picturesA huge highlight of my time in Costa Rica thus far has been the overnight trip to Cerro de la Muerte. In Spanish, this name translates to Mountain of Death. Oooh…scary! The reason for such a morbid name is that during the daytime it is hot and sunny because strong UV radiation, and as a result, people who get lost there tend to be wearing light clothing. When darkness falls, the temperature drops drastically (due to an elevation of 3,200 m) to the point that there was frost on the ground when we woke up. Many an unwary travel has frozen to death on this beautiful mountain. Luckily we had cozy mummy bags to snuggle up in. (But let me tell you that the alpine shower was beyond refreshing, It was painfully cold).
Here’s the schedule for our trip:
Feb 8th
5-5:30 AM breakfast
6:00 AM Leave
10:00 AM Reach Rio Mancho (2,500 m) and hike to Mountain Bog
Lunch
2:00 PM Reach La Georgina (3,300 m) and set up mist nets
5:00 Economics Class
6:00 Dinner
Feb 9th
6:30-11:00 AM Field Experiment
Stop at the Paramo
Natural Resource Management Class at the Paramo
Like during the trip to Gaupilles, we enjoyed the scenery of majestic mountains on our way up to Cerra de la Muerte. Our first stop was at Rio Mancho Forest Reserve. This reserve is part of La Amistad Conservation Area, which is the largest biological corridor in Costa Rica and it continues into Panama. This larger park, created in 1999, includes widely diverse ecosystems such as the Paramo, mountain bogs, oak and elm forests, and cloud forests. Though many of you will think I’m crazy, bogs are one of my favorite ecosystems. I love the earthy smell of decomposition and the slurping sound that the muck makes when you pull your foot out. Something really cool about wetlands is when one person jumps you can feel the ground bounce because of the interconnectedness of all the roots and organic debris.
In many places this waterlogged soil is several feet deep. Alongside the bog is a timber reserve of oaks and elms draped in vines, mosses, and epiphytes. The oaks are harvested for barrels, furniture, and charcoal production. The elms which are associated with nitrogen fixing bacteria are preferred for cabin and coffin construction because of their smooth slim trunks. There are three major types of logging practices: conventional logging, selective logging, and forest management. Conventional logging entails clear cutting. Selective logging has less of an impact and it is focuses on harvesting the largest, most profitable trees. Forest management takes the whole ecosystem into consideration to promote forest growth. The timber reserve we visited is managed through selective logging. In a primary rainforest (which I have yet to see), there are distinct layers between the canopy and the undergrowth which is not evident here. You can tell this is a disturbed forest because there are many small trees which all reach about the same height.
30 years ago there were many incentives to clear rainforest land (which was seen as unproductive) for cattle grazing so that developed nations could enjoy cheap beef. In the rainforest, there are many medicinal plants such as wintere (sp?), a spicy leaf I bit into, that is used to relieve toothaches. The people who live with the land have a vast knowledge of such plants. However, this knowledge is now diluted and is becoming endangered because of the emphasis on cash crops and technology.
Next we went onto Cerra de la Muerte and started our Hummingbird field experiment. Hummers serve as the dominant pollinators of tropical highland plants. Due to the harsh range of temperatures present in Costa Rica’s highlands, hummingbirds have developed the ability to thermoregulate. They do this by entering into a state of torpor which allows them to drop their body temperature from 28˚ to 12˚C during chilly nights. Just as hummingbirds have adapted to the tropical highland environment, highland plants have coevolved with the nectarivores for optimum pollination. For example, the flowers are long and tube shaped as well as brightly colored to attract hummingbirds. These plants are dependent upon hummingbird pollination for reproduction and genetic diversity.
The four species of hummingbirds that live at Cerro de la Muerte in the tropical highlands of Costa Rica are the Fiery-Throated (Panterpe insignis), Magnificent (Selasphorus flammula), Green Violet-Ear (Colibri thalassinus), and Volcano Hummingbird (Eugenes fulgens). Tourists enjoy watching the hummingbirds feed so many businesses such as La Georgina Lodge set out feeders. If birds preferentially feed at the artificial feeders, the populations of flowers that have coevolved with the birds may decline. As of yet, there has not been much research on the effects of artificial feeders on hummingbird and hummingbird dependent species.
The School for Field Studies has been gathering data on this topic from 2003-2006. Their method is to capture the birds with mist nets in order to sample the hummingbirds for mites and pollen and match them with pollen and mites from native flora. I found helping with this research thrilling! When I held my first hummingbird, a male Magnificent, I couldn’t tell whose heart was beating faster; my little friend’s or mine for fear of hurting him. Handling of the birds is kept to a minimum in order to reduce their stress. Note that the only reason we were allowed to handle the birds was because our professor has a wildlife license. IF YOU ARE NOT TRAINED, PLEASE DO NOT TRY THIS AT HOME AS HUMMINGBIRDS ARE VERY FRAGILE CREATURES. Thoughout the course of this study 180 birds have been marked, 13 of which have been recaptured. Currently the information gathered is insufficient to determine if the feeders are having a negative impact on pollen load. Regardless, planting hummingbird-pollinated flowers will help ensure the health of these codependent organisms.
