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.

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.

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.

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.