Camera traps and howler monkeys

Every morning I wake up to a chorus of howler monkeys. And chorus is a kind word for the ruckus they make. I am only a few kilometers from the equator, and the sun rises promptly at 6am and sets at 6pm. At dawn, the monkeys whoop and holler until I crawl out from underneath my mosquito net to start the day. The bamboo house is open to the elements – the forest grows right up through my bedroom window. It’s been an adjustment getting used to life here. Basic facilities have changed: only one sink has potable water, there is no internet connection, there is no refrigeration, the shower is a waterfall, and we have composting toilets. The first week involved a lot of orientation to life in the bamboo house and the lay of the land. Now that I have been introduced to the more permanent residents of JCR (including the animals!) and have a new basic routine, I have turned my attention towards my project.

What I am doing here is a simple yet groundbreaking idea. Camera traps are a relatively new technology, and I am using them to capture hummingbird feeding data. Normally, a scientist grabs a camping stool, finds a clump of flowers, and sits in front of it for hours while recording what hummingbirds come to visit. There are two types of hummingbirds with different feeding strategies. The classic method of observing feeding behaviors has (I speculate) favored nonhermit over hermit species. Hermit hummingbirds are solitary and travel long distances, following a “transect” of flowers through the forest. Nonhermit hummingbirds don’t travel as much. They tend to be territorial and defend clusters of flowers, making them easier to observe. At JCR, I am using camera traps to observe isolated flowers and their visitors over long periods of time. This will be conducive to hermit hummingbird feeding habits and will provide data from a “flower’s perspective.” Coming to JCR, I had no idea if camera traps would even work for this project. I had a lot of experimenting to do.

I first needed to test how the camera traps would respond to hummingbird visits. To do this, I set up two feeders filled with sugar water concoctions near the bamboo house. At this earliest stage of my experiment, I was already questioning if what I was doing was right. Two interns advised me on the ratio of water and sugar that most closely resembles nectar hummingbirds feed on naturally. I wondered if the sugar water I was feeding the hummingbirds was nutritious for the hummingbirds. I had no way of knowing if the sugar I used from the kitchen was metabolizable by hummingbirds, or if I was essentially feeding them junk food. I was especially worried my interference with the natural feeding habits of hummingbirds would create bad habits for local individuals or would provoke a dependence on my constant supply of sugar water over natural sources. As a scientist, I needed to gather as much data about this as possible, so I could understand the situation. Thinking about ethics, I needed to decide if my actions were justifiable or for a greater good.

Many techniques for studying birds have severe impacts. For example, the group of interns staying in the bamboo house are using mist nets (long lines of fine mesh) to catch birds and band them with metal rings. Occasionally there are accidents resulting in fatalities or entanglements that cause injury. These birds are obvious examples of collateral damage from these methods, but it is harder to quantify the costs of stress on the other birds. Scientists using this type of mark-recapture technique assume that the birds released continue to live natural lives, but no one can tell if capturing and recapturing birds affects their survivability. The catch-22 is that banding is the only reliable technique for estimating life expectancies and survivability. People continue to band despite the fatalities, injuries, and unknown costs because the biological and ecological data collected from these studies is deemed more valuable to the overall understanding and protection of the species.

There is a threshold where this data collection becomes a net-negative endeavor. The same goes with my hummingbird feeder tests. My first instinct is to figure out the reduction in survivability a data collection method causes and quantify how the information collected could be used to protect a species to determine net impact. Using hummingbird feeders may have unknown costs. It isn’t far-fetched to speculate that the feeders and the constant supply of sugar water are distractions from small and scattered forest flowers, which result in less pollination activity. The feeders concentrate local hummingbirds into a smaller area, perhaps increasing interactions and aggressive territorial behavior. My project advisor, Professor Stuart Pimm, explained that the sugar water is used to stock up on quick energy for short insect-hunting excursions, and therefore the sugar supplies are not a major source of nutrition. To the extent to which I can speculate, the impact seems to be minimal. Scientifically speaking, this makes my efforts justifiable. But this method of justification purely considers survivability rates as the cost of information. It doesn’t consider the value of individual animal lives. It also doesn’t question the right scientists assume they have to interfere with natural processes for the sake of their experiments. In my experience at Duke, scientists speak only in terms of the quantitatively justifiable. Little reflection is spent on the known and unknown costs on hummingbirds from an ethical standpoint. To lose sight of this is one way that I believe researchers are distancing themselves from the full implications of their research and avoiding ethical questions. I always want to be asking myself if a few fatalities or interfering with natural feeding habits is justifiable by weighing the value of life and avoiding the assumption that I have a right to experimentation as a human (“non-animal”) being.
The other residents of the bamboo house enjoy watching the feeders (as do I!) but I have decided to take them down after I have finished calibrating the ideal settings on camera traps for capturing hummingbirds. There are so many ways in which my life has impacted wildlife, and there are many ways that I cannot quantify. Even though I don’t know the overall costs of hummingbird feeders are, I think it is better to minimize my impact. The less that I interfere with hummingbirds in my scientific endeavors, the better I will be conducting my research – this, at least, I can control.

Andrea Kolarova is a T’20 Undergraduate and a 2018 Kenan Summer Fellows Participant. 

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