Bats, Macros, and Rafting the Sarapiqui - Day 2 of #CVCostaRica22

 

Binoculars out! Spotting a 3-toed sloth in the canopy less than 
2 minutes after jumping off the bus this 
morning!

 

We started Day 2 of #CVCostaRica22 back at the Tirimbina Rainforest Preserve by seeing a 3-toed sloth within 5 minutes of our arrival. No sooner had we started moving toward the classroom, our guides spotted a 2-toed sloth in another tree, so the group got the chance to see the differences between these species of sloths. Our guides noted this was exceptionally rare, so we knew the day was off to a great start! Students used binoculars and magifying scopes to focus in on these furry creatures and capture some unique images! 

I spy a 3-toed sloth!

The group visted the seed traps we set last night and collected bat guano captured overnight from bats in the open forest. Fruit-eating bats are the most abundant seed-dispersing mammals in the world. Costa Rica is no exception and is home to 30 species of frugivores. Each night, bats can communte several miles to find their food often venturing out of the rainforest into open areas in search of their favorite fruit tree. In this process, most of the seeds ingested from fruit pass through the bat's digestive system intact, then are defacated during flight. The seeds "raining" across the landscape can eventually germinate and become pioneer plants and assist in the process of reforestation.

Back in the classroom, teams worked to identify seeds found in the guano to indicate the location of nearby plants. Students used dissecting microscopes to zoom in and view the various seeds found in the bat guano. Our group was able to identify seeds from a pepper plant and a ficus plant. This event concluded our bat study last evening where students got to see a White Lined Bat, Sevas Short-Tailed Bat, and Black Motais Bat up close!

The morning ended with water quality testing and a macro-invertebrate study in the Sarapiqui River. In Costa Rica, the country is committed to ensuring that water is clean and free from pollutants. Before rafting down the Sarapiqui, students had to determine the pH and levels of phosphate and nitrate in the river. After a quick walk across our favorite suspension bridge and a trip down a spiral staircase, our group reached the banks of the Sarapiqui to work with our guide to conduct this
water quality testing. Groups returned a perfect pH of 7 and no detected nitrates or phosphates. 

After the water quality testing, students dispersed for 15 minutes to catch various macroinvertebrates using strainers. Macro-invertebrates are important in determining the history of a river and its water quality. A river with a high diversity of macros indicates a healthy ecosystem where a high abundance of pollution-tolerant macros indicates poor river health. Our groups found several skimmers, a beetle, and even a tiny fish! Overall, our guide said a high quantity of skimmers was a sign of a healthy ecosystem since we didn't locate any pollution tolerant species. 

Investigating the final count for each type
of macroinvertebrate

Students working with our guide William
to finalize water quality testing results

After lunch, the group enjoyed white-water rafting on the Sarapiqui! Our group was in 3 separate rafts and enjoyed a 7-kilometer journey down the river while observing more sloths, a monkey, and several bird species hunting for fish.