Nocturnal Migration

First, I hope you checked out my guest post, co-authored with Lewis Grove, at the Cornell Lab of Ornithology's Round Robin last week. The next post should appear this evening or tomorrow about spectrograms. Somewhat dry, but with audio of flight calls (!), then we can get into the fun stuff. Hopefully we'll be able to post some "predictions" of migratory events during the spring, but we'll definitely run a series of species-specific posts to help you learn some common flight calls and others about flight calls in general.

That said, tonight looks pretty good across portions of the eastern US, at least as of 10:30 PM. Compare these two maps, one what the radar looked like at 7:00 PM (EDT), the second just over two hours later.

Those two greenish blobs over the mid-west (Kansas, Missouri, Arkansas) and a bit farther east (Kentucky, Illinois, Indiana) represent storm systems, and are present in both maps. Then there are those circular blue blobs, a few present over the southeast in the first map but many, many more in the second map. Those are radar stations picking up objects in the sky that are not weather. They are birds, possibly bats or large insects, but the majority are birds.

The brownish washes seen across western New York, Pennsylvania, Michigan and interspersed in other areas, are less-active areas of migration - but migration nonetheless.

Looks like a good night to go out and listen for flight calls, even better, for listening for flight calls while training low-powered optics on tonight's full moon. Perhaps you'll see some shadows crossing the face of the moon while hearing calls dripping down from birds on the move. I'm heading outside now, let me know if you see/hear anything!

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Around the Pond, In the Pond

A walk around the backyard is something that keeps me grounded. At least I like to think so. I'm not comparing our quarter-mile loop to Darwin's Sand Walk, but I do know it calms my mind, teaches me new things about our habitat, and (most importantly) allows my daughter and I to engage nature as a team.

14-year-old Barron still accompanies us on our walks.

We've been curious about where our resident American Crows have nested - somewhere across the street in a stand of pines we assume, based on the numerous times we've watched one fly in that direction carrying a stick. Reina noted they're still flying in that direction, but not carrying sticks. Must be done building, egg laying can't be too far behind.

American Crow, perhaps retreating to its nest site.

The first round of migrant birds are back in force, and many of them caught our attention yesterday. Song Sparrow songs came from every corner, each the same as the others (they speak the same language) but completely different (they each have a unique voice). Our Red-winged Blackbird, which we like to think is the same as previous years, perches atop his favorite spruce and keeps rivals away. Soon the females will return and, being polygamous, he'll use his song to attract a few.

Dark-eyed Junco numbers increase daily, we counted more than two dozen under our feeder. Best of all the Eastern Phoebe is back, even checking out his nest from last year, and some of our native plants are returning.

Marsh Marigold, here emerging from the very edge
of the pond, creates habitat for amphibians.

But what caught and held our attention was something we found in the pond, not surrounding it. What first looked like a small algae bloom a few days ago didn't look like algae today. We're wondering if it's an egg mass of some sort, if you have any ideas, please let us know! (Click for larger images.)



On the floor of the pond, below the second of the green, algae-like clusters, were hundreds (if not thousands) of bubble-like . . . well, bubbles. Or, perhaps eggs scattered along the bottom? Or maybe the vegetation is wickedly photosynthetic? We're grateful for any ideas, either identifying them definitively, guessing what they might be, or definitively excluding eggs.



If this helps, we know we have healthy numbers of Spring Peepers, American Toads, and Bullfrogs. Fish-wise, the pond holds many, many catfish, several koi, and one gar. In a very non-naturalist way we've never identified them past those distinctions. We look forward to your thoughts!

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Road Kill Birding

On my Blue Highway drive to work this morning I came across a possum in the road. I was driving the way I usually do on these roads: slow, eyes flitting back and forth to both sides of the road, one hand on the wheel, the other clutching binoculars. The possum was doing what it usually does on a road: lying there, unmoving, after an unfortunate meeting with a non-birding car.

The vulture looking the other way, "Nothing to
see here, no carrion in sight. Keep moving . . . ."

The possum was not what first attracted my attention, it was the hulking bird standing in the middle of the road. I slowed to a stop while opening the window. My hopes of watching the bird pluck at a carcass were dashed, but not before I snapped a few shots of a beautiful Turkey Vulture. In my experience it's not often you get that close to one, at least without being vomited on. In the wild they always seem skittish, keeping their distance from observers.

The bird flushed, circled once, and landed in a tangle of branches directly above the possum. Clearly, this bird was not giving up on the possum easily. I captured a few more shots before leaving the bird its morning meal.

The bright red head and yellow bill really
stand out perched on top of the brown body.

As the bird was taking its lap around the field it displayed the diagnostic wing pattern, perhaps the most recognizable field mark of any bird. You can't miss the undersides of the wings as the birds (usually several) circle above you, the leading edge of the wing dark and the trailing edge white, from body to wingtip. Usually those wings aren't flapping, they're held stiff, angled upward from the body in the characteristic dihedral. When it does flap it seems effortless, casual, efficient, and lazy, all at the same time.


This bird reminded me of the wonderment of the feather. Try this: the next time you find a flight feather of any species, preferably one of the long primaries, bend it. It seems stiff, too stiff to flex. It takes a reasonable amount of force to get it to bend, or maybe that just says something about my lack of a weight-lifting routine.



How does the bird bend them so easily? It doesn't seem that the muscles attached to the quill could do that, could the bird do it of its own volition? Or is it something external to the bird, something to do with the flapping motion? So much to learn. And that's the thing about birding, isn't it? There is beauty, wonderment, and a never-ending source of questions to engage you, even watching a bald bird with a red-skinned head stalk a dead animal on the side of the road.

I can't wait for the warblers!

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Here's Looking at You

Anyone who has trained their binoculars or a camera on a bird knows this scenario: you work your way into a position to view the bird, you raise your optics, as soon as the bird is in your field of view it takes off - like it knows you're looking at it.

Well, that's because it does, according to new research published this week in Current Biology. Auguste M.P. von Bayern and Nathan J. Emery found that hand-reared Jackdaws, a crow found in Europe and western Asia, were highly sensitive to the focus of human eyes and their communicatory function.

The Jackdaw, Corvus monedula, knows
when it's the center of attention.

From the paper:

Article summary
Humans communicate their intentions and disposition using their eyes, whereas the communicative function of eyes in animals is less clear. Many species show aversive reactions to eyes, and several species gain information from conspecifics' gaze direction by automatically co-orienting with them. However, most species show little sensitivity to more subtle indicators of attention than head orientation and have difficulties using such cues in a cooperative context. Recently, some species have been found responsive to gaze direction in competitive situations. We investigated the sensitivity of jackdaws, pair-bonded social corvids that exhibit an analogous eye morphology to humans, to subtle attentional and communicative cues in two contexts and paradigms. In a conflict paradigm, we measured the birds' latency to retrieve food in front of an unfamiliar or familiar human, depending on the state and orientation of their eyes toward food. In a cooperative paradigm, we tested whether the jackdaws used familiar human's attentional or communicative cues to locate hidden food. Jackdaws were sensitive to human attentional states in the conflict situation but only responded to communicative cues in the cooperative situation. These findings may be the result of a natural tendency to attend to conspecifics' eyes or the effect of intense human contact during socialization.

Click here for full article (PDF).

Citation
von Bayern and Emery, Jackdaws Respond to Human Attentional States and Communicative Cues in Different Contexts, Current Biology (2009), doi:10.1016/j.cub.2009.02.062

Jackdaw image from Wikipedia.

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Stepping Out

Dear Feather and the Flower,

You'll probably find out about it elsewhere on the Internets, so let me come clean. The rumors are true. I've been writing with someone else.

It's only platonic, I swear - please know you are still my one and only blog. But I was approached by another blog, we innocently chatted about our shared interest in birds. We hit it off, the attraction was too great to resist; one thing lead to another, and as of today I've published on a different site.

I don't mean to hurt you, but the other blog means a lot to me. And given a chance, I think you would really get along - Round Robin is popular, attractive, intellectually-stimulating, and funny - what's not too like? Give it a try, see what was posted, I think you'll be excited.

Affectionately,
noflickster

ps I know you want the details, so here they are. Our nocturnal flight-call group wrote a piece about nocturnal migration for the Cornell Lab of Ornithology's blog. We are planning to contribute more throughout spring migration, we expect topics will range from when and where to listen, their importance in conservation and other fields, and several tutorials to introduce species so you can explore this frontier of bird watching. Please let me know (on this site) or the Lab know (on Round Robin) about your experiences in listening for nocturnal migrants, if you find the posts useful, and so on - we are looking for feedback! And if you blog, please consider promoting the posts to your readers: we'd like to reach a wide audience and hear comments about experiences across North America.

Now, I'm stepping out to see some birds - so I have something to post here before I get in dutch with my own blog . . . .

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Quiz Bird Answer

Quiz bird revealed, read on to learn its identity.

A headless passerine: who am I?

I photographed this headless-looking bird on a March 20^th trip to the Horseheads Marsh (aka, Holding Point) in Horseheads, NY. Those who guessed correctly narrowed it to one of the "Little Brown Jobs," and nishiki_85 noted the streaked, rusty back and the two white wing-bars, surmising the bird is an American Tree Sparrow.

A little more information here, the rusty cap and a gray face visible.

In addition to tree sparrows there are eight "LBJs" that we might expect in this area at this time of year, some more common than others. Looking carefully you may note the flanks are clean, not streaked, and slightly buffy. This helps eliminate several species: Song, Savannah, Fox, and Vesper Sparrows should all show streaking on the flanks.

Those relatively broad, white wing-bars are helpful, too. They reinforce this bird is not Song, Savannah, Fox nor Vesper, but also eliminate Swamp, White-throated, even White-crowned (I find it wonderfully bizarre those are winter residents at my folks place in Rochester, NY but rare here, 70 miles southeast).

House Sparrows, an honorary LBJ sparrow, do have white in the wings, but a large, single patch rather than two bars.

The only other possible (I wouldn't call it expected, but eBird allows it) sparrow is the Field Sparrow. How to separate these two without seeing the obvious differences, such as face and bill color/pattern? Well, hmmm. First, probability says American Tree Sparrows are much more likely than Field Sparrows, so lean in that direction. Then, wait until it shows its face. Seriously, in looking for differences in the visible parts (back, wings, tail), I'm not sure I could tell.

Gentle readers, how would you tell them apart?

Now you can see it all: bicolored bill, gray face with rusty cap and eyeline,
chestnut and black wings with white wing bars, brownish rump.

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Healthy Competition

eBird has released a new "data out" tool, the eBird Top 100. eBird users can now compare their species list and/or their total checklist submissions with other eBirders.

I'm not much into actively comparing life lists -- they really are measuring who has the opportunity to travel and the luxury to bird exotic places - but this is pretty cool. You can see how your life list (according to eBird) compares across the ABA area, in a particular country, a specific state/province, and so on. You can see how you rank in specific years, or all time.

More meaningful are how many checklists you've recorded. I suspect these indicate how often you collect valuable information that reaches beyond "the game" of birding.

That said, privately I do look. And I'm pleased to see I'm one of the Top 100 eBirders both for checklists entered (41) and species seen (91). I have no doubt I'll be dropping soon, as more and more prolific birders join eBird, as more and more people upload historical checklists, and as those more competitive than me get out and bird more.

My ego may take a hit, but I'll be taking one for the birds, and that's all right.

Check out the functionality on the eBird site.

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