Wednesday, October 2, 2013

Field work vs. lab work

During my first two years in Chile I worked primarily in the field. This year however, with the exception of one quick week in the field, I’ve been doing all my work in the laboratory. The field and the lab both have their advantages and disadvantages, pluses and minuses, ups and downs. My experience working in both environments has caused me not to pick a favorite, but rather to conclude that the strongest research approach contains both lab and field components. In this post, I’ve identified five major research concerns; experimental control, ecological relevance, animal maintenance, expenses, and working conditions. For each research concern, I’ve written a short discussion comparing and contrasting the relative benefits of lab and field approaches (note: this post is mostly geared towards those that work with vertebrate animals).

Experimental control
There are two types of things you want to control in an experiment; variables and sampling opportunities, and the lab clearly wins in both categories. In the lab, most variables can be controlled and sampling opportunities are only limited by experimental design or physiological limitations. In the field, however, there is only so much control researchers can assert over certain variables. For example, weather is pretty much uncontrollable. Sure, you can put a heating pad in a nest box or you can water an experimental plot during a drought, but that’s pretty insignificant in comparison to a temperature and humidity-controlled animal room. And as for sampling opportunities, oftentimes field researchers are subject to the whims of their animals.
                During my field research there were several variables I wish I could have controlled. For example, because degu pups are born in underground burrows and do not come aboveground until three weeks of age, there was no way for me to measure or sample the pups during this time. Additionally, because female degus live in social groups and raise their offspring in communal burrows, there was no way for me to determine which pups belonged to which mother within a social group. Using genetic information could have solved this problem, but the genetic tools for degus are still being developed.
                For my lab experiment, these problems don’t exist. I know the exact day my pups were born, who their mother is, and how much they weighed at birth. I can now weigh and measure the pups and mothers as frequently as I need to, and I can also observe the behavior of my degus by videotaping them whenever I want. This was another thing I couldn’t do in the field- because degus live underground, there was no way for me to see if my experimental treatment was affecting the level or quality of maternal care. In conclusion, the lab is a better environment for experiments that require a lot of controlled variables or specific sampling points. This comes at a cost, however, which brings me to my next research concern:

Ecological relevance
                As soon as you bring an animal into an artificial environment you alter its behavior and physiology. This can be exemplified by the struggles of captive breeding programs for endangered animals; over the years researchers have been able to determine necessary stimuli conducive to breeding, but there still are difficulties even with the best-studied species. In the lab, we know that degus will allonurse (meaning, a mother will nurse pups other than her own), but is this true in the field? Do degus only allonurse in the lab because they have plenty of food? Or maybe because of space limitations, it’s too difficult to keep litters of pups separate? Until we can put cameras in real degu burrows, we can only assume that degus allonurse in the wild.
                The point is that animals may behave differently in the lab because there may be significant factors that we, as humans, are not aware of. Animals may perceive or be more sensitive to certain wavelengths of light (unlike us, degus can see in the UV spectrum), odors, or noises. What may seem innocuous to a human may be stimulating or frightening to another animal. A combination of several factors ultimately creates an environment that is totally different and separate from an animal’s natural living conditions.
                However, there are ways to make laboratory experiments more ecologically-relevant. Some labs, for example, house their animals in outdoor enclosures. This limits the control of things like temperature and weather, and it may also be harder to sample or observe animals in such a large space, but it does allow animals to experience more natural conditions and cues. Experiments can also be more ecologically-relevant by using stimuli that animals would typically experience in the wild. For example, if you want to study the stress response of an animal, you could use more “natural” stressors such as cold, rain, or unpredictable food availability rather than something artificial like playing a loud radio for 30 minutes. Lab and field experiments aren’t necessarily separate things, and it’s up to researchers to decide where their experimental design will fit best on the continuum between experimental control and ecological relevance.

Animal maintenance
                Currently, I’ve been spending a lot of my time cleaning degu cages. I don’t mind doing animal husbandry, but at times I do feel a little under pressure because I know that I’m the sole person responsible for the health and wellbeing of my animals. It’s a responsibility I take seriously, so I make sure to give my degus the best care possible. The level of responsibility is different in the field, however. Besides checking traps often and giving degus an extra handful of oats while they’re waiting to be returned to their burrows, I can pretty much let the degus take care of themselves. So in terms of animal maintenance, the field usually wins, especially because animal care costs can be rather high, which brings me to my next point:

To successfully carry out experiments, researchers need to pay for equipment, supplies, and field or lab assistance. If the experiment will take place far from home, researchers may also need to pay for travel, housing, and other various costs such as permits, shipping expenses, etc. Both lab and field experiments can be expensive- it really depends on your experimental design and whether you already have some of the necessary equipment.
For me, it was the really the international component that made my experiments expensive. Both my lab and field experiments required me to pay for plane tickets and housing costs, which is something a researcher wouldn’t normally have to worry about. As for lab and field-specific expenses, they ended up being about the same; for my field experiment I had to rent a truck and for my lab experiment I needed to pay for animal care during the nine months I was back in the U.S. Equipment costs were more expensive for the lab experiment (terrariums, video cameras, etc.) but only because I had access to pre-existing equipment for my field experiment (animal traps, radiocollars, etc.). So, in the end, neither the lab nor the field was more expensive than the other, and the total cost of an experiment is really determined by experimental design.

Working conditions
                I hate getting up early. Maybe not as much as some people, but when the alarm clock goes off and it’s still pitch-black outside, my inner voice grumbles a steady stream of obscenities as I get out of my warm, cozy bed. Now, you might think that getting up early is a burden that only field researchers carry, but that’s not always true. For my current lab experiment, I’ve been getting up around 6am every day for two reasons: 1) in order to be consistent with my field experiment, I’m trying to collect blood samples before 9am and 2) the Santiago metro becomes a living hell during rush hour, and in order to keep my sanity I have to catch the subway or bus before 7am. While I did have to wake up even earlier when I was doing field work (4:30am, woo-hoo!), I would allow myself to take off one day per week. For my current lab experiment, though, there’s something I have to do every, single, freaking morning. So when it comes to early mornings and total work hours, neither the lab nor the field wins.
                Fieldwork can sometimes be miserable. It can be freezing cold or baking hot, or the dew from the grass can make your boots and pant legs soaking wet. Opening 150+ traps in the dark is no fun, either, nor is hauling traps up and down a big hill (or small mountain, it depends on your perspective). In all truthfulness, my fieldwork is relatively tame (one of my friends works in a very hot, humid forest where she spends several hours a day tramping up and down steep hills, all while looking out for venomous snakes) so I really shouldn’t complain. But, nevertheless, I’ve had my share of trials and tribulations. One time I had to go to the hospital because of a really bad hand rash. One time an opilion (a very large, creepy arachnid- see photo) crawled up my pant leg. I’ve also fallen down hills, tripped over rocks, and had serious wardrobe malfunctions (i.e. ripping open the seat of my pants).
But I would never give up field work for anything. I love being outside all day, and my time in the field has allowed me to witness and experience so many cool things. I’ve seen moustached turcas (see picture) carrying grubs in their beak, running to and from their nests. I’ve seen an iguana eat an akodont (a small, mousey-like rodent) and an eagle knock a caracara (a small bird of prey) out of the sky. One of the coolest things I saw was a wasp trying to drag a paralyzed tarantula through one of my degu traps. These wasps are called “tarantula hawks” and spend their days zooming over the ground, searching for tarantulas. When they find a tarantula, they deliver a powerful string which doesn’t kill the tarantula but effectively paralyzes it. The tarantula is then dragged to the wasp’s nest where it is eaten by the wasp’s larvae after they hatch. 
So while maybe the lab is more comfortable, the field is definitely more fun. And when stuff doesn’t work out or when you make an experimental mistake, if you’re in the field you can reason that “Well, at least I got to spend the day outside.” (this quote is attributed to Dr. Sara O’Brien). Wherever I end up after grad school, I’m sure I’ll be doing field research!

The opilion.

My favorite bird- the moustached turca!

The tarantula and the tarantula hawk.

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