Questionable anser

Yesterday, doing some back-to-school shopping at the Assembly Square Mall, I went and had a look at the river, and there was this goose.  It was there again today, among a dozen-strong flock of Canada geese.  Now, there's no question about the identity of this bird:  It's Anser anser, the greylag goose.  But after that things get a bit murky.

The greylag goose is not, after all, an American bird.  It's a Eurasian species that nests in the northern half of Europe and Asia, and migrates to the south of Asia, the Mediterranean, and North Africa.  Occasionally a vagrant fetches up in North America.  Is the bird above one such?  Maybe, but it's impossible to say.  It happens that the greylag goose is the ancestor of the domestic goose, a certain number of which have gotten loose in this country and gone feral.  The domestics are usually white -- like the notorious Charles River white geese -- or splotched with white.  But not always; some have the coloration of wild greylags.  The domestics are also said to be heavier-bottomed, but again, it's hard with an individual animal out on the river to assess its bottom-heaviness.

Just based on the probabilities, this is a feral animal, maybe some generations removed from the barnyard.  And in a sense, the question is purely academic, because wild greylags and those of domestic stock are the same species anyway.  But this is the first one I've ever seen in Somerville.

What are the chances?

Today there was a really weird assemblage of birds in my neighbor's tree.  The first one was this kinglet, above.  I usually see kinglets in the yard, but in April, not late May.  This bird didn't get the memo, apparently.

Then, a few minutes later, this:

This one is Wilson's warbler.  'Tis the season, I suppose, but I hadn't seen one in years.

Cue the next one:

Cedar waxwing, which I see singly basically never, and in my yard basically never.

And then finally, way in the top of the tree, for only a minute:

I'm pretty sure this is some kind of tyrant flycatcher, but it's hard to narrow it down beyond that.

This says something about the value of a single mature tree, even of a despised species like Norway maple. This particular tree looms over my yard and rains branches down on it, and moreover produces a million seedlings every year.  But I still would hate to see it go.

Sparrow Desert

Earlier today, I was looking at a list I made in May, 2014 of migrants I had seen in my yard.  And I was struck by the fall-off in numbers from 2014 to today.  By this time of the month in 2014, I had seen dozens of individuals across ten species of warbler.  This year, I've seen maybe five individuals across two species.  So what on earth happened?

I could be completely off base, but I'm blaming sparrows.  Bird feeders have caused the number of house sparrows to explode in this neighborhood.  Their numbers are up maybe tenfold or more over three years ago.  And as sparrow numbers go up, might not the number of everything else -- most conspicuously May migrants -- go down?  As sparrows' spring diet turns from seeds to insects, they start hoovering bugs out of all the trees and shrubs in the neighborhood, leaving the the larder somewhat bare.

If you're wondering whether sparrows could really have this much effect on insect populations, consider what happened in China during the Great Leap Forward.  When Mao tabbed the Eurasian tree sparrow (a species closely related to our own invasive house sparrow) as one of the Four Pests to be eliminated, people began persecuting the sparrow with such enthusiasm that the species was nearly wiped out.  Result?  Locust populations, previously kept in check by sparrows, boomed.  The ensuing famine killed at least 25 million people.

So if you're worried about locusts, by all means, keep a feeder.  But if you're worried about our native birds, particularly during their migration, consider the effect of your feeder on the local ecology.  It's instructive to take a walk around the block in Prospect Hill, and really listen for what birds you hear around you.  I think you'll be shocked at the omnipresence, and sheer numbers, of house sparrows.

Out with the old

The Mystic on Sunday offered a mix of the old and the new.  On the new side were blackbirds and grackles, here for several weeks already, as well as the more recently arrived cormorants and tree swallows.  Representing the old, we still had a few winter birds hanging around: a couple flocks of coots, a solitary bufflehead, and these mergansers -- surely the last -- two hundred yards below the dam.

And then there was an odd diving duck I couldn't make out with my naked eye.  You see it in the upper left of the photo above.  I was astonished at how long it could stay underwater, and what a distance it could travel -- a hundred yards at a stroke.

It wasn't until I got home and looked at my pictures that I realized what it was:

Now, you can disparage my identification skills as much as you like, but in all justice, you have to admit that I had the phylum correct.

Mismatched set

This blog has been threatening to die of starvation lately, but here's a tasty morsel. It's a prairie warbler, a new species for me, and an unexpected one at this time of the year.  The location is also a bit implausible -- Assembly Square.  I have to give a shout-out to this guy, because otherwise I'd have identified this bird as something else.

My confusion stemmed, partly, from the fact that there was another warbler in the same tree:

This one is a palm warbler, a species that's a bit more familiar around here.  Still, I shouldn't have assumed that these birds made a matched set.

Quel bon vent

Every year, in early May, there's a day when everything arrives at once.  Yesterday, the 11th, was that day.  I clocked four species of warbler:  yellow-rumped (above); Cape May:

...northern parula:

...and common yellowthroat:

The photography, as you'll notice, is what we might call security-camera quality:  just sufficient to identify the guilty.

But the warblers were not even all of it.  The catbirds came back, as did the chimney swifts, and we had a couple of white-throated sparrows, some chipping sparrows, a ruby-crowned kinglet, a Swainson's thrush up by the monument, and even, strangely enough, an osprey circling overhead:

And then today, nothing.

State of the list, 2015

Before I get to the halfway point of 2016, I should give an account of the state of my Somerville list as of 2015.  As I noted before, this was not a good year for me, birdwatching-wise.  Lack of time outdoors translated into a meager tally of new species.  I only had five (American wigeon, common loon, great egret, green heron, and redhead), against two species I deaccessioned (hooded warbler and Philadelphia vireo, in both cases because I lost confidence that I had really seen them).  All the ones I added were waterbirds, as it happens.

For 2016 I have a couple new species, and I'm hoping that over the next few weeks, I'll pick up a few migrants I haven't yet seen.