Showing posts with label fall in numbers. Show all posts
Showing posts with label fall in numbers. Show all posts

Wednesday, 14 December 2016

Santa's Reindeer Feel the Heat as Numbers Shrink Worldwide




By Tia Ghose, Senior Writer | December 12, 2016 05:11pm ET


SAN FRANCISCO – Santa Claus better stock up on reindeer, because he may have trouble scrounging up replacements in the not-too-distant future, new research suggests.

Reindeer populations in northern Russia are falling, according to a new study. The new findings dovetail with other research showing that reindeer populations are falling in other parts of the Arctic as well.

But Santa's trusty steeds aren't the only iconic wintry beasts facing worldwide declines. Polar bear populations could decline by about one-third over the next 30 or 40 years based on sea ice estimates, another study found. 

And hotter, drier conditions in the western U.S. could mean steep reductions in mountain lion and mule deer populations.

Worldwide changes
For a while now, scientists have documented many changes in the Arctic that suggest trouble is brewing.

"The reindeer population in the world, and caribou, are declining pretty rapidly," study co-author Andrey Petrov, a geographer at the University of Northern Iowa, said here today (Dec. 12) at a news briefing at the annual American Geophysical Union Meeting. "We don't know why it's happening."

To get a better understanding of why, Petrov looked at reindeer populations in the Taimyr Peninsula in Far North Russia. The Taimyr reindeer population, at 600,000 animals, makes up 24 percent of the global reindeer population. The population peaked in 2000 at more than 1 million creatures, after the dismantling of the Soviet management system led to dramatic reductions in hunting. However, since then the population has been falling.

Petrov used satellite views of the region's vegetation, along with the vegetation and the corresponding presence of reindeer. The herds of reindeer are clearly visible in land satellite imagery, which allowed Petrov to map reindeer movement across the Arctic during the winter, their spring calving season and summer. He found that, overall, the reindeer have a strong tendency to return to the same places over and over again.

Wednesday, 5 January 2011

US sees massive drop in bumble bees: study

WASHINGTON (AFP) – Weakened by inbreeding and disease, bumble bees have died off at an astonishing rate over the past 20 years, with some US populations diving more than 90 percent, according to a new study.


The findings are of concern because bees play a crucial role in pollinating crops such as tomatoes, peppers and berries, said the findings of a three-year study published in the Proceedings of the National Academy of Sciences (PNAS).

Similar declines have also been seen in Europe and Asia, said Sydney Cameron, of the Department of Entomology and Institute for Genomic Biology at the University of Illinois, the main author of the study.

"The decline of bumble bees in the US is associated with two things we were able to study: the pathogen Nosema bombi and a decline in genetic diversity. But we are not saying Nosema is the cause. We don't know," said Cameron.

"It's just an association. There may be other causes."

He added that the decline is "huge and recent," having taken place in the last two decades.

Nosema bombi is a bee pathogen that has also afflicted European bumble bees.

Researchers examined eight species of North American bumble bees and found that the "relative abundance of four species has dropped by more than 90 percent, suggesting die-offs further supported by shrinking geographic ranges," said the study.

"Compared with species of relatively stable population sizes, the dwindling bee species had low genetic diversity, potentially rendering them prone to pathogens and environmental pressures."

Their cousins, the honey bees, have also experienced catastrophic die-offs since 2006 in a phenomenon known as "colony collapse disorder," though the causes have yet to be fully determined.

Bumble bees also make honey, but it is used to feed the colony, not farmed for human consumption.

They are however raised in Europe for pollinating greenhouse vegetables in a multi-billion-dollar industry that has more recently taken off in Japan and Israel and is being developed in Mexico and China, Cameron said.

"We need to start to develop other bees for pollination beside honey bees, because they are suffering enormously," he added.

There are around 250 species of bumble bee, including 50 in the United States alone.
http://news.yahoo.com/s/afp/20110104/ts_afp/usanimalagricultureresearch_20110104011323;_ylt=AjLRd8WnGrHkJH1uGeCbE6KFOrgF;_ylu=X3oDMTMzNDMwZnFwBGFzc2V0A2FmcC8yMDExMDEwNC91c2FuaW1hbGFncmljdWx0dXJlcmVzZWFyY2gEcG9zAzEwBHNlYwN5bl9wYWdpbmF0ZV9zdW1tYXJ5X2xpc3QEc2xrA3Vzc2Vlc21hc3Npdg--
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