Noise Pollution Makes Crickets Less Picky When Mating

Traffic and other human-made noise could impact the health of the species.

Close up of two brown crickets
Man-made noise affects a cricket's choice of mate. Mint Images / Getty Images

The mating behavior of crickets is significantly impacted by the sounds of traffic and other human-made noise pollution, a new study finds.

When a female cricket is in the vicinity, a male cricket will rub his wings together to create a song. The behavior, known as stridulation, is a way that the male can communicate information about some of his best qualities.

“Courtship songs, one of a number of songs crickets can produce in this way, serves to ‘convince’ female crickets to mate with the performing males,” lead author Adam Bent, who performed the study as part of his PhD at Anglia Ruskin University in Cambridge, England, tells Treehugger.

“In Gryllus bimaculatus, the species of cricket we studied, we know courtship song performance is linked to energetic expenditure and immunocompetence, and females are known to prefer songs correlated with these traits.” 

For the study, researchers placed female crickets with silenced male crickets in ambient noise conditions, artificial white noise conditions, and traffic noise conditions which were recorded on a busy road near Cambridge.

In some cases, an artificial courtship song was played when the males attempted to sing and court the females. The recording was either a high-quality courtship song, a low-quality song, or no song at all.

In the ambient noise, which was the control condition, the females chose to mate with the males much more quickly when they heard the high-quality courtship song. 

“Under ambient noise conditions, females behaved as expected, by preferring males paired with high-quality (and thus high energy) songs over those paired with low-quality songs or no songs at all,” Bent says. “This preference was measured by the female's choice to mate and, if she did, how long this took to initiate.”

But the same song offered no advantage in the white noise or traffic noise situations. The researchers found that the duration of courtship and frequency of mating wasn’t impacted by the quality or presence of a courtship song.

"Female crickets may choose to mate with a lower-quality male as they are unable to detect differences in mate quality due to the man-made noise, and this may lead to a reduction or complete loss of offspring viability," Bent says.

The results of the study were published in the journal Behavioral Ecology.

Long-Term Health Impacts

The findings suggest that noise pollution changes how female crickets regard males when choosing mates. This could affect the male’s fitness as they could work harder and spend more energy trying to produce a higher-quality courtship song. All this, in turn, could affect the health of the species’ population.

“Long-term impacts are hard to predict for a selection pressure that is this recent, evolutionarily speaking. However, it is likely to go one of two ways; either the species will adapt and thrive despite the additional noise, or they won’t be able to adapt quickly enough, and the species will deteriorate,” Bent says.

“Given the trend of how other species have been impacted by our activities, I would assume the latter is more likely.”

View Article Sources
  1. Bent, Adam M., et al. "Anthropogenic Noise Disrupts Mate Choice Behaviors in Female Gryllus Bimaculatus." Behavioral Ecology, 2021, doi:10.1093/beheco/araa124