Drosophila flies are cool too!

Our second day in Cuerici, I took a hike along the trail up the mountain searching for different moss morphotypes. Before reaching the stream about ¾ of the way up the trail, I noticed a large mushroom patch growing on a fallen log with quite a few Drosophila flies aggregating on top of the mushrooms. I saw that there were males on top of each mushroom and females flying around the mushrooms, occasionally landing and checking out the underside of the mushroom. There appeared to be a dominant male on each mushroom and any time another male landed on the mushroom, the male would aggressively chase the male off the mushroom. If the male refused to leave, the dominant male would physically fight the competitor until he left.

The mushroom patch

This was a tad more unique than moss growth along the trail, so I changed project ideas and tested if these flies were using the mushrooms as a food resource or territory to attract females (since Drosophila sometimes use fungi as a food source and the males seemed to be defending each mushroom as a separate territory). Within a 5 minute trial period, I counted the number of competing males and females that landed on the mushrooms. I also measured mushroom size and captured the dominant flies to see if their body size mattered in determining their dominant role. I saw a mating event on a mushroom but didn’t find any eggs underneath the mushrooms (where the females were going immediately after landing), indicating that the mushrooms weren’t being used as a food resource but, in fact, the male Drosophila were lekking!

Lekking is an unusual mating behavior (not often seen in Drosophila) in which males travel to a specific location to display and females come to watch and choose mates. Lekking is often seen in birds such as Manakins, but it also has been recorded in butterflies and fish.

If you had told me I would come to Costa Rica to study fly behavior and think it was cool, I would never have believed you. But I guess the Biology FSP is full of surprises for students from all backgrounds!

Besos,

Amelia

Advertisements

More on hummingbirds

This is our last night in Monteverde, and as excited as we are for Cuerici, I think we’ll all be sad to leave. This cloud forest is one of those incredibly humbling places that make you feel like amazing things are going on around you that you might never see or understand. It’s dense, wet, and lush, and it’s often hard to get your bearings among the vines and countless shades of green. As humbling as it is, though, the secrecy of the cloud forest is also promising –  you’ll have new things to see and discover every time you return!

I actually didn’t get to spend that much time wandering through the forest for my project this time around, though. Adam, Allegra, Emily, and I did an observational study on the thermoregulatory costs of hummingbird dominance behaviors, and we spent a glorious few days watching the tiny, charismatic things forage. Since they’re so small and have such high metabolic rates, hummingbird survival and reproduction depend heavily on how much food they can get. They often perform aggressive displays against other hummingbirds to gain control of feeding areas (the males, especially), but these behaviors can be energetically costly and produce excess metabolic heat that might be risky for a hummingbird at relatively high ambient temperatures. So we looked at whether dominance behaviors would decrease with increasing temperatures (They did!).

Figuring out how to collect any meaningful data on the beautiful blurs zipping by our faces was a challenge, but we were excited to find that Vivek’s wonderful camera (a Nikon D600) could take good enough footage for us to slow the video to 1/4 of its original speed and clearly see every interaction that happened around the feeder. Well, see and hear. We recorded chirps, chases, and contacts (when one hummingbird physically tackled another), and you could hear a little thunk when they hit each other on the contacts. It was incredible to watch them that slowly – you catch a lot more behavioral nuances, and in some cases, you could see every wingbeat!

Here’s a sampling of the species we saw:

Image
Green-crowned brilliant (juvenile)
Image
Green-crowned brilliant (male)
Image
Purple-throated mountain gem (male)
Image
Purple-throated mountain gem (female)
Image
Purple-throated mountain gem (male)
Image
Green violet-ear
Image
Violet sabrewing (male)
Image
Stripe-tailed hummingbird
Image
The feeder in early evening.

All in all, a wonderful week!

Pura vida,

Becca Novello ’14

Monteverde: the town beneath the clouds

Today I woke up early and ran down the mountain to the little town of Monteverde. It was a lovely run down, except for the nagging thought that every step I took downhill would have to be repeated far more slowly and painfully on the way back up if I wanted breakfast. But I wanted to run to town to see what a Monteverde looked like to the average visitor.

I passed cattle farms, a bakery, several Italian restaurants, and the Monte Verde Friends School (deserted on account of it being Saturday. I would like to take a moment to petition for a “no work on Saturday on the Bio FSP”. Not a chance—science takes no vacations, we have papers to write!)

The Friends School reminded me of the one task I was given by my grandparents before I left home for Costa Rica. My grandparents are both Quakers and nature lovers—Monteverde, they told me, was their dream vacation spot. While our program was there for the incredible biodiversity, apparently a group of Quakers from Alabama was drawn to the same spot in the 1970’s by its cool climate (ideal for dairy farming) and its non-violent, army-free constitution. My grandparents spent a week here sometime in the 80’s, and apparently had made several good friends who they were sure I’d be able to locate and pay my regards to. They gave me a name and an address, which I sadly forgot to bring with me.

As I ran through town, I imagined my grandparents walking the same sidewalk, marveling at the birds and flowers and making new friends with every step. I didn’t pass anyone over the age of 50, so I figured their friend must not be up and about yet. I headed back up the mountain, hoping my grandparents wouldn’t be too disappointed with my failure to complete my mission. I figured I could make it up to them: when I get home, I’ll explain for them the biology of orchid dispersal, demonstrate the water shedding mechanisms of understory plants, and show them my pictures of the Resplendent Quetzal I took in the Cloud Forest Reserve. That’s been my Monteverde experience, and it’s been a dream spot for me as well, although not much of a vacation.

-Claire

In the cloud forest

Our fifth day here began with a delicious smell coming from the kitchen, which we followed to find French toast, Adam’s favorite breakfast food. Sunshine, new to us in such quantities since we arrived at Monteverde, also greeted us in the morning and stayed around for much of the day. Luckily my group still had some data collection to do, so we could remember what sunlight felt like for a while before sitting down to input our data and figure out what it all meant.

After lunch various papers were edited and adventures were had- a few ventured in the park to see the waterfall, others ran to the continental divide, some just caught up on sleep or work before joining back with their most recent project groups to get ready for our symposium that evening. As my group sat outside to talk about our presentation, a coati (a very cute tropical mammal) interrupted us, attempting to get inside. Amelia bravely fought him off with a chair.

At dinner we discussed the exclusivity of the fear of snakes and the fear of spiders and the universal fear of writing another paper. Then we trekked out to the classroom to hear what each group had been off doing for the past week. We learned about hummingbird aggression, ecosystem engineers in the forest, orchid biodiversity and tradeoffs in leaf inclination (or, as some would prefer to say, declination). The quality and energy of projects pushed us well past the expected time.  Finally we ended so that groups could finish writing some papers and start others until the Internet went down and we decided it was a sign to sleep.

-Lexi

Pura Vida, Santa Rosa

Screen Shot 2014-01-20 at 9.00.14 PM

After turning in all of our final projects at Palo Verde, we woke up early Friday morning and headed to Santa Rosa. Santa Rosa is a beautiful national park hosting, among other beaches, Playa Naranjo- a sea turtle nesting hotspot and surfing paradise. We hiked around 8 miles from the park entrance to the beach, starting in a tropical dry forest similar to Palo Verde and ending in the mangroves near the beach. We were totally unplugged for the weekend, camping near the beach and swimming and relaxing during the day. It was a much needed break from our experiments, but we did get some great lectures on sea turtles, vertebrate biology, and mangrove ecology.

IMG_6774

Playa Naranjo was not only a beautiful beach, but also has some crazy biodiversity. Before we hiked in we were warned that the day before a jaguar had hopped onto the hood of the park ranger’s car on that very trail! We were also incredibly lucky with nesting sea turtles – Ryan warned us that they haven’t seen sea turtles on this FSP in the last five years, but as a group we saw 3+ nesting mama sea turtles (Olive Ridleys and Hawksbills) and then stumbled across a nest hatching our first night! It was such an incredibly organic and awesome experience to watch the little hatchlings fight their way down the beach into the ocean.

IMG_6824

IMG_6838

IMG_6769

We’re in the cloud forest of Monteverde now, nursing our sunburns and going out of our minds about this brand new ecosystem- wet, muddy, and cool, with hummingbirds overhead and so much plant diversity I just can’t wrap my mind around it. Today we did some orientation hiking and started brainstorming ideas for our new projects. More on the bromeliads, orchids, epiphytes, and hummingbird projects to come!

– Emily Goodwin ’14

Learning the Ropes

Hi all! This is Annie Fagan ’15 coming at you live from the dry forest of Costa Rica. Here’s a quick update on our way out of Palo Verde National Park this morning. (Next stop, Santa Rosa!) 

Costa Rica is a small country, but it has ~4% of the world’s biodiversity, and that became obvious within the first 24 hours. In the last week I’ve seen coatis (kind of like raccoons), actual raccoons, geckos, deer, herons, whistling ducks, crocodiles (6-7 feet long!!!), peccaries, ctenosaurs (huge lizards that can run on 2 feet if you make them move fast enough), howler & capuchin monkeys, scarlet macaws, snakes, king vultures, fire ants, scorpion spiders (the love children of scorpions & spiders, if that wasn’t clear from the name), and so much more. It’s mind-boggling what you can find around here when you’re not even trying. One night, we saw a coral snake (super poisonous, thank goodness we didn’t step on it) and a tarantula bigger than the palm of my hand. We’re definitely not in Hanover anymore.

Now to the projects! They are real fun. So fun that it’s hard to believe we’re getting credit for doing them. Apparently the only difference between playing around in nature and science is writing down your results. My favorite project from the last week involved tracking monkey troops – a logistical nightmare. My group had to get up at 5:30 every morning to find them, as they are most active before it gets hot, and we had nothing to go on but a) hearing their calls or b) coincidentally sighting them in trees. There was a lot of bushwhacking required, and I think we probably all hiked ~15 miles in two days. But the rewards made all the hard work so, so worth it. Sometimes the monkeys came so close to us that I forgot to breathe. We saw lots of howlers, lots of capuchins, baby monkeys, female/male monkeys… and lots of interesting primate behaviors. One howler male got really aggressive towards us and started howling, pooping on us and dropping branches on our heads. It was AWESOME. Howler monkeys can poop on me any day as long as I get my data. 

As for the scorpion experiment, well, that was crazy. A few nights ago I found a baby scorpion in my room (about the size of my thumbnail) and had to get Lars, another FSPer, to kill it with his hunting knife because I was so nervous. 24 hours later, I was helping my teammates to design a study that would require us to go out into the park at night and catch 3″ scorpions. (If any of you can follow my logic there, please let me know.) Before we left, we consulted with Park Ranger Sergio, and he told us that these scorpions are poisonous but wouldn’t land us in the hospital if we were stung. Instead it would just hurt a lot, and we might feel dizzy and nauseous for a couple hours. I think he was trying to be reassuring. He then gave us 1 piece of advice for reaching down to pick up a scorpion: “Don’t miss”. With this in mind we set out into the night, and ended up finding & capturing about 15 scorpions over 2 nights. Then we proceeded to do science, which in this case consisted of us constructing forts in the library (to simulate darkness since scorpions are nocturnal) and feeding crickets and grasshoppers to our scorpion prisoners. The trials were simultaneously exhilarating and terrifying and inspired lots of would-you-rather questions about scorpions (would you rather fight a cat-sized scorpion or 200 regular-sized ones?).

Scorpion update: After 2 days of safely capturing and handling finger-sized, very angry, scuttling, fast-moving scorpions, my friend Amelia reached into her backpack and got stung by a scorpion hiding at the bottom of it. The irony was so great that she laughed through her tears. Sergio’s response? “Welcome to the tropics!”

Stay tuned to hear more about our adventures over the next 9 weeks!

Over and out.

Annie