Friday, September 20, 2019

"A new study finds US and Canada have lost more than 1 in 4 birds in the past 50 years"............. "Hardest hit are sparrows, warblers, finches, and swallows who are critical in ecosystem seed dispersal and pest control"............"The major factor driving these declines is loss and degradation of habitat, due to agricultural intensification and urbanization"..........."Other bird-killers include domestic cats; collisions with glass, buildings, windmills and solar farms, deforestation and pesticides"

https://phys.org/news/2019-09-canada-lost-birds-years.html

New study finds US and Canada have lost more than 1 in 4 birds in the past 50 years

A study published today in the journal Science reveals that since 1970, bird populations in the United States and Canada have declined by 29 percent, or almost 3 billion birds, signaling a widespread ecological crisis. The results show tremendous losses across diverse groups of birds and habitats—from iconic songsters such as meadowlarks to long-distance migrants such as swallows and backyard birds including sparrows.

Multiple, independent lines of evidence show a massive reduction in the abundance of birds," said Ken Rosenberg, the study's lead author and a senior scientist at the Cornell Lab of Ornithology and American Bird Conservancy. "We expected to see continuing declines of threatened species. But for the first time, the results also showed pervasive losses among common birds across all habitats, including backyard birds."

The study notes that birds are indicators of environmental health, signaling that natural systems across the U.S. and Canada are now being so severely impacted by human activities that they no longer support the same robust wildlife populations.

The findings showed that of nearly 3 billion birds lost, 90 percent belong to 12 bird families, including sparrows, warblers, finches, and swallows—common, widespread species that play influential roles in food webs and ecosystem functioning, from seed dispersal to pest control.

Among the steep declines noted:

Grassland birds are especially hard hit, with a 53 percent reduction in population—more than 720 million birds—since 1970.
Shorebirds, most of which frequent sensitive coastal habitats, were already at dangerously low numbers and have lost more than one-third of their population.
The volume of spring migration, measured by radar in the night skies, has dropped by 14 percent in just the past decade.
the largest factor driving these declines is likely the widespread loss and degradation of habitat, especially due to agricultural intensification and urbanization.
Other studies have documented mortality from predation by free-roaming domestic cats; collisions with glass, buildings, and other structures; and pervasive use of pesticides associated with widespread declines in insects, an essential food source for birds. Climate change is expected to compound these challenges by altering habitats and threatening plant communities that birds need to survive. More research is needed to pinpoint primary causes for declines in individual species.

The study also documents a few promising rebounds resulting from galvanized human efforts. Waterfowl (ducks, geese, and swans) have made a remarkable recovery over the past 50 years, made possible by investments in conservation by hunters and billions of dollars of government funding for wetland protection and restoration. Raptors such as the Bald Eagle have also made spectacular comebacks since the 1970s, after the harmful pesticide DDT was banned and recovery efforts through endangered species legislation in the U.S. and Canada provided critical protection.

"It's a wake-up call that we've lost more than a quarter of our birds in the U.S. and Canada," said coauthor Adam Smith from Environment and Climate Change Canada. "But the crisis reaches far beyond our individual borders. Many of the birds that breed in Canadian backyards migrate through or spend the winter in the U.S. and places farther south—from Mexico and the Caribbean to Central and South America. What our birds need now is an historic, hemispheric effort that unites people and organizations with one common goal: bringing our birds back."
More information: K.V. Rosenberg el al., "Decline of the North American avifauna," Science (2019). science.sciencemag.org/lookup/ … 1126/science.aaw1313
Journal information: Science

Monday, September 16, 2019

As we have reviewed many times in the past, research has revealed that hunting cougars or thinning their numbers as a method of wildlife management can actually increase the number of young male cats on the landscape, upping the likelihood of those inexperienced felids getting into conflicts with people and livestock"..................Reiterating this finding-----“There is evidence that densities of young, dispersing cougars are likely to be comparatively high where local densities of resident adults have been depressed by hunting, as long as other nearby and less-heavily exploited areas serve as sources of dispersers from other meta-populations".................."Under such a scenario, heavy localized hunting of older cougars could increase rather than reduce exposure of people to close-threatening encounters with cougars".............."Additionally, sport hunting of cougars to benefit wild ungulate populations is not supported by the scientific literature"..............…"Any effort to control cougars should be part of an effort that addresses all factors impacting the ungulate population"..............."Finally, the odds of increased complaints and livestock depredations increased dramatically (36% to 240%) with increased cougar harvest"

https://www.google.com/url?rct=j&sa=t&url=https://www.boulderweekly.com/news/are-state-actions-increasing-the-risk-of-cougars-attacking-people/&ct=ga&cd=CAEYBCoUMTQ1Mzk4NDc2OTIzNjQ4NzEyNTYyGjQzMDgzYjIxMTY2OGE5NzA6Y29tOmVuOlVT&usg=AFQjCNHyzLIPdxnP8l1KWlt-x96MDlz07w

Are state actions increasing the risk of cougars attacking people?

Rico Moore

September 12, 2019

Mark Elbroch-credit all pictures below

Monday, September 9, 2019

Orca Killer Whales from the Eastern Tropical Pacific Ocean are rarely spotted off of the southern California coast............But this summer, a pod of the Orca's were seen first hand chasing and getting a dolphin calf meal for their efforts..........Like a pack of Wolves on land, Killer whales are among the world's fastest-moving marine mammals"............."They are capable of clocking speeds over 30 miles (48 kilometres) per hour (an impressive feat when you consider that they can weigh up to 11 tons!)".............."The black-and-white predators are armed with a mouth full of large, interlocking teeth and are highly intelligent and social – which makes them particularly efficient hunters"..........."When it comes to elusive and agile common dolphins, the hunt often sees killer whales teaming up in a coordinated attack and pursuing their quarry at high speed".............Click the link below to witness first hand the teamwork and persistence of Orca Whale pods

https://www.earthtouchnews.com/natural-world/predator-vs-prey/incredible-aerial-footage-shows-orcas-hunting-down-a-dolphin

Orca Whales hunting Dolphins(video-click to view)
https://youtu.be/IZTSd-CMEno

Incredible aerial footage shows orcas hunting down a dolphin

BY EARTH TOUCH NEWS AUGUST 06 2019Whale watchers off the coast of Orange County recently witnessed firsthand the hunting prowess of killer whales when a pod, believed to belong to a population from the Eastern Tropical Pacific that is rarely seen in waters around California, dispatched a dolphin calf after a high-speed chase. Photographer Matt Larmand witnessed the hunt from a Dana Wharf Whale Watching boat and used a drone to capture amazing aerial footage of the actionOrca with its Dolphin catch

The orcas were initially spotted cruising up the coast towards Orange County, but things heated up when they narrowed in on a pod of common dolphins. "It was surprising to me with what persistence they chased this dolphin pod,” Newport Coastal Adventure owner Ryan Lawler told The Mercury News. "They chased it for two miles at a constant pace – like wolves chasing down their prey, trying to tire their prey out."

Killer whales are among the world's fastest-moving marine mammals, capable of clocking speeds over 30 miles (48 kilometres) per hour (an impressive feat when you consider that they can weigh up to 11 tons!). The black-and-white predators are armed with a mouth full of large, interlocking teeth and are highly intelligent and social – which makes them particularly efficient killers.

For the moment, a Dolphin eluding an Orca

Hunting tactics are typically defined by what's on the menu: schools of fish are snared in a net of bubbles from below, while sharks are likely rammed and then their bodies torn open just below the pectoral fin so the orcas can hoover up their nutrient-rich livers. But when it comes to nippy and agile common dolphins, the hunt often sees killer whales teaming up in a coordinated attack and pursuing their quarry at high speed.

"They went after that [dolphin] baby. I guess that was an easier target," Larmand recalls. "They’d come from different directions, they were corralling it and getting it to go in the direction they wanted it to go. They knew exactly what they were doing and how to do it. It was crazy to watch."

A large pod of Orcas

Whale-watching guides and marine researchers identified the orcas as belonging to a group usually found in the Eastern Tropical Pacific (ETP) and – according to Alisa Schulman-Janiger, co-founder of the California Killer Whale Project – it's unusual to encounter them at this time of the year. ETPs usually hang out in waters off Mexico or Costa Rica and turn up occasionally in California from November through January when the water is a bit warmer, she explains.

Schulman-Janiger will be analysing photos in an attempt to identify the individuals, but she suspects that this group is not the same one that turned up in town late last year. Not much is known about ETP orcas, but marine mammals do seem to make up, at least, part of their diet.