Month: April 2015

Some birds are common, some are tough to see, and others are downright rare as mangos in the arctic. As if a tropical fruit next to a Gyrfalcon wasn’t improbable enough for you, we also have these bird species that are enigmas. These are situations like the 21st century Ivory-billed Woodpecker, Pink-headed Duck sightings, and in Costa Rica, the Alfaro’s Hummingbird. If you want to look for Alfaro’s Hummingbird, scour the high elevations of Miravalles Volcano but don’t get your hopes up. Only one specimen was ever collected, and subsequent searches came up zilch.

I don’t want to discourage searches for the Alfaro’s by any means because after all, who knows? Not to mention, you will probably see some cool birds anyways and have close encounters with other tropical biodiversity. However, if you really want to solve a bird enigma in Costa Rica, give a shot at finding the Wing-banded Antbird.

We know that this bird does indeed exist and it’s not even endangered. BUT, what we don’t know is if or where it occurs in Costa Rica. In Stiles and Skutch, the Wing-banded was mentioned as a possibility based on one possible sighting in the forests of the Fila Carbon in southeastern Costa Rica. No sightings have been substantiated since then BUT…it…just…might..occur (if William Shatner was a birder, that’s how he would say it…).

Seriously though, I believe that this funny cross between an antthrush and an antwren probably does occur in Costa Rica. Or, at least it did, if it hasn’t recently been extirpated from the country. It couldn’t have been widespread because if that were the case, the antbird would have turned up in a mist net somewhere. So, it sure ain’t or never was common but why insist that it’s a possibility anyways?

I wish I could say that I have seen or heard one but nope, that wouldn’t be honest. However, I did speak with someone who insists that he did see one and not just once but twice. He was a guide who worked at Rara Avis for many years and therefore knew the birds in that area quite well. I found his story to be very credible because after all, he wasn’t exactly bragging about it. Basically, he said that when he saw the bird, he didn’t know what it was it because it didn’t look like any of the birds in the book nor like any he had seen around Rara Avis during literally years of birding. He said that the only bird it matched was the picture of the Wing-banded in Stiles and Skutch. Not only that, but his description of its behavior also matched that for our enigmatic target species. He also showed me exactly where he had seen it. Despite always looking for it, though, he never saw it again after a brief second sighting.

No picture, so no inclusion in the guide but if one considers that his sighting came from a nearly inaccessible area of dense foothill forest around 600 meters elevation, that could partly explain why it hasn’t been found again or at other sites. Interestingly enough, that elevation is somewhat similar to the elevation where Josh Beck and Kathi Borgmann found Wing-banded Antbird at Cerro Musun, Nicaragua. What? It lives in Nicaragua and Panama but not Costa Rica? Yes, but as strange as that may seem at first glance, “leap-frog” distribution patterns occur for a number of taxa in tropical forests (probably explained by evolutionary history and tropical forest ecosystems being more heterogenous than we think). BUT, maybe it does (or did) live in Costa Rica albeit in the following situations:

• Low density populations: This is the case for most tropical forest species and maybe even more so for the Wing-banded Antbird. After all, it doesn’t appear to be common in most parts of its range.

  

• Large areas of lowland and foothill rainforest: No, it was never recorded at La Selva but maybe it never lived there either. Maybe it lived in the hilly rainforests of the San Carlos lowlands, now mostly deforested and never adequately surveyed before the trees were cut down. But what about foothill sites like the Arenal area and Braulio Carrillo? Maybe it never occured there either or perhaps it just lived in spots with the right microhabitat.
• Microhabitat: Speaking of microhabitats, Josh and Kathi noted something else about their sighting- the bird was found in an area of old growth forest with an open understory. I have heard others say the same thing about sightings of this species in Panama and the Guianas so maybe that is the key to finding them. If you don’t find this particular microhabitat within a large area of primary forest, then maybe you are looking in the wrong place.

But back to why it might live in Costa Rica. The possible sightings from Rara Avis/El Plastico aside, there are definite records for this species from Refugio Bartola, Niacaragua. This amazing gem of a site is literally across the river from Costa Rica. Sure, rivers can act as barriers for species like the Wing-banded Antbird BUT when one takes into account that very few surveys have taken place in Costa Rica just across the San Juan river, and that this area (Crucitas) and nearby is rarely if ever visited by birders, it sounds like a worthwhile place to search.

So, based on the information here is where to look for Wing-banded Antbird in Costa Rica:

• Hilly forests in the Las Crucitas area: This includes the forests just east of Las Crucitas and indeed, I think that area is the place where the bird occurs because based on Google Earth, there seem to be intact rainforests at elevations up to 200 and 300 meters in elevation. I’m not sure if hilly areas play a factor but they might if such topography results in well-drained forest.
• Forests in the Maquenque and Laguna del Lagarto area: If the hilly forest west of Maquenque can be accessed, this seems like a good place to look. The same goes for rainforests near Laguna del Lagarto. It wouldn’t hurt to look near those lodges as well but since they have been well birded, the presence of the species at those sites doesn’t seem likely.
• El Plastico and Ecolodge Yatama: El Plastico is on the way to Rara Avis and one of the spots where a possible sighting occured. Ecolodge Yatama is near there and situated in a large area of good forest. Elevations are around 400 to 600 meters.
• Fila Carbon and the base of the Talamancas: Since a possible sighting occured there, why not check again? Also, given the amount of habitat and few surveys carried out in forests along the base of the Talamancas, it’s worth checking there as well. Sites to check would be Yorkin, Hitoy Cerere, and Barbilla National Park. Since there are no sightings from adjacent Panama, this might not be the best region to look but since we are talking about a very secretive, very difficult species no matter where it lives, you never know!
• Well drained, primary forest with a fairly open understory: Since this situation matches places where it is seen most often, this could be the microhabitat that this species needs.

Why look for Wing-banded Antbird in Costa Rica when you can see it in Panama and northern South America? Well, not only would you possibly document this species for the country, you would also certainly see a lot of other rare species in the process. Bird those remote rainforests near Maquenque and Crucitas and I think you have a chance at both huge eagles, Red-throated Caracara, White-fronted Nunbird, Great Jacamar, and everything else. The main challenge is accessing the sites mentioned and carrying out intensive surveys for at least a week. If you can manage that in the forests east of Crucitas, I bet you will find it.