I and the Bird #50

Yes, it's the 50th edition of I and the Bird, and it's up at A Blog Around the Clock, graciously hosted by Bora. Another wonderful collection, stories of discovery, danger, resolution, and general good times that have been had by birders from around the world.

Go by and check it out, and be sure to take a look at Nuthatch's contribution from Bootstrap Analysis. Her post Where I've been & who I've been seeing about her field work this spring and her observations of the effects of the rather strange weather patterns we experienced--both in Michigan and here in Thomasburg. Without getting out all that much, I had the impression that things were different this year--catbirds were late and scarce, the white-crowned sparrows that usually spend some time with us in May in good numbers just barely showed up at all, among other anomalies. I was very interested to read this impression confirmed by a much more rigorous set of observations.

Next up at The Birdchaser on June 14th, 2007, so send your entries to Rob at: birdchaser AT hotmail DOT com.

An Alert from the Searchers

It has slowed down over the last few days, but for a while there my most popular page was "Who's that Eating the Mugo Pine?" a post I wrote on May 31 of 2006 about the European pine sawfly (Neodiprion sertifer). So finally, a couple of days ago, I thought I really must take a look at the mugo pine (Pinus mugo).

Heads reared up--they think this will scare me off
Sure enough, there they were, sawfly larvae munching the pine needles (European critters feasting on a European tree--if only it always worked out this way). Last year was a bumper year for this critter on this particular tree. I got rid of a lot of them with soapy water, and pruned away about half of the tree to reduce the number of denuded branches, but enough survived, or perhaps came from away, to produce a new crop.

Okay, this is a bit scary
There aren't too many this year, and they came later than they did for my many sawfly-mugo pine visitors (though about the same time as last year, judging by their size), but they must go. The tree looks weird enough now from the pruning it got last year--I don't want to put it through that again.

Eat while you can, my friends

I'll sing what I want to sing

So I was out in the far field yesterday, getting on for seven in the evening. I was tired from little sleep the night before, but wanted a quick amble around.

At the northwest corner I heard a song duel--very clear, very even, first one bird, then answered by the other, about 20 metres or less apart. I listened for a bit, I didn't know the song, but it was pretty ordinary, a mere trill, with a note or two at either end. But I didn't know it. Didn't sound like a warbler I knew, didn't have a sparrow quality to it. Should I track down one of the birds for a look, or let it go as one of the many mysteries of the field?

One bird was too close, sounded like I'd be able to get a look without much trouble, so I started to move over in its direction, slow, casual like, looking away as much as looking in the direction of the sound. And then it flew up to a bare branch and I got a very good look. I could hardly believe my eyes. It was a male golden-winged warbler, and it sang for me as I looked, so there was no doubt who was singing this song.

As I wrote recently, while reporting the return of the Brewster's Warbler to the far field, I haven't seen a golden-winged warbler back there since the summer of 2004, and so I was some pleased. But what the heck was that song? And who was the other duelling singer?

Caught up in the moment of discovery, I decide to see if I could track down the other bird. It was singing from a denser bit of foliage, fewer bare branches, fewer chances for a real look. I knew where it was, and saw it fly, but we moved around the field some, from tree to tree until finally it let me see it. A Brewster's.

The Brewster's warbler is a hybrid of the golden-winged and the blue-winged, too very closely related species, who are recently coming into contact as habitat changes and other factors are affecting the range of the blue-winged warbler. The blue-winged isn't as fussy as the golden-winged about habitat, and as a result of this (and, again, other factors) there is concern that the blue-winged will eventually swamp the golden-winged out. I've written about this a number of times, as I've watched it happen. But what I saw last night was a first for me.

The song was the song of the blue-winged warbler--at least pretty close to it. When I was collecting data for the Ontario Breeding Bird Atlas (due out in September 2007) I was instructed to only record blue-winged and golden-winged if I saw them, not to make a specific identification on the basis of song alone, because each will sometimes sing the song of the other. The golden-winged I got to know in the summer of 2004 sang a perfect golden-winged song, a nice series of 3 buzzes (the example I've linked is a 4-buzz song--just goes to show).

The Brewster's I've known since, including the one I reported earlier this year, have all sung the same perfect combo song. Of course, it might be the same bird I'm hearing each year.

The little scene yesterday between the male golden-winged and the male hybrid made one thing clear--these guys really don't distinguish (discriminate) between conspecifics and nearly conspecific. But it also raised an interesting question. Is it just a coincidence that these guys sang exactly the same song? Or, as seems more likely, were they singing the same song because they were singing at/for each other? Perhaps one started, then the other came by, heard the first, and matched him, to show he was the better bird.

In any case, now I'm hoping that there's a female golden-winged around who will take up with this male, and start a new, pure line alongside the Brewster's that I suspect have a territory already staked out further down the field. I will report developments.

Dolomedes triton--NOT!

Correction

I try to be careful--but sometimes I'm not--and then even if I'm corrected, a misidentification may persist forever in the Google cache.

I've adjusted the text below, and the title, in response to the comment Bev of Burning Silo kindly left on this post, pointing out that this is another spider altogether--probably a Pisaurina mira. The linked page includes a photo of what I think is a female of this species. Mine was probably a male, given the clubbed appearance of the palps.

Back in April, as described in this post, I found a spider on the kitchen floor that was identifed for me as a Dolomedes triton (six-spotted fishing spider). Well, that's crazy. What would a fishing spider be doing in my kitchen?

Fishing (?) in the kitchen sink
Then the other morning I found the critter above--same similar markings (though the white strip around the body doesn't show as well in this photo, it was there in life), but bigger, and in a posture I associate with the watery spiders. One difference is in the shape of the marking outlining the body, not the crisp line of the Dolomedes triton, but a more scalloped affair. In the earlier post I mentioned that I thought that this is a familiar spider around the house.....I guess I was right. Familiar yes, in the sense that there are many species in and around the house, and some are vaguely alike. but this one is not Dolomedes triton.

Dolomedes triton is one of the spiders being recorded in Spider WebWatch, so I take this as a sign that I really must sign up and submit the record be more careful when I identify a spider, and not jump to hasty conclusions before 6:00 am (or even later in the day!).

Burning Silo has an excellent post from earlier this year with photos and accounts of a number of quite beautiful spiders in the genus Dolomedes.

And since it's Friday: All aboard the Friday Ark!

Becoming

Courtesy of Bill Newman, a Scarlet Tanager (Piranga olivacea) transitioning into breeding plumage:



Singing:



All aboard the Friday Ark

Found Poetry: I and the Bird #49

Dave at Via Negativa has composed (found) a beautiful poem about the biggest big day that's ever been: birds galore, from all over, it's the current edition of I and the Bird, the carnival of the best of recent bird and birder blogging from around the world. He has also provided a spoken version for our listening pleasure. Go on by and see. And follow the lines. Especially, if you've never been to Bell Tower Birding, be sure to click the line, "The super nova of the forest, the gaudy Prothonotary."


Next up at A Blog Around the Clock, May 31. Send submissions to Bora: Coturnix AT gmail DOT com by May 29.

Garlic Mustard

I'm staying down in Prince Edward County for a few days this week--and when I arrived I was shocked to see this:

A broad swath of garlic mustard--and not the only one.
Last year I noticed a small patch of this stuff up against the house here--I pulled it up and hoped for the best. There was also a little on the far side of the small woods below the house--I haven't gotten in there yet to take a look. So I've been pulling out what I can. Garlic mustard has a good strong taproot, like a carrot or dandelion, and will break off it quite easily, and then quickly grow back. After some rain, I was getting more out by the roots, but a lot of it is inaccessible, and a lot of root is left in the ground. I've been dumping it in the compost, but I suspect that the stuff with root intact may succeed in producing seeds in spite of having been pulled up.

Know your enemy
This powerful invasive was first brought to North America by European settlers for eating--but like so many that came this way, there were no natural controls on it here, so it spread terrifically. And then I read that it not only chokes out native spring flowers, but it also damages forests. (See this post from last spring at Bootstrap Analysis for more on this invasive and forests. See this page for what the Ontario government has to say. And a link to Wisconsin's Garlic Mustard Awareness Month I found at BirdFreak Blog)

The stuff seeds prodigiously, and the seeds can wait for years to sprout. Who knows what happened to this bit of earth I'm dealing with. Two patches occupy the exact same space as two clumps of daffodils--very suspicious, as if they've had some (inadvertent, I'm sure) human assistance to take hold. Other, larger patches are not in places where they would have been planted through the spreading of composted garden waste, or something like that--but maybe they're where torn up plants were tossed? I think I better pull the plants out of the compost and bag them up in black plastic trash bags and set them in the sun. Maybe cooking will prevent seed development.

Monday Moth

From inside the house this critter on the window screen looked like a bit of leaf or maybe a tree flower, with just a little more definition than you'd expect. So I went outside to get a better look, and found this pretty little, pretty well camouflaged, moth.

Moth on screen

I think this is a Lappet Moth (Phyllodesma americana), based on the colour and wing position. It's related to the tent caterpillar moth. Here's a link to a page with another photo of the moth, and of the caterpillar too. And here's the species page at BugGuide, which describes this moth as rare to locally common...

Chrysalis or Cocoon

Every now and then I come up against evidence suggesting that I'm not as fluent in my native tongue (English) as I thought. Chrysalis? Cocoon? I don't know. So I looked them up in the Oxford Canadian Dictionary:

cocoon: a silky case spun by many insect larvae for protection as pupae

chrysalis: a quiescent pupa of a butterfly or moth; the hard outer case enclosing it

Which didn't help all that much. The silky covering of the one in the yard is tough, but maybe not very hard--so I'll go with cocoon. The case that surrounds the Monarch pupa certainly looks hard--so, chrysalis?

Cocoon, April 28, 2007

During the winter I could see this from the back window, and for a long time thought it was a bird's nest. It's just about 10 cm (4") long. The spirea (flowering shrub, very common in gardens around here) it's in has pretty dense foliage at its peak, so it was not unreasonable to suppose that a bird could've nested there without me noticing. Song sparrows nest all over the place, and I usually can't really pinpoint their locations. Of course, I don't really try--it's rarely a good thing to locate a nest--it either puts it at risk, or it indicates that it isn't well located, i.e., already precarious. Anyway, inspection early in the spring revealed that this was no nest.

It's the cocoon of something big. We had some big stuff around last summer that I know about--and then there are all the things I never saw.... I put this on BugGuide.net this morning just in case it can be identified by size and/or location. I check on the cocoon three or four times a day, but still no sign of any change. After a hot week the weather has cooled considerably, so I wonder whether these guys can hold off if conditions aren't great, or if once they get on a certain timetable they can't get off. I'm taking off for a few days next week and I'd hate to miss the emergence.

Here's a link to some photos of an emerging moth of the family that I suspect is represented here, that were pointed out to me in the first response to my id request: Antheraea polyphemus. Mere moments later I got another response, identifying my cocoon as a probable Hyalophora cecropia, based on the relatively open weave. I love BugGuide.net (here's a link to my id request and the responses). I have always had extremely quick and helpful responses from that bug community. And cecropia fits--it is certainly well represented around here in the caterpillar season.

Update (later the same day): Because the shape of this cocoon is unlike the other examples of cecropia cocoons at BugGuide, there is uncertainty over the identification. Check the page to see why. And I'll post updates as they develop.

Update #2--next morning: Okay, the issue is resolved. Apparently Hyalophora cecropia shows up in two different kinds of cocoons--neat, narrow ones, and big baggy ones (such as mine). So Robin moth it is--very nice. I've got my fingers crossed that I actually get to see one of these beauties. For more about the moth, check out its species page at BugGuide.

And just one more: Here's a link provided by Bev of Burning Silo in the comments below, to another good site for cecropia info.


Here's a post I wrote last August about the cecropia caterpillar pictured below. Apparently the adult moths only live a couple of weeks, so all the more I hope I get to see this one emerge!

Hyalophora Cecropia, August 2006

The Brewster's Back

It's been a couple of days since I got out back--last time, not a warbler to be heard (although I've heard a black-and-white a number of times from across the street over the last ten days or so). Last weekend hummingbirds, house wrens, and chimney swifts arrived in the hamlet--now tree swallows and wrens are squabbling over the two nesting boxes in the yard. Chipping sparrows are getting very serious in their various battles and courting dances. Then this morning, warblers. Out in the far field, my old friend the Brewster's Warbler was singing from the same perches that have accomodated this bird over the last few years. Joining him, one of those American place-name warblers, Nashville, I think. Didn't get the best look, and don't know the song well enough to be sure. In the woods beyond, an ovenbird and a wood thrush sang.

The Eastern Towhee has been back for a while now--but there seemed to be a number of them singing back there this morning. And at least one of them was letting me get much better looks than I normally do of this bird. The towhee has been a difficult bird for me for some reason. It took me years to learn its song. It has a very distinctive call and song, very beautiful. And for several years at first hearing it sounded like something marvellous I'd never heard before. Last year I felt like maybe it'd sunk in. And, voila, this year I knew the call the first time I heard it. Today I was treated to the song as well.

The Brewster's has never been a problem. It's song is distinctive and memorable, for me--at least the song sung by my birds. This bird, a hybrid of the Golden-winged and Blue-winged Warblers, was one of the most interesting things I discovered during my days as an atlasser. The expansion of the range of the Blue-winged Warbler has been a problem for the Golden-winged, or at least has added to its troubles. The birds are very closely related and hybridize happily. The consequence is likely to be the eventually swamping out of the Golden-winged Warbler. (Click here for the Golden-winged Warbler Atlas Project at Cornell) I had a Golden-winged singing in the far field for most of the summer of 2004. Since that summer it's been all Brewster's. The next year, 2005, I saw a Brewster's in the company of a female Blue-winged Warbler, both carrying food for nearby, noisy fledglings. My surmise is that the 2004 bird mated late, with a blue-winged, starting the dynasty that still breeds back there. The bird I saw this morning was singing the same mixed song I know so well, and had the classic Brewster's markings, except that he had yellow under his chin as well as on the top of his head. Others have a different idea of the classic Brewster's, this page has photographs of a couple of interesting examples, and a blue-winged for comparison.

The Golden-winged warbler has recently been designated a "species of special concern" in Ontario.