Shifting feeding grounds bring shorebirds closer

Bruce Di Labio photo Our largest swallow, the purple martin is a cavity nester and is famous for using multi-dwelling birdhouses. During a banding session on July 6, purple martins were feeding their young dragon flies.

Bruce Di Labio photo Our largest swallow, the purple martin is a cavity nester and is famous for using multi-dwelling birdhouses. During a banding session on July 6, purple martins were feeding their young dragon flies.

Water levels continue to be high along the Ottawa River and, as a result, many shorebirds have been forced inland to more suitable feeding habitat. A case in point being the Carp River, where water levels have been receding and exposing highly desirable mudflats. As a result, four species of southbound shorebirds took advantage of this rich feeding area along the river in Carp early this week. On July 7, two lesser yellowlegs, one greater yellowlegs, two solitary sandpipers and two least sandpipers were found as they fed in the flooded farm fields along the edge of the river. The Carp River has also attracted a number of wetlands species including Virginia rail, sora, common gallinule, marsh wren and the rare least bittern. A visit on July 10 produced nine great blue heron, two green heron, one great egret and two upland sandpiper flying over the field. I’d recommend checking any recently flooded areas as shorebirds will be looking for good feeding grounds.

Locally, the birding has been picking up with a number of interesting observations. A flock of three adult sandhill cranes were found on July 7 by David Hinks. These cranes were feeding in a field in the Marathon Village area. Along Upper Dwyer Hill Road near Panmure Road, two upland sandpipers were observed along with a small number of bobolink and eastern meadowlarks. On July 2, Dan Brunton found a singing male cerulean warbler and a yellow-throated vireo near Ferguson Lake north of Calabogie. These birds were still present on July 9 and observed by Ray Holland. Outside of the Chaffey’s lock area, the cerulean warbler is rare in eastern Ontario.

We are now in the “overlap” season where birders can witness both breeding season as well as signs of the beginning of fall migration. While some shorebirds have started their southbound migration, the cedar waxwing and American goldfinch for example, are just beginning to nest whereas other species like the American robin and eastern bluebird are finishing up with their second brood. In another week, the first warblers will start migrating including the yellow warbler and northern waterthrush. Watch for swallows flocking on hydro or fence lines as they prepare for migration. You will notice this behaviour along back roads where barn swallows, tree swallows and bank swallows have typically been nesting.

One of the most unusual stories reported this past week was from Christine Chesterman. While sailing from Toronto to Kingston, a tiny owl landed on the riggings just before sunrise on July 4. Since the ship was well off the shores of Port Hope, it was obvious this bird was lost and desperate for a parking spot to rest. Christine determined it was juvenile plumaged northern saw-whet owl. Amazingly, this tiny owl spent the next 12 hours aboard the 110-ft-tall ship perched on the riggings. During its stay, the saw-whet sat quietly and was not phased by the activity on board. Once docked in Kingston, the owl finally ‘jumped’ ship at nightfall. The northern saw-whet owl is a scarce breeder in eastern Ontario. The juvenile plumage is only retained for a short period of time after the bird has left the nest. The juvenile plumage is very striking with chocolate-brown on its head and back and under parts a pale brownish or cinnamon-buff. The eyebrows, forehead and lore’s are white, forming a pale “X” on its dark face. Christine definitely had a rare sighting of this unique plumage. In more than 45 years of birding, I have only seen the northern saw-whet owl in juvenile plumage once.

Another interesting report this past week came from Lee Harper of Massena, N.Y., who has been monitoring and banding common terns along the St. Lawrence River for the past 24 years. Between Cornwall and Morrisburg, he has noticed a significant decline this summer in the nesting population of common terns from 920+ nests in 2012 to 720+ nests in 2013. Harper reports that the peregrine falcon and great horned owl are depleting the population and has captured this on video. There has been a recent increase in the peregrine falcon nesting population in eastern Ontario and peregrines are nesting along the St. Lawrence River. The once endangered peregrine falcon has recovered well since the days of DDT in the ’60s and early ’70s.

I received a number of emails from readers after last weekend’s inquiry regarding ruby-throated hummingbirds. Reports were received from Chelsea, PQ, St. Albert, Eganville, North Gower and Ottawa. Most reported that their ruby-throated hummingbirds were doing well and have been regulars at the feeders since mid May.

The first session of purple martin banding was well attended and 59 babies were successfully banded. This is down from previous years when usually 100 to 200 babies are banded on the first day. With the population of adults remaining constant, it appears some animal may be preying on the nestlings. For those interested in bird banding, the second session for banding purple martins will take place Saturday, July 13, starting at 9:30 a.m. at the Nepean Sailing Club, 3259 Carling Ave. Join Peter Huszcz for this interactive and educational experience, especially for youngsters.

Send bird observations and/or photographs to bruce.dilabio@sympatico.ca with subject line: “Ottawa Citizen Birds.” Please provide date, location and photographer’s name. The birding Code of Ethics and guidelines of the Ottawa Field-Naturalists’ Club can be found at http://www.ofnc.ca/birding/Code-of-Conduct.pdf and to reach the Wild Bird Care Centre for orphaned and injured birds, call 613-828-2849. Report bird bands to http://www.pwrc.usgs.gov/BBL/bblretrv/

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100,000 Purple Martins roost in Austin near Highland Mall

Purple Martins roost near Highland Mall. Courtesy of KVUE News

Purple Martins roost near Highland Mall. Courtesy of KVUE News

Swooping high up in the sky as the sun sets over Austin, Purple Martins swell in numbers, putting on a display for more than a hundred bird enthusiasts at Highland Mall.

“They are the fighter jet of the bird species,” said Danny Sinclair, who owns a business called “Purple Martin Propagators.”

His company makes Martin houses you may have noticed around town for the birds to nest in.

“We make our cavities look like bottleneck gourds,” he explains, which is an ideal nesting shape for the Martins.

Nestled in the background of the Austin skyline is a Purple Martin sanctuary filled with Sinclair’s gourds off Barton Springs.

“We have 15 poles here, which will accommodate approximately 160 nests,” said Gardner Sumner, who visits the nests three or more times a day.

“I really get a lot of pleasure out of doing what I can for these creatures, they’re truly remarkable.”

But Purple Martins purpose goes far beyond flying. Sinclair explains: They’re extremely valuable as a means of insect control.

“Anything that’s flying, house flies, gnats, wasps, crickets, grasshoppers, beetles: It’s food for a Purple Martin.”

So as tens of thousands of Martins prepare to roost at Highland Mall the rest of the month before flying to Brazil, watchers of all ages gather to celebrate these aerial acrobats.

Source: austin.culturemap.com

Scientists study effect of climate on purple martins

Chuck Fullmer and the purple martin houses he has at his business near Harbeson.

Chuck Fullmer and the purple martin houses he has at his business near Harbeson.

REHOBOTH BEACH — In a suburban backyard near Rehoboth Beach, Carlton Updyke’s colony of purple martins is thriving.

The same is true of Chuck Fullmer’s colony – along a commercial strip off Del. 5 southeast of Georgetown.

But for martin landlords further north in Pennsylvania, the picture is less robust and some researchers believe that as we experience earlier springs – a possible impact from a changing climate – there may be a mismatch between the time when insects hatch in huge numbers and the arrival of insect-eating birds like purple martins.

“There’s a disconnect and it’s getting bigger,” said Nanette Mickle, a purple martin researcher who maintains a research martin colony in northern Virginia and has been working with a team of scientists to figure out what is happening with martin populations to the north. “Our northern birds cannot keep up with climate change.”

Martins are flying insect eaters. They are completely dependent on human landlords for nesting sites east of the Rocky Mountains so folks like Updyke (who also maintains nest sites at Rehoboth Beach Yacht and Country Club and Delaware Seashore State Park) and Fullmer, along with dozens and dozens of other folks in Delaware, play a part in keeping the population stable and growing here.

The state’s most recent Breeding Bird Survey indicates an increase both in population and distribution, probably because of state residents installing nesting houses to attract colonies, said Anthony Gonzon, with the state Breeding Bird Survey.

It hasn’t always been this way, according to the Purple Martin Conservation Association. Back some 12,000 years ago, before human settlement, martins probably nested in abandoned woodpecker nesting chambers or other tree cavities. Then, Native Americans started putting up nesting gourds to attract the birds.

The martins likely thrived being closer to people, with the added protection from predators and a bounty of nesting spots.

In return, the martins arrive on a regular schedule each spring, set up nesting in houses or gourds and take a bite out of flying insects. Contrary to popular belief, they aren’t big mosquito eaters. But they do eat lots of other flying bugs.

Because of their diet, weather can be a big factor. If it rains for several days in a row and insects aren’t flying, martins can starve. If it gets too hot, the baby birds can perish.

Purple martins on one of Chuck Fullmer's colonies. / GARY EMEIGH/ THE NEWS JOURNAL

Purple martins on one of Chuck Fullmer’s colonies. / GARY EMEIGH/ THE NEWS JOURNAL

Last summer, Fullmer hand-fed one of his baby birds to keep it alive through a summer heat wave. That spring and summer were among the warmest and earliest on record for the Mid-Atlantic region.

A study by the U.S. Geological Survey looked at last spring and the impact it had on everything from flowering plants to animal life cycles. Spring came as much as 20 to 30 days early in the East and Midwest last year, according to the USGS report.

But purple martins don’t base their migration on temperature or weather patterns. Instead, Mickle said, they migrate based on daylight and day length.

Mickle is part of a research team that outfitted martins with geolocating “backpacks,” small devices that record daylight and length over the course of the year.

Last year, the migration of the birds was out-of-sync with the bloom of plants and insects, she said, especially in areas to the north.

In a newly published study, the research team that Mickle is a part of found no evidence that purple martins adjust their migration to adjust for warmer temperatures in their breeding areas.

The team is now looking for genetic variations in the birds to see if migrants that go to more southern breeding areas may be more adaptable to changing climate and weather conditions than their northern-migrating relatives, Mickle said.

The northern population decline isn’t new, she said. Initially, researchers thought the problem might be some environmentalchange on the wintering grounds. Martins migrate in the late summer and fall to Brazil and then return to the Atlantic Coast in the winter and spring.

“They basically came up with nothing,” she said.

Meanwhile, populations are stable in places like Delaware but declining in Pennsylvania. with dramatic declines in parts of Canada, she said.

With the geolocators, the team has learned lots of new things about the birds. One of Mickle’s birds, for instance, left northern Virginia and was in the southern tip of Florida – 900 miles away – in one day.

“It traveled at night” something we didn’t know these birds did before the geolocating work began.

Fullmer has found the ideal location for a martin colony at his business, Pontoon Express, off Del. 5. The birds seem to like open areas.

He said that it can take a couple of years to establish a colony but once you get 10 to 12 pairs “you’ve got a solid base . . . getting to that point is tricky.”

By mid-August, the birds start to converge along telephone lines as they stage for their southern migration and Updyke takes down his houses in preparation for hurricane season.

His advice to people who want to try being martin landlords is to be patient but he has one other recommendation.

“You must be willing to control house sparrows and starlings,” he said. “Otherwise there’s no need in even trying.”

Purple martins
SIZE: Smaller than a robin, larger than a tree swallow.

APPEARANCE: Males are iridescent, dark purple; females are more drab with gray flecks on head and chest with a white lower belly.

HABITAT: Nesting in colonies, they favor open habitats near water.

• European starlings and house sparrows are common threats to purple martins. They take over nest sites.

• Purple martins converge and roost in late summer – after chicks have left the nest – this roosting behavior occurs in advance of southward migration. A major roosting spot is the old Manns Harbor Bridge just west of Manteo, N.C. in the Outer Banks. In Delaware, birds begin to flock and roost at utility lines along Del. 1 at Delaware Seashore State Park.

• The spring early birds are often referred to as “scouts.” People used to think they returned to make sure an area was safe for nesting. But in reality, they are older martins returning to the place where they have nested before.

• Martins get all their food in flight. To drink, they skim the surface of ponds, pools and other water sources.

• The story goes that martin houses were so common that artist and ornithologist John James Audubon figured out where he would stay the night on his travels based on the quality of the martin house in the yard.

• Purple martins spend the winter in open, grassy areas and agricultural fields of South America such as Brazil and Bolivia.

• At night, they flock to cities and towns to roost in trees of village plazas.

To learn more about martins go to The Purple Martin Conservation Association website at purplemartin.org

Source: www.delmarvanow.com

Birds migrating at wrong time for warmer climate

The purple martins were tracked using a tiny geolocator attached to them via a little 'backpack.' (Nanette Mickle)

The purple martins were tracked using a tiny geolocator attached to them via a little ‘backpack.’ (Nanette Mickle)

Some songbirds can’t alter their migration schedule to take into account earlier, warmer springs as a result of climate change, and that could be deadly, Canadian researchers say.

The researchers, led by ecologist Kevin Fraser at York University in Toronto, reached their conclusion after tracking purple martins, members of the swallow family that range as far north as southern Canada, all along their spring migration route of more than 7,000 kilometres.

The results of the study were published in the journal PLoS ONE.

Fraser and his colleagues found that two populations of birds that their research team was tracking took off from their wintering grounds in Brazil’s Amazon Basin for their breeding sites in the northeastern U.S. at the same time every year for five years in a row, no matter what the temperature was like at both their summer and winter homes.

Record high spring temperatures at their breeding grounds in 2012 didn’t break the pattern.

“There wasn’t really any difference in what they did in the really warm year compared to other years,” said Fraser in a phone interview Monday afternoon from Texas, where he is in the process of tagging a southern population of purple martins.

Fraser said that means the martins likely arrive at their breeding grounds “too late,” after the spring population of the insects they eat has peaked and started to decline, and the reduced food supply could hamper their ability to breed successfully.

Songbird populations falling
Populations of many songbirds have fallen drastically in North America since the 1960s — more than 75 per cent in the case of some species, such as the rusty blackbird, the olive-sided flycatcher, the Canada warbler, the American black duck and the evening grosbeak. A variety of factors may play a role, including habitat destruction and climate change.

Currently, purple martin populations are declining by three to four per cent per year in the northern part of their range, around the Great Lakes, said Fraser, a postdoctoral researcher working with Bridget Stutchbury, a York University ecology professor who co-authored the paper.

Some scientists have suggested that an increasing mismatch between the birds’ migration times and the start of spring may be to blame. European studies show insect populations have been peaking earlier and earlier each year, and that places where the peak happens earliest are where populations of migratory insect-eating birds called pied flycatchers were declining the most. The flycatchers did not appear to migrate earlier to compensate.

Fraser and his team wanted to see if they could get more direct evidence about the timing of the spring migration of purple martins in relation to spring weather conditions all along their 7,300-kilometre migration route.

Fraser said there is some evidence that certain weather patterns in the Amazon and the northeastern U.S. are correlated. He wanted to see if individual birds could respond to those cues, or perhaps change their migration speed in response to conditions along their route.

Tracking backpack
In order to find out, he and his colleagues captured purple martins at their breeding sites and attached tiny tracking devices to their backs using a little “backpack,” starting in 2008. The devices log light levels, providing data about latitude from the timing of sunrise and sunset, and data about longitude from the timing of the solar noon, which varies with longitude. Studies show that the backpacks do not appear to affect the birds’ ability to fly, breed or survive.

In 2012, the researchers managed to recapture 52 purple martins that had been tagged in Erie, Penn., and Woodbridge, Va., and to retrieve the tracking devices, with their data. They then matched the tracking data with data from weather stations along the route to find out what conditions were like as the birds flew by, and compared it to data from previous years.

Fraser said he was surprised to find that the birds did not seem to respond to temperatures or rainfall.

“I thought there would have been some climate signal somewhere along the route,” he said. “I thought … that if they found warmer temperatures, they could pick up the pace a little bit.”

The findings suggest that individual purple martins can’t compensate for short-term changes in the timing of spring, unlike species with shorter migrations, such as tree swallows.

Fraser said purple martins and the dozen or so other songbirds in North America that migrate to very distant wintering sites “might be particularly at risk with changes in climate because they’re further away and less likely to get the signals they might need of changes up north.”

Scientists expect that natural selection will eventually cause the birds to shift their migration times, but Fraser said that so far, that’s happening too slowly.

“It could take lots of generations of birds,” he added, “and if they’re declining at such a strong rate, ‘Will that be too late?’ is the question.”

source: cbc.ca

Early spring doesn’t bring early birds, Canadian research shows

Purple martins populations in northern regions are in decline, possibly because the birds have been slow to adapt to the ever-earlier arrival of spring. (Photograph by: Craig Cunningham , THE CANADIAN PRESS )

Purple martins populations in northern regions are in decline, possibly because the birds have been slow to adapt to the ever-earlier arrival of spring. (Craig Cunningham , THE CANADIAN PRESS )

OTTAWA — The spring of 2012 was the earliest on record, shattering heat records across Eastern North America. But many common songbirds didn’t migrate early to take advantage.
Locked into a schedule that doesn’t change, they missed the best breeding time, raising questions about whether they will adapt to a warming world.

“What’s new is that Mother Nature did a fabulous experiment, giving us a window into how birds might or might not respond to dramatic shifts in weather patterns,” said biologist Bridget Stutchbury at York University.

“It’s the sort of experiment that you can’t conduct by yourself, or plan ahead of time.”

Purple martins migrate to Brazil and back. Stutchbury’s group tied tiny “geolocators” tracking individual bird’s movements during migration.

Spring of 2012 was “ridiculously warm,” she said. Ottawa, for instance, had a string of days with highs in the upper 20s in March.

Leaves came out early and insects hatched early, creating the perfect breeding environment for songbirds.

But the birds didn’t come. Instead they waited for the normal departure time from Brazil, arriving after their food supply of insects had passed its peak.

“They spend a month just non-stop feeding their kids, and the number of kids they produce is directly limited by how much food there is,” Stutchbury said.

As the northern hemisphere has a series of early springs, “there’s a mismatch between when the birds breed and when the food is available, and so there’s a real cost in not getting back (to Ontario) early.”

And she and co-author Kevin Fraser feel that some martins are genetically more early birds than others, passing down their preference for slightly early or late migration through generations. If so, it could take many decades for the bird population to adapt, as the early birds gradually produce more offspring in a series of warmer springs, and the genetic pattern of the martin population shifts.

But if the birds can learn to adapt, the pattern might change in just a few years.

Purple martins are in the swallow family.

Northern populations of martins and other insect-eaters are declining whereas the same species are doing fine in Texas and Arkansas, she said.

She says the new research provides evidence that an inability to adapt to early springtime in the north is one reason.

There has been one other quirk of nature to study since last year’s warm spring. Huge numbers of cicadas have emerged in the eastern United States this spring, an event that comes once every 17 years.

“They’re seeing the fattest purple martins ever,” Stutchbury said. “It’s like eating at McDonald’s all day every day.”

source: ottawacitizen.com

Many Connecticut Bird Species Declining In Population

black-crowned night-heron

This black-crowned night-heron found in New Jersey won an honorable mention in last year’s Great Backyard Bird Count. (Credit: Chandra Jennings/Great Backyard Bird Count)

The Connecticut Audubon Society has issued its annual report on the state of birds in the Northeast – specifically Connecticut.

As WCBS 880’s Fran Schneidau reported the Audubon Society’s findings this year about the state of birds in Connecticut is not good.

“This whole group of birds, swallows, swifts, et cetera, are declining and we don’t know why,” said Milan Bull of the Audubon Society. Continue reading