Monday, February 23, 2009

Playa Las Hojas

I’m back in El Salvador for a couple of weeks. I’m here volunteering to assist principal investigator Oliver Komar with data processing of the Golden-cheeked Warbler data that I and others collected on the wintering grounds in Central America these past three winters.

In other words, office time. These days I don’t spend as much time in an office environment as I used to, but two weeks is totally fine for me. Plus, I get to do more birding in El Salvador in between.

Like yesterday, when Oliver, his wife Lorena and his daughter Yvonne and myself went to Playa Las Hojas, an estuary near the airport. Other SalvaNatura staff members Roselvy, Oscar and Lety joined us, to look for a rare gull photographed at this location two weeks earlier.

The gull was a dark-mantled, yellow-legged gull, most likely a Yellow-footed Gull. I saw photos of this bird a couple of weeks ago, and was keen on seeing it in the wild.

Well, we found a large concentration of shorebirds, herons, terns and gulls – Laughing Gulls – but no larger gull species among them.

Black-necked Stilts were quite numerous at this site. I think we saw more than a hundred. This bird came close enough for a photo.

Probably the most interesting sightings were of several single sulids, one of which appeared briefly – and barely – within the range of my camera. These photos are so heavily cropped that you can almost count the individual pixels, but all the same I think it should be possible to determine the species based on these photos. Shall we? (Please click on the photos for larger views.)

Let’s first determine the age of the bird, and review the possibilities. The bird in this photo appears to be an immature bird, although we should probably include adult Blue-footed Booby as a possibility. That’s a bird whose adult plumage isn’t as clean-cut as that of the other sulids. However, we can eliminate it on the basis of the dark head: an adult bluefoot would have a whitish head. Our bird has a mostly dark head, with mostly dark underwings but lighter underwing coverts. The tail on our bird is light, and there seems to be a bit of a light collar visible on the neck.

Brown Booby is a candidate, but it can be eliminated on the basis of the upperside: both adult and immature Brown Boobies have all-dark uppersides, including dark tails. Masked Booby can be eliminated on the tail pattern; it has a light rump but a dark tail. Our bird has a light tail. Red-footed Booby, another candidate, has all-dark underwing coverts, which our bird does not show.

Overall, the bird that fits much better is immature Blue-footed Booby. It is a large sulid, often seen from land. It has a mostly dark underwing, with light underwing coverts. It has a pale tail.

We saw three individuals in total, the other two even further away than this one. We were unable to identify them in the field, but the other two may have been the same species.

Monday, February 16, 2009

Rufous-capped Warbler

Today a picture of a Rufous-capped Warbler, one of the most common birds in the dry scrub forest here at Laguna de Apoyo. We're in the dry season, so the forest is a half-open mixture of greens and browns, with many bright yellow flowers in tree crowns. Walking the trails, you will occasionally see a Rufous-capped Warbler going about its business. It’s when you whistle the song of the Ferruginous Pygmy Owl that you discover just how abundant these warblers are around here. From patches of forest that seemed ‘dead’, suddenly several Rufous-capped Warblers appear, all busily looking for that owl. No matter where you do this, there are always Rufous-capped Warblers around to come and check you out. They’re not shy and will come close, but quickly lose interest when the ‘owl’ turns out to be just a birder.

Wednesday, February 11, 2009


I spent my weekend shorebirding in southwestern El Salvador, to help collect data for a monitoring project organized by SalvaNatura, a Central American conservation NGO. Jeffrey McCrary and I drove all the way from Nicaragua to El Salvador, where we met up with organizer and co-counter Roselvy Juárez. The three of us then visited a bunch of coastal spots on Saturday and Sunday to identify and count shorebirds. Robin Bjork, also of SalvaNatura, augmented our team on Saturday.

I’m not a seasoned shorebirder by any means, although I suppose I’ve gotten a little better over the years. However, this was the first time for me shorebirding in Central America. I was pretty excited about this opportunity, and didn’t really mind spending so much time in the car. We had a badly scratched copy of Led Zeppelin’s Latter Days with us, and just played it over and over and over.

On both days we encountered several larger shorebird flocks and many smaller pockets with birds scattered everywhere along the edges of rivers or small inlets. We found some Black-necked Stilts and Greater Yellowlegs (pictured above), as well as many Least Sandpipers, some Western and Semipalmated Sandpipers, lots of Semipalmated and Wilson’s Plovers, a few Killdeers, many Black-bellied Plovers, many Whimbrels, one Long-billed Curlew, a few Marbled Godwits, lots of Willets, several Short-billed Dowitchers, and a few Lesser Yellowlegs.

Least Sandpipers were by far the most abundant shorebird species we found.

When sorting through large numbers of shorebirds, you're looking mostly for subtle - sometimes dramatic - differences or irregularities. Here's a bird that, unlike all others we saw, is still in (heavily worn) juvenile plumage. Instead of wearing an understated gray office suit like everybody else, this bird is still wearing the equivalent of a ragged jeans and t-shirt. Having studied this bird for some time, I think it's probably a Least Sandpiper, based on structure more than on plumage. The bill, for example, is finely tipped and slightly droopy. Leg color is difficult to judge in this picture, although the submerged right foot appears to be light green or yellowish, which if correct would be diagnostic, of course. The legs appear darker, but they may be mud-stained. Click on the picture for a bigger view.

The bird probably has some kind of hormonal aberration going on that prevented it from molting into basic plumage last fall.

Accommodation was provided to us by SalvaNatura at one of their national parks, El Imposible. Never having birded there either, I sort of got that thrown in as a bonus. Monday morning – on my birthday – Roselvy and I went birding in El Imposible, before we headed back to San Salvador. Got two lifers that morning: a beautiful male Great Curassow, and an equally beautiful Fan-tailed Warbler!

Note to my readers: internet is really spotty at my current location, so I will likely post less often than usual.

Tuesday, February 3, 2009


These are euphonias of course, almost certainly Scrub Euphonias. Scrub Euphonias are common birds around Laguna de Apoyo. I hear ‘em all the time. When I took the photo, I just thought it was a great moment, an adult male feeding what I assumed was a young bird, or possibly a female.

Later on, looking at this photo on my computer, I started thinking. Wow, I thought, there’s an awful lot of yellow on the crown of that male euphonia… Scrub Euphonias have less yellow there than other, similar euphonias. The yellow on this bird extends to just a little beyond the eye, while the Scrub Euphonias I know – and the ones depicted in the guides – all have a yellow crown patch that ends just before the eye.

So I started wondering, which other euphonias are there to consider?

Well, there’s Spot-crowned Euphonia. It has a bit more yellow on the crown than Scrub – the spots are only visible from certain angles.

Here’s a photo of the same bird showing the crown really well. There are no crown spots visible, so I think we can rule out Spot-crowned. The female Spot-crowned, incidentally, has buff underparts and a buff crown spot, which the female/juvenile type bird in our photo doesn’t have. (I don’t know if a juvenile Spot-crowned would have the buffy coloration.) Spot-crowned is found in neighboring country Costa Rica, not in Nicaragua.

Orange-bellied Euphonia (which incidentally has a yellow belly) is from even further afield – South America – with records from Panama. It has more yellow on the crown, in fact a bit more than our bird. Altogether an even more unlikely candidate, one we probably don’t need to consider.

A bird that is found in Nicaragua is Yellow-crowned Euphonia. It has a lot more yellow on the crown than Scrub. As far the yellow on the crown is concerned, the bird in the photo is almost intermediate between Scrub and Yellow-crowned.

The birds I photographed are probably just Scrub Euphonias. There may be some regional variation in the amount of yellow on the crown that I wasn’t previously aware of. It has a fairly large range, all the way from Mexico to western Costa Rica. Two groups are known; one with a yellow vent and one with a white vent. This is the yellow-vented variety.

All in all, these birds provided an opportunity for me to study yellow euphonias with black throats a little bit more.

Postscript: Dana Gardner's illustration of the male Scrub Euphonia in the excellent Stiles & Skutch Guide to the Birds of Costa Rica actually shows exactly the same amount of yellow on the crown as the bird in my photos. This confirms the ID. Now I'm even more inclined to think that there is at least some clinal variation in the amount of yellow on the head, from less yellow on northern birds to more yellow on southern birds.

Sunday, February 1, 2009

Butterflies from Nicaragua

Today some photos of butterflies I found around the Spanish school here in Laguna de Apoyo. I haven’t been out much, devoting all my time in the mornings to the study of Spanish, and most of my afternoon time to practicing what I’ve learned, and just hanging out, socializing with the other students. The Laguna de Apoyo has a pleasant, relaxing atmosphere.

This afternoon I went out for a walk on the hillside behind the house. I was joined by Simba, one of the dogs here, who cheerfully ran ahead whenever I stealthily tried to approach a butterfly. With my old Zeiss bins I was doubly disadvantaged: they’re great, but they don’t close focus. I should have brought the Nikon Monarchs instead. With those and without the dog, I probably would have identified more than the meager 10% of butterflies I saw this time. I was pleasantly surprised by the variety of species I encountered here, even though I haven't been able to identify the majority of them just yet.

The butterfly at the top is called a Four-spotted Sailor (Dynamine postverta). It’s a male; the females have brown with white stripes on the upperside.

This is the underside of the same butterfly. It landed on the porch of the school during our coffee break.

This is a Two-eyed Eighty-eight (Callicore pitheas), a beautiful species with red and black bands on the upperside. I saw a brilliant fresh specimen also, but only this tattered thing was willing to pose for a picture.

A familiar species throughout Central America, this Gray Cracker (Hamadryas februa) perched on a tree at breast level. An easy photo target.

This is some brown-skipper spp, but I don’t know which one. It’s quite worn obviously, but if anyone can help me identify it, I’d appreciate hearing from you!

Tomorrow, Aura (one of the language teachers here and also a field tech on the Golden-cheeked Warbler project) and myself will go out looking for more butterflies in these parts. I will take a short break from my language studies and focus a bit more on birds and butterflies. Next weekend, Jeffrey and I plan to help folks in El Salvador with shorebird counts, and then I will return for a last week of language studies here in Nicaragua.