Monday, June 22, 2009

Black Terns

North American Black Terns winter along the Pacific and Atlantic coasts of Central and northern South America. In spring, they are a common migrant along both coastlines in Central America, and are also seen in smaller numbers at inland sites. Some non-breeders, presumably first cycle birds, will summer in Central and northern South America, primarily along the Pacific coast, and possibly also along the Atlantic coast. During this time, the species is rare inland (Heath, Dunn & Agro 2009).

And indeed, at the biological station in Laguna de Apoyo, Nicaragua, folks were quite surprised when I said that almost every other day, I’d see Black Terns fishing on the Laguna. Usually I’d see just one or two individuals, and then one day there were 7.

The next day I had a bird point count scheduled for a waterside location, and hoped to get them on the point count. I did: I got no less than 17 Black Terns! Jeffrey McCrary, the resident biologist at Laguna de Apoyo, has never seen the species at the Laguna in June.

Then today, after Wakako and I arrived in nearby Granada on Lake Nicaragua, we observed three individuals hanging around the ferry port for Ometepe, on the outskirts of town.

All birds I’ve seen here so far had whitish body feathers, indicating first cycle birds.

With birds showing up in multiple locations, I have to wonder: are these birds really so rare here in summer, or is it just that nobody has ever reported them before?

Wednesday, we have a birding trip scheduled to the northwestern side of a nearby volcano, which will include a boat trip on Lake Nicaragua. We will definitely be on the lookout for Black Terns...

Postscript: oddest thing - I report my sightings of three Black Terns today in Granada in eBird, thinking eBird will probably want to double-check that sighting, but no. But the Osprey that we also saw, that eBird finds remarkable! I don't think summering Ospreys are that unusual around here.

Literature cited:
Heath, Shane R., Erica H. Dunn and David J. Agro. 2009. Black Tern (Chlidonias niger), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online:

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