mentioned in Nature.

Keren Levy explains that “the distinction between day and night, light and darkness, is an important basis for life on earth. But humans, like the creatures of the day who fear darkness, disrupt this natural order: they produce artificial light that drives away darkness. and allows them to continue their activities at night.Today, more than 80% of the world’s population lives under light pollution, and the total amount of ALAN increases by 5% every year.ALAN negatively affects the environment and affects natural behaviors that have developed over millions of years of evolution. ALAN affects the length and quality of many animals’ sleep, leading to high mortality and altering the activity cycle of many creatures. For example, dung beetles navigating the Milky Way lose their way. , which hatches, the brightest surface in sight – supposedly the sea, and instead reaches the nearby promenade; just to name two of many examples. “

In the current study, the researchers examined the effect of light pollution on the field cricket, a nocturnal insect whose chirping can be heard during late summer nights – when the males ask the females to mate with them. Prof. Ayali says that “in the wild, chickens exhibit a very regular activity cycle. Squeaking behaviors that call for females occur at sunset and during the night, ending in the morning. We exposed field chickens to different levels of lifelong ALAN and observed its impact on two basic behaviors: chirping and movement. “

The researchers monitored dozens of chickens for life (from egg to adult stage) exposed to four types of light conditions. They found that chickens exposed to 12 hours of light followed by 12 hours of darkness exhibited cyclic activity rhythms of 24 hours: they began to chirp when the light went out and stopped when the lights were turned on again. Crickets that experienced partial lighting during the dark periods lost their natural rhythms and their synchronization with their surroundings: 80% followed an individual inner cycle, and 5% lost all rhythm. Crickets exposed to constant light 24/7 developed their own cycles (71%) or lost all rhythm (29%). The results indicated that increase in ALAN in the laboratory induces loss of rhythmicity at both individual and population level.

Keren Levy concludes that their “study shows that sheep chickens whose light-dark cycle is disrupted behave like teenagers on vacation: active or asleep according to their own internal clock or lacking any rhythm. In fact, light pollution caused by humanity causes field cricket. and causes loss of synchronization within the individual, at the population level and between the population and the environment. showing the serious impact of low levels of ALAN on nature, we therefore ask you to help protect our environment and surroundings by turning off the lights in your backyards, on the terrace, in parking lots, and where possible. to bring the night and the Milky Way back into our lives and enable nocturnal coexistence with the creatures around o s. ”


Light pollution associated with increase in premature birth


More information:
Keren Levy et al., Lifelong exposure to artificial light at night affects stridulation and movement activity patterns in cricket Gryllus bimaculatus, Proceedings of the Royal Society B (2021). doi.org/10.1098/rspb.2021.1626

Provided by Tel-Aviv University

Citation: Light pollution causes grasshoppers to chirp during the day and can disrupt reproductive processes (2021, November 2) retrieved November 2, 2021 from https://phys.org/news/2021-11-pollution-crickets-chirp-daytime-disrupt. html

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