In the northern places where winter chases some of the birds away from their breeding grounds, spring represents a dramatic, obvious, much anticipated change in the natural surroundings. Suddenly, the sun comes back to town, the snows melt, flying, honking skeins of geese come first, and when it gets warm enough, the green spaces play host to the songs and bright colors of breeding warblers, vireos, orioles, grosbeaks, and the other lovely birds of May. Depending on where you live, they come back in April too, and in Costa Rica, that’s also when most of them leave.
The migrants that is. Cool, crazy birds like the Great Potoo are here all year long.
The other birds show us spring with an abundance of song while the landscape becomes flush with new, green vegetation. Since a fair part of the country doesn’t really experience a dry season, the change from sleeping brown grasses to robust green fields takes place in the Central Valley and other parts of the northern Pacific slope. In addition to a more verdant landscape and the profuse singing of Clay-colored Thrushes, these are a few other aspects of birding Costa Rica during spring:
It rains more
Spring is really the change over from dry times to the official wet season, and in April, it is marked by heavy rains just about every afternoon. Don’t fret about the rains, though because the overcast weather results in better birding anyways.
Swifts
They were always present, just way up there too high to watch in a satisfactory manner. They do the same swift speck thing in spring but also come much lower just before a storm. When that happens, you might actually see the brown collar on a Chestnut-collared Swift, or markings on the faces of Spot-fronted and White-chinned Swifts. Knowing their vocalizations is still the best key to their identification but the best looks are had at the front of a storm.
Migration
It’s not as diverse or vocal as in the north, but we still bear witness to impressive numbers of birds throughout the month of April. Bird the Caribbean lowlands and coast (think La Selva, Tortuguero, and areas south of Limon) right now and there might be too many birds to look at. Literally millions of Chimney Swifts, Cliff Swallows, Purple Martins, and other birds move in a steady river towards the north along with kettles of Mississippi Kites, and groups of Broad-winged and Swainson’s Hawks. In the trees and bushes, Red-eyed Vireos race north along with some warblers, Eastern Kingbirds, pewees, and Scarlet Tanagers. Keep watching and you might pick out rarities for Costa Rica like Gray Kingbird, White-eyed Vireo, warblers that normally winter in the Caribbean islands, and Black-whiskered Vireo. Add shorebirds to the mix and there are a lot of birds waiting to be seen!
Cowbirds
Like the swifts, these birds are also here at other times of the year but seem to be more obvious during April. Unfortunately, it’s because, like their relatives up north, Bronzed Cowbirds also lay eggs in the nests of other birds. You will see them but I wish we would see less, especially because it seems that they like to parasitize the nests of the endemic Cabanis’s (Prevost’s) Ground-Sparrow.
These ones were courting in a site for the ground-sparrow.
If you happen to be in Costa Rica during April, enjoy the bird show and please enter sightings into eBird!