Found 5,805 Resources containing: Population
Old number 1420 (part)
Two drafts of a chart showing Siouan populations 1883-1892. Only see 1 page in folder- KTB 12/2/85
The rise of agriculture changed the world. And we don’t just mean the human world. At its onset, long before the Green Revolution paved the way for vastly improved yields, people were notoriously bad at using the land. To produce our food we used to cut down a staggering number of trees. Deforestation in the western world, driven by land clearing for farming, actually peaked hundreds or thousands of years ago. And, without things like fertilizer or irrigation, or the massive intertwined agricultural system we have today, local shocks—a fire, a drought, a flood—could cut vital food supplies for years.
So, while the rise of agriculture allowed human populations to blossom, it also opened the door for catastrophic collapses. Science News:
Researchers already knew that agriculture in Europe appeared in modern-day Turkey around 8,500 years ago, spreading to France by about 7,800 years ago and then to Britain, Ireland and Northern Europe approximately 6,000 years ago. Farming led to more plentiful, stable food supplies, fueling population growth. But little is known about long-term population trends among ancient European cultivators.
New research looking at the sizes of human populations in ancient Europe found that while agriculture helped populations grow, the burgeoning civilizations were not sustainable.
In most sections of Europe, populations at some point declined by as much as 30 to 60 percent compared with peaks achieved after farming began, Shennan’s team concludes. That population plummet is similar to the continental devastation wreaked by the Black Death, an epidemic that peaked in Europe between 1348 and 1350.
The scientists, says BBC History, are fairly certain that ancient climate change was not the cause of the collapses. The research is a nice reminder that any technology that lets you outpace your natural limits can also send you crashing back down when it fails.
More from Smithsonian.com:
There are only 50,000 or 60,000 orangutans left in the world. They were once widespread in Asian tropical forests, but they are now found only on the Indonesian islands of Sumatra and Borneo. And there, the shaggy primates’ forest homes are being lost to deforestation, as people cut down the trees and replace them with oil palm farms.
Some rare good news, though, recently came from a group of Nature Conservancy ecologists who had surveyed a near-inaccessible part of Borneo’s East Kalimantan Province back in December: They found 219 orangutan nests, which translates to at least a few hundred orangutans and perhaps as many as 2,000.
That we are still finding new populations indicates that we still have a chance to save this animal," said Paul Hartman, who heads the US-funded Orangutan Conservation Service Programme, adding it was not all "gloom and doom".
It has been a grim few years for southern resident orcas, which dwell in the waters off Oregon, Washington and British Columbia. Their numbers have declined dramatically as they struggle to find food, and in the face of dismal calf survival rates, experts worry that the population won’t be able to recover. But last week, a glimmer of hope emerged when a seemingly healthy baby orca was spotted frolicking amid one of the southern resident pods.
According to the Center for Whale Research (CWR), a Washington non-profit that monitors the southern residents, the new calf came to the attention of researchers after Seattle TV stations aired footage of groups of orcas near Puget Sound and “discerning viewers were able to see a very small whale among them.” Sure enough, when a CWR team was dispatched to investigate, the researchers could see a little orca swimming with the region’s “L” pod. (The other two southern resident social groups are known as “J” and “K.”) The mother of the new baby is a 31-year-old orca called L77, and the baby has been dubbed L124.
“The calf appeared to be about 3 weeks old,” the researchers wrote in a summary of the encounter, adding that it was “bouncing around” the other orcas. The calf’s sex is not known at this time, but Harrison Mooney of the Vancouver Sun reports that experts are hoping it is a female so it can help replenish the flailing southern resident population.
With the birth of the new calf, the southern residents now number 75—a welcome development, to be sure, but the population is still critically endangered. In 1995, there were 98 southern residents; in 2011, there were 89, and the orcas’ numbers have continued to drop. Their future is imperiled by a number of factors, including toxins in the water and rumbling from ship traffic, which can interfere with orcas’ ability to communicate about prey through echolocation. But a major threat pushing the animals towards extinction is a decline in Chinook salmon, the whales’ primary food source, due to habitat destruction and intense commercial fishing.
The fate of the new baby is also far from certain. Around 40 percent of calves do not survive past the first few years, according to the CWR, and southern resident orcas have particularly struggled to keep their young alive. Over the past three years, no babies born to the population have survived—a concerning reality that came to national attention last August, when a southern resident orca named Tahlequah pushed her dead calf through the waters of Puget Sound for 17 days.
L77, the mother of the new baby, has had two other calves: one, born in 2010, did not survive past its first year, but a female born in 2012 is still alive. Only time can tell how baby L124 will fare, but CWR founding director Ken Balcomb tells Lynda V. Mapes of the Seattle Times that the calf appears healthy. And so the appearance of the little orca, he says, is “great news.”