Recently I saw a blue-gray gnatcatcher fluttering about among the twigs of trees close to the porch of people I was visiting. It was a dainty, little bird that reminded me of a tiny northern mockingbird, with its long-tail, overall shape and pale-gray color on top. The white ring around each dark eye gave the gnatcatcher an innocent look. As its name implies, that small bird was busily catching and eating tiny insects from the trees' leaves and twigs.
Two kinds of kinglets and blue-gray gnatcatchers in eastern North America belong to the Old World family of warblers, with a few species in the New World. Kinglets and gnatcatchers, being related, have characteristics in common. They are all small, plain and thin-billed for eating tiny insects and insect eggs, but are still quite attractive. These dainty birds seem never to be still while flitting and foraging for food in the trees, making identification difficult. They flick their wings and hover briefly before leaves and twigs while inspecting them for food, then dart after a tidbit.
The kinglets are called golden-crowned and ruby-crowned because of the feathering on their crowns. Male golden-crowns have orange crowns bordered with black stripes, while their mates have yellow ones. Each male ruby crown has a red patch on top of his head. Both species are otherwise olive in color with two vertical, white bars on each wing.
Both kinglet species nest in coniferous trees in Canada's boreal forests and down the Appalachian and Rocky Mountains. And both species winter from the middle of the United States south to the Gulf of Mexico and Mexico. We here in Lancaster County, Pennsylvania usually see both types of kinglets during their spring and autumn migrations.
Blue-gray gnatcatchers, however, nest in the treetops of moist, bottomland forests in the southern United States, north to Pennsylvania. Though common, they aren't noticed much because the are small, camouflaged and stick to the trees where they can easily hide. Occasionally a post-breeding gnatcatcher will forage for food in an older suburban area with its many tall trees.
Gnatcatchers make beautiful nests but we seldom see them unless one is blown out of a tree and is lying on he ground. Gnatcatcher nurseries are lovely, deep, little cups of fine grasses, lined on the outside with lichens to camouflage the cradle and bound together with spider webbing.
Though, generally, not easy to spot because of their small size and camouflaged feathering, kinglets and gnatcatchers are handsome and energetic, little birds. They are worth watching for during the seasons they are in the reader's region.
Friday, August 14, 2015
Friday, August 7, 2015
Third Generation Monarchs
On the afternoon of August 7, 2015, I was driving through Lancaster County, Pennsylvania cropland on a few errands. As I slowly drove by about a half dozen hay fields in a mile stretch of a country road, I watched those hay fields intently for wildlife. Most of the fields were in flower, either with purple, fragrant alfalfa blooms, the lovely, pink blossoms of red clover, or both flowers together in the same field.
Cabbage white butterflies, yellow sulphur butterflies, silver-spotted skipper butterflies and bumble bees were among those flowers in abundance to sip nectar. Barn swallows and tree swallows cruised swiftly low over the hay fields to snap up flying insects. Then, suddenly, I saw a striking orange and black monarch butterfly on a red clover bloom, then another fluttering from blossom to blossom, and another until I had seen six monarchs in those flowering hay fields. I'm sure there were many more. That was a good number, considering I hadn't seen any monarchs all summer, mainly because they are down in numbers because of herbicides which kills milkweeds, their larval food, and pesticides that kills insects themselves.
The most interesting part of seeing those monarchs today is that they won't make the trip to certain forests on mountains in Mexico to spend the winter. But they are the parents of the fourth generation of monarchs, the generation each year that does make the trip.
The first generation of each year, which is the fourth one of the year before, leaves Mexico in March and migrates north into the United States. There is a second generation and a third each summer as each generation of monarchs continues to push north and east. But only the fourth generation of butterflies makes the trip to Mexico, starting about the middle of September.
Females of the third generation of monarchs, as all their species does, mate and lay eggs on milkweed leaves. The caterpillars hatch, eat milkweed foliage, grow, pupate and emerge as adult monarchs in September, ready to go to Mexico to escape the northern winter.
I was excited to see those beautiful monarchs today. Hopefully, they still have a bright future. But we need to quit poisoning the land and its plants and animals.
Cabbage white butterflies, yellow sulphur butterflies, silver-spotted skipper butterflies and bumble bees were among those flowers in abundance to sip nectar. Barn swallows and tree swallows cruised swiftly low over the hay fields to snap up flying insects. Then, suddenly, I saw a striking orange and black monarch butterfly on a red clover bloom, then another fluttering from blossom to blossom, and another until I had seen six monarchs in those flowering hay fields. I'm sure there were many more. That was a good number, considering I hadn't seen any monarchs all summer, mainly because they are down in numbers because of herbicides which kills milkweeds, their larval food, and pesticides that kills insects themselves.
The most interesting part of seeing those monarchs today is that they won't make the trip to certain forests on mountains in Mexico to spend the winter. But they are the parents of the fourth generation of monarchs, the generation each year that does make the trip.
The first generation of each year, which is the fourth one of the year before, leaves Mexico in March and migrates north into the United States. There is a second generation and a third each summer as each generation of monarchs continues to push north and east. But only the fourth generation of butterflies makes the trip to Mexico, starting about the middle of September.
Females of the third generation of monarchs, as all their species does, mate and lay eggs on milkweed leaves. The caterpillars hatch, eat milkweed foliage, grow, pupate and emerge as adult monarchs in September, ready to go to Mexico to escape the northern winter.
I was excited to see those beautiful monarchs today. Hopefully, they still have a bright future. But we need to quit poisoning the land and its plants and animals.
Fall Migrations of Grassland Sandpipers
We mostly know sandpipers as those drab, little birds that flock together on mud flats and beaches during May and again late in summer. Most of those sandpipers nest on the treeless Arctic tundra and winter in Central and South America. But two kinds of unusual sandpipers, upland and buff-breasted sandpipers, nest and winter in extensive grasslands. And when migrating south to avoid the northern winter, they even stop to rest and feed on invertebrates in grassland habitats.
Here in Lancaster County, Pennsylvania, we only see these kinds of sandpipers during their autumn migrations south to the Pampas grasslands of lower South America. Uplanders come through here uncommonly in August and buff-breasts are here rarely in September. But while they are here, they forage for invertebrates in extensive grass, such as at airports and sod farms, and recently harvested hay fields where the vegetation is still short. However, their plumage allows them to blend into those habitats so well, they are difficult to spot. One usually needs binoculars.
Their shared grassland habitat has shaped these sandpiper species to be what they are, similar in appearance. Uppies and buff-breasts are much alike in light-brown feathering, streaked with darker markings that camouflages them. They both have small, dainty heads, and long necks that periscope their eyes to see over the grass. But uplands seem twice the size of buff-breasts.
Upland sandpipers nest in grass habitats of Alaska, the Canadian and American prairies and the northern tier states of the eastern United States. Buff-breasts rear offspring on the Arctic tundra where there are no trees or shrubbery.
Every August, I cruise along country roads in Lancaster County and look at recently cut hay fields to spot upland sandpipers. I usually see a few, one or two here or one or two there. Sometimes they gather in groups of four to eight in a field for a few days, then they are gone, migrating to southern South America.
Buff-breasted sandpipers come through here for the most part in early September, but they are tough to spot, although I try to see them once in a while. Not only do they blend into their surroundings to the point of being invisible until they move, they are small, rare here and usually scattered among many fields in this farmland county. And most buff-breasts migrate through the central part of Canada and the United States. It's a red-letter day for me when I spot a buff-breast or two in local fields.
These two grassland sandpipers are ambassadors from far-away places that pass through Lancaster County and other places in North America. They are uniquely lovely birds, if spotted. Well worth the effort to find them.
Here in Lancaster County, Pennsylvania, we only see these kinds of sandpipers during their autumn migrations south to the Pampas grasslands of lower South America. Uplanders come through here uncommonly in August and buff-breasts are here rarely in September. But while they are here, they forage for invertebrates in extensive grass, such as at airports and sod farms, and recently harvested hay fields where the vegetation is still short. However, their plumage allows them to blend into those habitats so well, they are difficult to spot. One usually needs binoculars.
Their shared grassland habitat has shaped these sandpiper species to be what they are, similar in appearance. Uppies and buff-breasts are much alike in light-brown feathering, streaked with darker markings that camouflages them. They both have small, dainty heads, and long necks that periscope their eyes to see over the grass. But uplands seem twice the size of buff-breasts.
Upland sandpipers nest in grass habitats of Alaska, the Canadian and American prairies and the northern tier states of the eastern United States. Buff-breasts rear offspring on the Arctic tundra where there are no trees or shrubbery.
Every August, I cruise along country roads in Lancaster County and look at recently cut hay fields to spot upland sandpipers. I usually see a few, one or two here or one or two there. Sometimes they gather in groups of four to eight in a field for a few days, then they are gone, migrating to southern South America.
Buff-breasted sandpipers come through here for the most part in early September, but they are tough to spot, although I try to see them once in a while. Not only do they blend into their surroundings to the point of being invisible until they move, they are small, rare here and usually scattered among many fields in this farmland county. And most buff-breasts migrate through the central part of Canada and the United States. It's a red-letter day for me when I spot a buff-breast or two in local fields.
These two grassland sandpipers are ambassadors from far-away places that pass through Lancaster County and other places in North America. They are uniquely lovely birds, if spotted. Well worth the effort to find them.
Parking Lot Gulls
Ring-billed gulls and laughing gulls are both smaller species of their clan, and are common in the Mid-Atlantic States. The former kind is here in winter, along inland rivers and impoundments, and the Atlantic Seacoast, and the latter type along the Atlantic shore during summer. Both species are adaptable and take advantage of several feeding opportunities, including scavenging discarded tidbits from parking lots and feeding on invertebrates in recently plowed fields, which is a joy and entertainment to many people.
Adult ring-bills are pale gray on top with white heads, bellies and tails. They also have a diagnostic black ring on their bill. Their young, however, are mostly brown on top until they mature. Adult laughing gulls are dark gray above, with white bellies and black heads. Their young of the year are brown on top with white tails with a black terminal band on each one of them.
Ring-bills nest around lakes on the Canadian, mid-west prairies, and on the shores of the Great Lakes and the St. Lawrence River. But they winter in the Middle Atlantic States, as in much of the United States. Flocks of ring-bills often rest on large parking lots during winter, as they would on beaches and salt marshes. They rise into the air as one group at the approach of a vehicle, but quickly settle on the black top again. To them, our extensive fields and parking lots must seem like expansions of their ancestral beaches. Much of the civilized world was created for them.
Laughing gulls are even more entertaining to many people vacationing along the Atlantic and Gulf Coasts in the United States. These gulls nest in salt marshes along the Atlantic and Gulf Seacoasts, and catch crabs, small fish and other little critters from big bodies of water, scavenge dead fish and other animals and pick up edible tidbits discarded by people wherever those food items are found. And these gulls are everywhere along the coast, and inland to some extent, to get those foods, over the water, and on beaches, boardwalks, lawns, streets and parking lots. Many people purposefully feed laughing gulls to watch them hovering into the wind and dropping to the ground to get the foods thrown to them. And all the while, wherever they are, there is the constant laughing cries of these beautiful gulls.
Ring-billed gulls and laughing gulls are small kinds of gulls that are quite adaptable, taking advantage of many food sources almost everywhere between the two species. Look for them, at least on parking lots at the appropriate times of year. They are beautiful and entertaining.
Adult ring-bills are pale gray on top with white heads, bellies and tails. They also have a diagnostic black ring on their bill. Their young, however, are mostly brown on top until they mature. Adult laughing gulls are dark gray above, with white bellies and black heads. Their young of the year are brown on top with white tails with a black terminal band on each one of them.
Ring-bills nest around lakes on the Canadian, mid-west prairies, and on the shores of the Great Lakes and the St. Lawrence River. But they winter in the Middle Atlantic States, as in much of the United States. Flocks of ring-bills often rest on large parking lots during winter, as they would on beaches and salt marshes. They rise into the air as one group at the approach of a vehicle, but quickly settle on the black top again. To them, our extensive fields and parking lots must seem like expansions of their ancestral beaches. Much of the civilized world was created for them.
Laughing gulls are even more entertaining to many people vacationing along the Atlantic and Gulf Coasts in the United States. These gulls nest in salt marshes along the Atlantic and Gulf Seacoasts, and catch crabs, small fish and other little critters from big bodies of water, scavenge dead fish and other animals and pick up edible tidbits discarded by people wherever those food items are found. And these gulls are everywhere along the coast, and inland to some extent, to get those foods, over the water, and on beaches, boardwalks, lawns, streets and parking lots. Many people purposefully feed laughing gulls to watch them hovering into the wind and dropping to the ground to get the foods thrown to them. And all the while, wherever they are, there is the constant laughing cries of these beautiful gulls.
Ring-billed gulls and laughing gulls are small kinds of gulls that are quite adaptable, taking advantage of many food sources almost everywhere between the two species. Look for them, at least on parking lots at the appropriate times of year. They are beautiful and entertaining.
Thursday, August 6, 2015
Reason to be There
My wife and I visited Sunset Beach at Cape May, New Jersey for about an hour on the morning of August 5, 2015. Sunset Beach is where Delaware Bay enters the Atlantic Ocean and, as its name implies, has a broad, sandy beach. Several people were there fishing, walking on the sand and for other activities. We were there to experience the scenery and water birds. There weren't many kinds of birds at Sunset Beach, but they all had a reason to be there.
The first birds we saw were those icons along the Atlantic Seacoast in summer- laughing gulls. They are the abundant gulls with black heads and loud cries that sound like someone laughing. Their young of the year are mostly brown on top, without the black heads.
The laughing gulls at Sunset Beach were everywhere, in the air, on the water trying to catch small fish, and perched on utility poles. But when a gull noticed a tidbit of discarded food on the beach, it dropped quickly to seize and eat it. Gulls, like vultures, obviously watch each other for evidences of food. When one gull abruptly dropped to the beach to get food, other gulls saw that motion and realized food had been found. All gulls within seeing distance flew quickly to the spot to try to get their share, creating entertainment in the process.
We saw three types of terns at Sunset Beach- the large royals with their orange beaks, the tiny least terns with their yellow bills and common terns. Gulls and terns are done nesting by this time of year and have scattered along the shores of larger bodies of water to look for ample food supplies. All the tern tribe fly over the water in search of small fish near the surface. When prey is spotted, they suddenly hover, then dive beak-first into the water with a tiny splash. They catch their finny prey in their bills, rise from the water and swallow their victims whole and head-first.
A few double-crested cormorants were also in Delaware Bay to catch fish. They dive under water from the surface and swim deeper than the terns can dive to catch fish larger than the terns can handle. All that reduces competition for food between terns and cormorants.
We also saw two kinds of shorebirds on the sand at the shoreline at Sunset Beach, sanderlings and ruddy turnstones. Both these species are recently down from nesting on the Arctic tundra. Flocks of sanderlings flew low and swiftly along the beach, and one group trotted over the wet sand at the water line as they looked for invertebrates in the sand and water to eat.
Turnstones in twos and threes wandered over slightly drier parts of the beach to pick up invertebrates. That choice of feeding location reduced rivalry for food with the sanderlings.
While watching the water and beach birds, I noticed many green darner dragonflies, most of them flying north low over the beach like tiny helicopters. They probably were picking off flies and other flying insects as they rapidly moved along. In about a month, these dragonflies, and many others of their kind, will go south for the winter.
Sunset Beach was interesting during the short time we were there. And all the creatures I noticed had a reason for being there.
The first birds we saw were those icons along the Atlantic Seacoast in summer- laughing gulls. They are the abundant gulls with black heads and loud cries that sound like someone laughing. Their young of the year are mostly brown on top, without the black heads.
The laughing gulls at Sunset Beach were everywhere, in the air, on the water trying to catch small fish, and perched on utility poles. But when a gull noticed a tidbit of discarded food on the beach, it dropped quickly to seize and eat it. Gulls, like vultures, obviously watch each other for evidences of food. When one gull abruptly dropped to the beach to get food, other gulls saw that motion and realized food had been found. All gulls within seeing distance flew quickly to the spot to try to get their share, creating entertainment in the process.
We saw three types of terns at Sunset Beach- the large royals with their orange beaks, the tiny least terns with their yellow bills and common terns. Gulls and terns are done nesting by this time of year and have scattered along the shores of larger bodies of water to look for ample food supplies. All the tern tribe fly over the water in search of small fish near the surface. When prey is spotted, they suddenly hover, then dive beak-first into the water with a tiny splash. They catch their finny prey in their bills, rise from the water and swallow their victims whole and head-first.
A few double-crested cormorants were also in Delaware Bay to catch fish. They dive under water from the surface and swim deeper than the terns can dive to catch fish larger than the terns can handle. All that reduces competition for food between terns and cormorants.
We also saw two kinds of shorebirds on the sand at the shoreline at Sunset Beach, sanderlings and ruddy turnstones. Both these species are recently down from nesting on the Arctic tundra. Flocks of sanderlings flew low and swiftly along the beach, and one group trotted over the wet sand at the water line as they looked for invertebrates in the sand and water to eat.
Turnstones in twos and threes wandered over slightly drier parts of the beach to pick up invertebrates. That choice of feeding location reduced rivalry for food with the sanderlings.
While watching the water and beach birds, I noticed many green darner dragonflies, most of them flying north low over the beach like tiny helicopters. They probably were picking off flies and other flying insects as they rapidly moved along. In about a month, these dragonflies, and many others of their kind, will go south for the winter.
Sunset Beach was interesting during the short time we were there. And all the creatures I noticed had a reason for being there.
Sunday, August 2, 2015
Adaptable Bald Eagles, Ospreys and Peregrines
The large and majestic bald eagles, ospreys and peregrine falcons have all greatly increased their numbers in the Middle Atlantic States, as elsewhere, in recent years. They have all made an inspiring comeback. That happened because of a ban on using DDT on fields in the United States, federal and state laws completely protecting these three magnificent raptors, the birds' tolerating human activities and their adjusting to human-made habitats and structures, particularly for nesting.
But I think the most intriguing and, literally, concrete reason for their ballooning populations is their adapting to raising young on human-made structures. Several pairs of bald eagles, for example, build huge nurseries of sticks and twigs on power towers, mostly near larger waterways and built impoundments where they catch live fish and scavenge dead ones. Other pairs of eagles make cradles in large trees near water in farmland, a new environment for them. I think a reason why they nest in cropland is because they scavenge a lot of dead chickens and other farm animals there through the year. Today, more than 250 pairs of bald eagles nest in Pennsylvania alone.
Today, most pairs of ospreys build large stick cradles on human-made objects, including power towers, buoys in rivers and bays, bridges, and platforms erected in large bodies of water especially for ospreys to nest on. Ospreys also snare live fish in their clawed feet by diving from the air and plunging into the water. And they tolerate the presence of human activities well, such as at St. Michaels on the Miles River off the Chesapeake Bay in Maryland, and Stone Harbor, New Jersey.
There are about 150 nesting pairs of ospreys in five clusters in Pennsylvania. Clusters of these stately, fish-catching, nesting hawks include along the Lower Susquehanna River, the upper Susquehanna River, the Upper Delaware River, the Lower Delaware River and the Upper Ohio River.
Many pairs of peregrine falcons today rear offspring on tall buildings in cities in the Mid-Atlantic States, as elsewhere, including in Philadelphia, Allentown and Harrisburg in Pennsylvania and Wilmington, Delaware, and under river bridges at Philadelphia and in Lancaster County, for a few examples. The handsome and solid-bodied peregrines are stream-lined for diving from high in the sky on pigeons, starlings, gulls, ducks and other kinds of birds to kill them for food.
All protected fully by law, these large, diurnal raptors of great beauty and intrigue are also adaptable, making use of human-made habitats and structures to live and reproduce. And through our laws and their adjustments to human activities, they have increased their populations greatly and we get to enjoy their magnificent presence, even in farmland and cities, and around constructed reservoirs. It's a win-win situation for them and us.
But I think the most intriguing and, literally, concrete reason for their ballooning populations is their adapting to raising young on human-made structures. Several pairs of bald eagles, for example, build huge nurseries of sticks and twigs on power towers, mostly near larger waterways and built impoundments where they catch live fish and scavenge dead ones. Other pairs of eagles make cradles in large trees near water in farmland, a new environment for them. I think a reason why they nest in cropland is because they scavenge a lot of dead chickens and other farm animals there through the year. Today, more than 250 pairs of bald eagles nest in Pennsylvania alone.
Today, most pairs of ospreys build large stick cradles on human-made objects, including power towers, buoys in rivers and bays, bridges, and platforms erected in large bodies of water especially for ospreys to nest on. Ospreys also snare live fish in their clawed feet by diving from the air and plunging into the water. And they tolerate the presence of human activities well, such as at St. Michaels on the Miles River off the Chesapeake Bay in Maryland, and Stone Harbor, New Jersey.
There are about 150 nesting pairs of ospreys in five clusters in Pennsylvania. Clusters of these stately, fish-catching, nesting hawks include along the Lower Susquehanna River, the upper Susquehanna River, the Upper Delaware River, the Lower Delaware River and the Upper Ohio River.
Many pairs of peregrine falcons today rear offspring on tall buildings in cities in the Mid-Atlantic States, as elsewhere, including in Philadelphia, Allentown and Harrisburg in Pennsylvania and Wilmington, Delaware, and under river bridges at Philadelphia and in Lancaster County, for a few examples. The handsome and solid-bodied peregrines are stream-lined for diving from high in the sky on pigeons, starlings, gulls, ducks and other kinds of birds to kill them for food.
All protected fully by law, these large, diurnal raptors of great beauty and intrigue are also adaptable, making use of human-made habitats and structures to live and reproduce. And through our laws and their adjustments to human activities, they have increased their populations greatly and we get to enjoy their magnificent presence, even in farmland and cities, and around constructed reservoirs. It's a win-win situation for them and us.
Saturday, August 1, 2015
Dancing on the Ocean
Wilson's storm petrels are interesting little birds that live on the open oceans, including in the northern hemisphere during summer, when they are not nesting. We here in the United States sometimes see petrels off the coasts of the Atlantic Seaboard.
Wilson's storm petrels are abundant and circumpolar around Antarctica in the southern hemisphere during that hemisphere's summertime. An estimated 100,000,000 individuals breed on Antarctic coastlines during summer in the southern hemisphere, when it is winter in the northern hemisphere.
This species of petrels is seven inches long and has a sixteen inch wing span. They are dark brown with white rumps and flanks. And they have tube noses, which means they have one large nostril on top of the beak.
Wilson's storm petrels are the smallest warm-blooded animal that breeds in Antarctica. Each pair nests in a crevice in a rock cliff in great nesting colonies of these birds, near the ocean, on the Antarctica continent. Each female petrel lays one egg per year. Petrels must live several years to raise enough young per pair to make up for losses and to exist in the millions. And they have few predators on those rocky cliffs above the ocean. Unfortunately, however, drifts of snow could cover the petrel's nurseries, killing the young inside.
During their breeding season, petrels shuttle between the ocean to catch small fish, shrimp and other tiny creatures from the water's surface and their burrows to feed those critters to their young under the cover of night to avoid the predation of gulls and skuas. Each bird finds its burrow and youngster by a good sense of smell. Probably day-traveling petrels were caught and eaten by those large, daytime, predatory birds, which meant their chicks also died, without descendants. But those petrels that had been active at night, raised chicks to maturity, which reproduced. Now all petrels are active only at night during the breeding season, because they are descendants of night-flying ancestors.
After the breeding season, and during the summer in the northern hemisphere, millions of Wilson's storm petrels drift north into the North Atlantic Ocean to feed on plankton, tiny fish and detritus on the surface, up to New England on the American side and Europe on the other side of the ocean. Many of them can be spotted from shore at times.
When feeding from the surface of the oceans, these petrels are in great flocks "dancing on the water". Each individual flutters and hovers low over the water, with its long legs dangling to it. Its wings are held aloft or are flapping into the wind or breeze to maintain lift and position just above the water while its pattering feet on the surface tension maintains the bird's stability over the water. All these little birds, together, feeding just over the ocean water, look like dainty dancers.
We see Wilson's storm petrels here in the Northern hemisphere only during summer, and then mostly over the oceans. But their unique way of getting food is interesting to watch from a boat or shore while they are here between breeding seasons.
Wilson's storm petrels are abundant and circumpolar around Antarctica in the southern hemisphere during that hemisphere's summertime. An estimated 100,000,000 individuals breed on Antarctic coastlines during summer in the southern hemisphere, when it is winter in the northern hemisphere.
This species of petrels is seven inches long and has a sixteen inch wing span. They are dark brown with white rumps and flanks. And they have tube noses, which means they have one large nostril on top of the beak.
Wilson's storm petrels are the smallest warm-blooded animal that breeds in Antarctica. Each pair nests in a crevice in a rock cliff in great nesting colonies of these birds, near the ocean, on the Antarctica continent. Each female petrel lays one egg per year. Petrels must live several years to raise enough young per pair to make up for losses and to exist in the millions. And they have few predators on those rocky cliffs above the ocean. Unfortunately, however, drifts of snow could cover the petrel's nurseries, killing the young inside.
During their breeding season, petrels shuttle between the ocean to catch small fish, shrimp and other tiny creatures from the water's surface and their burrows to feed those critters to their young under the cover of night to avoid the predation of gulls and skuas. Each bird finds its burrow and youngster by a good sense of smell. Probably day-traveling petrels were caught and eaten by those large, daytime, predatory birds, which meant their chicks also died, without descendants. But those petrels that had been active at night, raised chicks to maturity, which reproduced. Now all petrels are active only at night during the breeding season, because they are descendants of night-flying ancestors.
After the breeding season, and during the summer in the northern hemisphere, millions of Wilson's storm petrels drift north into the North Atlantic Ocean to feed on plankton, tiny fish and detritus on the surface, up to New England on the American side and Europe on the other side of the ocean. Many of them can be spotted from shore at times.
When feeding from the surface of the oceans, these petrels are in great flocks "dancing on the water". Each individual flutters and hovers low over the water, with its long legs dangling to it. Its wings are held aloft or are flapping into the wind or breeze to maintain lift and position just above the water while its pattering feet on the surface tension maintains the bird's stability over the water. All these little birds, together, feeding just over the ocean water, look like dainty dancers.
We see Wilson's storm petrels here in the Northern hemisphere only during summer, and then mostly over the oceans. But their unique way of getting food is interesting to watch from a boat or shore while they are here between breeding seasons.
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