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.

Thursday, September 12, 2013

Research is hard.

It’s a simple statement, but I can guarantee that every professor, post-doc, and graduate student would agree that research, while rewarding and ultimately worthwhile, is nevertheless a difficult thing to do. Every type of biologist faces their own unique set of challenges: the biological modeler may struggle endlessly with programming code, the molecular biologist may spend months troubleshooting an experiment, and the ecologist may watch helplessly as a severe storm decimates their study species. Catastrophes befall all scientists, but there are ways to prevent and mitigate the effects of bad luck. Here are a couple of challenges I faced during my research and how I dealt (or wish I dealt) with them:

Rule #1) You can never be too prepared.

Before my first field season in Chile I spent a lot of time thinking about how I was going to collect my data, and I ended up writing several drafts of equipment lists. In the end, I brought down some equipment that ended up being unnecessary (for example, I brought 10 radio trap transmitters, these nifty gadgets send out a signal when the trap door shuts. While it was great in theory, it didn’t work well in the field because birds would get caught in the traps and cause false alarms, and also 10 transmitters wasn’t very helpful when I was  generally using 100 traps at a time). But, I also ended up bringing some equipment that really saved the day, like a hand-crank centrifuge that I was able to use when we stayed in a cabin without electricity in Parque Nacional Fray Jorge. The conclusion is that it’s best to bring more things than you think you’ll need (as long as you stay within your luggage limit).

But being prepared is more than just bringing the right equipment- it’s also about reading everything you can and communicating with your collaborators and other, more experienced researchers. Grant writing was actually a great way to prepare for this- by thoroughly reading the literature and getting feedback from my mentors, I was able to iron out some of the more theoretical aspects of my projects.

Rule #2) Don’t put all your eggs in one basket

There’s always the chance that an experiment will completely and utterly fail, so it’s a good idea to have multiple projects so you’ll be able to come home with something. During my first field season in Chile, it became apparent that my main project would require another year of field work, which meant that I would have to secure more funding. In addition to this uncertainty, my main project was also ambitious and risky. So, to make sure that my first field season (which was five months long) wasn’t wasted, I also pursued two, additional projects. In the end, I completed one of these side projects during my first field season and was able to publish a manuscript, so even if things hadn’t worked out with my main project, I would have at least gotten something out of my time in Chile.

Rule #3) Make contingency plans

No matter how much you prepare and no matter how familiar you are with your study system, key events may still not go according to plan. For example, this year I’m doing a laboratory experiment that examines the effect of stress on the quality and quantity of maternal care. The easiest way to do this experiment would have been to catch pregnant degus in the field and bring them into the lab where they could then give birth. However, transference to captivity is stressful, and I didn’t want pre-natal stress (stress while the mothers are still pregnant) to affect the pups. I could have also caught pregnant females very close to parturition, so then there wouldn’t be much time for the mother’s stress to affect the pups in utero, but then the disadvantage would be that females would still be adjusting to captivity after they gave birth and maybe this would affect maternal care.  So, I instead caught females a year before the experiment and then mated them in the lab. However, I knew that my degus might have a low fertility rate, so I made a plan in case this happened (another thing would have been to collect more animals than I needed, but this wasn’t possible logistically because of space limits. Also, it would have cost a lot more money to buy more terrariums, food, and animal care. And it also has ethical problems- you don’t want to use an unnecessary number of animals).
So what happened? Unfortunately, only 40% of my degus got pregnant, so I went according to my contingency plan and trapped some very pregnant degus in the field and brought them into the lab. While this wasn’t the ideal situation, I will at least be able to compare my lab-mated degus with the field-mated degus. In the end, I think it will work out, and the important thing is that I planned for this and made sure that I had the time and resources to trap these additional degus. And because the current experiment isn’t totally ideal, I’ve decided to collect some additional data to take advantage of the new group of degus (some of these wild degus, due to individual differences, will be “more stressed” than others, so I’m measuring the mother’s CORT levels to see if they correspond with the amount of maternal care they give to their pups).

Rule #4) Be realistic

Don’t try to take on more than you can manage, and if things get too busy or crazy, figure out if there’s some project aspect you can drop, delay, or share with a collaborator. I’ve had chances to collect additional data or even add projects to my current research, but I’ve sometimes passed up these opportunities so I could spend more time writing papers and grants, sleeping (this is actually really important because I had to safely drive a truck at 5:00am almost every day last season), and having fun. Before I go to Chile my advisor always says “Be safe, work hard, and make sure to have some fun,” so I try to do those three things in that order.

Rule #5) Be flexible

As I explained in Rule #3, not everything goes to plan. But oftentimes an experiment can be salvaged by altering data collection methods or changing the number of treatment groups or controlled variables. Working in the field means you can’t control everything, and this is especially true when you work with wild animals because they can leave your study area, get eaten, or refuse to be recaptured. Being a successful field researcher means you have to know when to make compromises- if you compromise too much your data may lose a lot of significance, but if you refuse to compromise you may end up with no usable data at all.

Rule #6) Always, always, always back up your data.

I’ve always strictly adhered to this rule, and it really saved my bacon when my computer completely and utterly died two days after arriving in Chile this year (screw you, Apple). Luckily, I had just backed up my data on my portable, external hard drive so I was able to easily move my files to my new laptop (I now have a Lenovo which I really like except for the Spanish keyboard). When I’m collecting data, I back up my computer at least once a week, and I also try to make sure that my data is stored in at least two separate places. I’ll also occasionally email my data spreadsheets to my advisor and collaborators, just in case. And finally, I make sure to record all my data in a lab or field notebook, and I always try to enter these data into my computer within a day of collection. For field notebooks, I highly recommend Rite-in-the-Rain notebooks which are tough, waterproof, and are used by field biologists everywhere.

Rule #7) Accept defeat gracefully and with humor

This may be the hardest rule to follow, but if you can manage to keep a positive outlook and not get overly stressed when everything goes to hell, then you’ll be a happier, healthier researcher. Every researcher, at some time in their career, will have a project that will totally fail. The best thing to do is to salvage what you can or go to one of your back-up plans, but if all else fails, then it’s best to just move on and plan for future experiments. I’ve only spent a few years in academia, but from what I have seen so far, I think that the most successful researchers are those that are resilient and optimistic. To be a successful researcher you have to accept that failures will occur, because if you give up after one or two failures, then you’ll never get a grant funded or a paper accepted.

While these seven rules are not exhaustive, they do provide a good, general philosophy for any scientist working in the field. If any readers have some additional advice, please feel free to send me your comments and I’ll post them on this blog!  

Friday, August 30, 2013

Chile, 2013!

Welcome back! This is my third and final trip to Chile, and at the end of this October I should (cross your fingers) be finished collecting data for my thesis. While I was primarily working in the field in 2011 and 2012, this year I will be spending most of my time in the laboratory. Here’s a quick synopsis of my past and current research:

As I’ve mentioned before, I’m primarily interested in the development of an animal’s hormonal stress response. The main stress hormone in degus (and humans) is cortisol (CORT), which is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Previous work on mice has shown that experiences after birth (termed “post-natal effects”) can influence the development of the HPA-axis. Mouse pups that do not receive enough licking and grooming from their mothers will end up with hyperactive stress responses, which means that they will secrete high levels of CORT in response to stressors and will have a harder time bringing CORT levels back to normal after a stressor has passed. Because stressed mothers lick and groom their pups at a lower frequency, this means that maternal stress can affect the development of the offspring stress response.
One of my main research goals is to see if stressed mothers produce pups with altered stress responses. The other main goal of my research is to determine whether the degu’s social structure can help buffer the negative effects of post-natal stress. Because degu females live in social groups and will care for other female’s pups (this reproductive strategy is called “plural breeding with communal care”), if one mother in the social group is stressed, then other females within the group may be able to compensate for the lack of maternal care.
In 2011 and 2012, I did a manipulative field experiment where I implanted certain degu mothers with CORT pellets after they gave birth. In some social groups all the mothers were implanted with CORT, while in other groups 0% or 50% of the mothers received CORT implants. After the pups emerged three weeks later, I trapped them and took blood samples to determine their stress responses.
However, one thing that I was not able to do in the field was to confirm that the CORT pellets decreased the amount or quality of maternal care. Because degus spend the first few weeks of their lives underground in burrows, it’s impossible to observe mother-pup interactions during this important time. So, what I’m doing now is basically replicating my field experiment in the lab so I can also observe the behavior of the mothers and pups.
Currently, I have 32 pregnant female degus in my collaborator’s animal rooms at the Universidad Católica de Chile. My females are housed in pairs in acrylic terrariums, and as soon as they give birth I will implant certain females with CORT and start filming them with a home security camera system. I’ll be watching the videotapes later and will score behaviors such as time spent at the nest, how often the pups nurse, and the rate of licking and grooming. When the pups are about three weeks of age, I’ll take blood samples so I can compare their stress responses to those pups that I caught in the field.

So that’s a basic overview of what I’m doing this year, and stay tuned for more posts! I’ll be writing about the importance of flexibility and contingency plans in scientific research, the comparison between doing lab and field research, and the different theories about why the HPA-axis is plastic during development.

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