Independent Research

Since we have returned from our field trip to the Atlantic Coast, we have been extremely busy preparing for and conducting our independent research projects. It has been a long month taking data and writing papers, but it has been so amazing to get the opportunity to conduct research in one of the most beautiful places in the world.

I had two goals for my project: (1) to determine whether hummingbird feeders have an effect on the pollination of a native plant, Stachytarpheta frantzii, and (2) how pollination is affected across a disturbance gradient. 

Some background information: 

Pollinators are super important in the life-cycle of plants. Hummingbirds are one of the most widely used pollinators, especially in the tropics. They have adapted to their role as pollinators with their ability to hover over flowers, which requires a high amount of energy. This need for energy correlates with high flower visitation in order to sustain their energy needs. 

As the ecotourism industry continues to expand in the tropics, hummingbird feeders have become increasingly popular. Tourists love to see the brightly colored birds, and these feeders provide the ideal way of providing this service to tourists. Hummingbird feeders provide a constant and reliable food source for hummingbirds, but this can have a serious impact on pollination of surrounding flowers. 

Stachytarpheta frantzii is a plant native to Costa Rica. It is very abundant and is literally found everywhere in Monteverde - from gardens, next to high-traffic roads, and near secondary growth forest. This plant also flowers throughout the year, which makes it an ideal food source for insects and hummingbirds in the dry season. This plant was used as my study organism, primarily because of its abundance in Monteverde and that it attracts large numbers of hummingbirds. 

Stachytarpheta frantzii being visited by a Scintillant Hummingbird at one of my sites.

Methodology

I established four sites throughout the Monteverde / Santa Elena region. Each site contained two patches of my study plant. One was the experimental patch (with a hummingbird feeder) and the second was the control patch (without a feeder). These two patches were a minimum of 50 meters apart and had a similar number of flowers. The four sites were chosen along a disturbance gradient, with two sites considered "least disturbed" and the other two considered "more disturbed." Disturbance was quantified by proximity to a nearby forest and the amount of surrounding vegetation. 

Here is a map of my four study sites and where they were located around Monteverde and Santa Elena: 

My homestay house, if anyone was interested, was very close to Finca Santa Maria, in the Cañitas region of Monteverde.

Bajo del Tigre is part of the Children's Eternal Rainforest and was therefore considered the "least" disturbed of the four sites. Cabinas Capuliín is a hotel that is within very close proximity to a forest, and was therefore considered a lesser-disturbed site. Both Finca Santa Maria and Cerro Plano were considered the most disturbed sites.

An example, from Finca Santa Maria, of how my sites were set up with the feeders.

The hummingbird feeders contained a 4:1 water to sugar solution, which closely resembles the nectar hummingbirds frequently find in flowers. Feeders were refilled every 3-4 days at each site. 

Data was collected every morning between 7:00 and 10:30 am. I visited two sites per day, and observed each patch at each site for 30 minutes. Sites were rotated every day, and patches within each site were also rotated to ensure that the time of day did not play a role. Flower visitation was used as a means of quantifying pollination. Every time I was at a patch, I took note of the following: (1) hummingbird species (2) number of flowers visited per bird (3) number of feeder visits, but only for experimental patch, and (4) the total time spent foraging.

Results of my Study

So what I found through all of my data collection was that hummingbird feeders actually played little role in affecting pollination of Stachytarpheta frantzii (actually they played no role since I had zero feeder visits throughout my sites). When I just compared control vs experimental patches, disregarding the feeder altogether, there was a difference at Bajo del Tigre in the number of flower visits between patches. The experimental patch had a much higher mean number of flowers visited than did the control patch for this site. When the number of flowers visited was combined for both patches at each site, I found significant differences between the four sites. There was a trend in there being greater differences between lesser disturbed sites, such as Bajo del Tigre, and Finca Santa Maria, one of the more-disturbed sites. This observation helped show that plants in areas more impacted by humans are more at risk for a decrease in hummingbird visits than plants in areas less impacted by humans.

A Little Piece of Panama

Following our sea turtle adventure in Parismina, we continued southward to Panama! After a long day of travel, we reached the border on our bus and spent close to an hour moving the group over the border into Panama. The border was literally an old train bridge with small wooden boards for people to walk over. 

The bridge we used to cross the border into Panama
Photo courtesy of Google

Once we all got across the border (along with our bus), we drove for about 45 minutes to a port town in the Northeast corner of the country. As we were driving through the countryside, it was interesting to draw comparisons between Panama and Costa Rica. The mountains of Panama were not severely deforested like those of Costa Rica. I'm assuming it's because they don't have as much of a history with agriculture as Costa Rica. It was so much prettier to drive through the mountains of Panama - more trees to look at :)

Once we arrived at a small port town, which would be where we caught some boats over to the island where we would be staying. The name of the province we were in, which I forgot to mention earlier, is Bocas del Toro (mouth of the bull). We were staying on an island in the Archipelago de Bocas del Toro. We specifically stayed on Isla Colón.

Archipiélago de Bocas del Toro. We stayed on Isla Colón (the big one on the left).
Photo courtesy of Google. 

Loading into the boats!

It was a pretty long boat ride from the port to Isla Colón, but it was so beautiful. The wide open ocean, beautiful scenery to look at - absolutely breathtaking.

So our home for the 3 or 4 days we were there was a cute little beach house type place! It was super cute and it was so fun to have an entire house to ourselves. The house was about a ten-minute walk to the restaurant where most of our activities and meals took place. 

Minus the first day (spent doing species reports), we spent just about our entire time in Panama snorkeling around the islands. We had some lectures (of course) on marine diversity and bats. While snorkeling, we saw so many fish and corals and it was really just amazing! I don't think any words could describe how great of an experience that was. I don't particularly enjoy swimming that much, but I had so much fun! One entire day was devoted to snorkeling. We had lunch at this really cute restaurant right over a small reef! It was super cool to just sit on the dock, eat lunch, and see all of the fish swim underneath you.

One afternoon, we took a boat ride out to "bird island," which is where birds nest offshore. There were hundreds of brown boobies and red-billed tropicbirds flying around. That island was so pretty and the birds were amazing!

Bird Island

Red-billed Tropicbird

The following day was our last in Panama, and so we spent the morning snorkeling some more, and then headed into town for lunch and the afternoon. The town is called Bocas del Toro, and is actually the capital of the province. It was a really cute town, with some really good restaurants, too! A few of us went out to a vegetarian place, which sold pizzas and sandwiches and all of that. I must say, their food was amazing! We spent the next hour or so doing some shopping in town before we were meeting the rest of the group to go to a bat cave! This was super cool, as the bat cave is actually a religious site as well as being important biologically for housing numerous species of bats.

Entrance to the bat cave

There was a small stream that ran through the bat cave, however, there was one part of the bat cave got rather deep. For a handful of us, "deep" meant mid-waist. So some of us got a tad bit wet.... 

Nonetheless, Panama did not disappoint. The people were beyond nice, the food (though not my favorite) was good, and the experiences were absolutely one of a kind and an amazing way to end our second field trip.

Here are some random pictures accumulated from our boat rides / time in Panama:

Susan with our adopted puppy

The puppy!

View from the restaurant we stopped at for lunch during our day of snorkeling

Horse who lived across the street from our house