Spying on Birds

“So, like, what do you do every day?”

I get asked this often and I’m not always sure how to explain it to people without pictures at hand or infinite patience for follow-up questions. So, in this blog post, with the benefit of time to pick the right words and theoretically infinite space to write them out, I figured I would try to provide an adequate answer.

View from the field, a week or so ago

Why fieldwork?

This, I feel, is the question at the crux of the what-do-you-do-every-day question. Why do you have to go to Kenya to do your work? Right, the bird you study is only found there, but why do you have to be out on the savanna everyday – can’t you just bring the birds back to the lab or study them in a zoo?

Of course, you can (nowadays, only with the right permits) and that is precisely what early zoologists did, collecting specimens – alive or dead – from around the world and bringing them back to examine them under microscopes or in aviaries in a rainy British country garden. While this may be convenient, it inevitably renders your conclusions about a bird’s diet or the adaptive nature of its plumage coloration suspect, because they are arrived at out of context. Without the bird having been examined in the environment it’s found in, with different factors that might affect its behavior and morphology in play, it is impossible to understand why it acts the way it does and why it is the way it is. Hence, fieldwork: observing and sampling critters in the wild.

What do you do in the field?

Fieldwork comes in all shapes and sizes. Depending on what you’re studying and what kind of samples you’re collecting you could be doing anything from flying around in a small plane with radio telemetry equipment to measuring the width and height of every single tree in a 5 x 5 m plot.

My fieldwork: observing starlings interacting over food, using the car as a blind. Photo by Andy Johnson.

I am currently collecting information on the dominance relationships and association indices between individuals in cooperative breeding groups of superb starlings. (Cooperative breeding = some individuals forego breeding and help raise chicks of other individuals in the social group). In most social groups of animals, there is a social hierarchy among the individuals that maintains the group’s overall stability and prevents fights from breaking out that unnecessarily waste energy and make it costly for individuals to stay in the social group. Additionally, individuals in a social group might be more or less “friendly” with each other, with some individuals hanging out with others all the time while others are loners. This level of “friendliness” – termed “association” – could be dependent on factors such as relatedness and breeding success, and could also determine subsequent breeding success, number of helpers at your nest, and, ultimately, fitness. What I’m interested in, then, is how these two social factors determine (a) who stays in the group and who leaves, year after year, and (b) who breeds, who helps whom, and who doesn’t breed or help.

Me spying on starlings. Photo by Andy Johnson.

To get data to answer these questions, I observe superb starlings interacting over a food resource. Basically, every morning I drive out to the sites of one of nine banded groups of superb starlings, plonk a fresh papaya slice on a certain flat rock on the ground (we put food at the same spot every time, to establish a kind of “feeding platform”), set up my scope in my car parked around 30 m away, and wait.

Soon a couple of starlings fly in, landing on the ground near the papaya and running up to it on their quick legs, and I start collecting data. Since each individual is identifiable by a unique combination of color bands (their “names”) on their legs, I note down the identities of the “winner” and “loser” every time one bird chases another away or displaces another bird at the papaya (dominance). I also note down the “names” of every single bird at the papaya every minute, in order to collect data on who hangs out with whom (association).

A chase. The bird on the right is the “winner” and the bird on the left, who is chased away, is the “loser” in this dominance interaction. Video by Andy Johnson.

I usually do this for 3-4 hours at a stretch, with the starlings coming and going. They don’t stay put at the food for very long, and while they are gone foraging or flying around elsewhere, the papaya tends to attract all sorts of other visitors: francolins, barbets, dik-diks, hornbills, bulbuls, sparrows, and once even a pair of black-backed jackals. Suffice to say, fieldwork is never boring!

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