Dealing with Extremes – by Jack Ewing

photo: Jack Ewing

Have you ever seen a caiman on a mountainside in a primary forest more than a kilometer from the nearest water? At Hacienda Barú National Wildlife Refuge there is a trail called the “caiman trail” because one of our guides sighted a caiman there in  March of 2016. 

Late in the dry season, competition for possession of the few puddles that remain in the lowlands is so intense that caimans and otters are sometimes driven to walk great distances in search of water. With the arrival of the rains of the green season, they breathe a sigh of relief and return to the rivers, estuaries, and swamps where they thrive. Of course, viewing them is easier when water is scarce. All kinds of wildlife will be concentrated in the wettest locations at that time.

The Path of the Tapir Biological Corridor is situated along the Pacific coast, spanning the area between the Savegre and Terraba rivers. Hacienda Barú is in the middle. It is ecologically important because its natural forests extend from the Coastal Ridge all the way down to the beach. January, February, and March are the driest months, September and October are the rainiest, and all the others are somewhere in between. According to 43 years of precipitation records, February has been the driest month with an average of only 53 mm (2.1 inches) of precipitation, while October has averaged the wettest with 752 mm (29.6 inches). How do wild creatures cope with these extremes?

Peccaries, paca, coatis, and other mammals tend to be more populous in the upper parts of the coastal ridge during the rainy season. If you want to see them during the dry season, go to the coastal lowlands near the mangrove estuaries and other bodies of water. Snakes also prefer habitats that are moist but not too much so. 

Campesinos or rural residents know that you have to be on the lookout for poisonous snakes near streams during the dry season. Once the rains start, most move to higher ground. During that migration, they tend to be nervous and much more likely to bite than when they are settled into their territory and feel safe. Medium size venomous terciopelos sometimes remain in the lowlands and prey on frogs that abound there during the wettest time of year.

Bird watchers know that bird populations are highest during the dry season because all of the northern migrants are here for their winter. Swifts and swallows are the exception, not appearing in the area until the rainstorms are frequent. There is a saying in the rural areas of the biological corridor that you know the rainy season is here to stay when the golondrinas (swifts and swallows) arrive. They come to eat the mosquitoes, which are mostly absent during the dry season. 

Frogs love both water and mosquitoes. When you see the swifts and swallows darting here and there and hear the frogs singing after a big rain, you probably aren't plagued with mosquitoes.

Puma sightings near the beach at Hacienda Barú aren’t particularly influenced by wet and dry weather. Rather, they are often seen during turtle season from July to November. 

Raccoons, coatis, and domestic dogs, all of which are favored puma prey, dig up the olive ridley marine turtle nests and eat the eggs. When baby turtles hatch later in the season, they fall prey to the same predators that dig up their eggs and many others. Pumas don't bother the turtles or the eggs; rather they come to hunt these smaller predatory mammals that do eat turtle 

eggs and baby turtles.

Most birds and some mammals have an oily protective coating on their feathers or hair that repels water. Apparently, sloths lack any such protection because they get absolutely soaked. The best time to see a sloth is on a sunny morning after a big rain.  They hang out in the sun to dry, just like clothes hanging on a line.

Biodiversity is exceptionally high in the Path of the Tapir, and every one of Mother Nature's creations has its own method of dealing with seasonal extremes. Those mentioned above are but a sample.

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From the cattle business in the USA to becoming into an environmentalist and naturalist in Costa Rica, Jack is currently president of two environmental organizations, ASANA (Frends of Nature of the Central & South Pacific) and FUNDANTA (Foundation for the Path of the Tapir Biological Corridor)

A natural–born storyteller, Jack’s articles have appeared regularly in Costa Rica publications, and he is author of several books, Monkeys Are Made of Chocolate and Where Tapirs and Jaguars once Roamed: Ever–Evolving Costa Rica. His latest book is titled Monkeys Are Made of Mangos.