Monarchs abound at Las Cruces

OTS owns and operates three field stations- Palo Verde, La Selva and Las Cruces. After La Selva we spent a lovely week at Las Cruces, so I have now collected the trifecta of OTS field stations. Las Cruces is at a much higher elevation than La Selva (1400 m), and so is both cooler and less snake-filled. The station itself is surrounded by the Wilson Botanical Garden, one of the largest and most extensive botanical gardens in the world. The Wilsons started collecting plants for the garden in the 1960s, and OTS acquired the station in the later 70s. There are some thousands of different tropical plants here, each conveniently organized by group – you’ve got the palm patch over there, and the bromeliad hill over there- you get the idea.

My work here was mostly focused on another type of ant-plant. At Palo Verde I worked on the Acacia trees which housed Pseudormyrmex ants inside of hollow thorns. Here at Las Cruces you can find a whole lot of Cecropia trees, which house Azteca ants inside of hollow stems. The plant not only houses but also feeds the ants with food bodies it makes near the leaf stems. To pay the rent, the ants defend the plant from insects that want to eat it.

One of our faculty resource people, Cindy Sagers, introduced us to the Cecropia-Azteca work her group is doing. She brought us out to the forest with her eight foot sling shot, which they use to pull down large branches of the Cecropia trees. It’s harder than it sounds, getting a good slingshot-shot up and over a hundred foot limb that is surrounded by other vegetation. It is also a lot of fun to fire.

With my classmates Natalie, Haydée and Rick, we worked on Cecropia peltata, a species that lives along most roadsides in the tropics. By accident while trying to inspect a small sapling, I broke it off at the base, so Rick and I decided to dissect it and see if we could find the queens inside of the hollow stem. Amazingly, there were a lot of queens! In one of the hollow internodes, we found four queens of two different species. This seemed weird to us, since most large mature trees are thought to have only a single queen.

After our random discovery, and the fun of dissecting the saplings (it’s like opening Christmas presents since you never know what you’ll find inside), we changed our project to look more specifically at how ant queens were founding colonies.

The next day, with the queen founding in mind, we happened upon another incredible discovery- some queens actively founding a new colony! Because their colonies are inside of the Cecropia trees, they have to dig a hole using their teeth to get inside. This activity can be quite energy consuming, and so it would make sense to cooperate to dig a hole. That day was kind of crazy- I was doing a lot of running around, trying to capture all the activity of the ants. In total, we saw 13 fouding events, a third of them being cooperations between multiple queens. We watched three queens cooperate in digging a nest entrance for almost 6 hours- it sure took a lot longer than we’d expected! They kept digging and digging with their little ant teeth, and made very slow progress getting into the plant.

Aside from spending a lot of the day watching ants and dissecting their nests, I had a nice time at Las Cruces hiking around in the forest. There was a beautiful river trail, and lots of beautiful flowers everywhere.

I also enjoyed some delicious meals with friends in the comedor- we would sit down and eat family style, which is a nice change from cafeteria style serving. My favourite part of the day is sitting down to eat with my OTS family and enjoying some good laughs. They had some great bread for breakfast at Las Cruces, which was a nice change from the gallo pinto (rice and beans) of the past six or so weeks. I have had a bit of a gas baby lately (from too much gallo pinto I think), which has been the subject of many jokes. I hope the due date is soon! I am tired of having a bloated hurting belly! 

Return to La Selva

A long overdue update, but alas a necessarily less visually pleasing one because of the slow internet connection. (ie: Pictures to come once back in America).

It's been a couple of weeks since you've heard from me, and much has happened. We have been at three different field stations- La Selva, Las Cruces and Cuerrici, and I'm going to dedicate a post to each in turn. So, first off, La Selva! 

La Selva Biological Station is one of the most frequented tropical field stations in the world. It is the only field station in Costa Rica that I had visited prior to this trip, so I have a lot of fond memories of being there. First I visited in January 2010 for an OTS short course on plant animal interactions, which was fantastic, and then I returned in June of that same year for a short stint of field work, and had a lot of fun with my friend Erin CB who helped me deal with bullet ants. 

Returning to La Selva, while a bit nostalgic, was also a great opportunity to explore new parts of the station property and to do new things. We had some great resource faculty at that site. One of my favorite faculty was Mo Donnelly, the advisor of my course-mates Mike and Michelle, and a real firecracker. She gave a couple of lectures while at La Selva (one of which she delivered with beer in hand), about her work on the herps, or the reptiles and amphibians of La Selva.

Her dissertation work was on the insanely cute strawberry poison frog, which has a red body and looks like it has little blue jeans on. A tiny creature with a very interesting reproductive strategy. The males defend a territory full of bromeliads and tasty leaf litter creepy crawlies, and calls all day for females. The females show up, assess their man, and if they decide to mate they’ll lay some eggs in the litter. The male guards the eggs in this young stage until a couple weeks later when the tadpoles are ready to hatch. At this point, the female returns and encourages the freshly hatched tadpoles to wiggle up onto her back. Once they’re piggy-back ready, she climbs a tree and drops the little tadpole into a bromeliad full of water. The incredible thing is she puts each tadpole in its own bromeliad and also remembers where each of them live, returning to lay unfertilized eggs for them to eat. Every day she climbs up and down a dozen or so trees, feeding her tadpoles until they are adults. Truly incredible.

I’ve always thought herpetologists were a special breed, and the week and a half at La Selva certainly offered more ammo for that observation. For example, one random day while hanging around the lab, this guy walks out of the forest with a ten foot long boa constrictor wrapped around his arm. While most people’s instincts are to run from snakes, there are folks out there who pounce instead. It was an impressive animal, with a terrifyingly angry gurgling hiss, and you would have to be crazy to NOT consider this guy crazy. That snake was one of the most scary animals I have ever seen up close. Not venomous, but very strong- imagine ten feet of solid muscle, in some places as large as your thigh.

While not quite so crazy (‘I stay away from the venomous ones!) Mo is a lot of fun in the field. She took us on two very memorable night hikes. The first was along the boardwalk in the biological reserve swamp. We heard an awful lot of frogs crawling, and I saw (among many things) a bunch of red eyed tree frogs, the most photographed animal in Costa Rica. We also saw a snake eating frog eggs, which was really cool- it’s not often you get to see those types of interactions in person.

Our second hike was a bit more adventurous, because instead of walking along a nice boardwalk in a swamp, we actually walked IN the swamp. I’ve done a couple of swamp walks before- one memorable one in Argentina as an undergrad comes to mind- but it’s been a while since I’ve been waist deep in swamp water. A couple of my colleagues braved the cow-paddy muck of Palo Verde, but I kept my feet dry. The research swamp at La Selva though, that was a whole other experience. Definitely the most memorable moment was when Kevin started shrieking and grabbing his rear- he had a baby iguana in his shorts. Later when Mo asked if we had fun, Kevin replied ‘I had faun-a in my pants!’

All in all, the nights were a lot of fun at La Selva- some of the faculty field problems even involved 24 hours of sampling. They were looking at the respiration of trees over a night, and some of my friends, notably Paulo and Michelle, were pretty out of it for a few days afterwards. Fortunately my faculty field problem was diurnal sampling only. For our project, we looked at palm tree demography (ie: the age structure or number of seedlings, saplings and mature trees) in old growth and secondary growth forests. Lots of transects and bush walking through bullet-ant invested understory. Natalie, one of our team, did get stung on the finger but made a remarkably good recovery. Fortunately I still haven’t experienced the sting of the bullet ant, but I sure am curious. Our FFP was a lot of fun fieldwork- biking down the STR trail, hiking an hour or two out to field sites, getting lost in the forest, having a field lunch of omelete sandwich, egg salad sandwich and hard-boiled eggs.

At La Selva I also collected a lot of ants (surprise!), a couple hundred or so from at least 40 species. One of the highlights of my fieldwork (aside from the jungle biking, ant-lion wrangling, and spider monkey watching) was to visit the canopy towers, in search of arboreal ants. I only got a couple of ants, but man, the view was incredible. As promised, photos will follow shortly.

The recreation at La Selva was also quite different and memorable. As a field biologist sometimes you need to make fun for yourselves. I have heard a lot of fun tales from old-timers and the crazy antics they’d get into (Mo Donnelly has quite a few of these stories). I’m not sure how far back this tradition goes, but on the fourth of July, in celebration of the founding of La Selva (and America), there is a toad race. The toad race is set up so that a pair of toads race each other across a span of about 15 feet or so, and the first to hop over the finish line wins. I entered a toad last minute with Ty (our toad was named ‘Frog), and from our class there was also Courtenay’s toad (Gallo Pinto – the breakfast mix of rice and beans), and Rick’s toad (Camel Toad – no explanation required). Your toad would start at the start line, and using a spray bottle of water you would spray its butt to make it jump. Our little Frog got pretty far but was knocked out in the quarter finals. In a surprise victory, Rick’s toad won the whole race, and he was given a homemade sloth sculpture made of beer cans and aluminum foil.

I really hope I get to return to La Selva someday- my third visit there was just a great as the previous  two. It’s a lovely forest to work in, and there are a lot of conveniences for researchers, as well as a great comraderie (the forty person soccer game on Wednesday was super fun!). We’ll see what is in store for me, but I’m hoping I can return one day and make more memories there.

***

No toads were harmed in the making of this blog post.

The Association for Tropical Biology

Last week, we were in San Jose for the annual meeting of the Association for Tropical Biology and Conservation (ATBC). It happens to be the 50th anniversary of both ATBC and of OTS (the Organization for Tropical Studies, or in spanish OET, la Organizacion para Estudios Tropicales). It was quite interesting being at a 50th anniversary meeting because everyone was in a very nostalgic mood, and I got to hear a lot of fun stories about 'the good ole days'.

One of the people I was most looking forward to meeting (but alas, it did not pan out) is Mary Jane West-Eberhard. She is one of the foremost authorities in wasp social behaviors and is also a really kick ass female biologist, who has lived in Central America most of her life. She works in both Costa Rica and in Panama. On the historical panel a few days ago, she shared a very interesting story about how she started out in biology in the early 60s.

Field biology, especially in the tropics, is very different today than it was in 1964. Back then, most work was done in a very exploratory way, on a series of expeditions. It was true exploration, working in very new and (literally) uncharted territory. A far cry from our air conditioned lab and high speed internet situation at La Selva today.  Mary Jane was a grad student and interested in traveling to the tropics, but since the only women allowed to go were the wives of expedition members, she was hard pressed to get herself invited. One day, a student she'd tutored mentioned that he was looking for biologists to visit his home country of Colombia, and invited her to live in Colombia and do research there.

She packed everything (but the kitchen sink) for her trip to Colombia - from 50 pound machines to measure temperature and humidity, to a little black dress for social outings. (Just for comparison's sake, the 50 pound thermo-barometer she used has been replaced by tiny dime-sized iButtons.) Apparently the little black dress got used only once- for a funeral and alas, not for a date.

One of the most interesting proofs of the gender differences of the time was the fact that women weren't allowed to wear trousers in public. Poor Mary Jane, who would take the bus to her field sites everyday, had to wear a skirt or dress on the bus, change into her field clothes for work, and then back into a ladylike froc for the ride home. She also wasn't allowed to have a backpack (how unfeminine!) so she used a giant straw purse to carry all of her field gear.

I must say, I sure am glad that times have changed!

The cloud forest has fog like San Francisco!

I have finished the second leg of my trip in Costa Rica, and things just keep getting better and better. We spent a couple of days in the beautiful cloud forest of Monteverde, at the University of Georgia research station, which is basically a glorified resort. The hot water, lack of mosquitoes, rocking chairs on the porch overlooking the mountains, and wonderful butterfly filled jungle made a lot of us feel like we'd ascended to heaven after a hellish visit in Palo Verde. There were many not-too-fond reflections on poor Palo Verde. I do love the dry forest truly, but I think everyone on our trip can agree we like it a lot more when it is dry.

Colton, Shivani and Mike enjoying the rocking chairs on the deck at our Monteverde station.

Monteverde is one of the last protected areas of cloud forest in Costa Rica. This montane habitat is called 'cloud forest' because you truly are in the clouds. All of the life is adapted to living with the intense cloudy humidity, and moss covers everything. A lot of really unique flora and fauna are found in the 'sky islands' of mountain peaks. Just like an island in an ocean, the things living on tops of mountains are isolated from each other by deep valleys, and this can create some really cool patterns in species distributions. For example, one of the species endemic to (meaning found exclusively in) the cloud forest is this beautiful turquoise tiger beetle.

Tiger beetles are only found in the cloud forest- they are an indicator species of good cloud forest health.

Joining us at the Monteverde site was the eminent coleopterist Terry Erwin, who curates the beetle collections at the Smithsonian Museum. He directed the Faculty Field Project that I participated in, and we looked at (you guessed it!) beetles. Terry is such a wealth of neotropical knowledge, particularly when it comes to insects. He has lived for more than 15 years in the Amazonian rainforest. He's famous for his estimate that 30 000 species of insects live in the Amazonian canopy. Thirty years later, that number seems like a huge underestimate. Much of the collecting Terry does involves fogging the canopy- he sends up a spray of insecticide, and all the insects fall to the ground to be collected, sorted and counted. In Ecuador, there can be 400 000 individual insects in one square meter of fogged canopy. That is a lot of insects.

In the field with Terry Erwin near our field site under a fig tree. 

For our FFP we also dealt with a lot of insects, counting up more than 3000 of them. My winkling skills are really sharpening themselves down here, since we used the litter sifting technique for this project as well. We collected litter from underneath fruiting fig trees, and compared what we found there to areas of the forest not supplemented by the delicious falling fruit. Figs are what we call a 'keystone species' in this type of forest, meaning that the fig fruits give important energy to a lot of different species, including monkeys, birds, and of course, bugs.

We found a lot more predatory beetles under figs, and also some fig-specialist beetles who eat the seeds of these trees. Those 3000 individual creepy-crawlers came out of only 8 square meters of forest leaf litter, including 323 beetles. You would not believe the diversity and abundance of life you are walking right over everyday in the forest. A lot of the work I am doing here is analyzing the data we collect and writing it up, so I'm going to share a graph of our data with you.

Figure 1. There are a lot more predatory beetles inside fig fruit falls than outside. Science!

To be honest, I probably spend more time making graphs and tables than I do taking pictures. So it's always a welcome reprieve when I can be out and enjoying the forest and focusing on using my camera instead of my forceps. Thankfully, after all the long hours of sifting and sorting through insects, we got the chance to visit the lovely cloud forest preserve a few kilometres up the hill and enjoy the forest for the forest, and not for its data. I got some great pictures, so I'm going to just sum up with some photo captions.

One of the highlights of the trip so far- I got to hold a nestling bird!
One of our professors, Gustavo, is a bird specialist and he spotted the nest this little guy was in.
The baby felt super warm- a bird's ambient body temperature is around 40 celsius, so a fair bit warmer than us.
 

A blue morpho on the wing...

...and with tattered wings. This guy has probably survived a couple of bird attacks. 

Bromeliads are really important plants in tropical forests- the water pools they create are home to
all kinds of interesting life. They grow on other trees, usually in the canopy. 

This orchid is the national flower of Costa Rica. Beautiful!

Strangler figs grow around other trees to get up to the canopy for sunlight.
When the host tree dies, the fig remains, creating a hollow ladder you can climb.

Glasswing butterflies are really abundant at Monteverde.
The see-through wings help them avoid predators. 

Who wouldn't think this little grub is cute?

One of our instructors (Nacho) is an expert on harvestmen, also known as daddy-long-legs.
These guys aren't spiders, but they are arachnids.
Unlike spiders, they have no venom and no silk.

A lot of the understory plants have huge leaves, to collect more sunlight.
 Here, my Mexican friend Haydée stands next to a giant Philodendron leaf to show just how big these leaves are. 

The mot-mots are beautiful birds found throughout Costa Rica.
This poor guy got stuck in the greenhouse and I got Ana (the bird specialist instructor) to help him out.
The tail feathers don't naturally grow like that- instead, the males pluck out the feathers.
Apparently female mot-mots like the showy plummage.

Sheet webs like this one get really dewy in the cloud forest. See the spider on the right?
Just waiting for something to fall into the web.

Tree ferns are large tree-sized ferns. Very ancient plants, and pretty rare.

Hola raña!

The only thing wrong with this waterfall was the no swimming sign posted right next to it. Beautiful.

Cloud coming over the mountains reminds me of the fog drifting over the San Francisco Hills.

Now we're in San Jose, the capital city of Costa Rica, for the Association of Tropical Biology and Conservation (ATBC) conference which is going on until Thursday. I'm looking forward to hearing about cool tropical biology research happening around the world, and hopefully meeting some cool people. More soon!

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!  

No surprise: Spiders like insect buffets

Field courses run by the Organization for Tropical Studies are generally intense research experiences. It has been a little over a week, and I've already completed one project and am making my way well through a second. Our first project out here was a faculty field project (FFP), led by Nacho, our class TA. Nacho's a Costa Rican (a tico) who specializes in spiders, so our first project was to investigate (you guessed it!) spiders.

The spiders we studied are Peucetia viridans, a type of lynx spider. For those not versed in scientific names, they are generally italicized, because they are in latin. The first part is the genus name- there are lots of species in a genus usually, and they have a lot in common with each other. The second part is the species name, and together the genus and species name make up a unique binomial for that species. Anyways- that was a tangent. I'll just refer to it as the green lynx spider which is the common name.

The lynx spiders associate generally with plants that have a lot of trichomes, which are little hairs on the leaves that can make the leaves sticky. The sticky leaves help trap insects, which the spider eats. We surveyed all of the plants we could find, to figure out why some plants have spiders and others don't.

A lynx spider female defending her plant.

Basically, spiders liked plants with more insects on them- they like to live somewhere with something to eat. No real surprises with that one!

The song of the zancudo

My first day in the dry forest of Palo Verde in Costa Rica, passed very differently from the last time I was in the dry forest. My last dry forest visit was in 2007 when I visited Chamela in Mexico, during the dry season. It was a turning point in my life as a scientist. In the dry season in the dry forest, all looks very dead. How could there be life in such a desolate looking place? Much to my surprise, a dozen leaf cutter nests surrounded the field station, and fed on everything from juicy cactus fruit to the kitchen leftovers. Every night, I spent hours watching those ants move along their trails, fascinated. Anyone who can recall seeing leaf cutting ants for the first time probably has a similar story- watching them carry their massive loads, wondering at what the different ants did in the nest. I caught not only a deliciously evil amoeba from drinking the tap water (cured thankfully!) but also caught a real love for ants.

Indeed, this time in the dry forest, in the rainy season, is very different. Why? Well, for starters everything is green. There is almost no rain here from January to May, but since the end of May, there has been a lot of rain. That means green leaves, wetland wonderfulness, and of course, MOSQUITOES.

The view of Palo Verde marsh just before sunset- beautiful reflections of the clouds in the water!

What this has meant for my ant watching is that I have limited it a fair bit more than I would have if the zancudos (as they are locally known) were not so voracious. I have only experienced them this bad before in Northern Canada. I also contended with black flies, no-see-ums, and horseflies in Canada, so I suppose I should consider myself lucky. Either way, I have resorted to using bug spray, which I am loathe to do. Usually I would try to avoid the stuff so that I can pick up cool amphibians, and not chemically destroy any ants I am collecting. But desperate times call for desperate measures.

Despite the zancudo serenade at all hours of the day and night, I have grown to love this place in the short time I have been here. Our first day here we had two great orientation hikes, and I saw both howler and capuchin monkeys. (No pictures alas, but I'm working on it!). I saw agoutis, great curassows, frogs, lizards, snakes, and lots of other cool creatures.

Some insanely cute and fuzzy caterpillars!

A coati - the racoon of central america- says hello!

Ctenosaurs are everywhere- they run upright on two legs when they get really afraid.
They are a type of iguana, and love to sun on rocks outside our house.

Palo Verde used to part of a giant cattle ranch, and was made into a national park in the 70s. Unfortunately, after the cattle left major changes started happening to the area. The wetland became inundated with cattails, which prevented other plants from growing. This drop in diversity in wetland plant life had cascading effects on other species. There are 68 aquatic bird species that use the marsh of Palo Verde, and many migrant birds that stopover on their way to other parts of Central or South America. Once cattails started to dominate, the birds started to dwindle. What to do? Bring back the cows! Yes, there are a bunch of cows in this National Park.

You can usually see several cows and cattle egrets enjoying the cooling marsh.

We are working now on our first faculty field projects (FFPs), and soon we'll start our independent projects. I'll report soon on how that goes- we are working on a spider-plant interaction. Until then, zzzzzzzzzzzzzzzzzzancudo!