Monday, February 22, 2010

Birding New York Bay

This weekend, Wakako and I went birding in the Upper and Lower New York Bay areas. Saturday we set out for Great Kills Park on Staten Island, while Sunday we visited Coney Island.

On Saturday, we saw some of the best birds right off the bat, while riding the Staten Island ferry. As we pushed away from Lower Manhattan, there was an adult Lesser Black-backed Gull in the modest gull flock. It did not follow the boat and went quickly out of view. The ride itself was uneventful, with very few birds visible from the deck, but close to the Staten Island ferry dock, gull numbers picked up, and a Kumlien's Iceland Gull was our treat here.

At Great Kills, we found many of the winter target species there, like Greater Scaup, Bufflehead, Horned Grebe, Double-crested Cormorant, Red-breasted Merganser, Brant, Boat-tailed Grackle, American Black Duck, Red-tailed Hawk; and Ring-billed, Herring and Great Black-backed Gulls.

Among the more interesting birds there was a Tree Swallow (a species that around here winters coastally in very small numbers) and this cooperative Red-throated Loon. The bird that I had hoped to see - Western Grebe - could not be found. Northern Gannets were also curiously absent.

Saturday night I read online that a Western Grebe had been seen off Coney Island Saturday. Could that have been the same bird that for several years now has wintered off Great Kills on Staten Island? It's 11 km distance as the grebe flies between Great Kills and Coney Island.

Alright, so off we went the next day to Coney Island, in search of this westerner. It would not have been a lifer, but a cool bird to see nonetheless.

And you've probably guessed it: we did not see Western Grebe there. The best sighting there was a group of three Purple Sandpipers on one of the jetties.

Tuesday, February 16, 2010

Ring-billed Gull behavior

Birding can be many things to many people. For some, nothing beats chasing a rarity in their home state. For others, the passion is holding a bird in the hand and studying molt limits. Or it can be witnessing the spectacle of massive bird migration, just being engulfed by huge numbers of birds on the move.

I enjoy all these things, but for me, I think what I like best about birding is observing bird behavior. I like holding a Wilson's Warbler in my hands, blowing its belly to determine body molt and breeding status, or stretching out a wing to look for feather wear, but in the end I find it more interesting to observe that Wilson's Warbler in the wild.

Today I have a sequence showing part of the behavioral repertoire of Ring-billed Gulls. The previous post, also about Ring-billed Gulls, was mostly about plumage. Now I want to focus on behavior.

Today I went back to the same spot where I photographed Ring-billed Gulls a few days ago. This time I brought some bread myself. It didn't take long for the gulls to realize what I was up to, and they posed very obligingly for a morsel of bread. The photos are a bit dark, because it was snowing at the time.

Take a look at the two left birds in the top picture, both adult birds in basic plumage. The bird on the left is out of focus on this first picture, but we can still see the red eye ring and red gape of the mouth, good marks for an adult (3+ years) bird. The next bird - focused - also shows these marks. The time of this photo is 9:51:26 AM, i.e. 51 minutes and 26 seconds after 9 AM.

9:51:28 AM. The left bird has started to move a little closer to its neighbor, which, judging from the way it has retracted the neck and raised the bill, seems to be threatened by that behavior.

9:51:31 AM. Both birds are now engaged in calling, with lowered head posture. The left bird is a bit smudgier on the head than the right, but both have yellow eyes and red eye rings and gapes. In this posture, the head is lowered but the neck is raised. The other birds on the railing seem relatively undisturbed.

9:51:33 AM. Both birds now engaged in a head-toss, while still calling. The BNA account for Ring-billed Gull mentions a study by Southern & Southern (1982) of aggressive behaviors in this species. According to them, the Head-toss is "a single extreme backward toss of the head, given before call terminates."

9:51:36 AM. Both birds still calling, but each bird stretching its neck in opposite direction, possibly to see the other bird better. My impression of their body language is that the light-headed bird appears to be dominant over the dusky-headed bird, but it's hard to know for sure what's going on inside their heads... Note how the birds behind these two are alertly observing this, and that a third bird is also calling.

9:51:39 AM. Our two protagonists are still calling, and the light-headed bird still seems to have the upper hand.

9:51:42 AM. The light-headed bird appears to have established dominance over its neighbor, and seems ready to terminate the aggressive behavior. (Observe also how the unfocused bird in the foreground has barely changed posture during the last five frames, i.e. for 11 seconds. It's just looking down.)

9:51:45 AM. Uh-oh - excitement! One of the birds in the back is taking off, while our dominant bird, still excited, resumes calling. The dusky-headed bird now strikes a very submissive pose, acknowledging the dominance of the light-headed bird.

9:51:55 AM. This is what all the excitement was about: a first-cycle bird landing on the railing and chasing off adults! Generally I would expect older birds to be dominant over younger ones, but this young bird, full of chutzpah, is not afraid to charge his way to what it thinks must be the best seat in the house. It shamelessly landed on a spot where an adult was standing earlier - the bird taking off in the previous photo.

9:51:59 AM. The young bird is moving closer. How will the light-headed adult, with the victory over the dusky-headed adult still fresh in its mind, react to this sudden act of juvenile aggression?

9:52:03 AM. The first-cycle bird is still charging forward. It wants to be as close to the photographer as possible, because it has observed that the photographer has bread in his pockets. Note the feet of a bird in the air in the top right corner: that bird was standing next to the first-cycle bird in the previous photo.

9:52:06 AM. I think - but I am not sure - that the young bird is now chasing away our earlier duo. Both seem pretty much resigned to indulging the younger bird's aggression. They've already seen it chase away three other adults, and figure they are next.

9:52:09 AM. Having cleared the entire railing of conspecifics, this bird is ready for some bread.

Monday, February 15, 2010

Ring-billed Gulls

Today we're taking a closer look at one of the most common, most easily observed North American birds, the Ring-billed Gull. Somebody was feeding these birds yesterday on the Inwood Hill Park Bay, providing me with close range photo opportunities. Practically anyone in North America can easily observe these birds most of the year, and if you've done so extensively, this post is probably not going to show you anything you didn't already know.

It's a three-year gull, meaning the bird goes through three plumage cycles to reach the adult basic (non-breeding) or alternate (breeding) plumages.

This is a first cycle bird. The eyes are dark; the bill and legs are pinkish; the black on the bill hasn't become a ring yet; the majority of the mantle feathers are brown; the tail is white with a broad black band. Some brown juvenal feathers are being replaced by grey second cycle feathers, such as the mantle feathers and tertials.

Same individual. Note the brown smudges all over the head and neck. In winter, first and second cycle birds show such extensive mottling, while adults in basic (winter) plumage show limited mottling on the head. See for example the middle bird in the top picture.

Still the same individual, photographed merely seconds after the previous photo was taken. Plumage-wise we're not seeing anything different, but note how the head shape is subtly different now that the bird is more alert. In larophology, larophiles often stress the shape and structure of the bird, because plumage is so tremendously variable in this family. This may be true, but so is shape!

Here's a head detail of a second cycle bird. The bill now has a ring, and the tip of the bill is already yellow. The proximal part of the bill is now greenish gray. Note that there is considerable variation in coloration of bare parts also, so not every second cycle ringbill is going to show a gray bill in winter.

Same bird. Not only the bill is gray - so is the eye. The spotting on the head and neck seems less than on the first cycle bird, but more than on the basic plumage bird. Although this bird is intermediate in age class, I don't think the intermediate spotting is age-related; I believe it to be rather a function of individual variation. Anyone wishing to correct me on this, please do!

Again the same bird. Note how this second cycle plumage resembles the basic plumage. Two major differences are obvious in this photo: color of bare parts, and absence of white spots in the wings. The birds standing behind the second cycle bird are both in basic plumage, with yellow, not gray legs, and with white spots in the wingtips.

All these birds were photographed 14 February 2010 in Inwood Hill Park, Manhattan. The previously reported ringbill with an auxiliary marker (APP) was still present. I haven't heard back yet where this bird was banded.

Saturday, February 13, 2010

The Beatles Complete On Ukulele

A couple of postings ago I wrote about the shorebird count in El Salvador, now a week ago. During this count, while traveling between sites, we listened to Karla's iPod on the car stereo. She is a huge Beatles fan, and played us the soundtrack of Across the Universe, a 2007 feature film I not only had not seen, but hadn't even heard about. That's what happens when you spend most of your time in the field or 'on the road' as it were.

Karla assured me I "had to see this movie". Meanwhile, we listened to the soundtrack which has Beatles songs performed by other, mostly well-known performers (like Bono). The songs are great obviously, but I wasn't blown away by the majority of the performances. Somehow they didn't seem to eclipse the average tribute band output, and in every case the original version was far superior - more imaginative, more daring, older but just way fresher.

Karla, incidentally, is totally on board for the concept of the tribute album, for she also played us bossa nova versions of the Guns 'n' Roses songbook, as well as bossa nova versions of Bob Marley songs. To my ears these albums were downright gimmicky, and in the case of the Marley, rather distasteful. They were sung by a forgettable chanteuse in a hoarse, whispery voice that was probably meant to sound sexy, but in fact only sounded trashy. They were played by slick studio musicians and - to me, anyway - sounded flat and completely devoid of any humanity or personal warmth. (Sorry Karla!)

All this leads into something I just found today and feel compelled to share with the rest of the universe via this blog, namely The Beatles Complete On Ukulele. That too sounds very gimmicky of course, but give it a listen and you'll quickly discover how imaginative the arrangements are, and how utterly charming these performances.

As I understand it, it's two guys from Brooklyn - Roger and Dave - who set out to record all 148 Beatles songs in the catalogue, collaborating with a different set of musicians on every single track. These musicians are from all walks of life, ranging from local New York indie bands to the Fort Greene Children's Choir. Sure, there's ukulele playing on each track, yet they all sound very different. It seems as if the arrangements were made in close collaboration with the guest artists, and the results are both idiosyncratic and timeless.

It's been going on for over a year, but they're not done yet.

You can download the songs as a podcast into iTunes, or you can download them directly from this site, which also has hilarious, perceptive commentary on each track. Enjoy!

Next time back to birding...

Thursday, February 11, 2010

Snow in Inwood

Here's "Appie", a Ring-billed Gull with an auxiliary marker (APP) photographed today in a little bay on the East River at Inwood Hill Park, in northern Manhattan. I reported it to the Patuxent Wildlife Center, and will let you know when I hear back from them where this bird was banded.

Snow all day yesterday and blue skies today made for a photogenic walk in the park this morning. It may not be obvious, but this is in Manhattan!

As everybody knows, these days you can see many raptors of various species in New York City. There's Peregrine Falcons on the city's bridges and skyscrapers, American Kestrels all over the city (saw one on 14th St between 6th and 7th Ave today), sometimes in winter a Bald Eagle over the Hudson, several Cooper's Hawks in various city parks, and of course the resident Red-tailed Hawks. Pale Male is only the most famous, certainly not the only, redtail breeding in the city. For years, Inwood Hill Park has had a breeding pair, and this morning one of these birds perched briefly in a tree overhead. As real urbanites, they have become so habituated to humans that they can be approached quite closely.

Wednesday, February 10, 2010

Shorebird count

Writing this from a New York City apartment, I look outside and see snow falling down. How far away the tropical heat of last weekend's shorebird count in El Salvador already seems! Here are some snapshots of that very enjoyable experience.

These are my co-counters Roselvy (front) and Karla, with Juanito, a Barra de Santiago park ranger in the back of the boat. This was the fourth year of this volunteer shorebird count, which takes place twice a year, in February and again in April, and is organized by the Salvadoran Ministry of Environmental Affairs. Last year February I was also part of Roselvy's team. This year, Roselvy was again our team leader, Karla provided her vehicle and companionship, while Juanito assisted us Saturday afternoon on the Barra de Santiago part of our busy program. He enjoys local semi-legendary status as "the man who found the penguin". A few years ago, a very lost Galapagos Penguin washed up on the beach at Barra de Santiago, and Juanito told us the story of how he found it.

Saturday we started the day early - 4:30 AM early - to get from our free lodging up in El Imposible all the way down to Cara Sucia, a small coastal town near the border with Guatemala where we had breakfast at 6 AM. After that, we visited four different sites that day, including Garita Palmera and Barra de Santiago. We were still counting shorebirds as the sun was setting, and had a boat ride back among the mangroves in the dark.

Spotted Sandpipers were common at every site. Here's a sequence showing two individuals engaged in what is probably a boundary dispute over their respective winter feeding territories.

The birds did not call, but there was much strutting left and right along an invisible line that probably forms the border between their territories.

Perhaps one of these birds was interested in expanding its territory, but then found the neighbor not wanting any of that.

We watched them carrying on for several minutes. I was surprised to see them behave this way, for there appeared to be very little aggression involved. It wasn't one bird telling another bird to buzz off, it was more like a silent dance not unlike the courtship behavior performed in the water by certain grebes. In fact, I wasn't even 100% sure that this wasn't courtship behavior. A territory dispute seemed more likely, for these birds after all were on the wintering ground, in winter plumage.

A cool find was this American Oystercatcher, a bird we didn't see last year. Species we saw this year included both yellowlegs; Least, Western and Semipalmated Sandpipers; Sanderling; Ruddy Turnstone; Willet; Whimbrel; Marbled Godwit; Black-necked Stilt; Black-bellied, Wilson's and Semipalmated Plovers; both dowitchers (three Long-billed, the majority Short-billed); and a Pectoral Sandpiper.

Here's our team just having finished the last field site Sunday afternoon. It was pretty intense but a lot of fun.

Friday, February 5, 2010

Plumage details

Our Golden-cheeked Warbler field work in Honduras is done. We described 25 insectivorous mixed-species flocks at 5 different pine-oak forest locations throughout the country, and encountered 32 individual Golden-cheeked Warblers. Some of them were outside the flocks we described. A scientific paper describing the results of our field work and that from four other Central American countries is in preparation. Without going into too much detail, I can report for Honduras that the vast majority of the birds we saw this year were adult males. Most were first seen in a thin-leaved oak species called Quercus sapotifolia - clearly a favorite foraging tree species for Golden-cheeked Warblers on the wintering grounds. Practically every photo I've posted here of goldencheeks shows them in this oak species.

Throughout this season and the previous winter, I have talked here in this blog about plumage details of Golden-cheeked Warblers: how to separate this species from closely related warblers, and within the species how to distinguish the various sex and age classes.

Let's take that last subject to another level. I believe the bird pictured above is an adult male, most likely a second-year male.

In this photo of the same bird, the throat and chin appear solid black, while the eye stripe also appears black or blackish. These are field marks for an adult male Golden-cheeked Warbler. Females have a yellowish or whitish upper chin, while the chins and throats of immature males tend to be black with whitish feather tips.

But look more carefully at the top photo. One of things that's notable in that photo is that the mantle or upperparts are not entirely black. The crown and eye stripe appear black, but the mantle seems dark olive with thick black streaks. That last field mark is better for adult female or a younger male. Adult females and first winter males, however, don't have black chins.

Here's another photo that shows the mantle. Again, the mantle appears dark olive with broad black streaks - not black.

Also, in the lower white wing bar on the median coverts we see dark shaft streaks. These wing bars are completely white on adult males only.

So what we have here is a bird that shows some field marks for an adult male, and some for a younger bird.

Now take a look at this one. Here the sunlight hits the bird sideways, and as we saw earlier, the black on the throat goes up all the way to the chin. However, now we also see some yellow feathers in there that were practically invisible from other angles, for example in the second photo from the top. All these photos are of the same individual. (Go back to that second photo, click on it for a larger view, and you will see a hint of yellowish on the throat...)

I photographed this bird in the morning of January 31, 2010 near Monte Uyuca in Honduras. Over lunch that day, I looked at these photos with my field assistants Kashmir and Fabiola, and with Salvadoran banders Roselvy and Lya. For Roselvy, one of the most experienced banders in Central America and someone well versed in the subtle art of looking at plumage details on warblers, it was clear that this bird had to be a second year male.

During previous field seasons, I sometimes wondered whether it's really possible to separate immature males from adult females in the field. This year, with more field experience with the species, I felt more comfortable assigning sex and age classes to the birds we saw. In some cases, we saw the bird only briefly or from a distance, but in most cases we were able to observe the birds for extended periods of time and from various angles. Paying close attention to plumage details helped us separate different individuals in the same warbler flock, even if we didn't get the opportunity to see them feeding side by side.

This weekend I'm set to count shorebirds in western El Salvador. This will be the fourth year of this count, and the second year of my participation in it. This shorebird count is organized by the Salvadoran Ministry of Environmental Affairs, and each year is repeated in April. I'm hoping our team - Roselvy, Karla and me - will find some interesting species! We're going to do this without a telescope, only binoculars, so finding the rarer species will be quite a challenge...

Shorebirding is very different from following a mixed warbler flock in a forest, yet here too it pays to look for plumage details, as well as structure and behavior. Monday I'll be traveling, but I should be able to post some shorebird photos around mid-week.

Monday, February 1, 2010

Sedge Wrens

At our last field site, in the neighborhood of Reserva Biológica Monte Uyuca, we found a population of Sedge Wrens. They're not in the reserve, but are quite common in nearby pine-oak forests with a grassy and shrubby understory on the other side of road Tegucigalpa - Danli.

Howell & Webb's Guide to the Birds of Mexico and Northern Central America (1995) mentions small, disjunct populations in northeastern El Salvador, western Honduras and western Nicaragua. Their map for the species shows two dots in western Honduras, none in the area where are in now, between Tegucigalpa and Danli. I had never seen this species in Honduras before, but we found several pairs at yesterday's and today's field sites.