Caño Negro National Wildlife Refuge**(6):
This nearly 10,000 hectare refuge is important as a wintering site for migrant waterfowl, as well as a year-round habitat for resident wetland species. From October to April, when the migrant birds are at the refuge, the variety of species and sheer quantity of individuals creates a spectacle that even non-birdwatchers will marvel at. Among the many birds usually present then are: Wood Stork, White Ibis, Glossy Ibis, Black-necked Stilt, Anhinga, Black-bellied Whistling-Duck, Great Potoo, Green Heron, Snail Kite, American Widgeon, Northern Shoveler, and Blue-winged Teal. One species that birdwatchers hope to see here is the Nicaraguan Grackle, since in Costa Rica it is found only in marshy areas just south of Lake Nicaragua.
During the winter residents' visit, the habitat at Caño Negro undergoes a dramatic seasonal change. With the water accumulated in the rainy season, a shallow lake of some 800 ha. is formed. As the dry season progresses from December to March, the lake dries up. By April, all that is left is the main channel of the Río Frio (Cold River).
On the San Carlos region we will drive to the town of Los Chiles, near the Nicaraguan border. Here our boat at the town dock will take us for the approximately 15-kilometer trip upriver to Playuelas on the northern edge of the refuge.
Fishing: The Río Frio is just now becoming discovered by vacationing fishermen, and although it doesn't yet have much infrastructure available, it has good fishing for snook, guapote, alligator gar, drum, and huge tarpon (up to 90 kg., by some sight estimates). The legal fishing season for this area is from September 1 to March 31.
Climate: Daytime temperatures are quite warm and it is usually humid. Although Caño Negro is on the Atlantic side of Costa Rica, it is far enough inland in the northern plains to have a weather pattern with a short but distinct dry season from January to April.