UKARUMPA, PNG — The sun came out between downpours, and a familiar, insistent call pulled me out the door. I sat on the decaying concrete steps while mannikins swept like a small chestnut cloud through the kunai.

I have a only few days left here, whether I can believe it or not. I’ve solved so many mysteries with patience and time, but some of them remain, gnawing at my mind.

That is why I went outside — or at least, that was one of the reasons. The call has become quite familiar, but I never saw the body that produced it, not properly. I knew it was the grassbird though, so I suppose it was no longer a mystery. It was instead an unattained challenge.

The grassbirds called at intervals while the jittery mannikins fretted. Brush Cuckoos sang mournfully, and they are another challenge, but a challenge for another day.

The brisk call sounded close, and again I studied the grasses. Then, there, at the edge of a tangle my eyes caught the slightest stirring. Was it …?

Yes, and for the next few moments, I peered as if through a window into the private world of the grassbird. I watched it slipping through the stalks and blades, long tail often cocked a bit, crown red-brown in sun.

The window closed as suddenly as it had opened, as if the dense green growth had absorbed the bird like water into a sponge.

Whether the bird’s first name is Tawny, or Papuan, or something else again, the people who wear labcoats have not made up their minds.

And if the grassbird knows its name, it didn’t tell me this day. It gave me a glimpse of its world instead, and for that gift I’m grateful.

UKARUMPA, PNG — I didn’t manage to see very many birds on a brief walkabout this morning, but I did get a few marginal photographs of two of our grassland passerines.

UKARUMPA, PNG — For more than a year, I have been looking for a satisfactory, comprehensive list of the world’s birds. I thought my requirements were relatively straightforward: The list should be widely accepted, updated regularly, and available freely and electronically. But reality is not so simple.

There have been several recent attempts to list all the birds of the world and hypothesize about their relationships with each other.

Sibley and Monroe’s controversial list grows more obsolete with each new ornithological paper that’s published. It is rapidly becoming a part of history. Some of the taxonomy used in the impressive Handbook of the Birds of the World is also going out of style — unfortunately, even before the entire series has been published. (This, of course, reflects not on the value of the awe-inspiring series but on its utility as an international taxonomic standard.)

As far as I know, this leaves Clements’ “Birds of the World: A Checklist” and “The Howard and Moore Complete Checklist of the Birds of the World” as contenders for an up-to-date taxonomic standard.

Reviews of Howard and Moore have been mixed. The ABA still names Clements’ taxonomy as its standard for world lists.

Until this year, the Ibis Publishing Company has provided semiannual updates to Clements’ fifth edition. Following Clements’ death, however, the Cornell Laboratory of Ornithology has taken over his project, and the Cornell University Press will publish a sixth edition of Clements’ checklist later this year.

Because Clements’ list is copyrighted, it is not available electronically except with a few relatively expensive birding software packages. Even then, the license is for personal use only.

What Cornell will do with the list remains to be seen, but for now, it appears that the only comprehensive and relatively up-to-date bird lists will be confined to expensive paper volumes or software packages.

Meanwhile, our knowledge and hypotheses about bird taxonomy are growing and changing at a very rapid rate. DNA studies in particular are shaking up traditional views on taxonomy, and it appears the changes will continue for years to come. For example, see these recent proposals for the ‘Sylviidae’.

Though some birders grumble about the constant upheaval, I’m convinced that this is an exciting time to be a birder. But we need a taxonomic ’standard’ (see Ronald Orenstein’s comments about the nature of taxonomic lists) that can readily adapt along with our knowledge.

Birders all across the Web are wishing for a freely available electronic list that we could adopt as a de facto standard. The benefits to such a list would be tremendous. An online database could respond quickly to new discoveries, unlike a printed book of 800 pages. (See, for example, Don Roberson’s ever-changing list of world bird families.) Enterprising birders and geeks would surely create a fantastic array of new services and mash-ups to enhance our birding lives.

But the demands in putting together and maintaining such a database would be enormous. The project would require extensive ornithological knowledge and experience, great technical competence, and the time and energy required to analyze perhaps hundreds of scientific papers and other documents every year. It seems that there is no one with both the ability and the desire to undertake such a project, or at least not yet. Perhaps the day will come.

Until it does, I’m left wondering: Should I order Cornell’s new book?

KOKOPO, PNG — Crows’ eyes are blue here — blue like the sky through the coconut fronds. Their calls are high and abrupt; their tails and wings are short.

Checklists call them Torresian Crows, but I don’t buy it for a minute. Maybe one day they’ll receive recognition as a full species. This is an ornithological frontier, after all.

I haven’t had much internet access of late. I’m sorry for the long silence; maybe I can fill in the gaps someday.

UKARUMPA, PNG — Ready to stretch my eyes after a day staring at the monitor, I flopped into a chair on the porch. I elected not to grab the binocs.

You can probably guess what happened next.

I’d sat there quietly a few minutes; then, I jumped out of my chair. A raptor had appeared, and it hung in the sky, hovering high above the ground.

The fastest I could fetch my binoculars wasn’t fast enough. I returned to the porch, and the bird was gone. I was disgusted, but I couldn’t shake the feeling that the bird had dropped from the sky and still lurked somewhere in the trees below.

What would hover? I wondered. A Black-shouldered Kite, or whatever they’re called?

Long moments passed.

I almost felt, rather than saw, a pale raptor moving through the trees. By the time I brought up the glasses, it was in the open. Black shoulders. White tail.

Kite!

The bird tried to land in the flimsy branches of a pine, but it gave that up and flew to the top of a snag. As it flared to land, I had another clear (if distant) view of its large black wing patches and its white tail, which showed a tapering gray streak down the center of the upperside.

It sat there facing me, far across the stream. I could barely see its pale breast with my unaided eyes.

I saw a flash as it took off again, and I scarcely breathed as it veered toward me, approaching swiftly with deep, steady strokes of its wings. It circled once or twice, gliding briefly on V-shaped wings. Its back looked brownish gray to me, and I thought at the time that it must be young.

Then it landed in the tall, droopy conifer in the garden — the one where I see gerygones and myzomelas. But the thick foliage obscured it almost completely, and I was disappointed that I didn’t have a chance to study it so close.

Even when Carter drove into the yard on his motorbike, the bird stayed put.

But finally, it dropped, not tucking its wings and plunging but instead fluttering down on strongly uptilted wings. Its tail pointed down, and its yellow talons stretched downward too as it descended dozens of feet and — I lost it.

I thought it must have reached the ground and disappeared in the grasses. Surely it would reappear soon. As the moments stretched on, I theorized that it had been successful, that it was still on the ground enjoying fresh meat.

Movement caught my eye. Another raptor flew over the same spot, this bird all brown. I fumbled with the binoculars, and I watched the bird fly far away. I never saw its head, but I saw no bars or patches of color anywhere, and it flew with steady wing beats, very unlike the goshawks I’ve glimpsed before but never identified. I watched it until it disappeared in the shadows of the pines on the hillside.

Puzzled, I turned my gaze back to the grass where my kite had disappeared. The evening grew darker, and I wondered if the kite had flushed and vanished while I followed the other bird. June called us all for supper. So I left, not knowing what had become of the kite.

Quickly running through possibilities on the brown bird, I guessed that it could have been a Brown Falcon. Nothing else seems to fit, but then, I sure didn’t see much either.

As I started reading about Elanus kites, I quickly realized how little I knew. I remembered that the New World form had been split from the Old World form, but I had never paid enough attention to see that Australia has two species, neither of which occurs in PNG, and one of which is nocturnal. There are four Elanus species in the world — for now, at least — and the one in PNG (E. caeruleus) is the same species that occurs all the way back through Asia and into Africa.

When I saw pictures in the Aussie field guide, I was distressed to realize that I hadn’t seen black patches on my bird’s underwings. I’d had at least one good look at the underwings; why had I missed that?

Well, because caeruleus doesn’t have the black underwing patch. That’s one difference between it and the other three. Google rewarded my persistence with a very interesting paper on the taxonomy of Elanus kites, and I learned a lot about the differences among the taxa.

The paper describes hunting behaviors of caeruleus and leucurus, the New World form. Caeruleus hunts from perches, just as I’d watched my bird do, but leucurus almost never does. I never had a look that would have let me see the bird’s wing-to-tail ratio when perched, but that’s another predictable difference.

Some scientists suggest that the elanid kites (Elanus and closely related genera) are far more different from hawks (and “kites” in genera like Milvus and Haliastur) than is currently believed. They may in fact constitute their own order, showing affinities to falcons and owls.

And what of my assumption that the bird was young? I don’t have enough information to say for sure, but I’m relatively certain that it did not show pale fringes on its feathers, and I saw no rusty coloration. I didn’t find a good description of the differences between young kites and adults.

Sometimes I find the questions and information overwhelming, but I’m too enthralled to just give up. And when it does become too much, I can retreat to experience. I can see the kite dropping, dropping through the air, bright yellow talons reaching down.