Beavers, like humans, change their surroundings to fit their needs. Known as Nature’s engineers, they tear trees down to build lodges to live in and dams to raise water levels for protection from predators. Dams also slow water’s flow while blocking sediment (沉积物) that would otherwise flow downstream. The resulting wetlands often attract wildlife diversity where none had existed. There are challenges, though. Beaver dams sometimes cause flooding, and most people prefer trees alive and upright.

Communities face a delicate balancing act, learning to coexist with beavers. In late 2019, many people enjoying Washington & Old Dominion (W&OD) path became beaver fans as one furry family transformed Sparrow Pond -a sediment-filled, man-made storm-water management area- into an oasis for birds, frogs, turtles and deer.

Yet such activity caused concern. As beavers worked, they raised water levels about five feet. The increased depth allows beavers to survive underwater if the pond ices over in winter. But county officials were concerned about how higher water would affect the steep soil bank supporting the paved hike and bike path.

To find a good balance between protecting the W&OD path and the beavers, in April, the county installed a “beaver baffle” — a pond leveler. Beavers often rush to plug leaks in their dams. Baffles stabilize water levels by creating a hidden exit for high water to escape through the dam, unnoticed by the beavers.

Recently, Andrew Jones, 18, organized a tree-caging event -- putting wire cloth around large tree trunks to discourage beavers from biting them. It also protects people from injury due to random trees falling.

“We cover the trees we don’t want them to eat, while providing others they like,” said Luisa Robles, Greenbelt’s sustainability specialist. Some new trees are periodically planted just for the beavers. “We need to learn to yield a little of our wants to share the Earth’s resources.” she said.

Sparrow Pond’s 2023 restoration project will restore proper water depth and improve wildlife habitat without creating problems for the path. “A beaver baffle will also be included so beaver families can make the pond their home in the future,” noted the project’s flier.

The balancing act continues.

On December 26, 2004, an earthquake along the Indian Ocean caused a huge tsunami that killed thousands of people in Asia and East Africa. However, wildlife officials at Sri Lanka’s Yala National Park reported no mass animal deaths. Yala National Park is home to hundreds of wild animals.

Some researchers believe the animals at the park were able to sense the earthquake and moved to higher ground before the earthquake hit. Animals have good senses that help protect themselves from being hunted by their natural enemies. It is thought that their senses might also help them sense the coming disasters. Several countries have done research on the prediction of earthquakes by animals. There are two theories about how animals may be able to sense earthquakes. One theory is that animals sense the earth’s shake. The other is that they can sense changes in the air. However, so far there has been no strong evidence about how animals may be able to sense earthquakes.

Other researchers are skeptical (怀疑) about using animals for earthquake predictions. The United States Geological Survey (USGS) officially states, “Changes in animal behaviors cannot be used to predict earthquakes. Even though there have been many cases of unusual animal behaviors before earthquakes, a connection between a specific behavior and an earthquake has not been made. Because of their fine senses, animals can often feel the earthquake at its earliest stages before the humans. That’s why people say that the animal knew the earthquake was coming. But animals can also change their behaviors for many other reasons.”

Although scientists disagree on whether animal behaviors can be used to predict earthquakes, they all agree that it is possible for animals to sense changes in the environment before humans. Researchers around the world are continuing to study the connection between animal behaviors and earthquakes. It is hoped that these studies will help to predict earthquakes.