Sandpipers: the migratory birds that come from afar!
Fernando Igor de Godoy, Folha de Florianópolis, Oct. 2021
Have you ever noticed those gray birds, known as sandpipers or curlews, that are on the beach? Maybe not, because they're not very flashy and don't usually arouse people's interest. Well, these birds have many peculiarities and an incredible history. To begin with, in general, sandpipers are just passing through our coast. This means that they are migratory, coming from much colder regions of the planet. Most come from North America, more precisely Canada, where they breed in the different environments of a plant formation known as tundra. After the hatchlings grow, adults and juveniles set off on a journey south, as the tundra tends to freeze over and resources become more limited.
Some species, in smaller numbers, make the opposite movement, leaving the extreme south of South America, such as the Patagonian region, towards the north. Thus, species that come from North America are more common on our coast during the Brazilian spring and summer, while species from the south are more common in the winter. These birds are extremely adapted to travel great distances, even managing to orient themselves by stars and mountains. There are several migration routes, some of which include the interior of the continent, but the main ones are coastal.
Sandpipers make these annual movements, covering tens of kilometers in search of food and resting places. Therefore, the conservation of wetlands is extremely important for the maintenance of these birds. Many species are already showing population declines, meaning they are threatened due to the impacts that wetlands suffer, such as human occupation, sewage and effluent pollution in general, and transit on beaches. There is even a National Plan for the Conservation of Migratory Wader Birds.
There are many types of curlews, and the best way to identify them, in addition to their plumage, is to observe their shape, size, environment they are using, and behavior. Some sandpipers can be identified just by the way they walk, how they move their neck and tail! They have two main plumages: the reproductive, which is usually more showy, contrasting, and sometimes colorful; and the non-reproductive, which tends to be duller and predominantly gray-white in color. In general, species remain in our wetlands with non-reproductive plumage, changing plumage before migration.
However, individuals with remnants of reproductive plumage can be observed both during the arrival and return periods. Each species can use a different environment (river flowing into the sea, lagoon, mangrove, or even low tide), or use the same environment to obtain different resources and/or in a different way. For example, the sandpiper takes advantage of the return of sea water to catch mollusks that come with the waves. The crooked-billed sandpiper is found on beaches near the mangroves and is an expert at catching crabs. Now that you know a little more about curlews and we are in an excellent season for sightings, how about looking for them on beaches and lagoons?