Boat-billed Heron (Cochlearius cochlearius panamensis)
24 January 2009, CATIE Botanical Garden, Costa Rica
This was another digiscoping challenge with intervening branches and poor
light.
We were pleased to find over a dozen of these ungainly and unique herons
roosting in a large tree over the pond. The tree was mostly festooned with
Cattle Egrets, but these dark hulking birds could be seen deep in the
interior shade. They are largely nocturnal and we did not see them active
during our visit. Many appeared to be dozing with their eyes covered with
a nictitating membrane.
The enormous eyes attest to their nocturnal habits. Their plumage and
compact shape recall Night-Herons, but their unique outsized bill and eyes
are so different that early authors placed it in its own family,
Cochleariidae, separate from the typical herons. The huge bill is used as a
scoop, a behavior unique to the herons and reminiscent of the African
Shoebill.
Despite it's similarity to Night-Herons, genetic data suggests it is closer
to Tigrisoma, the Tiger-Herons.
Five races are recognized. This is C. c. panamensis which is the darkest
subspecies. Some authors split birds ranging north into Mexico into a
separate species, but evidence for such a split is poor.
Panasonic Lumix LZ5 / Nikon FieldScope 3 / 30X WA hand-held (no adapter)