Phil Wise is a wildlife scientist from the Save the Tasmanian Devil (袋獾)Program. The scientists working with this program study Tasmanian devils, check their health, and track the devils found in the wild. Because a disease is reducing the number of devils, Oddity, a young Tasmanian devil, and 14 others were raised in a preserve and then brought to Maria Island to be set free into the wild.

Life on this island off the coast of Tasmania was a big change for Oddity and the others. These devils bad little experience with other kinds of animals and had to explore the land and find new bones.

Though they are raised in zoos all over the world, devils live wild only in Tasmania. They eat dead animals they find, which helps clean up the environment. Devils also eat animals such as wallabies, wombats, and possums, helping to keep those populations balanced.

But a disease called Devil Facial Tumor Disease (DFTD) is killing devils on mainland Tasmania, putting them in danger. DFTD spreads when a diseased animal bites a healthy animal. The goal of the scientists w ho set Oddity and the others free was to create a lot of devils which are free of DFTD on Maria Island. Oddity is a part of this “insurance population” of devils raised in zoos and wildlife preserves. This means that if the facial disease causes the Tasmanian devil to die out in the wild, devils like Oddity can be sent back into disease-free areas of Tasmania, giving devils a chance to survive.

Oddity started his new life on Maria Island. And the other animals did so well that 13 more devils were set free. The 28 original Tasmanian devils have reproduced; there are now around 80 devils. They are doing well on Maria Island. and the plan is considered a success. Wise says he is “very happy to know that animals are getting a chance to be free in the wild in an area that is free of DFTD It is the final aim of all who work to protect animals.”

Although it has been revealed in recent years that plants are capable of seeing, hearing and smelling, they are still usually thought of as silent.But now, for the first time, Itzhak Khait and his colleagues at Tel Aviv University in Israel found that tomato and tobacco plants made sounds at frequencies humans cannot hear when stressed by a lack of water or when their stem is cut.Microphones placed 10 centimetres from the plants picked up sounds in the ultrasonic(超声波的) range of 20 to 100 kilohertz, which the team says insects and some mammals would be capable of hearing and responding to from as far as 5 metres away.A moth(蛾) may decide against laying eggs on a plant that sounds water-stressed, the researchers suggest.Plants could even hear that other plants are short of water and react accordingly, they guess.

Plants exposed to drought stress have been shown to experience cavitation—a process where air bubbles(气泡) form, expand and explode inside tissue that transports water.These explosions produce sound, but they have only ever been recorded using devices directly connected to the plant.

On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11.When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15.Unstressed plants produced fewer than one sound per hour, on average.

The researchers trained a machine-learning model to distinguish differences between the plants’ sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound’s intensity(强度)and frequency.Water-hungry tobacco appears to make louder sounds than cut tobacco, for example.

Enabling farmers to listen for water-stressed plants could “open a new direction in the field of precision agriculture”, the researchers suggest.They add that such an ability will be increasingly important as climate change exposes more areas to drought.Anne Visscher, working at the Royal Botanic Gardens, Kew, in the UK, warns that the results can’t yet be broadened out to other stresses, such as salt or temperature, because these may not lead to sounds.In addition, there have been no experiments to show whether moths(飞蛾） or any other animal can hear and respond to the sounds the plants make, so that idea remains speculative for now, she says.