Tuesday, 18 October 2016


Aussie Backyard Bird Count has eye on ibis and cockatoos


The white ibis might be the bane of picnic goers and workers on their lunch break, but they are one of the birds researchers are keeping a close eye on during National Bird Week.

Researchers are calling on all residents across Australia to take part in the Aussie Backyard Bird Count from October 17 to 23.

The week-long census requires people to count and identify the birds they see in their garden or park and report their findings via the Aussie Bird Count app or website.

"We want to know what's happening in people's backyards," Holly Parsons, Birds in Backyard Count program manager, said.


"Australia is one of the most urbanised countries in the world, we're continuing to take up more space for ourselves and leaving wildlife with nowhere to go.

"Gardens, the habitats in our cities are one way to help as many species as possible.

"We need to know what's there so we know how to better manage habitat and how to create spaces for them."

This is the third year the national bird survey has taken place.

Last year, 42,000 people recorded their sightings and reported 1 million birds across Australia.

The rainbow lorikeet, noisy miner and the magpie were the most common birds.

Ms Parsons said they hoped to record at least 1.5 million birds this week.

Big white birds

In a separate study, ecologists from the Sydney Botanic Gardens will use data from the Aussie Backyard Bird Count to study the white ibis and the sulphur-crested cockatoo.
Dr John Martin said they wanted to better understand the distribution and abundance of the ibis and cockatoo population across New South Wales and the country.


He acknowledged the ibis was one of the birds most people loved to hate.

"The Australian white ibis has shifted to the urban environment.

"A few decades ago it was uncommon to see the white ibis — they're not always loved.

"We need to learn about the distribution of the species ... and about the pockets they are moving into."

There were 23,000 ibises counted last year and 20,000 sulphur-crested cockatoos.

Dr Martin said that in the 1980s, white ibises were mainly found in the western wetlands across the eastern states.

Since then their numbers have dramatically declined due to habitat degradation and the birds shifted into urban areas.

Similarly, cockatoos have moved into the cities in the past 10 years.

"We're cutting down our big old trees and clearing hollows ... the species isn't currently at risk but importantly its habitat is at risk," Dr Martin said.

"These are generational issues, it would be great if they are on people's radars."
What bird is that?

The Aussie Bird Count app allows people to add descriptions and match birds against visual criteria — helpful if they are unable to identify the species.

In Sydney, Ms Parsons said residents might be lucky to spot a powerful owl in their tree.

"It's a threatened species, a nocturnal bird, but will sit in the tree during the day so you can do the survey night and day," she said.

More common birds that might fly into people's backyards include the sulphur-crested cockatoo, Australian magpie, currawongs, Australian raven, rainbow lorikeets and red wattle bird.

In wetland areas, Dr Martin said the purple swamphen, coot, black swan, Pacific black duck and masked lapwing may be spotted.

Smaller birds include the willy wagtail, fairywren, Indian myna, pigeons, crested pigeon and peaceful dove.

Sunday, 16 October 2016


തിരികെ പോകാൻ കൂട്ടാക്കാത്ത പക്ഷി; അറിയാം ഈ അപൂർവ സൗഹൃദം



രണ്ടു വർഷം മുൻപാണ് തടാകത്തിൽ മുങ്ങിത്താണു കൊണ്ടിരുന്ന വാത്തക്കുഞ്ഞിനെ മൈക്ക് ജിവാൻജീ രക്ഷിച്ചത്. ഓറിഗണിലെ ഓസ്‌വിഗോ തടാകത്തിൽ നിന്നാണ് മൈക്കിനു വാത്തക്കുഞ്ഞിനെ കിട്ടിയത്. ഒറ്റപ്പെട്ട വാത്തക്കുഞ്ഞിനെ മറ്റു വാത്തകളുടെ വാസസ്ഥലത്തെത്തിച്ചെങ്കിലും അവർ കൂടെ കൂട്ടാൻ തയാറായില്ല. അങ്ങനെയാണ് മൈക്ക് വാത്തക്കുഞ്ഞുമായി വീട്ടിലേക്കു പോയത്. പിന്നീടിതിന് കൈൽ എന്നു പേരുമിട്ടു. ആരോഗ്യം വീണ്ടെടുത്തു പറക്കാറാകും വരെ വാത്തയെ സംരക്ഷിക്കാമെന്നാണ് മൈക്ക് കരുതിയത്. എന്നാൽ ആരോഗ്യം വീണ്ടെടുത്തെങ്കിലും മൈക്കിനെ വിട്ടു പോകാൻ കൈൽ തയാറായില്ല. കൈലിനെ സ്വതന്ത്രയാക്കി വനത്തിലേക്കു തിരികെ അയയ്ക്കാൻ പഠിച്ചപണി പതിനെട്ടും പയറ്റിയിട്ടും നടന്നില്ലെന്നു മൈക്ക് പറയുന്നു. ഓരോ തവണയും മൈക്ക് കൈലിനെ ദൂരെസ്ഥലങ്ങളിൽ കൊണ്ടുവിട്ടിട്ടു വരുമ്പോഴും മൈക്കിനേക്കാൾ മുമ്പിൽ കൈൽ വീട്ടിലെത്തിയിരിക്കും. ഒടുവിൽ മൈക്ക് ആ ശ്രമം ഉപേക്ഷിച്ചു.

പറക്കാൻ പഠിച്ചതു മുതൽ പകൽ സമയം എവിടെയെങ്കിലുമൊക്കെ പോകുമെങ്കിലും വൈകുന്നേരമാകുമ്പോൾ മൈക്കിനരികിൽ തിരികെയെത്തും. മൈക്കാണു കൈലിന്റെ ലോകമെന്നു പറയാം. മൈക്ക് എവിടെ പോയാലും കൈൽ പിന്തുടരും. ബോട്ടിങ്ങിനു പോയാൽ ക‍ത്യമായി ആ ബോട്ടിനരികിലെത്തും. ഷോപ്പുകളിലും റോഡിലുമൊക്കെ മൈക്കിനൊപ്പം കറങ്ങുകയാണു കൈലിന്റെ വിനോദം.

ചിലപ്പോൾ മനുഷ്യരുടേതു പോലെയാണു കൈലിന്റെ സ്വഭാവമെന്നും മൈക്ക് പറയുന്നു. മൈക്കിനരികിൽ പെൺകുട്ടികൾ വരുന്നതൊന്നും കക്ഷിക്ക് ഇഷ്ടമല്ല.എന്നാൽ എല്ലാവരോടും ഇഷ്ടക്കേടുമില്ല. ചിലരോടു മാത്രമാണ് അപ്രിയം. മൈക്കിന്റെ മിക്ക പെൺ സുഹൃത്തുക്കളോടും കൈലിനു വിരോധമൊന്നുമില്ല. അവരോടൊപ്പവും കൈൽ സമയം ചിലവഴിക്കാറുണ്ട്. എന്നാൽ ദേഷ്യം വരുന്ന സന്ദർഭങ്ങളിൽ എന്താണു ചെയ്യുന്നതെന്നു കൈലിനു പോലും നിശ്ചയമുണ്ടാവില്ല. ചിലപ്പോൾ മറ്റു ബോട്ടുകളിൽ കയറി ബഹളമുണ്ടാക്കും ഇല്ലെങ്കിൽ അയൽവീട്ടിൽ അതിക്രമിച്ചു കടന്ന് എന്തെങ്കിലും മോഷ്ടിക്കും ഇതൊക്കെയാണു കൈലിന്റെ കലാപരിപാടികൾ. കീചെയിനും വാലറ്റും പോലുള്ള ചെറിയ സാധനങ്ങൾ അയൽവീടുകളിൽ നിന്നു മോഷ്ടിച്ചു വെള്ളത്തിടുന്നത് കൈലിന്റെ പ്രധാന വിനോദമാണെന്നും മൈക്ക് പറയുന്നു.

വീട്ടിൽ ഒന്നിച്ചുള്ള സമയങ്ങളിൽ ടിവികാണുകയാണു ഇരുവരുടെയും പ്രധാന പരിപാടി. ഡിസ്കവറിയും ആനിമൽ പ്ലാനറ്റുമാണ് കൈലിനേറെയിഷ്ടം. അയൽക്കാർ അവധിക്കാലമാഘോഷിക്കാൻ പോകുമ്പോൾ അവിടെ ചുറ്റിത്തിരിയാനും കൈലിനിഷ്ടമാണ്. എന്തായാലും ഇണക്കങ്ങളും പിണക്കങ്ങളുമായി ഇരുവരുടെയും ജീവിതം സന്തോഷത്തോടെ മുന്നോട്ടു പോകുന്നു. 




തൂവലുകളില്ലാത്ത തത്തക്കുഞ്ഞാണ് ഇന്‍സ്റ്റഗ്രാമിലെ താരം



ബഹുവർണങ്ങളിലുള്ള തൂവലുകളാണു പക്ഷികളുടെ സൗന്ദര്യത്തിനു മാറ്റു കൂട്ടുന്നത്. മഞ്ഞിൽ നിന്നും മഴയിൽ നിന്നും വെയിലിൽ നിന്നുമൊക്കെ ഇവർക്കു സംരക്ഷണം നൽകുന്നതും ഈ തൂവലുകളാണ്. ചുരുക്കി പറഞ്ഞാൽ പക്ഷികളുടെ വസ്ത്രങ്ങളാണു തൂവലുകള്‍ എന്നു പറയാം .അപ്പോള്‍ തൂവലില്ലാത്ത പക്ഷിയെ എന്തു വിളിക്കണം? അങ്ങെനെയൊരു പക്ഷിയുണ്ടാകുമോ എന്നാണു ചോദ്യമെങ്കിൽ തെറ്റി. പക്ഷികളിൽ ഏറ്റവും സൗന്ദര്യമുള്ള തത്തകളുടെ ഗണത്തിലാണ് തൂവലുകളില്ലാത്ത ഈ തത്തക്കുഞ്ഞുള്ളത്.


പക്ഷെ തൂവലില്ലാത്തതിനാല്‍ തനിക്കു സൗന്ദര്യമില്ലെന്നു പറഞ്ഞു വിഷമിച്ചിരിക്കുകയല്ല റിയ എന്ന ഈ മിടുക്കി തത്ത. ഇന്‍സ്റ്റഗ്രാമില്‍ മാത്രം റിയയെ പിന്തുടരുന്നത് ഒന്നര ലക്ഷത്തോളം ആരാധകരാണ്. തൂവലുകളില്ലെങ്കിലും ഓരോ ദിവസവും വ്യത്യസ്തമായ വസ്ത്രങ്ങളണിഞ്ഞാണ് റിയ ഇന്‍സ്റ്റാഗ്രാമില്‍ പ്രത്യക്ഷപ്പെടുന്നത്. റിയയ്ക്കായി ഫാഷന്‍ വസ്ത്രങ്ങളൊരുക്കി ചിത്രങ്ങളെടുക്കുന്നതും സമൂഹമാധ്യമങ്ങളിൽ അവ പോസ്റ്റു ചെയ്യുന്നതും റിയയെ എടുത്തു വളര്‍ത്തുന്ന ഇസബെല്ലയാണ്.


വൈറസ് ബാധയാണ് റിയയുടെ തൂവലുകള്‍ പൊഴിയാനുള്ള കാരണം. പിങ്ക് നിറത്തിലുള്ള തന്‍റെ ശരീരവും തലയേക്കാള്‍ വലിയ കൊക്കുമായി നിന്ന റിയയെ മാസങ്ങള്‍ക്ക് മുന്‍പാണ് ഇസബെല്ല ബോസ്റ്റണിലെ മൃഗാശുപത്രിയിൽ നിന്നു വളര്‍ത്താനായി ഏറ്റെടുക്കുന്നത്. തൂവലുകള്‍ ഇല്ലാത്തതിനാല്‍ താപനിലയിലെ വ്യത്യാസങ്ങള്‍ ബാധിക്കുന്നതാണു റിയ നേരിടുന്ന പ്രധാന ആരോഗ്യപ്രശ്നം.


ഇതു മറികടക്കാന്‍ തത്തയുടെ രൂപത്തിനനുയോജ്യമായ കമ്പിളിപുതപ്പും മറ്റും ഇസബല്ല തയ്യാറാക്കിയിട്ടുണ്ട്. കൂടാതെ ഭക്ഷണ കാര്യത്തിലും പ്രത്യേകം ശ്രദ്ധിക്കും. ഇസബല്ല തയ്യാറാക്കുന്നതു കൂടാതെ തത്തയെക്കുറിച്ചു സമൂഹമാധ്യമങ്ങളിലൂടെയറിഞ്ഞ് നിരവധി പേരാണ് റിയയ്ക്കു വേണ്ടി സ്വെറ്ററുകളും മറ്റും തയ്യാറാക്കി അയയ്ക്കുന്നത്. എന്തായാലും തൂവലുകളില്ലെങ്കിലും റിയ ഹാപ്പിയാണ് ഒപ്പം ഇസബെല്ലയും.

Oldest known squawk box suggests dinosaurs likely did not sing

Study of the first fossil vocal organ from the Mesozoic provides insight into the evolution of bird calls and song. The fossil syrinx is from the late Cretaceous of Antarctica. Within dinosaurs there was a transition from a vocal organ present in the larynx (present in crocodiles) to one uniquely developed deep in the chest in birds.

Credit: Nicole Fuller/Sayo Art for UT Austin.
The oldest known vocal organ of a bird has been found in an Antarctic fossil of a relative of ducks and geese that lived more than 66 million years ago during the age of dinosaurs.

The discovery of the Mesazoic-era vocal organ -- called a syrinx -- and its apparent absence in nonavian dinosaur fossils of the same age indicate that the organ may be have originated late in the evolution of birds and that other dinosaurs may not have been able to make noises similar to the bird calls we hear today, according to findings published in Nature on Oct 12. Birds are direct descendants of dinosaurs and are considered living dinosaurs by scientists.

"This finding helps explain why no such organ has been preserved in a nonbird dinosaur or crocodile relative," said Julia Clarke, a paleontologist at The University of Texas at Austin Jackson School of Geosciences who discovered the fossil syrinx and led the analysis. "This is another important step to figuring out what dinosaurs sounded like as well as giving us insight into the evolution of birds."

The syrinx is made of stiff, cartilage rings that support soft tissues that vibrate to produce the complex songs and calls of modern birds. Cartilage does not fossilize as well as hard tissues such as bone. But the high mineral content in the syrinx's rings sometimes allows for fossilization. All other known examples of fossilized syrinxes occur in birds that lived well after nonavian dinosaurs went extinct.

The syrinx was found in a fossil of Vegavis iaai, a bird that lived during the Cretaceous. Clarke described the species in 2005. It was discovered on Antarctica's Vega Island in 1992 by a team from the Argentine Antarctic Institute. However, it wasn't until 2013 that Clarke noticed that the Vegavis fossil included a syrinx. During the past two years, the team searched the dinosaur fossil record for other examples of a syrinx, but so far has found none.

The asymmetrical shape of the syrinx indicates that the extinct species could have made honking noises via two sound sources in the right and left parts of the organ. The researchers also scanned syrinxes of other birds to compare with the Vegavis syrinx. This included 12 syrinxes from living birds and the next oldest fossilized syrinx, which had not yet been studied.

Franz Goller, a co-author and physiologist at the University of Utah, said the study is the beginning of the work to determine what the fossilized organ can tell us about the sounds of early birds.

"Here, we begin to outline how fossilizable characteristics of the syrinx may inform us about sound features, but we need a lot more data on living birds," Goller said. "Remarkably, prior to this work, there is almost no discussion of these important questions."

This study follows research that Clarke and other collaborators published in July 2016 that found some dinosaurs would likely have made closed-mouth vocalizations akin to ostrich booms that don't require a syrinx. Together, the two studies have major implications for dinosaur sound-making throughout time, Clarke said.

In addition, the evolution of vocal behavior can give insights into other anatomical features, Clarke said, such as the appearance of bigger brains.
"The origin of birds is about so much more than the evolution of flight and feathers," Clarke said.
To study sound production in more detail, part of the team is working with engineers to model sound-producing organs, a project funded by the Gordon and Betty Moore Foundation.

Tuesday, 11 October 2016



American Oystercatcher

Haematopus palliatus


Conservation status Numbers declined seriously in 19th century, then recovered well in 20th century. Despite disturbance in beach habitats, the species currently is doing fairly well, often nesting on dredge spoil islands.

Family Oystercatchers

Habitat Coastal beaches, tidal flats. Strictly coastal, in areas with extensive sand beaches, tidal mudflats, salt marsh. Key element is presence of good food supply, such as oyster beds, clam flats. May nest among dunes, on islands in salt marsh, or on dredge spoil islands.

A very large, unmistakable shorebird of Atlantic and Gulf Coast beaches. Solitary or in family groups in summer, American Oystercatchers may gather in large flocks in winter.
Photo Gallery



Feeding Behavior

Often forages by walking in shallow water, searching for food by sight. The birds have two methods of opening the shells of bivalves. In one, finding a mussel with its shell slightly open, the oystercatcher quickly jabs its bill into the opening, cutting the muscles and then cleaning out the contents. In the other method, the bird simply hammers on the shell to break it open.

Eggs

1-4. Buffy gray, usually speckled with dark brown. Nests attended by two females and one male may have 5-6 eggs. Incubation is by both sexes, 24-28 days. Young: Downy young leave nest shortly after they hatch. Both parents feed young for at least 2 months after hatching, although young may attempt to forage on their own well before parents stop feeding them. Age at first flight about 5 weeks.

Young

Downy young leave nest shortly after they hatch. Both parents feed young for at least 2 months after hatching, although young may attempt to forage on their own well before parents stop feeding them. Age at first flight about 5 weeks.
Diet
Mostly shellfish and marine worms. Feeds mostly on mussels, clams, oysters; also marine worms, sand crabs, limpets, sea urchins, jellyfish, and other small creatures of the intertidal zone.

Nesting

First breeds at age of 3-4 years. Sometimes may mate for life. In areas with high populations, may form trios, with one male and two females attending one nest or two nearby nests. Nest site is on ground, on marsh island or among dunes, usually well above high tide mark. Nest (apparently built by both sexes) is shallow scrape in sand, sometimes lined with pebbles, shells.

A Bald Eagle Is Somehow Fine After Getting Stuck in a Moving Car's Grille

The bird, nicknamed Matthew, miraculously escaped with no major injuries and should be released back into the Florida wild soon.


An inconvenienced Matthew the Bald Eagle. Photo: Billi West

In life, sometimes you're the grille, and sometimes you're the Bald Eagle. Alright, so that's not exactly how the saying goes, but it turned out to be true for an unlucky Bald Eagle in Florida this past weekend. 

According to a Facebook post by Florida's Clay County Sheriff's Office on Saturday, a Bald Eagle had to be rescued from the grille of a Saturn after the bird collided with the car and got stuck in the vehicle's lower air intake. Fortunately for the eagle, members of the Sheriff's Office and Fire and Rescue were able to safely remove the raptor. "The bird is alive and was turned over to the B.E.A.K.S. Wildlife Sanctuary," the post said. "Great job by all involved."

Perhaps what's more amazing than the bird’s survival is the fact that the driver apparently didn’t notice hitting the bird in the first place.

Talking to CNN, B.E.A.K.S. owner, Cynthia Mosling, said that another driver at an intersection saw an "odd shape" in the vehicle's grille and thought it was a decorative prop until the bird's head moved. After chasing down the other car to notify its driver that America's national bird was wedged in the front fascia, the good Samaritan dubbed the eagle Matthew for the Hurricane that had brushed Florida's coast the day before. 

In a follow-up interview with The Florida-Times Union on Monday, Mosling said that she was surprised that the bird, an adult male at least seven years of age, didn't have any broken wings or a single broken bone. As of Monday, after having a bit of time to recover from the ordeal, Mosling said Matthew was eating and able to fly to some of the higher perches in his cage. 

"He’s feisty now,” Mosling told The Florida-Times. “His wings are working.”
As soon as Matthew passes a flight test in a larger enclosure, Mosling says she'll release him back to wild, where, if he believes in signs, he'll immediately go buy a Powerball ticket.

Sunday, 9 October 2016

Disappearing Ice Means New Ways of Life for Arctic Birds

Arctic seabirds are adapting as climate change brings warmer weather, shifting food sources, and a polar bear invasion.



It’s that time of year again: crisp air, pumpkin lattes, sweaters, and, of course, our annual reminder that the world is gradually getting warmer. At the beginning of each fall, when the Arctic's ice is done melting from the summer heat, the National Snow & Ice Data Center announces how much ice remains (what's called its minimum annual extent). According to this year's announcement, sea ice covered only 1.6 million square miles on September 10, its lowest point for the year. That figure, based on preliminary data, ties this year with 2007 for the second-lowest minimum on record. (For comparison: Between 1979 and 2000, the average minimum was 2.59 million square miles, and the record low was set in 2012 with 1.32 million square miles of ice cover.)

While the announcement of the ever-shrinking Arctic sea ice minimum serves as a clear visual reminder of the earth's warming temperatures, for Arctic wildlife, the picture is more complex. All summer long, the melting ice edge unleashes a rich food source when trapped algae encounters sun-warm water for the first times in months. The resulting algae bloom attracts zooplankton, and then small fish, bigger fish, and top predators such as whales, seals, and seabirds. Changes in the extent and timing of Arctic ice means a shift in food resources, to which birds are adapting and adjusting—some better than others. Here’s how four birds are finding new ways to survive as the icescape around them becomes increasingly unpredictable.

Mandt’s Black Guillemot

Mandt’s Black Guillemots are ice specialists. The birds (pictured above, and a subspecies of the widespread Black Guillemot) roost along the ice edge in the high Arctic, diving for Arctic cod—the preferred food for Arctic predators—and even plucking the fish from cracks in the pack ice. 

But because Arctic cod prefer cold water, they’re now out of reach—too far north or too deep in the water column—when chicks at Cooper Island on the northern tip of Alaska hatch in the summer. So Mandt’s Black Guillemot parents feed their chicks whatever they can catch, and that often means sculpin, a froglike fish that's followed warm water north. Sculpin are bigger than cod, and chicks struggled to swallow their new food at first. Some even choked to death. But guillemot parents seem to be learning. They now bring back smaller sculpin that chicks can swallow. “We were very surprised this past year to have some nests have parents really specialize in sculpin and the chicks have rather decent growth rates,” says George Divoky, who’s monitored the birds with the non-profit Friends of Cooper Island since the 1970s.

As the birds adapt to new food, they must also contend with subarctic invaders moving north as the climate warms. In the 1970s, Divoky noticed Horned Puffins checking out Cooper Island from above, and by the 1980s, the birds had started nesting among the guillemots—and even ousting them. “They started going into the guillemot nests and displacing the eggs and killing the young,” he says. In 2009, they killed nearly half of the guillemot chicks in the colony. “They’re a real climate change signal. It’s good news for the Horned Puffins, but not for the Black Guillemots.”

Ivory Gull


Ivory Gulls are the most northerly breeding birds in the world and the only ones known to nest directly on sea ice—including on icebergs. They migrate along the ice edge to hunt for Arctic cod and small invertebrates that gather there in the summertime bloom.

As sea ice declines, Ivory Gulls seem to be declining, too; their Canadian breeding population shrunk from 2,400 birds in 1987 to 700 birds in 2003, when the most recent survey was completed. The species is listed as endangered in Canada and near threatened on the International Union for Conservation of Nature Red List.

Because they live far from people, it’s hard to say how the population fares overall. But scientists’ predictions aren’t good. “Ivory Gulls are so highly specialized that it’s hard to see what they would do to survive in an ice-free Arctic,” Divoky says. “They’re now dealing with an ice environment that’s very atypical compared to what they’ve had to deal with for the last 10,000 years or so.”

Thick-billed Murre

Thick-billed Murres play the long game. Each May, when they arrive at Coats Island to breed, Hudson Bay is frozen solid around them. The patient parents-to-be will then wait for the ice to melt, and only once open water is exposed nearby do they lay a single egg, finally confident that they can catch enough food to feed their chick. If the water never appears, they fly off without breeding, set on returning and trying again the following spring at the only colony they've nested at for their entire lives.

Like Mandt’s Black Guillemots, Coats Island murres have seen Arctic cod vanish from their summer diets. Since the mid-1990s, Thick-billed Murre parents at Coats Island instead stuff their chicks with capelin, a warmer-water fish, “which they do perfectly well on, but it seems like they don’t do quite as well,” says Tony Gaston, senior research scientist emeritus with Environment and Climate Change Canada who studied Coats Island murres for 30 years. “The chicks are not growing as fast.”

Farther north, Thick-billed Murres stand to benefit from changes in Arctic ice. At Prince Leopold Island, a colony 800 miles north of Coats Island, ice occasionally perseveres throughout the cold summer and prevents the birds from breeding at all. That will change as the Arctic warms. “As those years become less frequent, they will have more breeding years,” Gaston says. “So things are probably improving for the birds in the high Arctic.”

Such improvements could apply to many bird species in the high Arctic—for a time, at least. The slow decline of well-studied nesting colonies might look like loss, but for the most part, populations are merely shifting. Many species will simply move north to stay within their preferred climates—a strategy that can only work for so long. An iceless Arctic summer is expected by 2060, and the birds can’t move north forever. “Eventually it falls off the edge of the world,” Gaston says. “But I don’t worry about Thick-billed Murres. I think they’ll hang on long after we’re gone.”

Common Eider

Unlike colony-nesting seabirds, Common Eiders don’t deliver food to their chicks—they bring the chicks to the food. Just a few days after hatching, eider ducklings follow their parents into open water so they can dive for mollusks on the seafloor. Even after feasting all summer, tragedy can strike during particularly cold winters. When the birds’ feeding areas freeze over, thousands of eiders have little choice but to crowd into the remaining small patches of open water. Beneath that water, food is quickly depleted, and when no other feeding areas are available, Common Eider populations can starve en masse. The loss of Arctic ice is expected to benefit their population: The less ice and the more water available, the better.

However, declining ice also means eider colonies will see more polar bears. The Arctic predator typically uses the sea ice edge as a platform to hunt seals, but the ice's early retreat leaves the bears with less time to hunt big prey. As a result, polar bears have resorted to scavenging for less nutritious food on land, which includes bird eggs. Polar bear visits to the biggest Common Eider colony in the Canadian Arctic increased sevenfold between 1997 and 2012, and at smaller colonies, they’ll devour nearly every egg and chick.

Polar bears gladly raid any seabird colonies within reach, including Thick-Billed Murres at Coats Island and Mandt’s Black Guillemots on Cooper Island. Gaston’s intensive monitoring of birds at Coats Island has ended after 30 years because the bears are too dangerous. “We can’t risk relatively inexperienced students in this kind of situation,” he says. 

While the bears do more damage to colonies of ground-nesting species like Common Eiders, those birds may prove to be more adaptable.

They’re already spreading out within their colonies in Hudson Bay and moving closer to the safety of human settlement—something murres and guillemots are unlikely to do. Those bird species instinctively nest in the same colony year after year. But their chicks, once grown, may take note of the bears and move elsewhere. Gaston thinks first-time murre parents born on Coats Island are already relocating farther north. “What evidence we have suggests that the colony has started to diminish,” he says, and he mostly blames the bears for that.