Friday, May 28, 2010

Banding in Monte Uyuca

This little ball of feathers is one of many, many hummingbirds we caught this week in Monte Uyuca, Honduras. It's an Azure-crowned Hummingbird, a common pine-oak resident that here in Monte Uyuca, a forest with an exceptionally well-developed middle layer, reaches high densities. This may be one of the plainer species, but the azure crown for which it is named is spectacularly beautiful. Brilliant colors on hummingbirds, however, are a product of refracted light, and are only visible from certain angles. From this angle, it does look rather plain.

The bird has just been processed, and is ready for release. They sometimes wait a little before takeoff. One moment it sits quietly in your hand, the next moment it blasts off full throttle.

This is a female Magnificent Hummingbird, a larger species. In SalvaNATURA's bird monitoring program, we don't band hummingbirds; a special permit is required for that. Thus, processing a hummingbird means determining its age/sex class; measuring its weight and its wing cord; assessing its breeding condition, its molt condition, and fat score; and determining flight feather wear by looking at the four outermost primaries. The tip of the right outermost rectrix (tail feather) is cut, and the bird is released.

We left San Salvador Monday morning and met with Honduran forestry staff at the ICF in Tegucigalpa in the afternoon; Monday late afternoon we arrived at the site. Although not fully recovered from the flu that kept him at home last week, Carlos Zaldaña joined Roselvy and me on this trip. In Montecristo, we had occasional assistance from park rangers. Here in Uyuca, it was just the three of us. We caught so many birds - nearly 200 in 25 hours - that it would have been difficult to do this with a crew of just two (one of whom - me - being less experienced). Especially hummingbirds need to feed constantly and have to be processed quickly. The first day of banding, Tuesday, we caught 103 birds, 70 of which were hummingbirds. Azure-crowned and White-eared Hummingbirds were particularly numerous, as were Green-breasted Mountain-gems, a hummer as beautiful as the name suggests. I did not take many photos on this trip, partly because we were just too busy processing birds and partly because it was overcast and dark most of the time. The top two photos show a few rays of sunlight but we had mostly light rain.

This Anna's Eighty-eight (Diaethria anna), a typical cloud forest denizen, found the collar of my rain coat to be infused with delectable salts and minerals from sweat, and fed on it for quite some time.

It's interesting how this site shows a mix of pine-oak and cloud forest residents. Birds that are primarily associated with cloud forest, like Slate-colored Solitaire and Resplendent Quetzal, mix here with pine-oak birds like White-eared Hummingbird, Olive Warbler, and Crescent-chested Warbler. Birds like Yellowish Flycatcher and Mountain Trogon, typical of transitional zones between pine-oak and cloud forest, are found here also.

Sunday, May 23, 2010

Banding in Montecristo

I just returned from a great 5-day bird banding trip to Parque Nacional Montecristo, in the northwestern mountains of El Salvador. I assisted one of SalvaNatura's bird monitoring staff, Roselvy Juárez, filling in for another SalvaNatura bird bander, Carlos Zaldaña, who was sick this week. The site consists of cloud forest at higher levels, and pine-oak forest at lower levels. SalvaNatura has been monitoring bird populations here for a number of years with two field stations, one in the cloud forest and one in pine-oak.

The first couple of days we worked in the cloud forest, where birds like the above Spotted Nightingale-Thrush are common. We caught a bunch of these beautiful but otherwise rather elusive birds.

Other very cool birds we caught in the cloud forest included Scaled Antpitta, Black Thrush, Tawny-throated Leaftosser, White-faced Quail-Dove, Blue-throated Motmot, Grey-breasted Wood-Wren, Slate-colored Solitaire (quite a few), Common Bush-tanager, and Golden-browed Warbler (several), among others.

Wednesday morning I briefly tried for Cocoa Woodcreeper, a species that was recently found at the site as a first record for El Salvador. Oliver Komar, who found the bird with Álvaro Moisés a few months ago, told me where they heard it. This was about a 20-minute walk from the banding station. I went out there knowing I'd have to be incredibly lucky to find it in very little available time and without playing a tape for it. I didn't see or hear that bird.

A bird that I am very familiar with but had never seen up close was this Rufous-browed Peppershrike. It's a bit of a generalist. We caught this individual in the pine-oak forest, but I've also heard it in scrubby edge-habitat in Cuscatlancingo for example, a suburb of San Salvador. Peppershrikes are very large vireos that feed on insects as well as fruit. They sometimes associate with mixed warbler flocks, and briefly become flock members, before continuing on their own. It's not uncommon in Montecristo, though it's only been captured a handful of times there. Last week we caught two individuals.

Here another familiar Central American pine-oak resident, Bushy-crested Jay. This bird too is common at the site but usually stays higher in the canopy, and is not frequently caught in the mistnets. Having seen groups of Bushy-crested Jays at practically every field site for the Golden-cheeked Warbler winter monitoring project I've worked on, I was really excited to find one in one of our nets. As I extracted it, I learned what incredible strength it has in its feet and bill. "This," as I said to Roselvy, "is a bird with personality."

Here I am holding it after I banded it. Note the raised crest of this excited bird. It pecked a little at my hand and also tried to remove the band I had just put on its right leg.

Obviously the neotropical migrants that winter here are all gone, so we only caught residents. This is a young Ochre-bellied Flycatcher, a bird that ranges from SE Mexico all the way to Ecuador and Brazil.

Magnificent Hummingbird. This is an adult male. Click on the photo for more detail. Aren't those colors fantastic?

One of the last and most exciting captures this week was this Olivaceous Woodcreeper, a very small woodcreeper that is not known from any other site in El Salvador and is not at all common in Montecristo. This was only the second time for this species to be caught in the bird monitoring program here.

After we released it, it landed in a tree nearby.

Tomorrow morning, I'm off to Honduras, for another banding trip, this time at Monte Uyuca. This site also happens to be one of the Golden-cheeked Warbler sites, and in late January and early February I was there also, first to collect GCWA data, and then to assist with bird monitoring. This time of year there won't be any goldencheeks there, obviously, but there will be a bunch of really cool birds and butterflies for sure. More about that next time...

Monday, May 17, 2010

Pulling an airplane

I'm currently volunteering for SalvaNATURA, a conservation NGO here in El Salvador. My volunteer work here usually consists in field work like assisting with bird banding, or office work like contributing photos to SalvaNATURA's audiovisual database, collaborating on reports or press releases, or whatever other capacity I can somehow be useful in.

Yesterday, I found myself pulling an airplane!

Rather to my surprise, I was asked at the last minute to fill someone's spot on the team to pull an airplane 50 m. This event, organized by SalvaNATURA, was a fundraiser for the conservation of biodiversity in El Salvador. Twelve teams competed to pull an airplane over a distance of 50 m in the shortest amount of time.

Here's a picture of the team that won, Benson Communications. On the right, in the orange safety vest, SalvaNATURA's Executive Director Álvaro Moisés, and on the left, in a white T-shirt, SalvaNATURA's Communications staff and presenter of the event, Rocío Juárez. Members of this winning team wore Flintstones outfits, and certainly exhibited primordial strength.

Our team, which went first, actually came in last. In fact, we didn't even finish! There was some discussion about whether certain team members perhaps stopped pulling, thinking we had finished already. Personally, I think the pilot in the cockpit braked too early, for the plane came to a sudden halt while we were still pulling.

This Airplane Pull was the second event of this kind. Another, longer-running fundraiser each year is SalvaNATURA's birdathon. Please consider becoming a sponsor of bird conservation in Central America.

I'm about to go on a bird banding expedition to Montecristo, in the northwestern mountains of El Salvador. I'll be offline this week, but will probably find time to post about this field work sometime next weekend.

Tuesday, May 11, 2010

Snail Kites over Cerrón Grande

This bird, carrying a snail in its bill, is of course a Snail Kite. I photographed it today during a 2-hour boat ride on the Embalse Cerrón Grande (sometimes called Lago Suchitlán), some 50 km north of San Salvador. Suchitoto is a pretty, colonial town near this reservoir. The town has been there for centuries; the reservoir, however, has not. It was created in the winter of 1976, when a hydroelectric dam was built.

Even more recent than the lake here is the bird: according to wikipedia, Snail Kite was first recorded in El Salvador in 1996 - 20 years later. Indeed, Howell & Webb's Guide to Birds of Mexico and Northern Central America does not show this bird for El Salvador, nor does the BNA account for the species. Both publications date from 1995.

I don't know if breeding has been recorded in El Salvador for Snail Kite. Today, I only saw adult males, no females or immatures. I wondered if maybe the females were incubating, but as I later learned, in this species incubation is shared by both sexes, with the females doing most of the incubation at night (Sykes et al. 1995). Given that scenario, I would have been at least if not more likely to see feeding females in the middle of the day...

It seems likely to me that Snail Kite breeds here, though, given the local abundance of apple snails...

Postscript 8 June 2010:
In Aratinga 4 (2010), the organ of the Salvadoran branch of Partners in Flight / Compañeros en Vuelo, which just came out today, Salvadoran biologist Ricardo Ibarra Portillo describes two Snail Kite nests found in July of 2008 at this very site! He also mentions that prior to these records, the species had already been found to nest elsewhere in El Salvador, in Lago de Guija to be exact. A paper describing first breeding of Snail Kite in El Salvador is in preparation.

Cited literature:
Howell, S.N.G. and S. Webb. 1995. A Guide to the Birds of Mexico and Northern Central America. Oxford University Press, New York
Sykes, Jr., P. W., J. A. Rodgers, Jr. and R. E. Bennetts. 1995. Snail Kite (Rostrhamus sociabilis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/171

Sunday, May 9, 2010

Wandering Tattler

Yesterday I set out for Los Cóbanos, a small community on the (Pacific) coast of western El Salvador, in hopes of encountering 'rock-pipers', a collective name for western shorebirds found on rocky shorelines. Some species in this group don't winter in Central America, so down here, looking for rock-pipers really means looking for Surfbird and Wandering Tattler. I also hoped to see a Red-billed Tropicbird - not a shorebird but a bird associated with similar habitat.

I knew Surfbird would be harder to find, but, as my friend Oliver Komar said, I'd have a good chance of finding some Wandering Tattlers. And indeed I struck out on Surfbird, but I did find a couple of Wandering Tattlers.

Wandering Tattler is a shorebird that breeds in Alaska, the Yukon and northwestern British Columbia, and winters throughout all but the southernmost portions of the Pacific Basin. It's not a common species, with current population estimates ranging from 10,000 - 25,000 (Gill et al. 2002). In spring, migrants move north from March through early June, while most subadults (i.e. those 10 - 34 months of age) remain on the non-breeding grounds through second and likely third boreal summers (Gill et al. 2002). Second and subsequent prealternate molts (i.e. into breeding plumage) take place on the wintering grounds from February onwards and are completed in May (Gill et al. 2002).

Both of the birds I observed were in basic, or non-breeding plumage, and likely subadults.

In alternate (breeding) plumage, this bird has heavily barred underparts. Basic-plumaged birds have whitish underparts. Note that the bird I photographed has a few dark feathers on the white belly and lower breast: an older subadult perhaps?

Walking around, this bird sometimes 'bobs' in the manner of a Spotted Sandpiper, although - from what I observed on yesterday's individuals - certainly not as frequently as that species.

I also found this Whimbrel, a bird that winters here. An influx of northbound migrants from points further south is noted in Central America from mid-March to early May (Skeel & Mallory 1996).

Incidentally, I did see a Red-billed Tropicbird, but I didn't get very satisfying looks, or indeed any photos. This was a 'life bird' for me, and exciting as it was to add a lifer, the excitement was tinged with a bit of disappointment, for the bird did not come close. It wasn't far out over the ocean; in fact I saw it flying over some scattered rocks near shore where I had birded some 30 minutes earlier. Immediately obvious was its odd way of flying, with rather fast wing beats that did not seem to propel the bird at a concomitant speed; I could also make out dark outer primaries. Beyond that, I was not able to see very much detail on this bird, and I hoped to see it or a conspecific at closer range. Despite some time spent searching air space over the water, this did not happen. I did see some Franklin's and Laughing Gulls, and many Black Terns, as well as several Royal Terns. I had hoped to see some Blue-footed or perhaps Nazca Boobies as well, but didn't see any sulids.

Literature cited:
Gill, Robert E., Brian J. Mccaffery and Pavel S. Tomkovich. 2002. Wandering Tattler (Tringa incana), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/642
Skeel, Margaret A. and Elizabeth P. Mallory. 1996. Whimbrel (Numenius phaeopus), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/219

Friday, May 7, 2010

Two heliconians and a cattleheart

This magnificent creature is a Heart-spotted Heliconian, or Heliconius hecale. It is found from Mexico to Colombia. I photographed it yesterday afternoon, in the botanical garden of San Salvador.

Heliconians, sometimes called longwings, are part of a subfamily of mainly tropical butterflies, formerly considered a distinct family, but now united with the fritillaries in the subfamily Heliconiinae. Together with fritillaries, crescents, checkerspots, milkweed butterflies, satyrs and many other subfamilies, heliconians belong to the family of so-called brushfoots (Nymphalidae). Like all members in that family, the front pair of legs are greatly reduced and covered with short hairs. In the field, it looks like they only have four instead of six legs, like all other insects.

Here's another shot of the same individual.

Also nectaring there was this heliconian, Acting Heliconian, or Eueides vibilia.

The larvae of most heliconians feed on passion vines, which contain toxic chemicals. This causes the adult butterflies to be unpalatable to predators, such as birds. Note that this particular individual shows some damage in the left forewing. Did a bird peck at it, or did it damage its wing in some other way?

The plant it's feeding on is common in Central America and a favorite among nectaring butterflies.

Cattlehearts are not brushfoots, and are more closely related to swallowtails. This is a Pink-checked Cattleheart, Parides eurimedes, a fairly common Central American species found from Mexico through northern Colombia.

As far as my computer problems are concerned I'm not out of the woods yet, but I am somewhat operational now with a largely empty new hard drive.

Tuesday, May 4, 2010

Computer crash

On the eve of my flight to El Salvador, one of my worst nightmares came true. My little Macbook crashed. The startup screen never got beyond what you see above; forever it would search for the hard drive.

I know I am to blame, because the last time I started the computer, it warned me that my hard drive was almost full, and that I needed to archive some items. I did this but at the same time imported new photos from the camera, with a net result probably close to zero. I should have archived much more but thought I could wait a day. My OS just shrugged its shoulders, thought to itself ¨OK be that way, you #$%/!...¨and crashed.

These things never come at an opportune time, but a day earlier would have made a world - or at least half a continent - of difference to me. I backed up the entire machine a couple of months ago, but to a hard drive that I don´t have with me right now...

I´ll work something out.

The blog will continue, but it may be a few days before I have everything back in working order. Please bear with me as I try to get organized...