The largest stronghold of Pacific coastline primary rainforest in all of Central and South America, the Osa Peninsula – and especially Corcovado National Park – contains one of the largest densities and varieties of wildlife in the world. The best base for organizing longer excursions into the park is Puerto Jiménez, a sleepy village on the Golfo Dulce. Even the village itself is a great place for spotting wildlife: right next to the “airport” (consisting of just a landing strip) is a swamp that is home to crocodiles, while scarlet macaws feed on the many almond trees scattered around the village.

The owner of my hostel suggested that to see the crocs, I should go to the butcher and buy US$2 worth of offal to attract them. So the next morning that’s exactly what I set off to do. Slightly nervous, I asked a local whether it would really be a good idea, but he reassured me the crocs were very “tranquilo.”

It only took a minute to spot a large one serenely gliding through the middle of the swamp. Tossing some pieces of bone in its direction, it at first didn’t seem interested, but only a short while later, there were four or five of them just below the bank where I was standing – only 5m away! Snapping with their fierce jaws at the chunks of offal I threw at them, they continued to hang around when the all the offal was gone, and I was beginning to think: OK, you can now – I’m not sure I like the way you’re looking at me…Then the largest of them started gliding in my direction and suddenly propelled itself forward…my heart stopped! But fortunately it only went after a smaller croc. A few split seconds of loud splashing followed, and the smaller of the crocs fled out of the water, right onto the trail, blocking my way. I had a tree to jump on in my sight the whole time, but after a while, the croc disappeared again into the water, and all of them slowly dispersed. I wasn’t quite happy with the photos I took, but had too much respect to go back.

The main reason for visiting the Osa peninsula is Corcovado National Park – according to National Geographic (and Wikipedia) “the most biologically intense place on Earth in terms of biodiversity.” I had hoped to go on a 3-day hike, spending a day hiking the 16km from the entrance at La Leona to Sirena ranger station, spending two nights at the station, and then hiking out again. Unfortunately, logistics meant that I had to fly in, allowing, though, an extra afternoon at Sirena.* I went with Steven Chacon of Osa Green Travel and couldn’t have picked a better guide.

Setting out on one of the trails from Sirena, he would stop and ask: “Do you smell that? That’s the smell of a tapir.” A few moments later, he showed me a tapir sleeping among thorny plants. What a great start! Shortly later, back on the trail, he asked again: “Do you smell that? That’s a cat.” And indeed, although we did not see a cat, we soon came across fresh ocelot prints on the trail. So it continued, with Steven’s keen nose and eyesight, as well as his knowledge of where to look, picking out animals that I would have walked straight past.

Although the cats – jaguar, puma, ocelot – proved elusive, we saw an almost endless range of other fascinating creatures. Apart from the tapir (which we bumped into again next to the ranger station when setting off at 4.30am the next morning), there were bull sharks at the mouth of the Sirena River, a black hawk that had just caught a shrimp, all four monkey species in the park (including the endangered squirrel monkey), a wolf spider, a fer-de-lance (Costa Rica’s second-most dangerous snake; according to Wikipedia, “[m]embers of this genus are responsible for more human deaths in the Americas any other group of venomous snakes”), pale billed woodpeckers, pelicans, more scarlet macaws, tent-making bats, a troupe of female coatis, and (sniffed out again by Steven) a tamandua (anteater). I was particularly happy about seeing the tamandua and couldn’t stop smiling after seeing how it clumsily slid down the tree, head first, not really being able to see where it was going.