‘Staggering’ number of birds have died off, and people are to blame — scientists
Jeck Deocampo • September 20, 2019 • 359
From grasslands to seashores to forests and backyards, birds are disappearing at an alarming rate in the United States and Canada, with a 29% population drop since 1970 and a net loss of about 2.9 billion birds, scientists said on Thursday (September 19).
People are to blame, the researchers said, citing factors including widespread habitat loss and degradation, broad use of agricultural chemicals that eradicate insects vital to the diet of many birds, and even outdoor hunting by pet cats.
“What we found was staggering,” said Peter Marra, director of the Georgetown Environment Initiative at Georgetown University and a co-author of the study published in the journal Science.
“It’s depressing that there was a decline in over twenty-nine percent of birds 3 billion birds lost over those 50 years. Birds that make up some of the most common species that we’ve been that we see red and black birds warblers thrushes Eastern metal a whole suite of species across diverse families. It was quite depressing.”
Most of the losses were not among rare species, but common ones across nearly every bird family and all habitats. They included sparrows, swallows, blackbirds, thrushes, finches, warblers and meadowlarks.
Some 90% of the total loss came from just 12 bird families and 19 widespread bird species such as the dark-eyed junco, common grackle and house sparrows. Each of those species lost more than 50 million individuals.
“It’s also happening with other organisms. Insect declines are now being seen in a variety of places. Monarch butterflies, one in the North America landscape that people have talked about for a long time, amphibian declines are happening. And it’s not just terrestrial. When you go out and look in the oceans: tuna stocks have declined, salmon stocks have declined. Lots of marine organisms are being impacted in horrible ways. And collectively, what this says is that we’re looking at a massive ecosystem decay. And why that’s important is: we as humans depend on this environment on this ecosystem just as much as these other organisms do,” Marra added.
The researchers tracked populations of 529 species using decades of bird counts taken on the ground as well as weather radar data that revealed similar declines in the volume of migratory birds.
Grassland birds were particularly hard hit, with a 53% reduction in population, amid agricultural intensification.
Shorebirds, reliant on sensitive coastal habitats, sustained a 37% drop. Most shorebirds are migratory and experienced habitat degradation and destruction in many locales where they migrate. In addition, many shorebirds breed in Arctic regions rapidly changing due to climate change.
The researchers documented a steep decline for migratory birds. They noted broad declines among birds that migrate to the tropics, where there have been devastating rates of habitat loss and degradation. Migrating birds also face threats at their stopover sites and on their North American breeding grounds.
The researchers said other studies have documented worrisome bird population losses in other parts of the world.
While climate change was not the major driver of the population plunge, it is likely to exacerbate the existing threats to bird populations in the future, researchers said.
The researchers said the extinction in the early 20th century of the passenger pigeon, once likely the most numerous bird on Earth numbering in the billions, showed that even abundant species can go extinct rapidly.
“What can people do is the really the important question,” said Marra. “Make sure you keep your own cat indoors. Plant native plants over non-native plants. This supports a really rich insect base that birds depend on to live. But you can also support decision makers that are pro-environment both at local– in your own town– as well as state and national levels. We have to protect our our air. We have to protect our water streams.”
Some types of birds showed gains. Banning the pesticide DDT allowed for the resurgence of raptor populations including the bald eagle, the researchers said. Waterfowl management policies including wetland protection and restoration enabled ducks and geese to thrive, they added.
“The good news is is that nature is resilient once given a chance. So if if we as humans act on this, if we start to really value nature, value birds, put policies into place that are going to protect these animals that we share in our common home, that these birds will respond over, respond rapidly. In five or 10 years, we could easily see some of these species starting to increase. It could happen that fast,” he added.
A year-long parliamentary inquiry announced on Tuesday (June 30) that koalas will become extinct in Australia’s most populous state by 2050 without significant intervention.
The report found that koala populations in New South Wales were on track to become extinct by 2050, prior to the 2019-2020 bushfire season, due to drought and habitat destruction.
However the recent bushfire season, which was one of the worst in Australian history, was particularly lethal to the state’s koala population and had only increased the rate of their extinction, according to the inquiry.
Whilst the committee was unable to determine the exact impact of the fires upon the koala population, it concluded that koala habitats in some parts of the state suffered a loss of up to 81%.
The report outlined 42 recommendations to the state government that could be taken to help revitalize the population. (Reuters)
Scientists are racing to read a rapidly melting archive of climate data going back thousands of years – the inside of Austria’s glaciers, which are falling victim to climate change.
Glaciers are threatened the world over as the average global temperature continues to rise, a phenomenon that is likely to be described in even more vivid detail than before in a report by the Intergovernmental Panel on Climate Change this week.
But glaciers in Austria, on the eastern edge of the Alps, are particularly sensitive to climate change and have been shrinking even more rapidly than most, making it all the more urgent to examine their contents before they disappear, Andrea Fischer, a scientist conducting that work, said.
Fischer, part of the research team from the Institute for Interdisciplinary Mountain Research in Innsbruck, is analysing a layer of ice at the top of the Weisseespitze, a peak more than 3,500 metres high.
At the top of this mountain, Fischer and her colleagues have drilled to the bottom of the comparatively undisturbed glacier to extract samples of its ice, which is being analysed for information on the local climate thousands of years ago.
Fischer believes the ice could be 3,000 to 5,000 years old, with the extracted samples being sent for lab testing to date them.
The lower layers are more densely packed than those at the top, meaning that one metre of ice could include thousands of years of data.
“At Weisseespitze several metres of ice disappeared, the ice there is just a few metres thick. So, in a few years, this peak will be totally without ice,” Fischer said.
While analysis of other materials, such as tree trunks, can provide information on the air temperature in summer, glaciers’ ice is a rare source of information on precipitation, she said.
The team’s challenge is to take current data on how the climate is changing and compare how the climate changed over it previous centuries and millennia to determine how exceptional or usual the current process is. (REUTERS)
Preliminary findings by scientists suggest that people who like their food and beverages to be warmer than 60 degrees celsius are at a higher risk of developing esophageal cancer.
In Kenya, hot food is widely believed to be healthier, while cold food is viewed as dull and unsatisfying.
“Most people prefer hot or warm food because this is the cold season. If you eat cold food, it will affect you. But if you eat hot food, you will feel warm and energetic,” said Nairobi resident Regan Dennis.
For years, researchers have sought to establish the effects of very hot food on the esophagus, the tube through which food travels to the stomach. A study published in the journal “cancer epidemiology” identified thermal injury from hot food and beverages as a possible cause of esophageal cancer.
“It’s an irritant, the heat. You are causing ulceration of the lining. The lining of the esophagus and the throat. And once you cause this constant damage to the lining, it leads to mutation and finally leads to cancer. So, it’s carcinogenic to cause constant irritation of the mucus lining,” said ENT Surgeon John Muiru.
Researchers found that tea drinkers who like their tea to be warmer than 60 degrees celsius and drank more than two large cups daily have a 90 percent higher risk of developing esophageal cancer.
This is bad news for tea-drinkers in Kenya’s western region, who are among those taking the hottest tea in the world. Their beverage is usually 72.1 degrees celsius.
“The ideal temperature is the body temperature, which is about 37 degrees centigrade. Anything above that will be damaging the cells. The cells are designed to survive within the body temperature,” Muiru said.
Esophageal cancer accounts for 11 percent of new cancer cases in Kenya. The latest discovery has had a jarring effect on tea-lovers. But the studies are not conclusive and researchers suggest that the evidence should be evaluated further.
As scientists seek a conclusive answer, tea-lovers begin to grapple with the idea that hotter might not be better after all.
“Food shouldn’t be too hot or too cold. It should be warm,” Saidi Gitau, a Nairobi resident said. (REUTERS)
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