I read something several days ago that stated that only three species of birds breed exclusively on the Antarctic Continent. I never thought about that before and did a little research regarding that statement. It set my imagination at work, though I have no intention of visiting Antarctica, even during its chilly summer.
Snow petrels, emperor penguins and south polar skuas are the three kinds of birds that nest nowhere but on the sea coasts of Antarctica. These are hardy, adaptable birds that exploited different niches, mostly free of competition from other bird species. And each species is well adapted to its role in life. Snow petrels and skuas have even been spotted flying over the South Pole.
Snow petrels are tube-nosed birds that are pigeon-sized and have a fluttering flight. Elegant, dainty birds, they have white feathering all over, with black beaks, legs and eyes. Their white plumage hides them when their little flocks rest on icebergs, pack ice and ice floes.
Snow petrels fly low over the Southern Ocean, close to the shores of Antarctica, to ingest krill, which is a kind of shrimp, and small fish. They also scavenge seal placentas, washed-up whale carcasses and dead penguin chicks. And they are able to drink ocean water because they excrete a high-saline solution from their tubed nostrils.
It's estimated that 4,000,000 adult snow petrels nest in colonies on rocky cliffs, usually near the ocean. Each pair's nursery is deep in a rock crevice, away from skuas.
The majestic, handsome emperor penguins are also masters of Antarctica. Thousands of them nest in colonies on pack ice many miles back from the Southern Ocean. This is the only bird species in the world that does not lay eggs on some kind of soil or rock. Emperors lay on frozen water- ice.
Male and female emperors court on the Antarctic ice shelf in autumn of the southern hemisphere. Each female lays one egg, which her mate puts in a flap of feathery skin and on top of his feet so the egg doesn't touch the life-stealing ice. Through the cold, sunless winter the males huddle together for warmth as each one incubates his mate's egg. Female emperors, meanwhile, went back to the sea to fatten up on fish and krill.
After two months at sea, surviving females return to their rookeries to relieve their starving mates of incubating duties. Each chick has hatched and is hungry for food stored in its mother's stomach. Each female repeatedly feeds her youngster and broods it on her feet. Meanwhile, the emaciated males march to the sea to feed up and come back later to feed their progeny. This routine goes on while the ice shelf melts until the young emperors are almost right at the ocean to dive in and do their own hunting of fish and krill. The habit of incubating eggs during the southern hemisphere winter insures that emperor chicks are on their own in the southern summer when the living is easier.
Emperors are adapted to their rigorous lifestyle. They have layers of fat and dense feathering that keeps them warm. They live off much of that fat when not feeding, and store food in their stomachs for their young.
The robust, eagle-like south polar skuas are related to gulls, but have strongly-hooked beaks for killing and tearing off chunks of meat and massive, barrel-shaped chests packed with powerful flight muscles for swift flight to pursue panicky prey. These web-footed, tawny-feathered gull relatives seem to be eagles in the making.
The aggressive south polar skuas are scavengers, feeding on unattended bird eggs, dead whales, penguins and other critters they find on ice and ocean water. They are also fierce predators, quickly killing and eating penguin chicks, and any other hapless critters they happen to come across on the sea or ice. They do what they must to survive and reproduce in a harsh habitat.
Snow petrels, emperor penguins and south polar skuas are the only birds in the world endemic to the Antarctic continent, where they live, feed and breed. Most people will never see them in their Antarctic habitats, but it's intriguing to know they are there.
Friday, February 22, 2019
Monday, February 18, 2019
Petite Polar Gulls
Two kinds of small, beautiful gulls, the ivory and Ross', spend most of their lives on the vast Arctic Ocean where ocean currents and wind create leads of open water in the pack ice. These gulls add beauty and interest to that ocean, particularly in winter when few other creatures are there. Few of us will ever visit the Arctic Ocean, but it's inspiring to know that an intriguing community of animals live in that extreme habitat, including those two kinds of handsome, interesting gulls.
Both these lovely gulls are well adapted to living on the Arctic Ocean. Their small bodies allow them to function well on limited food. Ivory gulls have white feathering, which blends them into the snow and ice of the Arctic. Predators don't easily see them. Ross' gulls are light in color, camouflaging them. Both species have strong, pigeon-like flight that carries them over ice to scattered, watery leads in the ice where they get food.
Ivory gulls are fourteen inches long, a bit larger than pigeons. They are white with black legs and a gray beak, tipped with yellow. Young ivories, however, have some dark dots and blotches on their white plumage.
At all times of the year, except their breeding season, ivories travel long distances to scattered food sources. They consume the dung of meat-eating Arctic wolves and Arctic foxes, scraps of meat and fat from mammals, including seals and whales, killed by polar bears and Inuits, and any other dead birds and mammals they find along their way.
Ross' gulls are eleven inches long, about the size of pigeons, and have red legs and small, pointed, black beaks. The pretty adults have pale-gray upper wings and tails and a blush of pink underneath. They also have a black ring around their necks during the breeding season. Young Ross' have a dark W across their upper wings and back.
Year around, except during nesting time, Ross' gulls follow leads in the pack ice to find and ingest small crustaceans such as scuds, plankton and tiny fish, all of which they pick out of the water with their small, thin bills.
Obviously, each of these gull species has food sources different from the other kind of gull, reducing competition for food between them. And each gull species' bill is suited to get its food, a case of form following function. Like all living beings, these gulls are built for what they do to sustain life.
Ivory gulls and Ross' gulls nest apart from each other. Ivories nest in colonies among rocks on sea-facing cliffs and gravel-covered, polar ice in northern Greenland and on Canadian islands just west of Greenland. Each pair builds a cradle of moss, lichens and seaweed. Meanwhile, Ross' gulls nest in colonies on the ground in river valleys and deltas in northeastern Siberia. But both species winter among icebergs, ice floes and leads on the edges of the polar pack ice on the Arctic Ocean, even during the long, dark, polar night.
Ivory and Ross' gulls are fascinating in themselves, and where they live the year around, a brutal habitat we can hardly imagine. Though most of us will never see them, it's intriguing to note where and how these hardy kinds of gulls live.
Both these lovely gulls are well adapted to living on the Arctic Ocean. Their small bodies allow them to function well on limited food. Ivory gulls have white feathering, which blends them into the snow and ice of the Arctic. Predators don't easily see them. Ross' gulls are light in color, camouflaging them. Both species have strong, pigeon-like flight that carries them over ice to scattered, watery leads in the ice where they get food.
Ivory gulls are fourteen inches long, a bit larger than pigeons. They are white with black legs and a gray beak, tipped with yellow. Young ivories, however, have some dark dots and blotches on their white plumage.
At all times of the year, except their breeding season, ivories travel long distances to scattered food sources. They consume the dung of meat-eating Arctic wolves and Arctic foxes, scraps of meat and fat from mammals, including seals and whales, killed by polar bears and Inuits, and any other dead birds and mammals they find along their way.
Ross' gulls are eleven inches long, about the size of pigeons, and have red legs and small, pointed, black beaks. The pretty adults have pale-gray upper wings and tails and a blush of pink underneath. They also have a black ring around their necks during the breeding season. Young Ross' have a dark W across their upper wings and back.
Year around, except during nesting time, Ross' gulls follow leads in the pack ice to find and ingest small crustaceans such as scuds, plankton and tiny fish, all of which they pick out of the water with their small, thin bills.
Obviously, each of these gull species has food sources different from the other kind of gull, reducing competition for food between them. And each gull species' bill is suited to get its food, a case of form following function. Like all living beings, these gulls are built for what they do to sustain life.
Ivory gulls and Ross' gulls nest apart from each other. Ivories nest in colonies among rocks on sea-facing cliffs and gravel-covered, polar ice in northern Greenland and on Canadian islands just west of Greenland. Each pair builds a cradle of moss, lichens and seaweed. Meanwhile, Ross' gulls nest in colonies on the ground in river valleys and deltas in northeastern Siberia. But both species winter among icebergs, ice floes and leads on the edges of the polar pack ice on the Arctic Ocean, even during the long, dark, polar night.
Ivory and Ross' gulls are fascinating in themselves, and where they live the year around, a brutal habitat we can hardly imagine. Though most of us will never see them, it's intriguing to note where and how these hardy kinds of gulls live.
Tuesday, February 12, 2019
Gulls Wintering on Impoundments
Many times in winter over the years, I have visited the several large, human-made impoundments in southeastern Pennsylvania to experience Canada geese, snow geese, tundra swans, a variety of ducks, great blue herons, bald eagles and ring-billed gulls that regularly winter on them, but not all at once and not on every lake. These are birds that traditionally wintered on the Susquehanna and Delaware Rivers and Chesapeake and Delaware Bays, but have adapted to built impoundments.
I visited Blue Marsh Lake, a huge impoundment in Berks County, one recent mid-afternoon to see if masses of ring-billed gulls were still spending winter nights there, as they have for several years. They were, by the thousands. Ring-bills are the main wintering bird species on that built lake, resting on its water, or ice, every winter night, as other ring-bills do on many other impoundments.
Ring-billed gulls have long adapted to wintering on local inland habitats, including harvested fields, parking lots and, most recently, landfills, to get food, and on built lakes to rest in relative peace. They have been a common, wintering species here for many years, bringing a touch of rivers, estuaries and sea coasts inland.
During winter days, thousands of ring-bills concentrate at feeding sites, especially landfills. Most gull species are preadapted to scavenging in open habitats and, therefore, can make good use of landfills. But by mid-afternoon, long lines and flocks of ring-bills wing swiftly across the sky, flock after flock, as if on an aerial highway, to return to their chosen lake, including the one at Blue Marsh, for example, to spend the night in relative safety in a familiar habitat. Each gull flaps powerfully and soars gracefully over the lake and eventually sweeps down to land on it, or a gravelly beach on its shore. And all those gulls together create quite an inspiring show of beauty and grace as they land on Blue Marsh Lake and beach, as on other impoundments.
The presence of the many adaptable ring-bills on built lakes may attract other, more common, species of wintering gulls to rest on those inland impoundments, including herring, great black-backed and, maybe most recently, lesser black-backed gulls. These three kinds of gulls, plus an occasional glaucous or Iceland gull, are also adapting to wintering on inland impoundments to some extent, and feeding at landfills. Herring gulls look like larger editions of ring-bills. Great black-backs are white with black upper wings and backs and pink legs. And the smaller lesser black-backs are white with dark-gray upper wings and backs and yellow legs.
Human-made impoundments and landfills have changed the wintering habits of the more adaptable and common kinds of gulls in southeastern Pennsylvania, and North America in general, to the birds' benefit. And those gulls help bring beauty, grace and excitement to those built habitats in winter.
I visited Blue Marsh Lake, a huge impoundment in Berks County, one recent mid-afternoon to see if masses of ring-billed gulls were still spending winter nights there, as they have for several years. They were, by the thousands. Ring-bills are the main wintering bird species on that built lake, resting on its water, or ice, every winter night, as other ring-bills do on many other impoundments.
Ring-billed gulls have long adapted to wintering on local inland habitats, including harvested fields, parking lots and, most recently, landfills, to get food, and on built lakes to rest in relative peace. They have been a common, wintering species here for many years, bringing a touch of rivers, estuaries and sea coasts inland.
During winter days, thousands of ring-bills concentrate at feeding sites, especially landfills. Most gull species are preadapted to scavenging in open habitats and, therefore, can make good use of landfills. But by mid-afternoon, long lines and flocks of ring-bills wing swiftly across the sky, flock after flock, as if on an aerial highway, to return to their chosen lake, including the one at Blue Marsh, for example, to spend the night in relative safety in a familiar habitat. Each gull flaps powerfully and soars gracefully over the lake and eventually sweeps down to land on it, or a gravelly beach on its shore. And all those gulls together create quite an inspiring show of beauty and grace as they land on Blue Marsh Lake and beach, as on other impoundments.
The presence of the many adaptable ring-bills on built lakes may attract other, more common, species of wintering gulls to rest on those inland impoundments, including herring, great black-backed and, maybe most recently, lesser black-backed gulls. These three kinds of gulls, plus an occasional glaucous or Iceland gull, are also adapting to wintering on inland impoundments to some extent, and feeding at landfills. Herring gulls look like larger editions of ring-bills. Great black-backs are white with black upper wings and backs and pink legs. And the smaller lesser black-backs are white with dark-gray upper wings and backs and yellow legs.
Human-made impoundments and landfills have changed the wintering habits of the more adaptable and common kinds of gulls in southeastern Pennsylvania, and North America in general, to the birds' benefit. And those gulls help bring beauty, grace and excitement to those built habitats in winter.
Tuesday, February 5, 2019
Wintering Geese in Southeastern Pennsylvania
Several kinds of handsome geese winter on many human-made impoundments in southeastern Pennsylvania, as they do elsewhere across much of the United States. And Canada geese are, by far, the most numerous goose species regularly wintering on southeastern Pennsylvania lakes. They rest on those bodies of water in flocks of hundreds, even thousands.
Snow geese are common here, too, but only in part of each winter because they move around a lot.
And five other kinds of geese, including Atlantic brant, cackling geese and barnacle geese in the Branta genus with Canada geese, Ross's geese in the Chen genus with snow geese, and white-fronted geese in the Anser genus, winter here occasionally in single-digit numbers for the most part.
The great, noisy flocks of stately Canada geese dominate the impoundments they settle on to rest, preen and socialize. When hungry, group after group of Canadas, all honking loudly, run across the water while flapping their powerful wings, and take swift flight off the lakes, into the wind, and off to harvested corn fields to eat waste corn kernels, or to winter rye fields to pluck the green shoots of rye. When arriving at a feeding field, Canada goose flocks that trailed each other across farmland, bugling loudly all the way, stream down into the wind to a field, gang after gang, as if on an aerial highway, each bird extending its wings like parachutes.
When full of corn kernels or rye blades, flocks of Canadas run across the field, in one minute intervals, and lift off into the wind to sweep back to their resting impoundments. There each gang swings into the wind again and floats gently down to the water, as each bird's reflection races through the water to meet its bird in splashing impact.
Canada geese are a large, picturesque part of southeastern Pennsylvania in winter. Great gatherings of these big, majestic birds are always exciting to see and hear, wherever they may be. They add much life to this area's lakes and fields, all of which are human-made habitats they adapted to. But great hordes of bugling Canada geese in flight are most exciting and inspiring to see and hear at sunrise and sunset when silhouetted black before the red sky.
Those masses of elegant Canadas attract other kinds of geese to this area's lakes and farmland, especially the awe-inspiring snow geese in their boisterous, overwhelming tens of thousands, often in one giant horde.
Snows usually arrive here in mid-February and stay until almost the middle of March. Like Canadas, snow geese rest on local impoundments and fly out to feeding fields in great, writhing lines, one after another, like waves sliding up a beach. The whole mass of snows often rise from water and fields at once, with a deafening roar of beating wings and high-pitched, honking voices, and looking like a giant sheet being lifted by one end.
Snow geese feed in the same fields that Canada geese do. But snow goose hordes are so large that the snows have to move from field to field every day to get enough to eat. Snows often clean out fields, causing Canadas to move to other feeding fields, too.
Brant, cackling geese, barnacle geese and Ross's geese are all small species, hardly larger than mallard ducks. These species of petite and attractive geese have short necks, and small heads and beaks. Cackling geese are miniature editions of Canada geese and Ross's are miniature editions of snow geese. In winter, these species of smaller geese, and a few white-fronted geese, join gangs of Canada and snow geese, adding more excitement to birders when those geese are spotted among the larger ones on impoundments and in fields.
Brant, and cackling and Ross's geese, raise young on the Canadian tundra. And brant and barnacle geese hatch offspring on the coasts of Greenland.
Barnacle pairs nest on sea cliffs to hatch young away from Arctic foxes and polar bears. But when their goslings hatch, those youngsters must jump off the cliffs to the ground or water below. A few goslings are killed or injured by the impact and some get caught and eaten by Arctic foxes, but the majority of barnacle goslings survive the leap.
Look for these attractive geese this winter and into early spring, or in successive winters. They are exciting and inspiring to experience.
Snow geese are common here, too, but only in part of each winter because they move around a lot.
And five other kinds of geese, including Atlantic brant, cackling geese and barnacle geese in the Branta genus with Canada geese, Ross's geese in the Chen genus with snow geese, and white-fronted geese in the Anser genus, winter here occasionally in single-digit numbers for the most part.
The great, noisy flocks of stately Canada geese dominate the impoundments they settle on to rest, preen and socialize. When hungry, group after group of Canadas, all honking loudly, run across the water while flapping their powerful wings, and take swift flight off the lakes, into the wind, and off to harvested corn fields to eat waste corn kernels, or to winter rye fields to pluck the green shoots of rye. When arriving at a feeding field, Canada goose flocks that trailed each other across farmland, bugling loudly all the way, stream down into the wind to a field, gang after gang, as if on an aerial highway, each bird extending its wings like parachutes.
When full of corn kernels or rye blades, flocks of Canadas run across the field, in one minute intervals, and lift off into the wind to sweep back to their resting impoundments. There each gang swings into the wind again and floats gently down to the water, as each bird's reflection races through the water to meet its bird in splashing impact.
Canada geese are a large, picturesque part of southeastern Pennsylvania in winter. Great gatherings of these big, majestic birds are always exciting to see and hear, wherever they may be. They add much life to this area's lakes and fields, all of which are human-made habitats they adapted to. But great hordes of bugling Canada geese in flight are most exciting and inspiring to see and hear at sunrise and sunset when silhouetted black before the red sky.
Those masses of elegant Canadas attract other kinds of geese to this area's lakes and farmland, especially the awe-inspiring snow geese in their boisterous, overwhelming tens of thousands, often in one giant horde.
Snows usually arrive here in mid-February and stay until almost the middle of March. Like Canadas, snow geese rest on local impoundments and fly out to feeding fields in great, writhing lines, one after another, like waves sliding up a beach. The whole mass of snows often rise from water and fields at once, with a deafening roar of beating wings and high-pitched, honking voices, and looking like a giant sheet being lifted by one end.
Snow geese feed in the same fields that Canada geese do. But snow goose hordes are so large that the snows have to move from field to field every day to get enough to eat. Snows often clean out fields, causing Canadas to move to other feeding fields, too.
Brant, cackling geese, barnacle geese and Ross's geese are all small species, hardly larger than mallard ducks. These species of petite and attractive geese have short necks, and small heads and beaks. Cackling geese are miniature editions of Canada geese and Ross's are miniature editions of snow geese. In winter, these species of smaller geese, and a few white-fronted geese, join gangs of Canada and snow geese, adding more excitement to birders when those geese are spotted among the larger ones on impoundments and in fields.
Brant, and cackling and Ross's geese, raise young on the Canadian tundra. And brant and barnacle geese hatch offspring on the coasts of Greenland.
Barnacle pairs nest on sea cliffs to hatch young away from Arctic foxes and polar bears. But when their goslings hatch, those youngsters must jump off the cliffs to the ground or water below. A few goslings are killed or injured by the impact and some get caught and eaten by Arctic foxes, but the majority of barnacle goslings survive the leap.
Look for these attractive geese this winter and into early spring, or in successive winters. They are exciting and inspiring to experience.
Monday, January 28, 2019
Blackwater Refuge-Two
On January 7 of this year, thousands of snow geese settled on the twin, freshwater ponds at Blackwater Refuge on Maryland's Eastern Shore of the Chesapeake Bay. Those ponds were bustling and noisy with the constant calling of elegant Canada geese and tundra swans, day and night, before the snows arrived, but were even more so with the continual honking of the new waterfowl on the ponds. Snow geese really cause a stir by themselves. They dominate whatever water or field they land on with their incessant, loud honking and numbers. Because of snow geese, with the help of the Canadas and swans, Blackwater was a pleasant bedlam of sound and activities. The ponds were full of geese, swans and a small variety of ducks, mostly pintails, all intermingling among each other. The swans and pintails "tip-up" to pull water plants from the bottoms of the shallow ponds. But both species of geese apparently fed on waste corn kernels and winter rye in the fields because I didn't see them feeding in the ponds.
Blackwater Refuge, in winter, as in all seasons, is beautiful with its flat terrain, dominance of water and marshes and a big sky. I observed the refuge on our computer, as if I was looking out the window of a houseboat. Many of the waterfowl were close to the camera.
The prettiest and most exciting time of day at the refuge is around sunset at the end of a sunny day. At that time, many Canada and snow geese, amid a ruckus of honking, run across the ponds while vigorously flapping their wings, stream off the ponds, flock after flock, silhouetted black against the yellow, orange or red western sky, and fly swiftly to nearby feeding fields. The geese, as all birds do, take off into the wind for lift and flight control. And all birds land into the wind for flight control. For several minutes the lovely evening sky at Blackwater is excitedly full of magnificent, noisy geese passing across it and swirling down, group after group, to a harvested corn or winter rye field. Both species, either in pure flocks of themselves or mixed together, slide down into the wind to a field as if on an aerial waterfall that fills the fields. Meanwhile, the whole landscape is drenched in the red glow of the western sky, that also adds more beauty to the geese.
Snow geese, in winter, do everything in great masses, causing exciting, inspiring spectacles. They rest together on rivers and larger impoundments, feed in fields together and migrate in large hordes.
When both kinds of geese are full of corn kernels and/or green blades of winter rye, they come back to the ponds, again group after noisy group. They sweep low over the water and descend into the wind for flight control, each one's reflection racing through the water to meet it at impact.
In the middle of January, when the weather was very cold for a few days, the shallow ponds froze. The snow geese and many each of the swans, Canada geese and ducks left Blackwater. The swans and ducks couldn't consume aquatic vegetation. But when the weather warmed and the water thawed, the swans, ducks and Canada geese returned to the refuge. The snow geese, however, did not come back. Snow geese are notorious for being unpredictable and shifting around a lot. They feed in such large masses that they soon clean out most edibles from a field or marsh and have to move on to another feeding place, and another, and another, almost everyday through winter.
I was thrilled to see so many pintail ducks on the twin ponds of Blackwater Refuge. I haven't seen so many of those handsome ducks in several years. And they are an interesting species because of their winter and early-spring courtship flights. A few drakes gather around a female pintail and take turns raising up in a bow, then raising their rears a bit. At some point, the hen takes off in speedy flight over a pond or marsh, and surrounding land, with all suitors following closely along. The whole little group sweeps high and low in dashing flight and its said that the male who keeps up with her best becomes her mate. Pintails present a show that should be enjoyed when and where one can.
In spite of the numbers of snow geese when they were at Blackwater and the majesty of tundra swans, the stately Canada geese ultimately dominated the refuge. They remained there the longest in the largest numbers, with lusty bugling to match their magnificent bearing.
By late January, the ponds were full of ducks, mostly pintails, Canada geese and tundra swans. At that time, I stopped watching Blackwater on our computer. Now I am waiting for spring activities at that refuge on Maryland's Eastern Shore.
Blackwater Refuge, in winter, as in all seasons, is beautiful with its flat terrain, dominance of water and marshes and a big sky. I observed the refuge on our computer, as if I was looking out the window of a houseboat. Many of the waterfowl were close to the camera.
The prettiest and most exciting time of day at the refuge is around sunset at the end of a sunny day. At that time, many Canada and snow geese, amid a ruckus of honking, run across the ponds while vigorously flapping their wings, stream off the ponds, flock after flock, silhouetted black against the yellow, orange or red western sky, and fly swiftly to nearby feeding fields. The geese, as all birds do, take off into the wind for lift and flight control. And all birds land into the wind for flight control. For several minutes the lovely evening sky at Blackwater is excitedly full of magnificent, noisy geese passing across it and swirling down, group after group, to a harvested corn or winter rye field. Both species, either in pure flocks of themselves or mixed together, slide down into the wind to a field as if on an aerial waterfall that fills the fields. Meanwhile, the whole landscape is drenched in the red glow of the western sky, that also adds more beauty to the geese.
Snow geese, in winter, do everything in great masses, causing exciting, inspiring spectacles. They rest together on rivers and larger impoundments, feed in fields together and migrate in large hordes.
When both kinds of geese are full of corn kernels and/or green blades of winter rye, they come back to the ponds, again group after noisy group. They sweep low over the water and descend into the wind for flight control, each one's reflection racing through the water to meet it at impact.
In the middle of January, when the weather was very cold for a few days, the shallow ponds froze. The snow geese and many each of the swans, Canada geese and ducks left Blackwater. The swans and ducks couldn't consume aquatic vegetation. But when the weather warmed and the water thawed, the swans, ducks and Canada geese returned to the refuge. The snow geese, however, did not come back. Snow geese are notorious for being unpredictable and shifting around a lot. They feed in such large masses that they soon clean out most edibles from a field or marsh and have to move on to another feeding place, and another, and another, almost everyday through winter.
I was thrilled to see so many pintail ducks on the twin ponds of Blackwater Refuge. I haven't seen so many of those handsome ducks in several years. And they are an interesting species because of their winter and early-spring courtship flights. A few drakes gather around a female pintail and take turns raising up in a bow, then raising their rears a bit. At some point, the hen takes off in speedy flight over a pond or marsh, and surrounding land, with all suitors following closely along. The whole little group sweeps high and low in dashing flight and its said that the male who keeps up with her best becomes her mate. Pintails present a show that should be enjoyed when and where one can.
In spite of the numbers of snow geese when they were at Blackwater and the majesty of tundra swans, the stately Canada geese ultimately dominated the refuge. They remained there the longest in the largest numbers, with lusty bugling to match their magnificent bearing.
By late January, the ponds were full of ducks, mostly pintails, Canada geese and tundra swans. At that time, I stopped watching Blackwater on our computer. Now I am waiting for spring activities at that refuge on Maryland's Eastern Shore.
Tuesday, January 22, 2019
Winter Jetties, Mussels and Birds
Jetties of boulders, fishing dock pilings and stone sea walls are recent, human-made habitats along the shores of oceans, including the North Atlantic of North America. These structures are like rocky, ocean shorelines in that aquatic vegetation, (seaweed of various kinds) multitudes of blue mussels and other sea invertebrates live on them where ocean breakers regularly crash and splash. Jetties, extending up to a few hundred yards into the ocean, were built to retain sand on public, recreational beaches. New Jersey has several rock jetties that protect its money-making beaches.
Masses of blue mussels cling on to and colonize the hard surfaces of pilings, seawalls and jetties. Those dark-shelled, oblong members of the mollusk family are packed tight on the boulders. And those mussels are an important food source, either directly or indirectly, for several kinds of handsome, wintering waterfowl and shorebirds.
At least nine kinds of sea ducks, all of them attractive in appearance, consume blue mussels on jetties, including long-tailed and harlequin ducks, two types of eider ducks, three species of scoters, greater scaups and American goldeneyes. All these species raise young in northern Canada and Alaska, but winter along sea coasts. And they all ingest blue mussels from jetties at some time or another in winter. A field guide to North American birds will illustrate how beautiful these duck species are and where they rear offspring.
Long-tailed ducks are so-named because each handsome drake has a couple of long tail feathers. Small groups of long-tails fly swiftly in low, picturesque lines where breakers rise from the ocean, fall over with a crash and sweep up the beaches. The strong-swimming long-tails dive under water from the surface to tear mussels off the wave-battered jetties with their tough beaks, backed by powerful muscles.
Harlequin ducks nest along swiftly-flowing streams in Canada. Both adults and ducklings swim and walk along the bottom of those waterways to eat a variety of invertebrates. This attractive species probably is the most typical one along rock jetties. Harlequins, too, dive under water to rip mussels from the water-washed boulders.
Elegant common eider ducks and king eiders occasionally feed on blue mussels on jetties, but not as regularly as long-tails and harlequins. These two species generally winter farther out in the oceans where they dive for mollusks and crustaceans.
The three, closely-related scoter species are mostly black, with other colors that identify them. Black scoters usually winter along breakers and jetties and dive for mussels, but their close relatives, the surf and white-winged scoters, generally spend winters where estuaries flow slowly into oceans. However, surf and white-wings will also ingest blue mussels off jetties at times by diving under water after them.
Greater scaups are members of the bay duck family. But certain individuals of this species also dive under water to feed on blue mussels on jetties, adding more diversity to this group of mussel-eating sea ducks.
Many American goldeneye ducks winter on the Susquehanna River and other rivers. But some of them winter near the shores of inlets and bays, and the ocean, where they dive for aquatic crustaaceans, mollusks and insects on the bottoms of large waters. Therefore, some goldeneyes dive for mussels on jetties. This species is often called "whistling ducks" because its wings whistle loudly when the birds are in flight.
Brant are a species of attractive, small goose that feed, in little groups, on plants along the shores of bays, inlets and oceans during winter. Some individuals of this interesting species, while floating, bobbing and swimming in the wave-tossed water beside jetties, sometimes feed on the vegetation growing on those ocean-washed lines of human-placed boulders jutting into the ocean breakers. Brant, by the way, are most attractive when flying in small groups low over bodies of salt and brackish water close to shorelines.
Purple sandpipers and ruddy turnstones are species of dark shorebirds that regularly winter on rock jetties, the sandpipers exclusively so. There individuals and little groups of these species feed on small, aquatic invertebrates that shelter among the mussels and vegetation. The dark feathering of these bird species camouflage them among the rocks, which helps conceal them from the good vision of peregrine falcons wandering along the seacoast.
Though devout beachcombers for edible tidbits washed onto the beaches by ocean waves, some sanderlings, which are a light-gray and white kind of sandpiper, feed on invertebrates among the mussels and seaweed on jetties. Sanderlings might give purple sandpipers and turnstones a bit of competition for invertebrates on jetties, but the former species isn't often on jetties.
Occasionally a few American oystercatchers eat some blue mussels on jetties. This is a pigeon-sized bird on stilts. This handsome species is black on top, white below and has a long, thin, blood-red beak. They use their bills to pry open mollusk shells to eat the body inside.
Rock jetties are intriguing, human-made habitats that benefit several kinds of feeding birds in winter. Some species consume the mussels, brant ingest aquatic plants and shorebirds eat small invertebrates sheltering among the mussels and vegetation. And we can experience some of these birds, if we are along jetties in winter.
Masses of blue mussels cling on to and colonize the hard surfaces of pilings, seawalls and jetties. Those dark-shelled, oblong members of the mollusk family are packed tight on the boulders. And those mussels are an important food source, either directly or indirectly, for several kinds of handsome, wintering waterfowl and shorebirds.
At least nine kinds of sea ducks, all of them attractive in appearance, consume blue mussels on jetties, including long-tailed and harlequin ducks, two types of eider ducks, three species of scoters, greater scaups and American goldeneyes. All these species raise young in northern Canada and Alaska, but winter along sea coasts. And they all ingest blue mussels from jetties at some time or another in winter. A field guide to North American birds will illustrate how beautiful these duck species are and where they rear offspring.
Long-tailed ducks are so-named because each handsome drake has a couple of long tail feathers. Small groups of long-tails fly swiftly in low, picturesque lines where breakers rise from the ocean, fall over with a crash and sweep up the beaches. The strong-swimming long-tails dive under water from the surface to tear mussels off the wave-battered jetties with their tough beaks, backed by powerful muscles.
Harlequin ducks nest along swiftly-flowing streams in Canada. Both adults and ducklings swim and walk along the bottom of those waterways to eat a variety of invertebrates. This attractive species probably is the most typical one along rock jetties. Harlequins, too, dive under water to rip mussels from the water-washed boulders.
Elegant common eider ducks and king eiders occasionally feed on blue mussels on jetties, but not as regularly as long-tails and harlequins. These two species generally winter farther out in the oceans where they dive for mollusks and crustaceans.
The three, closely-related scoter species are mostly black, with other colors that identify them. Black scoters usually winter along breakers and jetties and dive for mussels, but their close relatives, the surf and white-winged scoters, generally spend winters where estuaries flow slowly into oceans. However, surf and white-wings will also ingest blue mussels off jetties at times by diving under water after them.
Greater scaups are members of the bay duck family. But certain individuals of this species also dive under water to feed on blue mussels on jetties, adding more diversity to this group of mussel-eating sea ducks.
Many American goldeneye ducks winter on the Susquehanna River and other rivers. But some of them winter near the shores of inlets and bays, and the ocean, where they dive for aquatic crustaaceans, mollusks and insects on the bottoms of large waters. Therefore, some goldeneyes dive for mussels on jetties. This species is often called "whistling ducks" because its wings whistle loudly when the birds are in flight.
Brant are a species of attractive, small goose that feed, in little groups, on plants along the shores of bays, inlets and oceans during winter. Some individuals of this interesting species, while floating, bobbing and swimming in the wave-tossed water beside jetties, sometimes feed on the vegetation growing on those ocean-washed lines of human-placed boulders jutting into the ocean breakers. Brant, by the way, are most attractive when flying in small groups low over bodies of salt and brackish water close to shorelines.
Purple sandpipers and ruddy turnstones are species of dark shorebirds that regularly winter on rock jetties, the sandpipers exclusively so. There individuals and little groups of these species feed on small, aquatic invertebrates that shelter among the mussels and vegetation. The dark feathering of these bird species camouflage them among the rocks, which helps conceal them from the good vision of peregrine falcons wandering along the seacoast.
Though devout beachcombers for edible tidbits washed onto the beaches by ocean waves, some sanderlings, which are a light-gray and white kind of sandpiper, feed on invertebrates among the mussels and seaweed on jetties. Sanderlings might give purple sandpipers and turnstones a bit of competition for invertebrates on jetties, but the former species isn't often on jetties.
Occasionally a few American oystercatchers eat some blue mussels on jetties. This is a pigeon-sized bird on stilts. This handsome species is black on top, white below and has a long, thin, blood-red beak. They use their bills to pry open mollusk shells to eat the body inside.
Rock jetties are intriguing, human-made habitats that benefit several kinds of feeding birds in winter. Some species consume the mussels, brant ingest aquatic plants and shorebirds eat small invertebrates sheltering among the mussels and vegetation. And we can experience some of these birds, if we are along jetties in winter.
Saturday, January 19, 2019
Wintering Coastal Shorebirds
In winter over the years, I have gone to the Atlantic Ocean coast in New Jersey many times to see what birds winter on the sandy beaches, rock jetties and salt marsh mud flats. I 've seen a small variety of gulls on the beaches and jetties and clapper rails and more gulls on the flats. But my main interest has been the intriguing, little shorebirds that nest in the Arctic and winter in specific niches in those shoreline habitats, including sanderlings on beaches, purple sandpipers and ruddy turnstones on jetties and dunlin on flats.
Beaches, jetties and mud flats are all open habitats with little, if any, vegetation. But shorebirds have long ago adapted to those "barren" environments to spend winters searching for invertebrate food, with a minimum of competition for it. Shorebirds exploit natural and human-made niches that few other species of birds will.
These shorebirds escape the attention of peregrines and merlins, both bird-catching falcons, by blending into their open surroundings. Sanderlings are light-gray and white, which camouflages them on beaches. Purple sandpipers and turnstones are mostly darkly feathered, which makes them nearly invisible on jetties. And dunlin are mostly dull-brown on top, which camouflages them on mud. But if those falcons see through the shorebirds' camouflage and dive on them, the shorebirds take wing in speedy, erratic flight to avoid being caught by those swift hawks.
All these little shorebirds depend on the actions of the ocean to get their invertebrate food. Wind-pushed waves, washing up the beaches, bring in various organisms that little gatherings of sanderlings, which are a kind of sandpiper, pick up with their beaks and consume as the water slides down the beach again because of gravity. It is entertaining and amusing to see these little sandpipers running up the beaches on their black legs as fast as they can before incoming wavelets, then running down the beaches after the receding water and picking up invertebrates as they go. This they do most all day, every day through winter.
It's equally intriguing to see congregations of sanderlings flying low along beaches and breakers to a new feeding spot on a beach. They race a few feet above the water and sand, turning this way and that in unison, then abruptly pitch down to a beach to feed on invertebrates and other tidbits washed in by the incoming wavelets.
Jetties are human-made lines of boulders extending a couple hundred yards into the ocean. Their purpose is to protect the sandy beaches from being washed away by the power of waves, or breakers, as their called.
Purple sandpipers and ruddy turnstones have long adapted to wintering along rocky shorelines. There blue mussels and a few types of green vegetation flourish, which offer living space to a variety of small invertebrates, as on naturally rocky coasts.
These jetties give small, scattered groups of purple sandpipers and turnstones more feeding space in winter. They ingest invertebrates living among the mussels and plants, and eat tiny edibles that get dumped on the boulders by waves and lodged between the mussels and vegetation.
When the tide goes out salt marsh channels to the ocean because of the moon's gravity, flocks of wintering dunlin, which are a kind of small sandpiper, walk along the exposed mud flats in salt marshes to get invertebrate food sheltering in the mud. They poke their bills into the mud to pull out invertebrates until the tide of water comes back up the channels into the marsh, covering the flats. Occasionally, the dunlin will take flight in one big flock, swirl over the salt marshes a few times, which is exciting too see, then land on the flats again and immediately begin feeding.
Each of these interesting shorebird species, wintering along the Atlantic Coastline, has its own niche for gathering food, with a minimum of competition. And each kind is a joy to watch along the seashore in winter.
Beaches, jetties and mud flats are all open habitats with little, if any, vegetation. But shorebirds have long ago adapted to those "barren" environments to spend winters searching for invertebrate food, with a minimum of competition for it. Shorebirds exploit natural and human-made niches that few other species of birds will.
These shorebirds escape the attention of peregrines and merlins, both bird-catching falcons, by blending into their open surroundings. Sanderlings are light-gray and white, which camouflages them on beaches. Purple sandpipers and turnstones are mostly darkly feathered, which makes them nearly invisible on jetties. And dunlin are mostly dull-brown on top, which camouflages them on mud. But if those falcons see through the shorebirds' camouflage and dive on them, the shorebirds take wing in speedy, erratic flight to avoid being caught by those swift hawks.
All these little shorebirds depend on the actions of the ocean to get their invertebrate food. Wind-pushed waves, washing up the beaches, bring in various organisms that little gatherings of sanderlings, which are a kind of sandpiper, pick up with their beaks and consume as the water slides down the beach again because of gravity. It is entertaining and amusing to see these little sandpipers running up the beaches on their black legs as fast as they can before incoming wavelets, then running down the beaches after the receding water and picking up invertebrates as they go. This they do most all day, every day through winter.
It's equally intriguing to see congregations of sanderlings flying low along beaches and breakers to a new feeding spot on a beach. They race a few feet above the water and sand, turning this way and that in unison, then abruptly pitch down to a beach to feed on invertebrates and other tidbits washed in by the incoming wavelets.
Jetties are human-made lines of boulders extending a couple hundred yards into the ocean. Their purpose is to protect the sandy beaches from being washed away by the power of waves, or breakers, as their called.
Purple sandpipers and ruddy turnstones have long adapted to wintering along rocky shorelines. There blue mussels and a few types of green vegetation flourish, which offer living space to a variety of small invertebrates, as on naturally rocky coasts.
These jetties give small, scattered groups of purple sandpipers and turnstones more feeding space in winter. They ingest invertebrates living among the mussels and plants, and eat tiny edibles that get dumped on the boulders by waves and lodged between the mussels and vegetation.
When the tide goes out salt marsh channels to the ocean because of the moon's gravity, flocks of wintering dunlin, which are a kind of small sandpiper, walk along the exposed mud flats in salt marshes to get invertebrate food sheltering in the mud. They poke their bills into the mud to pull out invertebrates until the tide of water comes back up the channels into the marsh, covering the flats. Occasionally, the dunlin will take flight in one big flock, swirl over the salt marshes a few times, which is exciting too see, then land on the flats again and immediately begin feeding.
Each of these interesting shorebird species, wintering along the Atlantic Coastline, has its own niche for gathering food, with a minimum of competition. And each kind is a joy to watch along the seashore in winter.
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