First day of Spring! Hardly any difference down here in Costa Rica – hot and sticky…just like yesterday and the day before that and tomorrow. The discernible difference became recognizable in the birds that are around.
The beach in Tortuguero is made up of sand that is the ideal colour for Semipalmated and Spotted Sandpipers. The dark brown meshes perfectly with their backs and when hunkered down in the wrack they are virtually invisible. So shorebird counts are done at a leisurely pace so as not to miss anything. The beach here isn’t very wide, often only 10-20 meters wide, eaten away by the relentless surf and redeposited further along. Right next to the beach dense vegetation takes over. This is often a good place to see birds even if they aren’t shorebirds.
I’ve done a couple of shorebird counts now and they have generally been pretty unspectacular – 5 species in modest numbers: Whimbrel, Semipalmated Sandpipers, Spotted Sandpipers, Black-bellied Plovers and Sanderlings. So there’s lots of opportunity to take in any movement in or over the bordering vegetation.
Yesterday there was a “difference”. Swallow species were on the move, flying high but steadily north, paralleling the coast. Many I couldn’t ID accurately but I was able to pick out at least 10 Barn Swallows. ALL of these birds were moving north; NONE were flying in any other direction. These birds were on the move. And then, much to my surprise, I saw, in quick succession, 3 fairly tight flocks totalling 108 birds – Eastern Kingbirds! These surprised me for two reasons: 1/ they were in groups. In Ontario we are so used to them being strictly territorial and chasing both conspecifics and possible predators (crows, hawks) out of their areas. And here they were moving together in large groups. And 2/ the sun had been up for 2 hours by the time I saw them but they were definitely on the move. Like the swallows, they were high and following the coast, heading north. This was an example of “diurnal migration”. While swallows are known for this (as they can see to eat along the way) I was under the impression that birds like Kingbirds migrated nocturnally. It was actually exciting to see them on the move.
[Interestingly, a colleague down here, Luis Diaz, reported over 200 EAKI’s on November 21st heading south along the coast.]
After concluding the shorebird count we walk back to the boat that will take us to Cano Palma along a trail paralleling the beach. In the trees I saw at least 2 Baltimore Orioles and a Summer Tanager. The Orioles, at least, don’t winter in this area and had moved in very recently, possibly during the night.
So birds are on the move. I wonder how much longer it will be until those kingbirds (and orioles) show up in southern Ontario. I’m getting Zugunruhe (migratory restlessness) just watching them.
Rick