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Rex Graham
13,523 followers -
Founder of TopBirdingTours.com
Founder of TopBirdingTours.com

13,523 followers
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In winter, the iconic Greater Sage-grouse only eats protein-rich sage leaves. https://goo.gl/BpWCNR

The ecological support for sagebrush-obligate species, including the sage-grouse, has shattered like a dropped dinner plate.

Thousands of miles of overhead power lines, roads, wildfires, housing subdivisions, wind-energy and oil and gas infrastructure, and invasive plant species are part of “a death by 1,000 cuts” to sage-grouse habitat said Obama Administration Interior Secretary Sally Jewell. Sage-grouse numbers have fallen by roughly 90% since the 19th Century.

However, while under intense pressure not to restrict additional development, the U.S. Fish and Wildlife Service in 2015 said conservation efforts had “significantly reduced threats to the Greater Sage-grouse across 90% of the species’ [remnant] breeding habitat.” As a result, the service said the sage-grouse does not warrant protection under the U.S. Endangered Species Act.

Read more – https://goo.gl/BpWCNR

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The American Ornithologists' Union and the Cooper Ornithological Society have merged. They are now the American Ornithological Society. https://goo.gl/3uezG0

So what?

It’s like the merger of two airlines that share the same routes, pilots and passengers. Now, the planes of both can be repainted with one bird logo.

The merged avian organization will share data and teaching materials. It also will organize academic meetings.

The Auk (ornithological advances) and The Condor (ornithological applications), flagship scientific publications of the AOU and the COS, will continue to be published separately.

Consensus in ornithology is as hard to achieve, but after 6 years of breaking down psychological barriers the merger was made possible by “tremendous positive feedback from our members,” AOS president Steven Beissinger said in a news release.

The AOS bird checklists will be the new name of the authority for scientific nomenclature and English names of birds in the Americas.

The “American” in the organizational name might seem provincial. After all, birds are international creatures, and studying, conserving and understanding thousands of species requires international research, cooperation and agreements. (There are only a handful of non-U.S. associate editors on the editorial boards of The Auk and The Condor.)

The National Audubon Society and BirdLife International are, respectively, the biggest U.S. and worldwide conservation organizations for birds.

The AOS has recently initiated what could eventually be a vital role for ornithology in education for students of all ages. The program promotes ornithology as a STEM (science, technology, engineering and math) field. Its roughly 3,000 members are being asked to introduce the idea to local communities.

“Success requires a multi-dimensional approach that integrates science, new technologies, public policy and citizen outreach; works with other ornithological and scientific communities; and collaborates with local, state, federal and international government entities,” former AOU president Susan Haig said in a news release.

Read more – https://goo.gl/3uezG0

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Flowers throw an unexpected curve at Mrs. Gould’s Sunbirds in the form of nectar spiked with bitter toxins. https://goo.gl/T6UcEI

The sunbird with a hook bill co-evolved with similarly shaped flowers. But more than half of the world's flowers add toxic chemicals to their nectar. Scientists are only beginning to understand how these bitter-tasting meals affect the birds and insects that consume them.

These chemicals are part of the newly appreciated reality of sunbirds. These beauties can be enjoyed on spring trips to Bhutan and Myanmar. (I recommend a 2-week tour led by an experienced local guide working with an international birding tour company.)

On these trips, watch for Mrs. Gould’s Sunbirds at the corolla tubes of nectar-rich flowers. The length and shape of the tubes function as “exploitation barriers” to shorter-billed birds. However, some birds take nectar without providing pollination services. They either force their way into the flower opening or stab a hole in the base of the flower. Sunbirds chase them away.

Sunbirds guard floral gardens of red, orange, yellow and white. However, if the sunbirds suddenly depart, the nectar volume inside a flower tube can increase 10-fold. At some point the robbers return.

Read more – https://goo.gl/T6UcEI
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The rare Aquatic Warbler, a herd of European Bison, and 400-year-old oak trees (many individually named) are getting a major boost in Belarus. https://goo.gl/HmDKIi

How? The impressive Białowieża Forest, one of Europe’s last remnants of continental-scale primeval lowland forest, is being partially restored. A new conservation project started in November 2016 will return ancient water levels to 1,163 hectares (2,874 acres) of national parkland bordering Poland and Belarus.

The UNESCO World Heritage Site 70 km (43 mi) north of Brest, Belarus, is inhabited by the bison, Wild Boar and 250 bird species, including the Great Snipe, Greater Spotted Eagle and the vulnerable and elusive Aquatic Warbler, which hides in marshes with oxygen-rich waters.

“Most of our rare species are associated with water but have become rare due to water shortages,” Alexander Vintchevski, an ecologist and director of APB BirdLife Belarus, said in a news release. “If we restore the peatland, we will bring back these species.”

Read more – https://goo.gl/HmDKIi

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Argentina farmers have nearly whipped out Ruddy-headed Geese as “pests,” but Falkland Islands sheep farmers and the birds benefit by sharing pastures. https://goo.gl/2krcbN

Tierra del Fuego Island’s tall grasses are ideal breeding habitat, just as the lowlands of southern Argentina offer the geese a warmer retreat in winter. However, Ruddy-headed Geese there have been relentlessly hunted along with other geese, sometimes with the use of aircraft. The Argentinian government also promoted massive destruction of Ruddy-headed Goose eggs on Tierra del Fuego.

After Falkland farmers said the geese also competed with their sheep for grass, researchers at a Falklands grasslands organization investigated. They discovered that the digestive efficiency of Ruddy-headed Geese is only about 25%. They reported their surprising findings that goose droppings are a rich nutritional resource for sheep in the Journal of Applied Ecology .

“The feed value of goose feces to sheep, which often eat them, was measured in terms of digestibility and nitrogen content,” the researchers said. “They had a similar digestibility and nitrogen content to good quality grass.”

That study revolutionized the views of Falkland farmers: they allowed the geese to feed alongside sheep in their pastures.

Read more – https://goo.gl/2krcbN

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The Bat Hawk is a lethal cross between a falcon and a nightjar. It has the largest open-mouth gape of any raptor, and eats bats in single gulps. https://goo.gl/BqBrwd

Biologists in Africa watched one against the fading glow of sunset as it swallowed a swift-sized bat every 3 minutes during one 20-minute feeding frenzy. On average, it ate a bat every 5 minutes.

During 6 consecutive evenings, the hawk flew back and forth across the opening of Ngwerere Cave near Lusaka, Zambia, feeding on most of the 9 bat species that spewed into the sunset.

The large-eyed, Bat Hawk is an aptly named specialist. It exploits a little-appreciated ecological niche – the twilight torrent of biomass that emerges from caves.

Read more – https://goo.gl/BqBrwd

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Swallow Tanager ‘lenticular’ feathers shift from dazzling blue to camouflage green at light speed. https://goo.gl/B1oyaC

“One of the most gorgeously colored species of the entire Neotropical region” would seem to be an easy target for avian predators, but when they look down they see an emerald oval against the forest background.

Scientists described the male tanager’s lenticular feathers in The Auk: Ornithological Advances.

The blue color in all feathers comes from an interior nanostructure that looks like highly ordered foam. Under a sheet of keratin, the protein of human fingernails and hair, the foam is a highly ordered matrix of high-refractive-index elements alternating with lower-refractive-index elements.

When light passes through the barbs of Swallow Tanagers, blue light reflects in the direction of birdwatchers, and green light reflects toward the sun where hawks, Harpy Eagles and Bat Falcons soar.

The “double scattering” phenomenon is common among hummingbirds, but it also might be operating in other blue songbirds.

Read more – https://goo.gl/B1oyaC
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Elaina Tuttle didn’t set out to discover the first avian “supergene.” But she did just that while studying White-throated Sparrows for 27 years in New York’s Adirondack Mountains. https://goo.gl/oUhVkV

Males and females of each color morph exhibit subtle plumage and size differences as a form of sexual dichromatism. White-throated Sparrows also exhibit "behavioral dichromatism": white-morph males and females are more aggressive than the tan morphs.

Of course, males mate with females, and more aggressive whites, almost always mate with the less aggressive tans.

“The species operates as though there are 4 sexes,” Tuttle, the late biology professor at Indiana State University said in a paper published in 2016 in Current Biology.

Underlying the bizarre inheritance is a system in which multiple behavioral traits and crown-stripe color are inherited as if they are part of one supergene.

Tuttle, 52, died June 15, 2016, at a hospital in Indianapolis, Indiana. She published many scientific papers based on her studies of White-throated Sparrows in New York and Fairy Wrens in Australia. She was associate editor of The Auk.

Her pioneering works is being carried on by others. Supergenes also have been found in the Ruff, a Eurasian sandpiper, flower morphs of plants, shell morphology variants in some snail species, and some butterflies with multiple wing-pattern morphologies designed to mimic unrelated poisonous butterflies that predators avoid.

Read more – https://goo.gl/oUhVkV
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The Spotted Pardalote, a pretty Australian pipsqueak, uses bifocal vision to almost simultaneously see small insects underfoot and predators overhead. https://goo.gl/S8NFFZ

That’s the theory of Canadian neuroscientists who completed the most exhaustive and detailed study to date of a tiny structure in the avian midbrain called the isthmo optic nucleus, or ION. When present in a bird, nerve fibers link the structure to the bird’s two retinas, the light-sensitive inner lining of the eyes responsible for vision.

The neuroscientists studied the eyes of 81 bird species in 17 orders, and reported their surprising results in the journal PLOS ONE.

The ION was discovered over a century ago and has been found in many vertebrates, but its role has remained a mystery. Some scientists had theorized that it enables “pecking birds” to more accurately hit small food targets. Maybe it’s needed for gaze stabilization, dark adaption, shifting attention or detecting aerial predators.

The Canadian neuroscientists ascribe a more complex function to the ION that takes into account its size and complexity in the 81 species they studied, the birds’ visual habits, and the bifocal nature of their retinas.

“The ION is more complex and enlarged in birds that have eyes that are emmetropic [far-sighted] in some parts of the visual field and myopic [near-sighted] in others,” said the researchers, led by Cristián Gutiérrez-Ibáñez, a neuroscientist at the University of Alberta in Edmonton, Canada. “We therefore posit that the ION is involved in switching attention between two parts of the retina i.e. from an emmetropic to a myopic part of the retina.”

Read more – https://goo.gl/S8NFFZ
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The largest living tortoise is helping the Galapagos Islands’ biggest bird – an endangered master aerialist of the Pacific Ocean – the Waved Albatross. https://goo.gl/hDiuHQ

Only about 34,000 of the birds with 8-foot (2.4 m) wingspans survive. The Waved Albatross is the only tropical albatross in the world. It breeds almost exclusively on Española Island.

The fish- and squid-eater, like other seabirds, takes advantage of the island’s geographic position at the confluence of three ocean currents and the rich marine ecosystem there.

On Española Island, vegetation had grown unchecked after thousands of endemic Española Giant Galapagos Tortoises were eliminated by humans. The last 15 tortoises were evacuated decades ago to a captive breeding facility on another island.

Introduced goats made matters worse for the albatrosses. The goats quickly devoured the prickly pear cactus forests and other plants that had benefited tortoises. However, the goats ignored woody plants, which grew tall enough to interfere with the albatrosses’ takeoffs and landings.

The Charles Darwin Foundation for the Galapagos Islands has repopulated the island with tortoises from its captive-breeding facility.

The reptiles are munching their way through the vegetation, removing woody-plant seedlings before they grow tall enough to impede the birds. Scientists call it “ecosystem engineering.” More work is needed to clear all the tall, old brush, but conservationists and tortoises make a good team.

Read more – https://goo.gl/hDiuHQ
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