sounds

Elephants have names

July 11, 2024 By EarthWise Leave a Comment

Elephants are considered to be very smart creatures. They have the largest brain of any land animal and have three times as many neurons as humans. Of course, a lot of that brain hardware is needed to control those big elephant bodies, but elephants have also demonstrated impressive mental capabilities on many occasions.

A new study by an international team headed by researchers from Colorado State University has found that elephants call each other by name and respond when they hear others call their name.

The researchers analyzed hundreds of elephant calls recorded over more than a year in Kenya. With machine learning techniques, they were able to identify specific sounds that elephants made when calling each other. When the researchers played recordings of these sounds, the elephants responded to the sound of their own name by calling back or moving toward the loudspeaker. Their response to other names was much less enthusiastic.

Very few animals use names at all, and, in most cases, it is more a matter of imitation. For example, dolphins refer to other dolphins by mimicking their unique sounds.

These findings at least suggest that elephants may be capable of abstract thought and perhaps may have a vocabulary beyond names for each other. The researchers are investigating whether elephants can identify food, water, or locations using their calls. The great hope is that it might ultimately be possible to communicate with elephants directly. It would be wonderful to be able to alert them to poachers or other threats. The lead author of the study said that he would like to be able to tell elephants things like “Do not come here. You’re going to be killed if you come here.”

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Elephants Have Names for Each Other, Study Finds

Photo, posted April 24, 2016, courtesy of Neil Ransom via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Chasing The Ivory-Billed Woodpecker | Earth Wise

June 13, 2023 By EarthWise Leave a Comment

The ivory-billed woodpecker is or was the largest woodpecker in the United States. The last unassailable sighting of the bird was in 1944. Since then, there have various reports of glimpses of the bird or of hearing its distinctive sounds. But there has not been anything resembling proof that the bird still exists.

Despite this, the ivory-billed woodpecker has been legally protected under the Endangered Species Act. There has been a proposal to end that protection and formally declare the species extinct. Because of the controversy surrounding the bird, a final ruling on its status has been repeatedly delayed by the US Fish and Wildlife Service.

Very recently, a peer-reviewed study in the journal Ecology and Evolution makes the case that the ivory-billed woodpecker still exists and that it is premature to declare it extinct. The study cites visual encounters by expert observers, audio recordings, tree-damage, and rather grainy video evidence. The authors claim that there is intermittent but repeated presence of birds that at least look and behave like ivory-billed woodpeckers.

One might ask: why does it matter whether this bird is declared extinct or not? The answer is that there are limited federal funds for conservation efforts, and they should be spent on saving genuinely endangered species and habitats. The authors of the new study say that removing federal protection would be bad for any remaining ivory bills, which may be living in some swampy old-growth forests in Louisiana. Other scientists consider conservation resources expended on the ivory-billed woodpecker to be chasing a ghost.

As is the case for several other notorious objects, one really clear photograph of an ivory-billed woodpecker could solve a long-standing mystery.

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A Vanished Bird Might Live On, or Not. The Video Is Grainy

Photo, posted October 19, 2014, courtesy of James St. John via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Plants Make Sounds | Earth Wise

May 9, 2023 By EarthWise Leave a Comment

Some people talk to their plants. It is highly unlikely that the plants are listening, but recent research has found that plants are doing quite a bit of talking of their own.

It turns out that plant emit a variety of click-like sounds, especially when they are stressed in some way, such as being dehydrated or injured. The sounds are actually fairly loud – comparable to the volume of human speech – but occur at frequencies well above the range of human hearing.

The study at Tel Aviv University in Israel monitored plants in a greenhouse that were subjected to various stresses over time. Unstressed plants emitted less than one sound per hour, on average, while stressed plants emitted dozens of sounds every hour.

Recordings of the plant sounds were analyzed by specially developed artificial intelligence algorithms. The algorithms learned how to distinguish between different plants and different types of sounds. Eventually, they could identify the plant and determine the type and level of stress from the recordings. They could even do this in a greenhouse with a great deal of background noise.

The study resolved a very old scientific controversy about whether plants emit sounds. Not only do they, but the sounds contain useful information. We don’t yet know what the mechanism is for plant sounds. It is likely that in nature, the sounds are detected by various animals and perhaps even plants that can detect the high frequencies. And perhaps they react to them as part of seeking food, shelter, or other services that plants provide. Given the right tools, we humans may also be able to make use of the sounds being made by plants.

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Plants Emit Sounds – Especially When Stressed

Photo, posted February 20, 2009, courtesy of ProBuild Garden Center via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Sounds Of Coral Reefs | Earth Wise

June 23, 2022 By EarthWise Leave a Comment

Coral reefs around the world face multiple threats from climate change, pollution, and other impacts of human activity. Reef conservation and restoration projects must be able to monitor the health of reefs and that is not such a simple matter. Surveying reefs generally is labor-intensive and time consuming. But in a new study, scientists at the University of Exeter in the UK have found a new way to do it.

The fish and other creatures living on coral reefs produce a vast range of sounds. The meaning of these various sounds is for the most part unknown, but reefs nonetheless have distinctive sonic signatures.

The Exeter researchers decided to make use of machine learning technology. They trained a computer algorithm using multiple recordings of both healthy and degraded coral reefs. This essentially taught the computer to learn the difference between them. A computer can pick up patterns that are undetectable to the human year. This application of artificial intelligence can tell us faster and more accurately how a reef is doing.

The computer was then used to analyze a set of new recordings, and successfully identified reef health 92% of the time. The team then was able to use this technique to track the progress of reef restoration efforts.

It is generally much cheaper and easier to deploy an underwater hydrophone on a reef and leave it there instead of having expert divers make repeated visits to a reef to survey its status. Sound recorders and artificial intelligence could be used around the world to monitor the health of coral reefs and determine whether efforts to protect and restore them are working.

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AI learns coral reef “song”

Photo, posted January 11, 2015, courtesy of Falco Ermert via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.