Tag Archives: birds

If All The Human Race Had Perished

They live where we live and move where we move. They steal the grain from our fields and take their own measures from meals we have not yet finished eating. They seize our roofs, our railroads, and our drain pipes for their homes. Their chatter, as the rain, is little heard till it falls silent. When we kick them from our path, they scatter without fear, then quickly reappear. We have so much they need, and we have known them of old.

They were never summoned. They will never leave.

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Tom came into the lab last Thursday as I was carefully rolling up a small sheet of cotton, shaping it into the right form to place inside the skin of a Rose-breasted Grosbeak. I couldn’t see the specimen he was about to start on, and I have an everlasting curiosity about what that man holds in his hands. So:

“Are you working on another African bird, Tom?”

In response he made a strange sound. It was the amused noise a person makes when he is about to tell you a riddle whose ingenuity pleases him. “Mmm. Yes! But not a native one. It’s a bird you know very well, in fact.”

In fact, it was. It was a bird you know very well, too. There is very likely one present within a few hundred meters as your eyes skim over this paragraph, chipping tirelessly in your eaves with a sound like comfort and rebuke, clinging to the side of your building, bathing in the dust next to your street, or shitting extravagantly on the floorboards of your back deck.

It was a House Sparrow (Passer domesticus): a bird that is as common as dirt and only little more loved, perhaps because its personality reminds us of the worst aspects of our own nature. Though small in size, House Sparrows are bellicose in spirit—to protect their territory and their food they have, like some of us, the will to murder those more vulnerable and more rare. (They have been known to smash the eggs and kill the nestlings of competitors with their thick, finchy bills.) They lodge in nest boxes put out for more desirable confreres. They deluge and denude bird feeders, like plagues of locusts. They are like flies—ubiquitous.

What was noteworthy about this particular House Sparrow was that it had been collected in a surprising place. It hadn’t spent its life in any of the countries of Europe or Central Asia that have been its native habitat for millennia. And it wasn’t a specimen from North America, to which the species was introduced in small numbers in Brooklyn nearly two hundred years ago and across which it has since spread like a stampede. (As with some human newcomers, the House Sparrow’s arrival in America provoked a storm of avian xenophobia. But the bird itself has never spent a single breath on the worried contemplation of the difference between integration and assimilation. It quickly and simply chose occupation.)

No, this particular House Sparrow—as Tom explained, solving the riddle—had come back to the Field Museum from a research trip he and a few other Bird Division colleagues had made to Malawi.

Malawi is an African country of mountains, mists, and forests that is hugged, like the head of a little brother, between the shoulders of Zambia, Mozambique, and Tanzania. Its House Sparrow community, along with those that are now established in a host of neighboring countries, originated from the introduction of several small populations of birds to the coastal regions of South Africa around the turn of the 20th century. After landing in places like Cape Town, Durban, and Zanzibar—either stowaways or pets that traveled side by side with sailors on trading ships—the new immigrants came onshore, began to breed, and slowly spread inland.

Today, House Sparrows live in Malawi just as they live virtually everywhere in the world—as close to us as possible. Human settlements provide these birds with ready sources of food and an abundance of appealing nesting places. Passer domesticus is not exactly an obligate commensal (a species whose very survival depends on the benefits it receives from another organism), but it is vastly more likely to be found in proximity to people than it is to take its chances in open country.

Most House Sparrows are so spoiled by the year-round food supply our cities provide and the warm, protected cavities they find everywhere in our architecture that they have even forgone their old migratory tendencies. They are like distant relatives who, unaccompanied by invitations, came to visit with us for a week, remained a month, then three, then six, and now spend all four seasons snoozing on our sofas.

In this position, they are—domesticus in name, domesticus in nature—subject to the conditions of our lives.

Although they still seem ubiquitous to most of us in this country, House Sparrow numbers have actually been falling for several decades in much of Europe, some parts of Asia, and the United States. And given their intimate connections with humans, many of the proposed reasons for House Sparrow declines have to do with changes in how we live.

We use more pesticides in our agriculture, killing the insects nestlings rely on for food. We spill less grain and spread fewer weed seeds when we harvest crops, reducing food supplies for adults. The feral cats and metropolitan raptors that also inhabit our cities prey on House Sparrows. There is even some speculation that leaked electromagnetic radiation from cellphone towers could be having negative effects on the health and reproduction of many urban species, including this one.

They were never summoned; they will never leave. But they are not invincible.

Juvenile House Sparrow (Passer domesticus)

The 19th-century American naturalist Wilson Flagg, finding himself in what seems to have been a grimly apocalyptic mood some decades after the House Sparrow made its way to these shores, mused upon the unexpected comfort such an obstinate intruder might bring:

…since our people are resolutely bent on the destruction of our native birds, it may be fortunate that there exists a foreign species of such a character that, like the white-weed and the witch-grass, after being once introduced, they cannot by any possible human efforts be extirpated. When all our native species are gone, we may be happy to hear the unmusical chatter of the House Sparrows, and gladly watch them and protect them, as we should, if all the human race had perished but our single self, welcome the society of orang-otangs.


If Flagg is right, we would do well to keep one wary, sympathetic eye on the shadow-companions who came, and stayed, and bound their fate to ours.

On The Uses of the Macabre

Happy Halloween! Today seemed like an excellent day to make this post.

Entering the bird lab this past Thursday morning, I found Mary, who usually works at the sink, sitting on a stool beside the large metal prep table that dominates the room. In front of her were two plastic trays; on each, several tidy rows of specimens were arranged. The birds that made up this small collection represented three different species: Dark-eyed Juncos (Junco hyemalis), Nashville Warblers (Vermivora ruficapilla), and White-throated Sparrows (Zonotrichia albicollis).

All three are extremely common birds in the Chicago area at this time of year, either because they’re migrating through on their way to warmer southern climes, or because they spend the winter here.

And all three are known to me personally from morning walks through the Wooded Island in Jackson Park, the treed and windy urban oasis by the lakefront where I saw the distempered raccoon earlier this spring. I love the sight of dozens of dark gray Juncos against patches of snow on the ground, like a fireplace’s worth of cinders someone has rolled up into cozy little balls. Nashville warblers make jaunty little tail flicks as they forage through low trees and shrubs (often that’s all I see of them, an olive whisk-whisk-whisk before they rustle away through the leaves). And the mustard-yellow smudges next to each eye on White-throated Sparrows always make me imagine these fluffy, familiar creatures having just feasted messily on a stash of abandoned hot dogs.

The fact that Mary was working on these birds wouldn’t, in and of itself, have been of much note except that the specimens were in a form that I’d never seen before in the lab. Normally, these are species that Dave chooses to preserve as skeletons. One of the advantages of doing so is that there are many measurements it’s possible to take from a skeleton that it’s impossible to take from a study skin. To prepare a specimen for being skeletonized by the dermestid beetles, volunteers must first remove all its feathers and skin, a process called “roughing out.”

But the specimens Mary was working with seemed to have gone only part-way through this process. On the Nashville Warblers and the White-throated Sparrows, the feathers from their bodies had been removed, but those on their heads had been left in place. And on the Juncos, tail feathers remained as well.

White-throated Sparrows

In this state the specimens appeared, I confess, both fascinating and a little macabre. The juxtaposition of intact, feathered crowns, their plumage still beautifully soft and many-colored, with the dark red muscle of de-feathered bodies, created an incongruity—the likeness of life next to the unmistakable sign of death—that forced me to stop.

Why had some feathers been left on these birds?

Mary soon explained that in each of these species, subtle but significant differences in plumage coloration can be observed. Such variations raise a host of scientific questions (Are the disparities related to sex, age, or region? Can they be traced to genetic differences? Is one form of coloration more common than another, and if so, why? Does the prevalence of each pattern change over time?).

To document these variations, Mary was collecting caps from all three species, as well as tail feathers from the Juncos—because these were the parts of the birds’ bodies where the differences occurred. This way, the caps and tail feathers could become part of the museum’s collections and potentially help to answer some of these questions.

But when she was finished collecting what she needed, the beetles would go on to skeletonize the rest of the specimens’ bodies as usual, thus preserving the ability to take bone measurements from them in the future. The fact that I’d seen the birds’ bodies in this state was a coincidence: an accidental glimpse at a bit of scientific frugality.

Here are some of the variations this kind of data will hopefully help to quantify:

Junco caps and tail feathers

Juncos can have crowns that vary from a light gray to a deep black, sometimes tinged with brown—and while all Juncos have white outer tail feathers and black inner tail feathers, there can be considerable variance in the amount of white and black on the intermediary feathers. This photo doesn’t show the subtle differences in the shades of the crowns very well, but you can clearly see how much more black than white there is in the tail feathers of the bird in the foreground, and how much further out the black extends to the edges of its tail.

Nashville Warbler caps

Nashville Warblers can have a patch of wonderfully rich chestnut-colored feathers in the center of their crowns, something I’ve never noticed when birding because the tiny flecks of red are all but impossible to see amidst or underneath their otherwise gray head feathers. Adult males all have some red in their caps, but the amount can vary widely; and some adult females have a little ruddiness there, too, while others have none. These differences are unfortunately very hard to see in the photo I took, but if you squint you might be able to see some red stippling in the third specimen from the left.

White-throated Sparrow caps

Finally, White-throated Sparrows actually have two well-documented morphs, or variant forms. You can see these quite clearly in the photo above: one morph has distinct black and white stripes running vertically down its crown, while the other has black and tan stripes arranged in the same pattern. Both morphs can be found in both sexes.

DNA analysis has shown that this polymorphism in White-throated Sparrows arises from genetic differences. Both White Stripe and Tan Stripe birds, as they are usually called, show a slight preference for mating with individuals from the other morph. This opposites-attract tendency (which goes by the unwieldy name of “disassortative mating”) keeps the approximate proportion of each morph in the overall population stable, so that neither morph disappears or becomes dominant.

Most fascinating of all, at least in the case of White-throated Sparrows, the morphological variations we see in their crowns are also associated with clear behavioral differences. White Stripe males are more aggressive and more showy—they’re more likely to engage in “spiraling,” a wonderful-sounding behavior that involves singing as they ascend the branches of a tree by circling it. They’re also less dedicated providers of parental care, and less monogamous than Tan Stripe males. As for White Stripe females, they are almost as bold and selfish as their male counterparts. (This may explain why both WS males and females seek out calmer, more reliable partners from the opposite morph.) For more on this subject, I’ll point you to this excellent post by GrrlScientist, who explains the genetics behind these behavioral variations far better than I could.

What I love about my own experience of all this is that it illustrates so clearly a principle I’ve always felt to be true about the study of natural history. That is, the macabre (like beauty) is not a thing that exists as an inherent property of the world, not something with a palpable presence in time and space. Instead it arises out of the complex interaction between ourselves and the world. Even if disquiet is our first reaction to a memento mori, it need not be our last.

But to the extent that encounters with the macabre invite curiosity—like the curiosity that struck me so forcibly when I walked into the lab and saw those unusual-looking specimens on Mary’s trays, and led me to learn some of the things I’ve shared with you today—I think it’s an extraordinarily useful quality in science.

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I would be remiss if I didn’t tell you about two additional things I hope you will investigate:

1) Flinchy, the t-shirt company co-founded by my favorite fellow bird lab volunteer, Diana Sudyka, has several new designs available for purchase. I own one of them, and can testify to its quality and attractiveness. And greater luminaries than me endorse Flinchy shirts, too.

2) I wrote a piece for the Scientific American Guest Blog this week about my rather extraordinary friend Nina and her Field Museum project, LinEpig. You can find it here, under the curiosity-provoking (though not macabre) title “Internet Porn Fills Gap in Spider Taxonomy.” Nina picked the title, because she knows even better than I do that first you catch the eye, and then you tell the story.

Nina at work

Till next time, dear readers-mine. I hope it won’t be so long again.

The 100th Species

Since I started volunteering in the Bird Division of the Field Museum a little over two and a half years ago, many things have changed.

I’ve gotten much more confident and relaxed about preparing specimens than I was in my first tentative months, though I feel no less amazed by the process each time I sit down to begin.

The plastic ID card I use to beep myself in and out of the museum and to access the staff-only elevators (something which still gives me a thrill) has gotten scratched and worn.

I’ve made some wonderful friends.

And, as of today, I’ve worked on one hundred different bird species.

You can find the list in its entirety here, where it will continue to grow as Dave keeps putting out new species for me to work on. But I thought I’d give the 100th a bit of fanfare in this post, especially since it’s not a bird that tends to get a lot of fanfare.

The 100th species on my list is neither unusually large nor remarkably small, neither brightly colored nor glossy and dark. There’s nothing exotic about it. It’s just another little brown bird. Yet if there’s one thing I’ve learned over the past few years, it’s that the more data we have about a particular thing, the more meaningful that data is and the more useful it is to science.

Paradoxically, the fact that White-crowned Sparrows are extremely common in our collections—according to a search I just did of the Bird Division’s database, at least 1433 individual Zonotrichia leucophrys specimens already exist in the museum, dating back to 1863—makes every additional study skin we prepare of even greater value. With a healthy-sized data-set like that, any researcher wanting to do a genetic study, track migration patterns or wing-lengths over time, generate a set of characteristics that birders or bird banders can use to age or sex a bird in the field, or answer any of a thousand-and-one impossible-to-predict future questions, will have a larger body of information to work with and a far better chance of producing reliable results.

So here it is: One big milestone for me, one precious incremental addition to scientific data, and one beautiful bird.

White-crowned Sparrow

White-crowned Sparrow

100th species

P.S. You may have noticed that this little fellow, despite being called a White-crowned Sparrow, has no white visible on its crown. That’s because it was an immature bird, probably hatched earlier this year, and had not had a chance to moult into its adult plumage before it died. Females of the species also don’t live up to their name, and look similar to juveniles—but their tails aren’t quite so long as you see here, and they don’t have any white bars on their wings. Aren’t bird names wonderfully confusing?

New World Warbler

I’m back in the lab on Thursdays, and this morning I walked into it to find that Dave had set out three beautiful little New World wood warblers for me to prepare. Although I loved every bird I encountered in Sweden, I found myself missing many North American species while I was away, including our vivid warblers. It was a delight, therefore, to work today on a turmeric-yellow Pine Warbler (Dendroica pinus), an Orange-crowned Warbler (Vermivora celata) with an especially large splotch of rust on its head, and a sleek Magnolia Warbler (Dendroica magnolia).

Male Magnolia Warblers always make me think of gentlemen who’ve dressed themselves in suits of the most conventional gray, white, and black—and then decided at the last moment that they simply must put on vests as bright as any daffodil.

Magnolia warbler, before

Magnolia warbler, in process

Magnolia warbler, after

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The English word world can be traced, through only a few straightforward steps, to an ancient Germanic compound noun meaning “the age of man” (wer: “man”/ ald: “age”). Ald, in turn, is derived from an even older verb meaning “to grow” or “to nourish.” Thus, world: that place where human beings and their affairs flourish.

It’s a fine thing, friends, to be alive in such a place: whether Old or New. Ah; it is the only thing, you may remind me. But still—and despite all hardships—a fine, fine one.

Closing the Circle

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

Leaning over the work table in one of the observatory’s ringing huts last week, I raised a hand to smooth the lists of birds we keep pinned to the wall. They show each of the dozens of species we might encounter here: its common names in English and Swedish, its scientific name, the five-letter abbreviation by which it is identified in our protocols, and the standard ring size it takes.

(An aside: Some of the abbreviations assigned to bird species are tiny bits of sound-poetry, delicious to say. I like it when we catch a Redpoll, and not just because they are beautiful birds. Their code, derived from the scientific name Carduelis flammea—Redpolls are also known as Acanthis flammea by some taxonomists—is like the politest little cough. CAFLA!, I announce happily as I write it down. CAFLA! Forgive me; I have something in my throat—CAFLA, CAFLA, CAFLA.)

I don’t know if my fellow volunteer Peder saw my wedding band glinting as I stood with my hand on the wall. But perhaps that’s why he said at that moment—his voice rich with the delight of a clever observation—”But Meera’s been ringed. What size is your ring, Meera?”

I smiled, both because I like Peder’s sense of humor and because there was pleasure in taking his question, which required no serious answer, seriously.

What size was my ring? Did it conform to the requirements of comfort and utility assigned to every ring we put on a bird in this hut? Was it loose enough to slide easily up and down my finger, but snug enough not to fall off? When it was placed, did someone take care not to harm me? Was it unobtrusive, in no way impeding my flight, feeding, or other natural behaviors? Did its presence on my finger serve a meaningful purpose in the world? And could you trace my history by it?

I don’t remember what I said to Peder then, twisting my ring affectionately and thinking on these questions with ducked head and wondering mind. Today—watching my brown hands fly over the keyboard, marked by a flicker of white gold—I am still sitting with them.

But when it comes to the birds, at least, I have some answers I can give.

Katie and the Long-eared Owl Adventure
Size 8 rings—one was used in June to ring a Long-eared Owl chick in a nest in Handöl. Mostly we ring passerines, with much smaller rings.

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Many of you reading have first-hand experience with the processes and purposes of ringing (or banding, as it is called in the U.S.). You, friends, don’t have to stay for the rest of this post—although I would love it if you added a comment or let me know how you do things. For the rest of you—and for me, since I am learning these things along with you—I have written a small primer. Ready? Grab a fika. This will be long, and though I find it fascinating, it won’t be very poetic. Something sweet will help us all stay focused. 🙂

A Bird in the Hand

To work with a wild bird, of course, you must first have access to it. If you are ringing birds in nest boxes, as I was helping Stefan do earlier this summer, this is fairly straightforward. You simply check each nest box periodically, noting which are occupied, which have eggs, and later, which have nestlings in them.

If you know approximately how old the chicks were when you last checked on them and how old they will be when they fledge, you can pick a day to ring them—sometime when they’re well grown, but not quite ready to leave the nest. At that point, you can safely pluck the clutch of nestlings out one by one, ring them, and put them back inside. Depending on the species, you’re more or less likely to be able to ring the mother as well—flycatcher parents tend to flee the nest when you approach; tits sometimes stay inside.

Besides nest box ringing, the observatory also conducts mist-net ringing each summer. (This is what I’ve been helping with for the past few weeks, since the Great Snipe tracking began winding down.)

Mist nets are very fine nets constructed of strong black nylon, with mesh sizes that vary from about 16mm to about 120mm; you need a larger mesh to catch big birds like waders and raptors, and a smaller one to catch little birds like warblers and finches. The nets get their name, as you might imagine, because when unfurled they become virtually invisible to birds (and preoccupied humans, as I have proven on more than one occasion).

Each net comprises five vertical sections of netting separated by five horizontal threads; you set it up so that the horizontal threads run taut between two poles and the vertical sections hang loosely below them, forming several pockets into which birds can fly. Nets are usually set up in the early morning and taken down or rolled up in the early afternoon. In between, birds are active but the sun isn’t shining down too hard. If it becomes very hot, windy, cold, or rainy when you are using mist nets, they are promptly closed so that you don’t trap birds under adverse conditions.

Tom B and the net set
Amazingly, I have no unfurled mist nets among the nearly 500 photos I’ve posted of Sweden so far. Here is one from my wonderful Flickr contact Andy Jones, of the Cleveland Museum of Natural History. Ours look exactly the same, but surrounded by tall grasses and wildflowers.

Once you’ve opened a net, it is checked frequently so no bird remains caught for very long. The great majority of the time, birds become only lightly tangled, and removing them takes moments. Occasionally a bird will be more difficult to extract (in tricky cases, beginners like me should always call for help from more experienced ringers, so that the bird can be freed as efficiently as possible). Either way, you follow the same basic steps. First, determine which side of the net the bird entered on, and work on that side; next, free the feet, then the wings, then the head, since that’s the opposite order from which most bird parts encounter the net.

The removal process, though usually straightforward, is the most delicate part of the ringing operation. It requires patience, care, and a constant attention to the welfare of the bird you’re working with. You may be being swarmed by mosquitoes or gnats or tiny evil flies, for instance, but if you have a bird in hand, you can’t twitch an arm suddenly to shoo them away. (Me, if this gets very bad, I swear under my breath. I don’t think anyone but the birds has heard me yet.)

Once you’ve freed a bird, it is placed inside a cotton drawstring bag and taken somewhere else to be processed: in our case, a ringing hut.

A Minute of Science

While there are many steps in processing a bird, experienced hands can perform them incredibly quickly—usually in under one minute. It will take me longer to write about this and you to read it than it takes most birds to make their way out of the ringing hut, and I’m not even going to describe the steps in detail, just list them.

The first thing a ringer does after removing a bird from its bag is identify it. This dictates the ring size it will take, because that is dependent on the average diameter of each species’ leg. The smallest ring we have is a 0.5, which we put on tiny things like chiffchaffs; the largest, spares of which we own but almost never use because our operations aren’t designed to trap anything except songbirds, is a 93—for something magnificent like a crane.

Next, the bird is ringed using a special set of pliers with round openings. These help you to properly bring the edges of the ring together without any danger of squeezing the bird’s leg. I have seen experienced ringers do this so smoothly that I am barely ready to write down the ring number before they are done.

Stefan Rings Four Eurasian Nuthatch Chicks
Here’s a pair of ringing pliers being used on a Eurasian Nuthatch chick.

Finally, several pieces of information are taken that will be associated with the bird’s ring number.(Every country in which birds are ringed has a central database to which these records are uploaded.) Here, we sex and age the bird to the degree that this is possible using physical signs, and then take a fat score, a wing measurement, and weight. We also look for the presence of a brood patch (a wrinkly, swollen area on female birds’ bellies that indicates they are in nesting mode), and determine what stage of feather growth young birds are in and what stage of moult, if any, adult birds are in. None of this data is necessarily all that significant in isolation, but collecting it for millions of birds worldwide each year adds a tremendous amount to the knowledge we have about various species.

If an already-ringed bird is captured, all the same information is collected and its ring number taken down. When that record is uploaded, whoever ringed the bird originally is automatically notified, so they know where that individual has been. I imagine it must be rather thrilling to receive one of these notices. Perhaps it’s a little as if a message you’d put in a bottle had been found across the seas.

After all this, the bird—which, if it is typical, has stayed calm throughout—is released through a small hatch in the side of the hut. Or, if it is a fledgling, it is taken back to the area where it was caught, with its siblings if any were trapped at the same time. We do this so that young birds can easily find their way home. I have returned fledglings several times and I can’t tell you how reassuring it is to hear chicks and parents calling to each other as you approach their nest.

As I said, most often a bird is held in the hand for less than one minute. (It took me about 15 to write this, but things might have gone a little quicker if I hadn’t run out of coffee one section ago. How are you doing, by the way? Any fika left? I’ll try to be quick now, although this last bit is arguably the part I most want you to understand.)

Varför Vi Gör Det (Why We Do It)

It’s all very well to tell you what we do when we ring birds; what perhaps seems even more mysterious, at least if you haven’t thought about it before, are the reasons we do it at all. A dear friend—and I hope she doesn’t mind me quoting her, because I think her words reflect what’s in many people’s minds—commented last week on a photo I posted of a female chaffinch being processed: “I get science and all that, but from a bird perspective, where you are must be a torture chamber.”

Let’s talk about that second part first. It’s perfectly true that being caught in a mist net and ringed is no bird’s idea of a pleasant morning. To a human, handling birds is a fascinating and rewarding experience. It’s hard not to be emotionally affected, even if in a restrained and professional way, by the physical fact of a live bird in your hand. Feather to skin, a bird’s warmth, heartbeat, and softness transmit themselves directly to you in a way that can feel electric.

To a bird—there’s no getting around it—a ringer is a predator.

Having said that, most of the birds we trap are likely to have what are obviously far more dangerous encounters with actual predators every day. Many are migratory species which travel thousands of kilometers each year and face the most grueling environmental conditions. Birds are by constitution tough animals, capable of weathering stress—especially if it is temporary and causes no physical injury—very well.

I will not lie to you. The risk of physical injury does exist. But I believe it is safe to say that the overwhelming majority of the millions of birds ringed annually, under the supervision of ringers licensed by their home nations, emerge from the process completely unharmed.

If I had written this post a few months ago I wouldn’t have been able to make that statement as confidently, but thanks to a recently published study, beautifully unpacked here by a science writer I respect a great deal, I can tell you that when the records for over 600,000 mist net captures in the United States were analyzed, the average rate of injury (which includes events like wing strain, cuts, stress, or broken bones) was found to be less than 0.59%, and the average mortality rate about 0.23%.

baby blue
Most bird species show remarkable calm during handling; some—like tits—have characteristic defense responses.

While those numbers are extremely low, they would still represent an unjust harm to bird populations if ringing served no useful purpose. But it serves many—too many, in fact, to describe here in detail, especially since I am quite sure you are now, like me, entirely out of cookies and tea (I switched to tea a little while ago).

Here then—highly abbreviated—is a short list of scientific and conservation-related reasons birds are ringed:

• Ringing is the primary method of understanding bird migration. (Before the advent of ringing as a systematized process, migration was a deep and myth-producing mystery.) By recovering previously ringed birds at different points on their migration pathways, we can identify important nesting, wintering, and feeding grounds, and note changes in routes. Such knowledge is not only interesting for its own sake, but an important advocacy tool for conservationists seeking to preserve habitats or demonstrate the effects of human activity or global warming on bird populations.

• Ringing is the only way to gather data on the lifespan of individual birds and thus establish longevity records for bird species in the wild.

• Ringing and recapturing birds in the same site over a sustained period can enable us to roughly determine how many birds exist in a given population, as well as how well they are surviving and breeding. Ringing can also help to pinpoint the reasons for population changes. For instance, if a particular species is becoming rarer, but we know from nest box studies that it’s successfully nesting and raising chicks and we know from mist net ringing that the rate of juvenile survival has gone down, then we know that some condition affecting young birds, but not affecting adult birds’ capacity to breed, is responsible for the population decline—and we have a better idea of where to look next.

• Ringing game birds is vital for monitoring the impact of hunting and determining if existing regulations are effective or should be changed.

Peder with protocols
This is the protocol sheet we use to record data about newly ringed birds.

As I write, I can feel the cool contours of my own ring embracing my finger. Beyond its shape it bears no other resemblance to the small aluminum or steel bands we put on birds, except for one: both represent a promise from those who put them on.

Of the promise that was made to me, nothing more need be said. I appreciate it every day.

Birds, of course, have no such feeling about the promise their ringers make to them. But I believe it exists, despite this, in the closing of each circle around each protesting leg. To me it seems at heart a very simple vow: to know, to heed, to protect, to remember, and to look for again.

Nothing But a Promise

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

Since I had it ever-so-subtly pointed out to me today by a good Swedish friend that I had not—despite my promise to spend the summer writing—made a new post here in what was deemed too long a time, I hereby make the following solemn pledge to you all.

Come back in a few days, and I will tell you a little bit more about the steps that go into processing a bird that you catch in a mist net, the physical act of ringing, and what it’s been like for me to handle live birds. I hope that will satisfy. 🙂

In the meantime, in case you haven’t been following the journey on Flickr, I have this for you, too. Don’t we all feel like this sometimes—capable of crossing the world on our wings, if only something weren’t holding tightly to our feet?

Forsärla (Gray Wagtail)

The Vagrant in Sweden

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

I heard it as soon as I swung the car door shut: a dizzy, fever-pitched fizz more like an insect’s song than a bird’s, slicing through the cool Midsommar night. The meadow in front of me, glowing in the eerie illumination of a June’s-end one a.m., looked no different from so many others here. What covered its slope was a dense mat of close-growing, un-gardened stalks of the humble wildflower that is known in English as cow parsley, and which in Swedish goes by the even more embarrassing name of hundkex: dog biscuits. There was no sign that this was a place where you might find something rare.

Stefan and I had just spent several hours feasting with his family on pickled and fermented herring, potatoes, roasted pork, and all manner of breads and cheeses, and with both beer and cool, sharp snaps in my belly I had been ready for bed a long time ago. Instead, we were drawing out the longest day of the year in a sleepy haze beside a village road. We had come to the dog- biscuit meadow to see a single, very special, vagrant.

A vagrant is a bird that has, by some mistake of birth or meteorology, strayed far from the path it was meant to follow in its life. Vagrants are also called accidentals, and both names go some way toward capturing the pathos of their situation: not only lost, but alone. Somewhere in the meadow’s stalks perched such an individual. It was a male lanceolated warbler (träsksångare). As songbirds go, the lanceolated warbler is not particularly flashy; it lacks the jewel-like colors of a bluethroat or a goldfinch. It is, however, marked by a beautiful series of dark striations on its breast, crown, rump, and flanks. To look more closely is to see that the lines are formed from tiny lance-like shapes, each one a thin oval tapering to a point. It is these that give the bird its name.

In looks and song, the lanceolated warbler is rather similar to the grasshopper warbler, a relative that spends the spring and summer breeding in this region. But compared with a grasshopper warbler, a lanceolated warbler will have more—and more distinct —streaking, a higher voice, and a well-defined, as opposed to a diffuse, border between the dark center and pale edge of each of its tertial feathers. I could not have identified these subtle differences on my own. But they had not gone unnoticed when the little warbler appeared here some nights earlier, and a rush of expert Swedish birders had already given their say-so to the characteristics that separated it from its common relative. Let us say that if this bird had been aspiring to sainthood, it would have been five times confirmed by the highest of priests.

Because we knew its provenance, Stefan and I also knew that as far as we had traveled to see it—150km from the observatory in Handöl to Östersund, where Stefan lives; 32km from Östersund to Nälden, where we had celebrated the holiday in a tiny lakefront cabin with his family; another 27km or so from Nälden to Bleckåsen—the tiny bird in the meadow had come much further. A lanceolated warbler within its normal range can be seen throughout Siberia, on the lower slopes of Russia’s Ural mountains, and in Kazakhstan, Mongolia, China, and Japan. At this time of year, a male of the species ought to have been nesting with a female in a wet, shrubby meadow somewhere perhaps a thousand or two thousand kilometers east or northeast of the spot where we stood. This one was calling for a mate it would never find.

It’s a bit like a sewing machine, Stefan had told me three mornings earlier, after his first pilgrimage to this spot in Bleckåsen. The sound coming from the meadow wasn’t, in fact, so far from what he had described—notes of metal whistling and punching, whistling and punching, at speed. It was an obsessive little racket, the kind of sound that might come reeling at midnight from beneath the door of a red-eyed tailor in a fairytale, running stitches through cloth faster than his hands could keep up. This was the voice of instinct, I thought—the voice of conviction in the face of loss.

We saw the source of that voice as soon as we descended the makeshift path that dozens of eager birders had trampled over in the past few days. The warbler had alit on a branch in the midst of the hundkex blooms, singing with its bill so wide open that I imagined a great stream pouring from its mouth. As it sang it turned its head fastidiously from one direction to another, throwing its call to all points. And the singing lasted for minutes on end. This was unusual behavior for its species.

I hate to anthropomorphize; I hope I manage to avoid it here. But witnessing this unabating, probably futile summons (futile, anyway, unless a female vagrant happened also to have been blown here), it was hard not to feel that it resounded with a note of desperation.

To many birders—especially the ones who make a fetish out of each new species, but even those who don’t—vagrants are objects of fascination. It’s no trivial thing to be able to look upon a creature that you’d otherwise never expect to see. Real though they are, vagrants are so out of place, so unexpected, and so carefully inspected for signs of authenticity that seeing one is perhaps the closest any of us will come to seeing a unicorn or a mermaid.

Even if you can relate to it, though, you might dismiss this motive for visiting a vagrant as thrill seeking. That’s why, when Ulla first heard about the lanceolated warbler, she resisted making the effort to see it. Her serious heart didn’t want to think of itself as longing after the unusual and the rare. But days later, when the warbler failed to leave, Ulla too drove up to the incandescent meadow late at night. She listened, and she felt her heart contract.

Ulla didn’t have to explain why. What runs beneath the urge to see a vagrant is something more powerful than the desire to collect a rara avis. The wonder we feel, I think, is centered on the knowledge that this creature once had a plan—had an object, had a bone-deep, gene-deep map to follow—and somewhere along the way, got lost.

Since I have spent most of my life in search of such a map, the vagrant’s fate is bittersweet heartache to me. I cannot tell you how often I have found myself envious of another creature’s indelible blueprint. I have coveted the existence of periodic cicadas, which lie years in the buried dark readying for one great emergence, and somehow know exactly what to do when that day comes.

But I never realized how devastating certainty can be when it comes undone. There’s very little use in having a blueprint if you cannot follow it, and small comfort in a well-planned route if you find yourself so far off the map that you cannot return. It wasn’t until I heard the vagrant in Sweden that I understood my good fortune. I happen to know I am wandering; I understand there’s no such thing as a home that doesn’t change with you. And so, I now believe with all my heart, I can never be lost.

*******

We should go forth on the shortest walk, perchance, in the spirit of undying adventure, never to return—prepared to send back our embalmed hearts only as relics to our desolate kingdoms.

If you are ready to leave father and mother, and brother and sister, and wife and child and friends, and never see them again—if you have paid your debts, and made your will, and settled all your affairs, and are a free man, then you are ready for a walk.

—Henry David Thoreau, “Walking,” 1862

*******

P.S. As most of you know, I’m writing a little book of essays about my summer adventures. In case you were wondering what that might look like, consider this post—which will appear in the book, with revisions—a preview. And thank you, as ever, for reading.

Hands-On

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

I’ve never believed my hands were particularly nice looking. When I was 12, I was envious of the long, slender fingers on my friend Beth. You couldn’t really hope to be an artist, I thought, without the right pair of hands. Either you were born with both the temperament and the digits—which, according to all the Jane Austen and Lucy Maud Montgomery novels I was reading at the time, arrived together—or you were doomed to a prosaic life.

I’ve also never believed my hands were particularly strong or skilled. When I started volunteering at the Field Museum two and a half years ago, it was the first time in my life that I’d really done anything useful with them. But that work, satisfying as it is, didn’t do much to transform my hands into Tom’s hands—which I watch whenever he’s working on a study skin or a taxidermy mount in the lab. Tom’s hands perform the most deft and precise motions. Yet they’re also large, callused, and muscular, and marvelously capable looking. They’ve been out in the world.

A week ago, I returned to the observatory from a long afternoon of tracking. I had just fallen from my too-tall borrowed bicycle onto a dirt and gravel road while speeding downhill, and I was feeling particularly incompetent as I walked into the yard, brushing at my bleeding lips and forehead. There I found Jennie—who grew up here in the Swedish countryside—out by the shed, fixing the bottom of the observatory’s power boat by nailing wooden planks together. “You can do anything,” I told her, meaning “I can’t.”

My hands don’t know as much as Jennie’s. They haven’t built many things, or used many tools, or been trained to keep me alive when the world goes all to hell. They’re nice hands and all; they’re just not very experienced.

Or they weren’t until now.

For the past two and a half weeks, my hands have been busy carrying field equipment, helping me push my way through birch branches and willow trees, reaching out for balance on rocks, brush, and muddy ground as I stumble up and down mountainsides, wielding rakes and paint brushes, hauling stones, helping to pull a boat by its rope, measuring and cutting wood, and—today—building an owl-sized nest box with a hammer, nails, and a great mess of splintery wooden planks.

And do you know what? Small signs of change are showing themselves on my hands. They’re a little scratched up. They’re dry and rather rough. They’ve got some cuts and scrapes and blisters on them, and a good amount of dirt seems to be baked into a couple of my fingerprints.

My hands still aren’t Tom’s hands, or Jennie’s. They’re definitely not getting any more artistic. But they’re engaging with the world in ways they’ve never done before. And I like the way they feel.

small signs of change


P.S. Here is the nest box I made today:

My first Tengmalm's Owl-sized Nest Box

And here is the Great Snipe nest I found, a few hours later, hands on my antenna.

Finding #25

Stopgap

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

I keep making mental notes about things I want to tell you, and then finding that it is suddenly midnight and I don’t have it in me to write about the ferocity of lemmings, how it is possible to hear water levels changing, why I forgive the mosquitoes their pursuit of me, what almost-fledged nuthatches sound like when they are frightened, or the way you can see rainstorms coming for hours in the sky before they actually let fall their first fresh drops.

More on these subjects later. For now, I wanted to pop in to tell you one thing:

There is at least one Great Snipe here in the mountains with the grounds to take out a restraining order against me.

Convinced she had a nest and determined to find it, I spent an inordinate amount of time today tracking and flushing, tracking and flushing, tracking and flushing the poor creature, looking each time for that longed-for circlet of dried grass containing a clutch of four perfect mottled eggs. I never saw any such thing in the locations from which she scissored herself up when I came close.

Johan has already found seven such treasures, so it’s clear that some birds are currently nesting. But after having observed that this particular female (transmitting on channel #20 on my receiver) was never found in exactly the same spot twice, I concluded that she probably hadn’t actually built herself a nest yet. I’ll go back to that spot in a few days and check again, and hopefully by then she will be well on her way to motherhood.

In the meantime, I’ll do a little penance in my head for harassing her so today.

tools of my temporary trade
Teaser view of my radio antenna. I’ll do a post about that and the rest of my equipment soon. I swear.

Things I Learned in the Space of Two Hours in Handöl

The Science Essayist is volunteering at a bird observatory in Sweden this summer.

1. Tits prefer mosses and lichens for their nests; flycatchers prefer grasses…and sometimes, reindeer hair.

2. Reindeer hair is white, slightly oily-feeling, and very soft. I would not mind stroking a reindeer.

3. Pied flycatcher eggs are tiny and a beautiful pale blue, like the color of American robins’ eggs; blue tits lay bigger, creamy eggs mottled with brown.

4. There is at least one blue tit out there in the world that is not averse to building its nest on top of a dead relative: we found a corpse tucked into the bottom of an active nest box, buried under several strata of moss, its head perfectly preserved and its body mostly eaten. It was strange and interesting, and also made me feel oddly homesick for the lab.

5. Sometimes the smallest creatures are the fiercest. (Well, I knew that one already, I suppose.)

[flickr video=5777776255 secret=b14843c52e w=500 h=284]

I should have more for you soon. In the meantime, I bid you a very good night from that special time of day over here where the sun is neither setting nor rising, but hanging out just under the horizon being beautiful.