‘Tis the season

Since we are now in the peak migration period for Broad-winged Hawks in the northeast, I figured I’d share some videos I took this afternoon at the Quaker Ridge Hawk Watch in Greenwich, CT (over 6000 were seen there today). Broad-wings migrate in large groups, often forming “kettles” of swarming, swirling birds. Quite a sight!

Make sure you watch FULL SCREEN in HD for maximum effect!

(Be sure to also see Part One of this post.)

A spectacular Matinicus Rock sunset, with Moe's tower on the right.

If one visited Matinicus Rock during the day, finding evidence of Leach’s Storm-Petrels (short of checking burrows) would be hard to find. At night, though, Leach’s calls sometimes fill the air. We checked a plot of storm-petrel burrows on three occasions to assess the number of chicks fledged per nest (called productivity).

One night I walked down the boardwalk, recording with my phone. Almost immediately you’ll here a close storm-petrel, followed by some ones further away. Also notice a lot of Arctic Tern and Laughing Gull noise–and of course, the foghorn. Listen to some Leach’s Storm-Petrel calls.

The storm-petrel chicks are probably one of the cuter things in the world.

As I mentioned in Part 1 of this post, Manx Shearwaters nest on the island in small numbers, too, making Matinicus Rock the country’s only known breeding location for these birds (there are more in the Canadian Maritimes and off of western Europe). We used infrared cameras to detect activity in possible shearwater burrows, but shearwaters could also be heard calling on dark nights.

One night, I recorded a Manx calling in the distance. The bird starts after the first foghorn blast (at about 0:09) and continues for six seconds. It sounds like low, deep, labored breathing. Listen to a Manx Shearwater.

An infrared camera in position above a possibly active burrow.

Terns, shearwaters and storm-petrels are not all that Matinicus Rock has to offer–in fact, it’s much better known to be an alcid island. Razorbills, Atlantic Puffins, and Black Guillemots all nest on the island in numbers.

One of many charismatic Black Guillemots.

A Black Guillemot chick!

A guillemot showing off its red feet.

A guillemot with a rock eel, a major component of their diet.

Common Murres, while not island breeders, often hang out on the north end of the island.

Razorbills, though, are one of the island’s most interesting colonial nesters. Unfortunately, they nest early, so by the time I arrived in late July the Razorbill chicks had all fledged. Luckily, many were still hanging around during that time, though they had all but vanished when we left Matinicus Rock in mid-August.

Razorbills congregated at sunset strip, these with some puffins and a murre.

The real stars of the island, though, were the Atlantic Puffins.

Puffin with a mackerel.

We tried to recapture a puffin with a geolocator that had been affixed last year--and, although he sat right next to our box trap, he never stepped up.

A few second-year puffins were around.

Part of the work we did with puffins was resighting their bands. This consisted of sitting in blinds and finding close puffins with visible bands–then reading and recording them to note puffin presence and movement.

We “grubbed” over 200 puffin chicks this year–that is, we took them out of their burrows to band. Grubbing is sometimes a challenging process, taking strategy, skill, creativity, and determination.

A puffin chick, just asking to be grubbed.

Grubbers, the tools of the trade. Each grubber (one small, four large, and one supergrubber) has a small hook at the end that we can snag on a chick's leg to coax them to within reach. Puffins' legs grow very quickly and are very sturdy; no birds were ever hurt during the grubbing process.

The monstrously long supergrubber comes in handy with those hard-to-reach chicks.

A three-person grub in progress. We got the chick.

Burrow 591 with chick, "General Santa Anna" (we name all the chicks), barely visible in the back. This would be a job for the supergrubber.

The "complex". Lots of chicks to grub inside!

Another successful grub in the works. I got this one in the end!

We found a couple pairs of small alcid wings on the island as well, having apparently been killed by a Peregrine Falcon, probably this past winter. The wing chord, at 114 mm, fits perfectly for Dovekie!

We did have a chance to go off-island for a boat trip. A great boat trip, as it turned out.

A group of Great Shearwaters.

Great Shearwater.

Northern Gannet.

We saw a number of jaegers from the island and a couple from the boat.

Our target--Troppy, the Red-billed Tropicbird! This bird has summered in the area for years.

Troppy flew right over us!

Common Eiders nest on Matinicus Rock in addition to the other seabirds.

Another great sunset from the Rock.

And on our last day, we were treated by a brilliant Prothonotary Warbler!

(Be sure to also see Part Two of this post.)

I just returned from three weeks on Matinicus Rock, in Maine’s Penobscot Bay. About twenty miles off the coast of Rockland, the 23-acre Rock is home to a diverse array of breeding seabirds, including Atlantic Puffins, Razorbills, Black Guillemots, Arctic and Common Terns, and Leach’s Storm-Petrels. Matinicus Rock is also the only known breeding location of Manx Shearwater in the United States. I had the privilege of working with these species with others from the Project Puffin Seabird Restoration Program. It was a great experience.

Matinicus Rock is home to a historic 19th-century lighthouse and light tower, a boat house, and the one-room Audubon house. The house has no running water or plumbing–though, of course, there is a fast internet connection. Drinking water comes in jugs from the mainland, and there’s a rainwater cistern under the house for washing dishes, clothes and hands. Electricity good enough to power lights and small devices (no large refrigerators, for example) comes from a few solar panels out front. There’s a propane stove and small propane fridge. Oh, and the foghorn sounds every fifteen seconds and is loud enough to be heard for three miles.

The light house and light tower.

When I arrived on July 20th, tern work was starting to wind down. We stumbled across the occasional young chick, but the majority of the surviving progeny were approaching fledging age. Over 800 pairs of Arctic and 200 pairs of Common Terns were present on the island this year.

Common Tern. Notice the black-tipped long-ish bill, black cap with considerable white above gape, dark "wedge" in outer primaries due to molt, and lack of long tail streamers (all points to compare with Arctic).

Common Tern, again.

Commons also show a sizable black trailing underwing edge to the primaries.

When perched, the dark outer primary wedge is visible. One can easily see the newer, lighter inner primaries, and the older (4) outer primaries.

The size of the wedge can vary, though. This bird shows five dark outer primaries. Notice also the length of the tarsus (from the "knee" to the foot) on Common Tern.

Part of the tern work consisted of 3-hour feeding stints, during which we recorded all of the feedings that took place–including the time it occurred, the type and size of fish, which chick it was fed to, and which adult performed the feeding.

A tern plot. Each numbered stake corresponds to a nest, and (in most cases) a chick or two.

Common Tern carrying a mackerel.

Common Tern with a pollack.

Common Tern with a snipefish.

Common Tern with a sand lance.

Common Tern attempting to feed a butterfish--a fish that many chicks can't swallow. When butterfish makes up a large portion of tern diet, the chicks don't do very well.

Common Terns often dive-bombed us, while the Arctics were a bit less aggressive.

Arctic Tern. Notice the completely red bill, the smaller white space between cap and gape, and the long tail streamers.

Also notice the uniform upperwing on Arctic.

And, importantly, the thin trailing edge to the outer wing, instead of Common's thick edge.

Also see the short legs and the lack of newer primaries (Arctics always molt all their primaries before migrating north in spring).

Arctic Tern with a...larval lobster?

Juvenile Arctic Tern.

Young Arctics share the thin black trailing edge under the primaries.

And Arctic juveniles have light secondaries.

Common Tern juveniles are generally browner on top with more orange, larger bills, and darker secondaries.

(And, of course, the thicker dark trailing edge to the primaries.)

Also interesting were subadult terns. I noted a couple first-summer Arctic Terns (all in the inter-tidal zone), and several presumed second-summer Common Terns up in the colony, but I couldn’t confirm any were actually nesting.

First summer (second-year) Arctic Tern.

Apparent second-summer Common Tern--with white speckling in crown and remnants of a carpal bar.

A similar-aged Common Tern.

Another presumed second-summer Common with more white in the crown.

Sunsets on the Rock were spectacular, with each day a new variation.

Go to Part Two.

Costa Rica

For eleven days in mid-April, I had the opportunity to travel to Costa Rica with a group from my school. The goal was to have some fun and improve our spanish-speaking skills, but, of course, there were more important things to do: find birds!

We arrived at JFK around 2:30 AM, and by 5 PM we were in Monteverde, up in the Costa Rican mountains. After enjoying the cloud forest for a couple of days, including ziplining above the canopy and hiking around after dark one night, we moved on to Manuel Antonio, along the Pacific coast. Nicoya, on the Nicoya Peninsula (one of the warmest spots in Costa Rica–highs in the high 90s F) was our home for a few more days. Afterwards, we went back up into the mountains for spectacular looks at Arenal volanco, and not-so-good looks at the fog covering Poas volcano. Then it was back to San José for our flight out. Below, some pictures!

Rufous-collared Sparrow is a relatively common species of higher elevations.

Streak-headed Woodcreeper in Monteverde

The tail of a sleeping Orange-bellied Trogon on our night hike.

Purple-throated Mountain-Gem at the Monteverde feeders, a species endemic to CR and w. Panama.

The blurry form of a sleeping Wood Thrush, taking a well-deserved rest en route to North America.

A porcupine, definitely NOT sleeping!

Green-crowned Brilliant at the Monteverde feeders.

Blue-crowned Motmot in heavy cover at Monteverde.

Emerald Toucanet

Rufous-capped Warbler

Keel-billed Toucan, a lucky spot!

A pair of Scarlet Macaws at the Rio Tárcoles, an even luckier spot!

Capuchin monkeys in Manuel Antonio.

A two-toed sloth peers down from the treetops.

A beautiful Golden-hooded Tanager in Manuel Antonio.

A Plain Xenops in Manuel Antonio.

Superb views of an Ornate Hawk-Eagle devouring an iguana.

Orange-chinned Parakeets

Yellow-green Vireo in Nicoya.

Great Kiskadee in Nicoya.

Tropical Kingbird in Nicoya.

Roseate Spoonbill takes flight in Palo Verde.

This Whimbrel seemed out of place in the mangrove forests which are its home when not in North America.

There were tons of reptiles around, of course.

Common Black-Hawk (Mangrove subspecies)

A Mangrove Swallow, another resident of the mangrove forests.

Another iguana-type reptile (ID anyone?)

Birds weren't the only flying creatures around...

An awesome-looking bird, the Boat-billed Heron.

One of my favorites on the trip: Turquoise-browed Motmot in Nicoya.

The omnipresent Clay-colored Thrush.

Scaly-breasted Hummingbird near Arenal.

Spectacular views of Arenal volcano (click to enlarge!!!)

Another cool-looking bird, Common Tody-Flycatcher.

Green Honeycreeper, an electric turquoise-colored bird.

Toucan sweep! This one is a Chestnut-mandibled Toucan.

A common, but interesting bird, the Blue-gray Tanager.

Closer views of Great Kiskadee at Arenal.

One member of a troop of howler monkeys (congos, en español).

A Montezuma Oropendola leaving its nest--this species has an otherworldly call.

Superb looks at this male Green-breasted Mango marked our departure from Arenal.

There are many more photos, but there’s not room for all 1100 of them!

Croton Cackler

Yesterday afternoon (2/27) I stumbled across a Cackling Goose at Croton Point in Croton-on-Hudson, NY. While this species is more regular in New York State to the southeast of Croton (i.e., Long Island), this is a fairly good record for Westchester County–there are no prior county records on eBird, and, as far as I can tell, only two previous official county records (both from 2007).

Cackling Goose (center) with Canada Geese. A much smaller bird overall, with a stubby beak, shorter neck, and lighter back coloration (hard to see in this photo).

I watched the bird from the south side of Croton Point Park, as it slowly swam west in Croton Bay with a group of seven Canadas. Hopefully, it reappears!

Audio Quiz!

Put your ID skills to the test with this brief bird sound quiz! (Don’t worry, it’s not a songbird flight call.)

CLICK THIS LINK to hear the sound (20 seconds, 1 MB).

And here’s the spectrogram (an excerpt), just because I think it’s a really cool one:

This was recorded pre-dawn on 10/31/10 in Rye, NY. There is only one species in the recording. Feel free to answer in the comments!

(Oh, and if you are one of the couple of people to whom I’ve shown this recording, don’t answer please :).)

Good luck!

Cape May Warbler flight call from Rye, NY on 9/10/10.

Flight calls. Exceedingly short, often similar-sounding, most easily heard in the wee hours of the night–and present in substantial numbers during only a handful of nights per year. Sure, the idea is interesting: the ability to “tune in” to birds migrating overhead at night by listening to the calls they utter. But there is a notoriously steep learning curve for anyone who dares to delve further. No wonder many birders shy away from these vexing vocalizations that last–at most–two-tenths of a second.

So why bother? There are more reasons than one might think. Often we settle for the results–the aftermath–of a good migration night. Perhaps our local birding spot has some new arrivals, or a rarity is reported nearby. But rarely do we have the opportunity to experience thousands of birds pouring overhead, many of which may end up hundreds of miles away by daybreak. Sometimes, well-placed floodlights on skyscrapers can help. But in most other cases, flight calls can provide this window onto migration–both recreationally, and as a powerful tool to learn more about the species that do call.

One of my favorite aspects of listening to flight calls is the ability to hear species that are normally cryptic or hard to find. Catharus thrushes are great examples of this; whereas a lucky observer at a migration hotspot might find only a handful of thrushes during a good morning, call counts in the hundreds during good migration nights are not uncommon. It’s conceivable (though unlikely) that six North American thrush species could all be heard along the Atlantic coast on the right night in mid-September!

Swainson's Thrush flight call from Katonah, NY on 9/11/10.

Audio: Swainson’s Thrush flight call from Katonah, NY.

Veery flight call. Rye, NY on 9/10/10.

Audio: Veery flight call from Rye, NY on 9/10/10.

Routinely recording flight calls, in addition to allowing one to hear calling events at a convenient time, can provide important data about migrants that do call–from the migration timing of certain species to changes in relative abundance over many years. Acoustic monitoring can also shed light on which species use different areas for migratory stopovers during the day.

Three "whip-poor-will" calls. 8/26/10 in Rye, NY. This bird was not flying over the microphone, but if we had not been recording, we would not have known it had chosen Rye as a place to stay--this was recorded before 6 AM!

Audio: Whip-poor-will in Rye, NY.

Dickcissel flight call from October '10 in Rye, NY. Recorded flying over the microphone in the early morning hours (in daylight).

Audio: Dickcissel flight call (calls 3 times in recording).

Plus, there’s always the chance that interesting flight calls might be detected. Le Conte’s Sparrow is an interesting species–as a grassland bird, it tends to hide in inaccessible areas. Through January 2011, only twelve records of this species in New York State had been accepted. But it has a fairly distinctive flight call: long, high-pitched and descending. And interestingly, in the very limited time I’ve been looking through recorded flight calls, I’ve stumbled upon two presumed Le Conte’s Sparrow calls–one from Danby, NY in October 2009, and one from Rye, NY in October 2010. Is this just coincidence, or is Le Conte’s Sparrow a more common migrant through New York than previously thought? Only time–and more acoustic monitoring–will tell!

Presumed Le Conte's Sparrow flight call. 10/17/09 in Danby, NY.

Audio: Le Conte’s Sparrow flight call in Danby, NY

Probable Le Conte's Sparrow flight call. 10/25/10 in Rye, NY.

Audio: Le Conte’s Sparrow flight call from Rye, NY.

So when is the best time to hear flight calls? Peak migration is usually the best–in the northeast, that’s September in the fall and May in the spring. Of course, birds need to be migrating (northerly winds in the fall, southerly in the spring). And interestingly, although we know from Doppler radar studies that the amount of migrating birds in the atmosphere peaks 2-3 hours after sunset, flight calls peak much later in the night, in the hours before dawn. Why this is–birds forming flocks in anticipation of the day, perhaps–has yet to be determined. But it does mean that you might be better off getting up early, rather than going to bed late, to listen.

The vast majority of flight calls recorded in Rye, NY this past fall occurred in the later hours of the night.

If this has piqued your interest, I encourage you to try listening for flight calls this spring. Purchasing Bill Evans and Michael O’Brien’s flight call guide CD is also a good idea. But it’s really not that hard–don’t feel you have to identify anything–just pick a quiet spot with lots of sky (hills appear better than valleys, and coast better than inland), and listen!