Costa Rica just got some birds added to the country list! Well, at least some common name changes in eBird. Since the recent, latest taxonomic changes made to the super popular birding platform, if you happen to spot a Tawny-throated Leaftosser doing its reclusive ground bird thing while birding in Costa Rica, you won’t find it listed with that name. As of the latest taxonomic change, it has been officially renamed “Middle American Leaftosser”.
Why the new name? An official change in nomenclature for a bird can happen for a few different reasons, one of the most common being that the bird in question was split into more than one species. Since we have yet to be converted into robots, instead of calling the newly recognized evolutionary groupings something like Tawny-throated Leaftosser Number One, Tawny-throated Leaftosser Two, and so on, they are usually given names that reflect certain distinctive aspects of their plumages. But wait, don’t leaftossers look sort of you know, the damn same? Yes, many do but there’s an easy, fitting fix resolved by distribution. When the separate species look pretty darn similar, they can just be named after where they occur.
That works out just fine for Middle American Leaftosser. It fits and since vocalization differences and high molecular differences have been known for this taxon for some time, the split was also very much anticipated (welcome to the world of birding Middle American Leaftosser!). But why did the split take so long to happen? The reason why this particular renaming and other new names for birds in Costa Rica happened now is because studies were finally published that demonstrated evidence to propose splitting those birds. Proposals were then made to taxonomic committees (oh yes, they do exist!), and once accepted and included in the Clements List, eBird then also accepted those changes. And voila, here we are.
Since the official Costa Rica bird list also follows the Clements list, we can probably expect those new names in the next edition of the Birds of Costa Rica Field Guide by Garrigues and Dean, and in update for the Costa Rica Birds Field Guide app.
These are the other “new birds” for Costa Rica, the ones to look for when making those eBird lists:
White-browed Gnatcatcher– This is a split from the Tropical Gnatcatcher and is the name given to birds that occur in Central America and in some dry habitats west of the Andes. Although descriptive, now, in addition to worrying about separating this bird from the similarly plumaged White-lored Gnatcatcher, we can also worry about confusing their names (and they do occur together in many places too).
Grass Wren– See a Sedge Wren in Costa Rica? Not any more! The Sedge Wrens in Ohio and other places in the north have been separated from the non-migratory Grass Wrens of Mexico and lands to the south. Keep an eye on the birds in Costa Rica, you never know if or when the populations of “Grass Wren” there and Panama might be given species recognition. They are also very local and probably locally endangered.
Chestnut-capped Warbler– The many years in waiting and anticipated split of the Rufous-capped Warbler has finally taken place! This is a change that will certainly please listers, splitters, systematists, and wood-warblerists (if you like wood-warblers, this means you) and should be appropriately celebrated with your choice of libation. If you saw one of those white-bellied birds in Arizona, it was a Rufous-capped. See one in Costa Rica? Chestnut-capped!
Cinnamon-bellied Saltator– Now that name has a ring to it! Goodbye Grayish Saltator, hello three way split with birds from Middle and Central America now being known as le Cinnamon-bellied Saltator. A nice name for a common garden bird with an easy-going, whistled song.
But that’s not all! There are also birds that were split but continue to have the same name in Costa Rica. Speaking of splits, it would also be negligent to not mention a few good candidates for future splits in Costa Rica (although I have done it before, it’s still worth doing again). Keep an eye on these birds and celebrate the eBird armchair ticks!:
Gray-rumped Swift– Birds in Central America are at least separate from some other taxa in South America.
White Hawk– Not the same as the White Hawks from the Amazon.
Great Black-Hawk– A good one to look into as plumage and perhaps behavior differ from birds in the Amazon (which act more like Common Black-Hawk there).
Choco Screech-Owl– Make sure to see those birds in southern Costa Rica because they are probably something new.
Black-faced Antthrush– If you have seen “this bird” in Mexico or northern Central America (except eastern Honduras), open a beer for the Mayan Antthrush! If you have also seen it in South America, keep tabs on where because although it hasn’t been split yet, based on vocal differences, there could be anywhere from 1 to 3 more species waiting in the evolutionary wings.
Black-headed Antthrush– The birds that occur in Costa Rica and western Panama could have enough differences in their songs to separate them from the ones in western South America (and maybe the Darien).
Streak-chested Antpitta– This is a split I would probably bet on as the differences in song and plumage as as much as ones shown by similar, accepted splits of taxa from the Amazon. Try to see birds from the Caribbean slope and from the Pacific slope (easier said than done unfortunately).
Long-tailed Woodcreeper– An eventual split, at least from Amazonian birds.
Olivaceous Woodcreeper– Several distinct groups have been known for many years, one of them occurs in Central America including Costa Rica. The others occur in various places in South America which means that you have to try and see as many as you can!
Buff-throated Foliage-gleaner– The Chiriqui ws already split, hopefully, studies can elucidate how many other species are involved.
Sharpbill– There’s a good chance that each main group is a distinct species. Maybe, maybe not but always cool to see in any case (and not exactly easy in Costa Rica).
Scrub Euphonia- Crack open another cold one for the newly recognized Godman’s Euphonia of western Mexico!
Want to know how to identify and where to find these and other birds in Costa Rica? See “How to See, Find, and Identify Birds in Costa Rica”. Until then, I hope to see you in Costa Rica!