The rainforests are alive with the sound of animals. Besides the pleasure of the noise, it is also useful to ecologists. If you want to measure the biodiversity of a piece of land, listening out for animal calls is much easier than searching in the undergrowth for tracks. But such “bioacoustics (生物声音的) analysis” is still time-consuming, and it requires an expert pair of ears.
In a paper published on October 17th, a group of researchers led by Jorg Müller, an ecologist at the University of Würzburg, describe a better way: have a computer do the job. Smartphone apps already exist that will identify birds, bats or mammals simply by listening to the sounds they make. Their idea was to apply the principle to conservation work.
The researchers took recordings from across 43 sites in the Ecuadorean rainforest. Some sites were relatively clean, old-growth forest. Others were areas that had recently been cleared for pasture or cacao planting. And some had been cleared but then abandoned, allowing the forest to regrow.
Sound recordings were taken four times every hour, over two weeks. The various calls were identified manually by an expert, and then used to construct a list of the species present. As expected, the longer the land had been free from agricultural activity, the greater the bio-diversity it hosted. Then it was the computer’s turn. The researchers fed their recordings to artificial intelligence models that had been trained, using sound samples from elsewhere in Ecuador, to identify 75 bird species from their calls. “We found that the AI tools could identify the sounds as well as the experts,” says Dr Müller.
Of course, not everything in a rain-forest makes a noise. Dr Müller and his colleagues used light-traps to capture night-flying insects, and DNA analysis to identify them. Reassuringly, they found that the diversity of noisy animals was a reliable indicator of the diversity of quieter ones, suggesting that this method could be used to monitor the effectiveness of reforestation projects.
The study, published in Nature Communications, could have implications beyond ecology. Companies such as L’Oreal and Shell have been investing in forest restoration projects worldwide. Dr Müller suggests that this automated approach could provide a standardized way to monitor these efforts and verify whether they are as successful as claimed.
8. What information does paragraph 1 provide about “bioacoustic analysis”?
A.It requires special skill and time. | B.It can only be performed on land. |
C.It assesses biodiversity easily. | D.It makes animal calls attractive. |
9. What does “the job” underlined in paragraph 2 refer to?
A.Describing how the research was conducted. | B.Protecting the birds and mammals from danger. |
C.Measuring the biodiversity of a piece of land. | D.Monitoring how the smartphone works. |
10. What can be inferred from paragraphs 4?
A.Biodiversity can be enhanced by minimizing agricultural activities. |
B.Both light-traps and sound recordings can be used to identify noisy animals. |
C.The larger number of noisy animals, the smaller number of quieter ones. |
D.Al tools could potentially be used to monitor agriculture development. |
11. What can be a suitable title for the text?
A.Protect a Forest’s Inhabitants by Listening | B.Identify the Calls of the Wild with AI Aid |
C.Promote Rainforest Biodiversity Through AI | D.Find a Way to Monitor Deforestation Situation |