Improved air quality to reduce ozone (臭氧) pollution may have avoided the loss of 1.5 billion birds during the past 40 years, a study found. That’s nearly 20% of bird life in the United States today.

Ozone, a gas that appears in nature, is also produced by human activities, including by power plants and cars. The ozone in the upper atmosphere protects the Earth from the harmful ultraviolet rays (紫外线) of the sun. But ground-level ozone is harmful and pollutes the air we breathe.

To examine the relationship between bird populations and air pollution, the researchers used models that connected bird observations from the Cornell Lab of Ornithology’s eBird program with ground-level pollution data. They tracked monthly changes in bird populations, air quality, and regulation status (治理现状) for 3,214 US counties over a period of 15 years. The findings suggest that ozone pollution is most harmful to the small birds — such as sparrows, warblers and finches — that make up 86% of all North American land-bird species. Ozone pollution directly harms birds by damaging their breathing systems, and indirectly harms their food sources.

“Not only can ozone cause direct physical damage to birds, but it also can harm plant health and reduce numbers of the insects that birds eat,” said co-author Amanda Rodewald. “Not surprisingly, birds that cannot get high-quality habitat or food resources are less likely to survive or reproduce successfully. The good news here is that environmental policies intended to protect human health and return important benefits to birds too.”

This work contributes to our ever increasing understanding of the connection of environmental health and human health.

Scientists say a huge percentage of bird species are in danger because their habitats, or homelands, are disappearing.

Traditional migration paths take birds through countries that are not protecting the places for birds to stop, rest and feed. The scientists studied the migration or flight paths of almost 1,500 species. They decided that 91 percent of them passed through dangerous areas.

The major danger for migratory birds is development. Buildings and pavements have covered the places where birds stop and feed as they move from one part of the world to another. One of the scientists who worked on the study says “Many of these important places have been lost to land reclamation because of urban, industrial and agricultural land expansion”.

The problem, according to scientists, is that many of these small birds die along their migration paths because they don’t have a safe place to feed and rest. There is no place to restore their energy for the next part of their journey. Countries in North Africa, Central Asia and those along the coasts of East Asia are having the most difficult time in protecting land. The scientists say these countries do not have enough areas that are safe for birds. One species that doesn’t exist now is the Eskimo curlew. “Our world gets poorer every time we lose a species,” one of the scientists says.

The researchers say countries need to work together and come up with safe stopping areas for birds that pass through their boundaries. For example, one country might have preserved safe zones for migrating birds. But a neighbor country might not. A bird might die.

One scientist who is not connected with the report tells Los Angeles Times that while some habitats are changing, more work can be done to make urban areas safe for birds.

He says small changes, like planting more native plants or keeping cats out of the areas birds would be likely to use, could make a big difference.

How to Keep Betta Fish

Keeping betta fish can be a fun hobby that does not involve going outside. It does not require too much skill, either. But you do have to be willing to learn. How do you take care of betta fish?

Required parts

First, Etta fish need a home. 【小题1】 Second, the container needs small rocks or sand at the bottom. Third, a filter(过滤器)is needed to purify the water. Fourth. a heater is suggested to keep your fish in good condition.

Water quality

Make sure the water you add to the container is safe for fish. Tap water can be used. But it usually contains a chemical harmful to fish, so additional steps need to be taken to test the water. 【小题2】 But many fish stores are happy to test your water if you give them some money. They can also provide advice on keeping fish in your area’s water.

Betta fish care

【小题3】 You will need to feed your fish and change its water.

There are many choices for food. Pet stores will carry many of these. Feed your fish once to twice a day. Whatever food you choose, make sure it contains meat. 【小题4】

It is advised to change one fourth of your container’s water once every week or two. Remove the old water and add fresh water.

Friends

Male betta fish are kept alone because they are fighting fish. 【小题5】 H you have a larger container with other fish, they might live together peacefully. But do remember that male betta fish often attack other fish and may have to live separately.