Warbler wrapup, Spring 2020

I made a discovery this spring: the more time I spend in my yard, the more warblers I see.

In years past, I've worried about declining warbler numbers, at least as they manifest locally.  I've blamed house sparrows, and while it's true that sparrows compete with warblers for food, and on occasion harass them, I've come to doubt that there's a tight linkage between the number of sparrows and the number of warblers that pass through.  There are a ton of other factors that affect how many warblers I see, starting with level of effort, of course, but including such things as weather, overall population numbers, and even local vegetation patterns (for example, this last year I lost my apple tree, which was a bit of a bird magnet).

Just taking what I saw in and from my yard, I counted the following:

Black and white, 10
Black-throated blue, 2
Cape May, 2
Magnolia, 2
Ovenbird, 6
Northern parula, 1
American redstart, 3
Wilson's, 1
Yellow, 3
Common yellowthroat, 9
Yellow-rumped, 1

There are a few others I was unable to identify, or only heard singing, and some of these birds may have been continuing birds that got counted twice, but in general, I feel like this was a pretty representative year:  11 species, across five genera.  Ovenbird was the curtain-raiser, on May 3, and American redstart brought the season to a close on June 1 -- rather later than usual.

I also spent some time at the Mystic and Alewife Brook, and saw some species there that I didn't see in my yard:  chestnut-sided, prairie, and Blackburnian.

All taken in all, I saw the species I expected to see, with a few exceptions:  blackpoll, palm, and pine.  And I even added a new one for my Somerville list, in Blackburnian warbler.

Black-throated blue times two

There's a great deal about warbler migration that's a mystery to me.  But I had a piece of luck today that helped me answer at least one question that's been bothering me:  namely, do individual warblers hang around my yard for more than one day?  I'd always suspected that the answer was sometimes yes.

It happens that on Monday of this week, I saw a black-throated blue warbler in the yard.  And on Tuesday.  And on Wednesday.  So were they they same individual?

By luck, I got photos on both Tuesday and Wednesday of the bird in the same posture at about the same location.

Here's Tuesday:

And here's Wednesday:

Now, looking at pictures of this species on Google, I see that the white wing patch is a bit individual: in some birds, it looks kind of like Iowa, where in others it's a bit more South Carolina, and so forth.

So here's a closeup of the wing patches from the pictures above:

I make it as the same bird. No?

Meanwhile, in other news, a pair of mourning doves has been nesting outside my back door, and they have been on the nest for what seems like forever.

Ms. Blackburne's Warbler

I was standing today by Alewife Brook, peering into a tree full of warblers, when a driver stopped at the light called out to me, "I think that's a blackburnian warbler." Bless me if she wasn't right.