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.

Trash day

Despite appearances, this palm warbler is not keeping up with the Red Sox.  It's actually looking for its breakfast among the river of trash that lines the I-93 embankment.

On the subject of rivers of trash, the Mystic River Watershed Association is having a river cleanup on Saturday, April 30.  Be there!

Duck, duck, goose

Some ducks from the Mystic this morning.  First up, the cheerful-looking ruddy duck.

Next, a new species for me, American widgeon:

And finally, some geese: