A hundred or more times I must have walked along rocky mountain streams around the San Antonio area since I arrived here in 2007. Initially, from the almost total lack of birds typical of such habitat, I believed these rivers to be virtually fishless. After three years I discovered, to my amazement, that the Sunbittern occurs regularly on both Quebrada La Loca and the Rio Guayabito, and a year later I found a Torrent tyrannulet on the Rio Guayabo near La Muralla waterfall.
Then, last year, an immature tiger-heron appeared on Quebrada La Loca, only five minutes’ walk from the house. I posted to my blog at that time, indicating the identification problems involved. A photo of a Fasciated tiger-heron (Tigrisoma fasciatum) taken by Chalo Porras at the same location early this year made it easier because it was of an adult bird and confirmed that species. I then assumed that it was the same, perhaps stray bird, since I had never seen one in the previous six years. Now, in 2014, at least two birds of the same species seem to be resident on the stretch of Quebrada La Loca between the bridge and don Martín’s cabin.
I walked down to the bridge mid-morning in heavy rain and there, on a partly submerged rock in mid-stream, stood an adult Fasciated tiger-heron. This is only my second sighting of this species, and the first of an adult. This time the absence of the bare yellow throat that typifies the Bare-necked tiger-heron (Tigrisoma mexicanum) made for certain identification. The latter species seems to be quite common in the lowlands but would be out of place anyway at this elevation and in this habitat.
Karel Straatman’s excellent photograph of a Bare-necked at full stretch makes a good comparison with the shots of the Fasciated, the first of which I reproduce with the kind permission of Richard Garrigues, co-author of The Birds of Costa Rica. The illustrations in the guide make the Bare-throated tiger-heron look much bigger than the Fasciated, but in the field the size difference of 5″ is not a great help in identification of such large birds.
Don Martín took the following photos after his discovery at the same location of a Sunbittern nest with two chicks in June of this year. Quebrada La Loca is becoming more than just a quiet beauty spot.
Stay tuned for news of two more species, both new additions to my San Antonio list, that I found on Quebrada La Loca later the same day.