Sunday, June 19, 2011

A new hybrid hummingbird from Honduras

Our monthly bird monitoring pulse in Monte Uyuca, Honduras, yielded a surprise this week in the form of this hummingbird, an apparent hybrid of Azure-crowned Hummingbird x Berylline Hummingbird. Although hybridization is relatively common in hummingbirds, we believe this to be the first report of this particular combination. We're preparing a short paper documenting this remarkable find.

Roselvy, Lya and I had just started our bird banding Thursday morning and this was the very first bird I pulled out of the nets. Not recognizing the species, I was excited that we captured yet another new hummingbird for the station, after three new hummingbird species last month! A review of the Howell & Webb guide, however, quickly made us realize that none of the species found in the region fit this bird, and that we were holding in our hands either a vagrant or a hybrid.

The second possibility seemed the more obvious, and once we figured that out, it didn't take us long to arrive at the most likely parental candidates.

In this partial side view, the bird looks much like a regular Azure-crowned Hummingbird, a locally abundant species.

Turning the bird a little, however, reveals a heavily spotted throat and breast, where Azure-crowned has more white. The crown is not blue ("azure"), but green. (Go back a few blog posts for shots of a regular Azure-crowned Hummingbird.) Berylline Hummingbird has a green throat and crown.

The tail of this individual is not at all like an Azure-crowned tail, but a lot like a fresh Berylline tail. The purple gloss in the tail of Berylline hummingbird tends to fade to rufous on more worn individuals, usually notable on the outer rectrices especially.

Beautiful tail!

Here's a view of the underside of the bird, showing a mix of characters of Azure-crowned and Berylline Hummingbirds.

Berylline Hummingbird has a large rufous flash in the wings, absent in Azure-crowned. This individual has a weak rufous flash.

This weak rufous flash is also visible on the upperside of the wing.

What a lovely bird!

There's an extensive body of literature on hybridization of hummingbirds, handily summarized here. Intra- and intergeneric hybrids have been described for various Amazilia species, including Berylline, but apparently not Azure-crowned. The latter is common at the study site, Reserva Biológica Monte Uyuca near Tegucigalpa, Honduras, while the former has never been recorded there - at least not by us, during monthly banding pulses that started in January of 2010. Berylline does occur in Honduras, reaching the eastern edge of its range in the area of the study site.

We took photographs and measurements, before we released it back into the wild.

Postscript 2 July 2011:
It seems this hybrid has been reported once before, by a French ornithologist who sorted through the specimen collection of the British Museum, encountered what he thought was this combination, and published his notes. See Jacques Berlioz, 1932, Notes critiques sur quelques Trochilidés du British Museum, Oiseau 2: 530-534. Berlioz describes his find as the probable result of a cross between Azure-crowned and Berylline Hummingbirds, showing a perfect mix between the two parent species. He notes that this individual was collected near Jalapa, the capital of the Mexican state of Veracruz, where both species occur.

Thursday, June 9, 2011

Spotted Rail

Spotted Rail is a large rail from Central America, the Caribbean and parts of South America. Like most rails a highly secretive bird, this species is poorly known and patchily distributed throughout its wide range. Neither NatureServe nor the IUCN mention it for Honduras. Mark Bonta & David Anderson's Birding Honduras: A Checklist and Guide (2002), however, do list it for Honduras as a "possible breeder", citing a 1993 thesis by a UNAH student who encountered the species when she made an inventory of the birds of Lago Yojoa.

Today, Oliver and I were surprised to see this individual in the Tegucigalpa zoo. Apparently, someone had brought it in about a year ago. From what we understood, a woman from Tegucigalpa brought it in, although it was not clear where she had found the bird. At the time, the bird was injured, and the zoo's vet operated on one of the rail's legs. Now, a year later, the bird seemed to be in fine condition, perhaps ready for release back into the wild.

Bonta, M. & D. Anderson. 2002. Birding Honduras: A Checklist and Guide. EcoArte, Honduras.
IUCN Red List, downloaded 9 June 2011.

Saturday, June 4, 2011

Cinquera's butterflies

Today a couple of butterfly shots from Cinquera, El Salvador, where Roselvy and I went to take a little break from the accident and its tedious aftermath. I did manage to catch the flu the night before we left, so here we are, taking it a little easier still. It's very hot here and the flu has knocked the energy out of me. We've been on a couple of walks in the nearby forest but have not birded or butterflied it quite as thoroughly as we would have liked. We lucked into great and prolonged looks at a Thicket Tinamou walking on the forest floor. This is not a rare bird, but far more often heard than seen.

The butterflies at the top are Guatemalan Kite-swallowtails, common during the rainy season in edge habitat of Central American dry deciduous forests.

Another attractive lep we found yesterday is this Shining-blue Lasaia. Find these and other butterfly photos taken in El Salvador on the Mariposas de El Salvador Facebook page.