We began our first full day at La Selva Research Station in the classroom where we were taught how to conduct census exercises between older primary forests and more recently established secondary forests. There are ecological implications for the species richness and biodiversity present dependent on the age of forest. Hence, being able to identify the relative importance of primary and secondary forests has major conservation all implications. In groups we then conducted these exercises to determine the variety of species heard or seen in the different habitat types. During this strawberry poison dart frogs, capuchins, howler and spider monkeys plus many other species were recorded. During our lunch break there was a lot of excitement because a two-toed sloth was discovered chilling out in a tree above the reception. A personal favourite for many of us that we were desperate to see during our time here. Our lecturer mentioned that he had found one and we all started sprinting to his amusement, they are pretty slow moving so it wasn’t going anywhere.
In the afternoon we swapped to the other type of forest and during our explorations our findings included a juvenile yellow eyelash pit viper, green and black poison dart frogs, toucans, peccaries, vultures and crested guans.
After dinner we discussed the results of our census, with more species being seen and heard in the newer secondary forest. This was followed by a night session with a mammal focus where we spotlighted with flashlights or head torches looking for eye glow amongst the fauna. One group saw a woolly opossum whilst the other found a tree frog, a narrow mouthed frog and little-leaf toads. We had just finished for the night, acknowledging that it was a quiet night and were waking across the bridge back to our rooms when we found a Mexican hairy dwarf porcupine curled up on a branch, the first ever seen whilst this field trip has been run! Which just shows that sometimes the best things are seen when you aren’t searching!
The next morning we began with our last field session at La Selva where we saw lots of birds, baby howler monkeys and more poison dart frogs. Following this we had a class discussion on life-history evolution in the tropics and how species traits vary from temperate environments, for example slower growth rates, laying smaller and more frequent clutch sizes, longer lifespans, etc.
We loaded ourselves and luggage into a bus and drove a couple of hours northwards to lake Arenal, the largest lake in Costa Rica and overshadowed by an active volcano. We crossed the lake on a boat where we had lunch and a chance to sunbathe. Afterwards we travelled up to the Monteverde cloud forest reserve located in the Cordillera de Tilarán mountain range running down the centre of Costa Rica. On the final leg of our journey we had a pit stop at an amazing local shop which had a very cute cat that was completely indifferent to the local parrot living in the corner of the store. Here we stocked up on locally grown and produced coffee and chocolate to take home!
Arriving at Monteverde Biological Station we were struck with the difference in climate to La Selva, situated between 1400-1800m from the sea level in the mountains the environment is much cooler and wetter. The fact that we were now in a cloud forest was very evident as our surrounding forest was covered in them. The climate is influenced by the Pacific Sea which we can see from the station, although it is over 80km away. There was much excitement upon arriving because there were close encounters with coatis outside our rooms. Following dinner, we had a discussion about mimicry and aposematism, which are defensive strategies commonly adopted in the tropics to avoid predation. For example, poison dart frogs exhibit aposematism through their bright colours to warn animals that they are toxic, whilst mimicry includes methods such an mimicking poisonous species whilst lacking the toxicity. We ended the day with a night hike to set up camera traps, hoping to capture some footage of big cats such as pumas or jaguars on the trails whilst we are here.
Photo credit: Emily Hunter
Photo credit: Joel Stevenson
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blr211 January 10th, 2020 Costa Rica