Search and Serendipity

Variable Sunbirds feeding Klaas’s Cuckoo

David J. Ringer — Sat, 04 Jul 2009 20:27:09 +0000

NAIROBI, KENYA — A persistent, strident begging note emanated from the tree above our patio all afternoon. Tiny birds flew in and out, making dry ticking notes, leading me to believe that the Variable Sunbirds were feeding young. But the begging note didn’t sound sunbird-like to me. I finally got the binoculars and stepped out to investigate.

Following the sunbirds’ movements, I soon located this little creature:

Not a sunbird! Despite terrible backlighting from the late afternoon sun, I immediately suspected that this was a juvenile Chrysococcyx cuckoo. And based on its very stubby tail and limited mobility, it seemed quite young.

Every few minutes, Variable Sunbirds (Cinnyris venustus) arrived to feed the demanding youngster. Both male and female participated in the feeding. Chrysococcyx cuckoos, like many of their relatives, are brood parasites — they lay their eggs in other birds’ nests. The unwitting foster parents then raise a young cuckoo, usually at the expense of their own offspring.

The young cuckoo is already noticeably larger than its foster parents. Details of the bird’s plumage pattern and the fact that it’s being reared by sunbirds indicate that this is a Klaas’s Cuckoo, Chrysococcyx klaas, which often selects sunbirds as hosts. (Various cuckoo species prefer different types of hosts.)

Birds out my office window

David J. Ringer — Wed, 01 Jul 2009 20:03:27 +0000

NAIROBI, KENYA — My colleague Tom and I have been putting old bread and fruit outside our office window to attract birds into easy viewing and photography range. Here are some of our regular visitors:

I first started getting acquainted with Speckled Mousebirds (Colius striatus) in Cameroon two years ago. Mousebirds are distinctive birds endemic to Africa and are placed in their own order, Coliiformes, which is of uncertain affinity.

Mousebirds are odd, awkward, but sociable birds. Here two birds attempt to feed on the same fruit. They scramble rodent-like through the branches, often hanging perpendicularly and precariously rather than perching upright.

Mousebirds often feed on fallen fruit, but while on the ground, they sort of sprawl out like this instead of standing. Note the fine white speckling on this bird’s dark throat and the faint barring on its upper breast.

This is a robin-chat, a colorful, thrush-like muscicapid. I think that Rüppell’s Robin-Chat (Cossypha semirufa) is the species commonly found in Nairobi, but I’m having some trouble with the ID and would appreciate input.

Guides state simply that Rüppell’s Robin-Chats have “black” or “blackish” central tail feathers while the nearly identical White-browed Robin-Chat has paler brown central tail feathers. These are not black, but they aren’t pale brown either. It’s hard to make comparisons when I don’t know what the range of variations is. Help?

Dark-capped Bulbuls, Pycnonotus tricolor, are abundant and noisy residents.

Abyssinian (Mountain) Thrushes, Turdus abyssinicus, (a split from Olive Thrush) are the common Turdus thrush in some highland areas of East Africa. The birds here do not seem to show dark lores and pale throats like the ones in Ethiopia.

Despite their exotic name, Abyssinian Thrushes look and behave a lot like American Robins and Common Blackbirds, their congeners which are common in North American and Europe respectively. Their vocalizations are similar too, at least similar enough that the affinity is clear.

Weavers and their relatives are abundant in Africa. This is a male Baglafecht Weaver, Ploceus baglafecht, of the race reichenowi. Ploceus baglafecht is a a widespread and variable species. Compare this photo and the one below with the one I took in Ethiopia last month (the nominate P. b. baglafecht).

And this is the female Baglafecht Weaver, identified by her extensively dark crown and face. So, here’s something that’s been bothering me. What in the world does “baglafecht” mean? Mad props to anyone who knows or can find the answer!

Finally, here’s a male Red-billed Firefinch, Lagonosticta senegala. Unlike their relatives the mannikins, who hang out in little mobs, firefinches move quietly in pairs. They seem sweet-tempered — yes, I know that’s awfully anthropomorphic — and have tiny white spots on their breasts, like a field of stars.

Black Sparrowhawk

David J. Ringer — Sun, 28 Jun 2009 05:38:25 +0000

NAIROBI, KENYA –

This morning I stepped outside and saw this very impressive Black Sparrowhawk (Great Sparrowhawk), Accipiter melanoleucus, perched in a tree. It sat still for several minutes. This is a very large Accipiter, similar in size to the Northern Goshawk.

Flycatchers in Nairobi

David J. Ringer — Sat, 27 Jun 2009 13:59:30 +0000

NAIROBI, KENYA — Well, it’s a quiet weekend “at home” in Nairobi. (No, I haven’t moved here, but I’m living here for the next several weeks.) Watching birds from my balcony this morning, I saw several of the common residents that are quickly becoming familiar: Red-billed Firefinch, Variable Sunbird, Streaky Seedeater and Dusky Turtle Dove. And these two lovely flycatchers:

African Paradise Flycatcher, Terpsiphone viridis. This is a monarch flycatcher, allied with crows and birds-of-paradise.

White-eyed Slaty Flycatcher, Dioptrornis fischeri. This is a muscicapid flycatcher (also called “Old World” flycatchers). Muscicapids are allied with thrushes in the Passerida.

Paradise flycatchers are totally hot. I love the electric blue bill and orbital ring. Adult males have dramatically elongated central tail feathers (this individual does not). Birds are rufous or rufous and white above, but some adult males are pure black-and-white. I haven’t seen any white morphs around Nairobi yet, but I have seen them in Cameroon and Ethiopia. Spectacular!

Birds of Addis Ababa

David J. Ringer — Sat, 13 Jun 2009 06:26:07 +0000

ADDIS ABABA, ETHIOPIA –Well, I’ve been all over the world since I last managed to post, and I’m currently finishing up a week in Ethiopia. I had a day in the UK on my way here, and Charlie Moores of 10,000 Birds graciously took me out for a great afternoon of birding. Thanks again, Charlie! I will get a post up eventually….

Anyway, I’ve had no real birding opportunities here in Addis, but thankfully, several of the common city birds are endemic to the Abyssinian Highlands, birds like Ethiopian Cisticola, White-collared Pigeon, and Wattled Ibis. Other species are common across much of Africa, but still spectacular, like the African Paradise Flycatcher and the Red-cheeked Cordon-bleu.

I managed to get a few pictures out the office window this week:

Abyssinian Thrush, Turdus abyssinicus

African Citril, Crithagra citrinelloides

Baglafecht Weaver, Ploceus baglafecht. Both males and females of this race have green backs and crowns.

Black (or Yellow-billed) Kites are abundant.

Common Fiscal, Lanius collaris, a common African shrike.

Dusky Turtle Dove, Streptopelia lugens

Hooded Vulture, Necrosyrtes monachus

Red-eyed Dove, Streptopelia semitorquata

Red-rumped Swallow, Cecropis daurica

Streaky Seedeater, Crithagra striolata, a common finch related to canaries.

Swainson’s Sparrow, Passer swainsonii. Local member of the Grey-headed Sparrow complex, which fills the niche of the House Sparrow across much of Africa.

White-backed Vulture, Gyps africanus

A postcard from south Texas

David J. Ringer — Sun, 03 May 2009 05:34:36 +0000

MCALLEN, TEXAS — I’m still giddy from tonight’s encounter with Pauraque, and I’ve got to get up early to keep on birding, but I’m thinking of you, dear reader, and wanted to share a couple of today’s spectacular birds. I’ll post more when Charley, Lisa, and I return from our south Texas tour.

Altamira Oriole

Plain Chachalaca

Shorebirdonia

David J. Ringer — Mon, 27 Apr 2009 18:43:47 +0000

DUNCANVILLE, TEXAS — Saturday, Debbie Hatfield and I birded Richland Creek WMA (about 90 minutes southeast of Dallas) and surrounding areas. We got about 95 species for the day, including many returning migrants like Baltimore and Orchard Oriole, Indigo and Painted Buntings, Blue Grosbeak, Summer Tanager, and Dickcissel.

Shorebirding was grand in the WMA’s north unit. Wilson’s Phalaropes are beautiful and charismatic:

In phalaropes, females (right) are the more brightly colored sex. The bird on the left appears too dull even for a breeding male, so I think it’s still (partly?) in nonbreeding plumage. But I don’t know what, if anything, that means about its sex.

Calidris peeps are not so striking, but I really like working them over, analyzing subtle plumage and structural features. We had all five of the species I usually call “peeps” — Least, Semipalmated, Western, Baird’s, and White-rumped Sandpipers.

Three peeps! From left to right: Least Sandpiper, Semipalmated Sandpiper, White-rumped Sandpiper. Note that the White-rump’s folded primaries project well past the tail.

Three Least Sandpipers on the left. Western Sandpiper in right foreground. White-rumped Sandpiper in upper right.

We had a chance to study dowitchers too, which I have always found to be particularly challenging. In Texas, we have the tundra-breeding Long-billed Dowitcher and two subspecies of the taiga-breeding Short-billed Dowitcher (central hendersoni and eastern griseus) as migrants and winter residents.

This is a Long-billed Dowitcher. Several of this bird’s scapular and covert feathers show broad, blunt white tips. The white marks are confined to the ends of the feathers and do not travel up the sides, resulting in a contrasty black-and-white pattern.

These birds are the midst of molt, showing a mosaic of dull basic feathers and bright alternate feathers. The feathers on the sides of the breast have black bars and white fringes, characteristic of Long-billed Dowitcher, and some of the scapular and covert feathers that have been molted show strong white bars on the tips.

Note this bird’s very heavily marked neck and breast, another feature of Long-billed Dowitchers.

Cin-Ty Lee and Andrew Birch did some very detailed work with dowitchers a couple of years ago (two versions: New advances in the field identification of dowitchers and Advances in the Field Identification of North American Dowitchers (PDF)). This article is good too. I’m struggling to assimilate all of that stuff, but overlapping bell curves, feather wear, subspecific variation (in the case of Short-billed), and difficult structural variations leave my head aching.

I didn’t identify any Short-billeds among the dowitchers I saw and photographed on Saturday. While researching the problem, I found this gallery of alternate-plumaged hendersoni Short-billed Dowitchers. The photographs are spectacular, and they show very well some of the key plumage features of this taxon, which is the most similar to Long-billed Dowitcher in breeding plumage.

We had lots of other good water and marsh birds, including five Tricolored Herons, a Common Moorhen, several calling Soras, ibises, and most of the other herons and egrets. Ducks are mostly gone; Blue-winged Teal are still around along with a handful of shovelers, and we had a single male Lesser Scaup. Debbie spotted a lone male Yellow-headed Blackbird flying across the marsh. He seemed to be missing his tail.

We also had four Hooded Mergansers, a male and three females. The females kept flying up to a Wood Duck nest box, squabbling with the male Wood Duck. The female Wood Duck emerged from the box, and she and the male flew off, leaving the mergansers to perch atop the house and check out the entry hole. I didn’t see any of them actually go into the box. The TOS Handbook of Texas Birds notes that although Hooded Mergansers are typically only winter residents in Texas, there have been a few reports of females laying eggs in Wood Duck nests or nesting in boxes themselves. I don’t know whether something like that could be going on here, or whether the females are still headed north and just getting excited along the way.

And now for something completely different. This is quite possibly the worst photograph ever taken of a Swainson’s Warbler! But a Swainson’s Warbler it is (actually taken last week on another visit to Richland Creek).

The other lords of the air

David J. Ringer — Mon, 13 Apr 2009 23:28:11 +0000

Powered flight is a marvel possessed by only three groups of vertebrates. There are birds, of course, and bats. Birds are the usual topic of this blog, as regular readers know very well. And bats, though they are extraordinary creatures indeed, have never interested me to the same degree, perhaps because they are less accessible in many ways. Have you thought of the third group yet? It’s the pterosaurs — ancient flying archosaurs known only from the fossil record. This picture is by John Conway:

I had all the usual dinosaur books and toys as a kid. I don’t know why, but the images of pterosaurs never captured my imagination in any way. Maybe it was because they often looked so emaciated and improbable — stiff, oddly posed creatures colored green or brown. But apparently we’ve learned a lot in the last 15 years, and the latest work on pterosaurs is mind-boggling. My imagination has not only been captured, it’s being held for ransom at a secret facility somewhere in the desert.

Pterosaurs’ wings were supported by astonishingly elongated fourth digits (analogous to your ‘ring finger’). The creatures had hollow bones and and air sac systems, like birds. And they had fur! (For a brief physiological overview, see John Conway’s The Structure of a Pterosaur.)

The pterosaur above is currently identified as Nemicolopterus, thought to be a songbird-sized animal that lived in the forests of what’s now China and subsisted on insects. Chuang Zhao’s stunning depiction contains no trace of caricature and therefore makes this creature seem at once startlingly alive and absolutely alien.

Or, is it? Does that posture look familiar? It should. Vampire bats look remarkably similar when they fold their complex, membranous wings to their sides and run on all four limbs. (Yes, not only can they fly and drink your blood, they can run!) Fossilized pterosaur tracks and skeletal analysis indicate that at least some pterosaurs could move about on all fours, perhaps quite well. Which brings us to…

…Mark Witton’s breathtaking depiction of Quetzalcoatlus, a giraffe-sized pterosaur with a wingspan estimated at 10 meters or more. In a 2008 paper, Witton and Darren Naish argue against the traditional idea that Quetzalcoatlus plucked fish from the seas like skimmers or frigatebirds, suggesting instead that they fed on land like giant storks. (Greg Laden has a good summary of the paper if you don’t want to read the whole thing.)

Stunning.

And there’s more. Some artists and scientists believe that pterosaurs were brightly colored. Here’s a rendition of Tapejara by Dmitry Bogdanov:

Well, why not? Consider the Helmeted Guineafowl, for instance (Arno & Louise):

Scientists have learned some amazing things about these creatures, but there is much we don’t know and never will. We still don’t know how they actually flew. Analogies with birds and bats can be taken only so far, particularly for creatures that were the size of a giraffe. There’s only so much that could ever be deduced, even if we continue recovering better specimens and are able to refine various models and hypotheses.

Could pterosaurs rapidly change skin colors, like chameleons and some birds? Could they produce bioluminescence? Could they echolocate? Could they sing like birds? Were they polygamous? Did they emit scents? Were they nocturnal (image by John Conway)?

We’ll never know. And frankly, that makes me very sad. Pterosaurs were a very successful, very diverse group of animals that probably filled many of the niches that birds fill today. They lived, and then they died. They ruled the skies, but now all that’s left are a few fragments of their bones.

Long-lost South Florida photos

David J. Ringer — Sun, 12 Apr 2009 03:29:15 +0000

DUNCANVILLE, TEXAS — Last February (2008), my friend Tom and I had a 24-hour layover in Miami while traveling from Costa Rica to Buenos Aires, so (being the sensible folk we are) we spent the time driving around southern Florida and the Keys. We didn’t have time to pursue South Florida specialties like Mangrove Cuckoo, nor did we stumble across any, but we did get a memorable first glimpse of this very unique part of our nation. I thought that my pictures of the adventure got lost during months of travel, but I found them last week. Here are a few — enjoy!

An American White Ibis (Eudocimus albus) feeding among mangrove roots at the Florida Keys Wild Bird Center.

A Snowy Egret (Egretta thula) in breeding finery.

This isn’t a great photo, but it documents my first field experience with the “Great White” Heron, which is generally considered a color morph of the widespread Great Blue Heron (Ardea herodias). I’d always wondered just how distinctive these birds would be in the field, and as you can see from even this photo, the answer is very. (Oh, and not everyone agrees that it’s just a color morph.)

Boat-tailed Grackle, Quiscalus major. The resident population in Florida is dark eyed.

Mangrove habitat wasn’t something I’d had a chance to explore in North America before. I learned on this trip that a subspecies of the Prairie Warbler, Dendroica discolor paludicola, breeds in the Florida mangroves. They were singing when we visited in late February.

South Florida has plenty to warm a botanist’s heart too. Take for instance this spectacular Tillandsia fasiculata — or giant airplant — which is related to Spanish moss and is a distant cousin to the pineapple.

The spectacular tropical hardwood forests of the Keys are home to White-crowned Pigeons, or so I am told. Perhaps one day I’ll find out for myself.

This peculiar formation is called a ‘cypress mound.’ The land is flat, but the trees in the center of the swamp grow taller than those around the edges, forming what looks like a mound. Bald cypresses are deciduous, and they weren’t leafed out yet in February.

More photos are posted in the gallery, and putting together this post has made me eager to visit Florida again!

Birds of the Equinox online

David J. Ringer — Tue, 07 Apr 2009 13:56:43 +0000

DUNCANVILLE, TEXAS — Birdstack’s Birds of the Equinox compilation is up. There’s some interesting stuff — from Clare’s London-esque account of birding in the High Arctic to srvancott’s adventures in my old stomping grounds, Papua New Guinea. And I contributed a post about birding along the Trinity River in Dallas. Check it out!