Costa Rica’s biodiversity extends far beyond the lush rainforests and towering volcanoes. Our coastlines, bathed in warm tropical waters, teem with life. Today, we set our sights on a graceful avian acrobat – the Sandwich Tern.
A Coastal Charmer
The Sandwich Tern (Thalasseus sandvicensis) is a medium-sized tern, easily identified by its sleek build, contrasting plumage, and distinctive black crest. While primarily a coastal dweller, some lucky visitors to our retreats near the Pacific shores might catch a glimpse of these elegant birds during their migratory journeys.
Sharp as a Tack
The Sandwich Tern’s black bill, tipped with a bright yellow hue, is a formidable tool. They are adept plunge divers, soaring high above the ocean’s surface before plummeting headfirst into the water to snatch small fish. Their sharp eyesight allows them to spot prey from incredible distances, making them successful hunters.
A Fashionable Flock
These terns are known for their striking appearance. Adults boast a sleek, white underbody that contrasts beautifully with their pale grey upperparts. Their crowning glory is the shaggy black crest, adding a touch of drama. In winter, this crest transforms, becoming less pronounced, with a white crown taking its place.
A Song of the Sea
The Sandwich Tern is a vocal bird, filling the air with a variety of calls and whistles. These vocalizations serve several purposes, from communication within colonies to defending territories and attracting mates.
A Sandy Cradle
Unlike some of Costa Rica’s more vibrantly colored birds, Sandwich Terns prefer a simpler nesting style. They create shallow scrapes in the sand on beaches and islands, laying one to three speckled eggs. Both parents take turns incubating the eggs and feeding the chicks after they hatch.
Travel Buddies
The Sandwich Tern is a migratory bird, breeding in temperate regions during the summer months and journeying south for the winter. For those visiting our coastal retreats during these migratory periods, keep your eyes peeled for these impressive birds as they gracefully soar along the coastline.
Spotting the Sandwich Tern
While not as widely seen as some resident Costa Rican birds, the Sandwich Tern can be a delightful addition to any coastal birding adventure. Here are some tips for increasing your chances of spotting one:
- Visit during migration: Look for them during the spring and fall months (March-May and September-November) when they travel through Costa Rican waters.
- Head to the coast: Focus your birdwatching efforts on beaches, estuaries, and coastal wetlands.
- Look for feeding flocks: These terns often hunt in groups, so spotting one might lead you to a colony.
- Listen for their calls: Their vocalizations can be a helpful clue to their presence.
With a bit of patience and a keen eye, you might just be rewarded with a sighting of this elegant avian acrobat. So, the next time you find yourself on the pristine shores of Costa Rica, keep your gaze fixed on the horizon – you might just be lucky enough to witness the Sandwich Tern’s breathtaking aerial performance.
For more information, please view our comprehensive guide about the birds of Costa Rica
