Purple Gallinule (Porphyrio martinicus)

Purple Gallinules are some of the most brightly colored birds that you can see walking in Costa Rica. Indeed while they can also fly, they more commonly wade in shallow waters and in dense grass plains, looking for prey. I have seen them in Palo Verde in big numbers, and spotted individuals in Rio Frio, where they join chickens and forage in the backyards of houses; indeed I was able to see two adults rearing four young hatchlings, which were still covered in black fluffy hairs, getting along with the chickens just fine. The underside and head is entirely purple with a metallic look, showing a small light blue patch on the forehead. The beak is mostly bright red, with a yellow tip. The upperparts show blue to olive green hues, particularly on the wings. The yellow legs are long, letting them to wade in shallow edges of lagoons without having to swim.

Spectacled Caiman (Caiman crocodilus)

Caimans are easy to confuse with crocodiles, however both belong to different families in the Taxonomic hierarchy. While each species in both families has its specific characteristics, there are a few physical traits that differentiate species from each family:

  • Jaws: The Crocodile has a V-shape, while the Caiman and Alligator have a U-shape. This can be seen most notably from above or the front, not so easily from the side.
  • Teeth: In Caimans, due to the way the teeth are placed, the lower jaw’s teeth are not visible when the mouth is closed. Crocodiles do show both upper and lower teeth at all times.

The Spectacled Caiman in particular has become established and common in Costa Rica. Like most reptiles, being cold blooded, they bask in the sun during the morning to warm up their bodies, before going for a day’s hunt. During that time, they may lie motionless in almost any place, like fallen trees, beaches and riversides. Adults have a length between 1.4 and 2.5 meters.

Green Basilisk (Basiliscus plumifrons)

The Green Basilisk, also known as the Jesus Christ Basilisk due to its incredible feat to run on water, is one of the four species of the Basiliscus genus and of three species to occur in Costa Rica. The similar Striped Basilisk is brown with two yellow lines that run one through they, and a thicker one from below the eye, both ending in the upper portions of the back.

The male has a big crest that protudes both on the head, back and tail, which can be raised to signal that it is angry or defending its territory. Most of its body is green with light blue spots around the back, a color pattern that lets it camouflage very easily in foliage and vegetation, particularly during the morning when they bask in the sun to warm up their bodies. The female shows a lighter shade of green than the male. Their eyes are bright yellow. Both their fingers and toes are very large, with scales that can be extended, increasing the effective surface area of their feet and enabling them to run over water for short distances, up to 20 meters.

Striped Basilisk (Basiliscus vittatus)

The Common Basilisk, also known as the Jesus Christ Basilisk due to its incredible feat to run on water, is one of the four species of the Basiliscus genus and of three species to occur in Costa Rica. The similar Green Basilisk is (obviously) green, and the male has a big crest that protudes both on the head, back and tail, while the Striped Basilisk only has a crest on the head and a small ridge on the back.

It is brown with two yellow lines that run one through the eye, and a thicker one from below the eye, both ending in the upper portions of the back; this color pattern lets it camouflage very easily, particularly during the morning when they bask in the sun to warm up their bodies. Both their fingers and toes are very large, with scales that can be extended, increasing the effective surface area of their feet and enabling them to run over water for short distances, up to 20 meters.

Neotropic Cormorant (Phalacrocorax brasilianus)

The Neotropic Cormorant is an aquatic bird, hence it is popularly known is Costa Rica as the “Pato de Agua” or water duck. It dives underwater in search of prey, which is mostly comprise of fish, but also includes amphibians. Once their feathers are soaked, they spread their wings on a rock to dry under the sun. They can be found at the sea and in rivers, sometimes accompanied by Frigatebirds or any type of egret, like the Tricolored Heron. They are mostly dark in coloration with a yellow bill, and their feet are webbed, just like a duck, which is a feature that help them propel themselves while underwater.

Black-necked Stilt (Himantopus mexicanus)

The Black-necked Stilt is a wader bird, meaning it walks in shallow waters, looking for small prey to snatch. It does not dive and is not usually seen swimming. The stilt has a streamlined body and extremely long pink legs, allowing it to wade in deeper waters than other, smaller waders found in Costa Rica like the Plovers and Sandpipers. It has a contrasting black and white body. When startled, they usually fly away in a wide circle and return to a similar place they were before.

Snowy Egret (Egretta thula)

The Snowy Egret is a white bird, that can be confused with the Cattle Egret if not seen carefully, however Cattle Egrets have yellow bills and yellowish feathers on the neck. The Snowy has a black bill instead, with black legs that end in yellow fingers. Even if the name suggests otherwise, this bird is entirely at home in hot, humid climates like the coasts of Costa Rica. It is found in swamps, rivers and marshes, taking fish and crustaceans from shallow waters. Another interesting feature of this species is the longer feather barbs that decorate the chest, neck and rump of the bird, which are displayed mostly during the mating season.

Northern Jacana (Jacana spinosa)

The Northern Jacana is a waterbird that inhabits swamps and marshes, where the water is not too deep. The bird walks in the shallows, looking for small fish and crustaceans. It can even walk over some water plants whose leafs are big enough to sustain this delicate bird, thanks to very long toes that help to distribute the weight across a greater extent of water surface. Another unique behavior is its polyandrous nature, meaning that females will mate with many males, and it is the males that prepare the nest and care for the eggs and chicks. It is brown overall with black throat and head, with a yellow shield on the front (Wattled Jacana’s and Common Gallinules have a red shield). The juvenile has white underparts and lacks the shield seen in the adult.

Great Blue Heron (Ardea herodias)

The Great Blue Heron is one of the largest birds that occur naturally in Costa Rica. They can be found in watery environments like rivers and ponds, even artificial ones like the one in Concasa, which has been visited by a juvenile bird almost every morning from January 2018 to March of the same year. The name is misleading though, as the blue is color is rather dull on this bird. The juvenile is mostly grayish, with a darker cap, yellow eye and lower mandible, and black upper mandible. The adult shows a light dull blue on the back and wings, with brownish neck and white cheeks, maintaining the dark cap and yellow eye, but the upper mandible changes to yellow. They stalk prey from the edge of water ponds and lakes, and launch a forceful attack as fish pass by, able to snatch fish of considerable size and swallow them in one go.

Fulvous Whistling-Duck (Dendrocygna bicolor)

The Fulvous Whistling-Duck is a pretty duck, very similar in shape to the Black-bellied Whistling-Duck, to the point that it can be confused with a Juvenile of the Black-bellied. I was lucky because three individuals came to swim on the lake by Concasa, so I spotted them when I returned home in the afternoon. This was unexpected, because I already knew that they only inhabit the northwestern region of Costa Rica, and should be not be found in the Central Valley. I took out my camera and snapped lots of pictures, because I assumed the birds would leave next day. And so they did, in the days afterwards there was no sight of them. Since then, a single individual has returned a few times joining a flock of Black-bellied, which seems pretty unusual. I have seen the Black-bellied pecking at this Fulvous, seemingly trying to drive it away, but it stays with the flock.