It had been six days since I’d been in the field. A combination of illness, injury, and three straight days of rain had prevented us from getting any work done, and I had barely left my room. The house was damp and musty. Everything was flooded. I was even starting to miss the monkeys. Well, almost.
So when a friend of a friend offered to take us to Palo Verde for the day, I jumped right into my boots. I had never been to the National Park despite its proximity and the fact that it’s the largest protected Wetland in Costa Rica.
Tropical Ecology, regardless of environment, usually operates between extremes. Resources are only ever offered in abundance, or not at all. There is no middle ground, no moderation. Any addition–water, sunlight, etc, triggers a dramatic shift. Example: a Rainforest is nutrient-limited, and and addition of organic matter (animal carcass or fallen tree) causes an explosion of activity to reclaim it. A desert is water-limited, and any rainfall portends a mass emergence of sprouting plants and thirsty animals.
But Palo Verde is a Wetland surrounded by Dry Forest–an ecological oxymoron. And it doesn’t work the way you’d expect. Rather than mitigating each other, the two environments create a massive expanse of dynamic micro-habitats that push and pull at each others’ resources, constantly in flux and constantly disturbed. And if there’s one thing tropical biodiversity thrives off, it’s disturbance.
We arrived after a long rainfall, but after enough time had passed that the flooded plains had shrunk to isolated pools. Vegetation had been uprooted and waterlogged, then left to decompose high and dry. Aquatic life had been allowed to flourish, then trapped and concentrated. It was textbook Trop Ecology. Life was busy here. Things were happening. Everybody was out and about.
Spiny-tailed iguanas basked on every available surface and only grumpily moved out of our way when we got close. I plucked one of the biggest milipedes I’ve ever seen off the middle of a trail. Ponds swarmed with fish, some of which were squirming through the mud or even across the roads to find new water.
And the birds. My god, the birds. Palo Verde is a known birder’s Mecca in the dry season, but even now it didn’t disappoint. One spot, just off the road, was full of Wood Storks, White Ibis, several species of small heron, and all three species of egret. All perched together or wading through the flooded grass. I saw several Northern Jacana–small, delicate wading birds–along a boardwalk. We even caught a glimpse of Scarlet Macaws, something not often seen up North.
Oh, there were mosquitoes, too. Like, swarms and swarms of them. It was awful. Some didn’t just itch–they actually stung a little when they bit. We couldn’t stop moving, and every retreat to the car was followed by a swatting party as we tried to massacre all the ones that had followed us into the car.
But one place we managed to escape them was a lookout, a high point on a pinnacle of karst limestone that overlooked the river and flooded plain. It was a great view, with perfect weather. We took advantage of the fact that both the weather- and mosquito- gods were showing us mercy and took it all in.