Ecoducts: The Safe Way to Cross the Road

How does an animal cross a road safely? The short answer is: it often doesn’t! Every year around the word, thousands of animals are killed or injured by cars, trucks, and trains on our busy roads and railway systems.

France was the first country to build wildlife crossings to help animals get across roads safely. The French designed these structures to protect animals from the busy traffic. Since then, many other countries have also built wildlife crossings.【小题1】

Ecoducts, also called “ green bridges”, are structures that engineers build over big roads and highways.【小题2】Cars, vans, and trucks go under the ecoducts, through a tunnel, and the animals walk over the ecoduct, above the road or highway.

At Banff National Park, in Alberta, Canada, park employees have labored hard to make more than 40 ecoducts. Some of the ecoducts in Banff are bridges that cross over the highway.【小题3】Others are called underpasses. These are tunnels that go under a road. Most ecoducts have soil and plants on them which provide a good environment for wildlife and encourage animals to use the structures. Some ecoducts, including many in Canada and in Florida, are made extremely big so that black bears, deer, and the Florida panther will use them.

【小题4】Perhaps you’re distrustful about this idea. You shouldn’t be, because animals do use them! At first animals can be a little unsettled of the crossings. Experts say that some bears can take as long as five years to start using them. When animals realize that the ecoducts are safe, they use them a lot! So far, since Banff National Park began to make notes about the ecoducts in 1997, eleven different species of mammals have used the overpasses and underpasses more than 200, 000 times !

Ecoducts are a great way to protect wildlife from traffic.【小题5】But for now even snakes can get itself across a road safely thanks to ecoducts!

Dolphins and fishermen in Laguna, Brazil, like the same food: Mullets (鲻鱼). But rather than compete, the two have formed an alliance. Common bottlenose dolphins will chase schools of mullets toward shore, where a row of fishermen stand waist-deep in the water, nets in hand. The fishermen can’t see the fish through the murky water, so instead, they watch the dolphins. When the marine mammals slap their heads or tails against the water, they cue (提示) the fishermen to cast their nets, which in turn breaks up the schools and makes individual fish easier for the dolphins to catch.

Now, a new study suggests the dolphins are willing partners in this cooperation. They pay close attention to the humans, timing their actions to maximize their catch. The animals may even be guiding the people, says Simon Ingram, a marine biologist. He says, “It’s almost as if the dolphins are training the humans.” Fishers must understand the dolphins’ cues, learning them over time, Cantor, a behavioral ecologist at the University of Cambridge, says. “The dolphins are almost like teachers.”

This fishing partnership has passed down through the generations, lasting for more than a century. According to a study published in Proceedings of the National Academy of Sciences, researchers suggest dolphins that hunt with humans have increased survival rates over those that don’t. These cooperative dolphins are more likely to stay near the shore, reducing their chance of entanglement (缠住) in illegal fishing gear. Fishers were also more successful when they worked with the dolphins. When dolphins were present, the fishers were 17 times more likely to catch fish and netted nearly 4 times more mullets when they timed their casting with the dolphins’ signals. This is really incredible cooperative behavior.

Other populations of dolphins have also been known to cooperate with human fishers, herding fish toward shore or into nets off eastern Australia, Mauritania, and Southeast Asia. But these practices have either disappeared or are in decline.

While the human world is suffering from the novel coronavirus outbreak, our planet is actually showing certain signs of "recovery" from the damage caused by human activity. According to BBC, new satellite images released by the European Space Agency showed that the levels of air pollutants and greenhouse gases have "fallen sharply" in major cities in Europe and the United Stated ever since the lockdown started.

This is a great example of how the world can change overnight as soon as people change their behavior—especially after recent discoveries in Antarctica. An international team of 89 scientists found that the ice in Greenland and Antarctica was melting six times faster in the 2010s than it was in the 1990s. And in February Argentina's Marambio research station in Antarctica recorded a record high temperature of 20.75℃ in the continent.

So what exactly will happen if the temperature keeps rising and the ice keeps melting? A third study might give you an idea. A team of scientists drilled a hole into the seafloor in west Antarctica and obtained material from underground, in which they found traces of roots, spores and pollen— typical products of a rainforest — that dated back to 90 million years ago. In other words, Antarctica was very likely a rainforest back when the dinosaurs walked on Earth. But given the fact that the South Pole has four months of darkness during winter — even millions of years ago—scientists believe that the rainforest could only exit if the greenhouse gas concentration were extremely high back then to keep the continent warm when there was little or no sunlight. "We didn't know that this Cretaceous greenhouse climate was that extreme," Johann Klages of the Alfred Wegener Institute in Germany and a co﹣author of the research told the Guardian. "It shows us what carbon dioxide is able to do. "

Ice or no ice, Antarctica will be—and has always been fine with extreme changes. The human world, however, may not be. Now, during the coronavirus lockdown, we've seen the changes resulting from less human activity. Hopefully, we'll hold on to those changes—not for Antarctica or the planet, but for ourselves.