As a child, Charles O. Handley, Jr. (1924-2000) envied explorers who discovered new oceans, continents, mountains and rivers, and dreamt of becoming an ornithologist. Son of a life-long bird watcher, with every bird he spotted by his father’s side he imagined discovering and naming a new species. But he was born about 200 years too late for that. So instead of ornithology, he studied mammalogy and more than fulfilled his dreams of becoming an explorer; he named many species of lemmings, hares, bats, an armadillo, an agouti, and of course the pygmy sloth. This extremely rare and critically endangered animal is only found on one island in the whole world, and I almost died going there to see it. Almost dying is not the same as dying, so since I didn’t, I can now tell the story.
Millions of years ago, there were many families of sloths; they weighed more than elephants and were terrestrial (here, of course, family is in the context of biological classification, not referring to how many happy mother-father-and-son sloth households there were. If you ever forget where family fits in, just think Kings Play Chess on Fat Girls’ Stomachs).
In our lifetimes, there are two families of sloths in existence; two-toed and three-toed, which are both tree-dwellers. Handley’s discovery was that the smallest of all extant sloths, the three-toed pygmy sloth, was so different from its closest relatives that it should be classified as its own species. The pygmy sloth, or Bradypus pygmaeus as Handley named it, is indeed about 40% smaller in mass, 15% smaller in body length, and 12-16% smaller in skull length compared to the other species of sloths in the Genus Bradypus (three-toed sloths)– which it was once was before Isla Escudo drifted away from mainland Panama 9,000 years ago.
This is a result of a complex evolutionary process called insular dwarfism, which took place because the pygmy sloths were stuck on this island that was completely isolated. The island lacked predators or disease spreading animals like bats, rodents, cats and weasels, but because it was isolated, food and other resources were limited, capping the size the sloths could grow to. This process worked differently for the other animals; for example the Escudo hummingbird, also endemic to the island and considered to be its own species, got larger than its cousins on the mainland. The sloths on mainland Panama are comparable in size to large dogs, and those on Isla Escudo got miniaturized to the size fat house cats.
The moment I saw a pygmy sloth was one of the happiest moments of my life. Not because I am especially interested in insular dwarfism or seeing rare mammals, but because if I could see the sloth, it meant that I was not dead. Let me explain. During the time I worked in Panama, I had only one chance to go to Isla Escudo, and it was in the wrong season, with the availability of an unfit boat. Neither of those reasons, of course, should stop a curious person. So I got on the boat: the island was 17 km away from our research station, what could happen?
To put it modestly, I nearly died, or constantly wished I was dead in order to not be in the situation I was in. It was the worst seafaring experience of my life. And I am not new at this – I sailed high seas in many oceans, many times, even the Drake Passage to and from Antartica, twice. I get seasick but it does not linger; my brain usually adjusts to the situation after the first fish-feeding “incident”. On this day in February 2015, the “incident”, rather violent, lasted 4.5 hours until we got to the island (and repeated all over 3.5 hours more on the way back). It was a wet, cold, scary, painful ride; during which I was sure we were going to capsize, (and after my death the Panamanian authorities were going to find out I was conducting research in Panama while on a tourist visa). Once it was clear that this trip was going to be memorable (about 10 minutes into it), I closed my eyes and focused on just breathing, and tried to bring back visions of my happiest, most pleasant memories. Some of those included visiting art galleries with my mom, and some of them included reproductive activities not fit for this post, but nothing calmed my anxiety down.
I was not alone, of course. Usually it takes two curious people to do something memorable since they need affirmation from each other that what they are about to do will be great. In addition to our skipper and guide Daniel, my friend Irene Kopelman was on the boat, experiencing an equally unpleasant ride. At the end of that day – 8 hours of horrible sailing- I wanted to ask Irene to marry me. Because as miserable as we both were, neither of us complained out loud once. Later we talked about why we didn’t – because we were in a situation in which there was absolutely nothing to be done to make it better. How was complaining going to help? If this sounds obvious to you, envision yourself and your friend <--insert name here--> on a small boat, viciously rocking, water splashing from all directions, wind blowing over you to freeze it, while your stomach muscles are cramped from being overworked, and you cannot even see land or the nearest harbor for shelter. Could <--insert name here--> do this trip without complaining?
In the end, this unpleasant experience was worth the pain we endured, because we were with the most experienced guide among the handful who know Isla Escudo, and as soon as we made landfall, he took us to our first sloth. This was fortunate because we ended up staying only 1 hour on the island, as the sea was getting rougher. Only a month before us, Daniel had taken the BBC crew to the island for the filming of Planet Earth II, but of course the BBC crew was slightly more experienced and professional in that they went in the correct season, and waited for a calm day to sail.
It was once thought that there were only 89 pygmy sloths in existence. That estimate was based on the ones seen in the mangroves. In 2013, the Dallas Aquarium tried to take 8 animals (10% of the entire population) with somewhat complete paperwork for a captive breeding program. This became a local conservation scandal, and even though animals were already loaded onto the plane on crates, they were released back to the island the next day. Most recently, the estimate of their population is around 3,000, based on a new study that tracked them using radio-collars.
Currently, the biggest threat to these animals (whose natural predators would have been the harpy eagle from the skies, had they not been hunted to extinction, and jaguars if they had made it to the island before separation), are fisherman who inhabit the island and eat them. The island also lies on a convenient drug exchange route to/from Costa Rica, so occasionally its human population slightly increases. But this is still the good times; if this greedy marina and casino project is built on the island, the unique animals and plants that are only found on these 4 square kilometers will have even less space to exist, and probably eventually go extinct while on display in the Dallas Aquarium.