Palo Verde Field Station

We have migrated from the swampy mosquitoe infested field station of Palo Verde to the beautiful montane park of Monteverde. This is the place where tourists zip line through the canopy, and where you can sit outside of your bungalow on your computer and reflect in your blog on the past 10 days of intense field activity.

After our Faculty Field Projects (FFPs) at Palo Verde, we started working on our IPs, or Independent Projects. Around the field station, there are a lot of acacia trees- these are specialized trees which have (you guessed it) ants that live inside of them. The plants grow hollow thorns which the ants live inside of, and in return the ants defend the plant from insects and parasitic plants. It's a very well studied mutualism, with both the ants and the plants benefiting from living together.

While walking around and looking at the forest, it's not hard to notice that there is a clearing around acacia trees. The ants basically trim the grass around their home- just like any good suburban dad. By preventing other things from growing around or on their acacia tree, the ants keep out a lot of predators like army ants. You can pretty easily tell that there are big differences in the leaf litter, the ground cover, around acacias. Inside of that leaf litter there are thousands of specialized species, so I was curious about what the litter communities around acacias look like.

At least half of my pictures have mosquitoes in them- it reminds me of when you take a picture of snow and snowflakes catch the flash.

Here is a good picture showing the clearing around a young acacia tree.
There are almost no small seedlings growing around, and there is not much leaf litter at all.

For my IP I was working with Kevin and Marcela, two of my new biologist friends (you'll be hearing more about the folks I'm with in coming weeks). We gathered leaf litter inside and outside of acacia clearings, sift it to separate the big and little stuff, and then put the smaller bits into a trap called a Winkler Sifter. Basically, the ants and other little things that live inside of the leaf litter get really disturbed and move out of the litter into a collecting cup at the bottom of the trap. Then we can collect them, count them, and see if there are differences in the arthropod community inside and outside of acacia clearings.

Winkling in style. Yes, winkling is a verb.
These are the insect sorters inside of which the dirt hangs for a few days, and then they fall into the collecting cups in the bottom.

Here is a diagram illustrating the basic Winkling method.
1) You gather leaf into a big sifter, and
2) shuffle it around so the small stuff goes through to the bag in the bottom.
    3) You pour the sifted dirt/litter into a mesh bag, and then
4) Hang it inside of the Winkler sifter and let insects crawl out.

Surprisingly, there are no differences in diversity inside and outside of these clearings. Even though there is twice as much leaf litter outside of clearings, there are just as many species inside and outside of acacia clearings. Amazingly, in a 1/2 square meter we collected more than 30 different species of insects and up to 6 species of ants.

So, that is what I was working on for the past four days. Going out in the mosquitoe infested forest and picking up all the rotten leaves on the forest floor to find out what lives inside. (It's full of delicious worms, and ticks and mites.) There was a lot of microscope work sorting out insects- most of the mites and ants are smaller than pinheads. I'll be writing up these results in coming days, just as with the remaining 6 or so projects I'll be working on.

While at Palo Verde there were a lot of other adventures too. We had four birthdays, so I ate a lot of cake. We finally started playing soccer- I think from now on that will be a regular pre-dinner activity. My GPS died in the middle of the forest, but I was able to find my way out pretty easily, and miraculously came across a pencil I'd lost the previous day. Marcela nearly passed out in the forest and I had to run back to the station for rescue. I saw a 4 meter long crocodile at the Tempisque river (not much swimming is going to happen on this trip...). We found an army ant bivouac, which was SUPER COOL. Army ants don't make a nest in the ground like most ants, but instead are nomads and every morning when they settle down for the day, they build a nest using their own bodies by linking up their little legs. It is called a bivouac and would terrifying to fall into.

All in all a great start to the trip, but man, the best is yet to come. More on that soon.

If you look closely, you'll realize this picture is just a whole bunch of ants all linked together.
Army ant bivouac!