Watching pelicans (sort of)

Post date: Dec 18, 2015 4:09:27 PM

I promised an update on actual work. Unfortunately, lab- and office-work is not very photogenic, so it's hard to get inspired to write about it. But over the past week or so, I've been working on a project that reminds me a bit of being in the field, even as I sit in my concrete bunker office.

When I went to California in June, one thing I asked for was video of the pelicans we GPS-tagged. In the field, we don't have the luxury of watching pelicans immediately after we put tags on them, since they usually fly away from the colony and sit on the water to adjust their harnesses and preen off the effects of capture. I was curious to see whether the tag affects their behavior immediately afterward, and if so how this might influence their ability to continue breeding normally after tagging.

Luckily, OWCN has a great photographer on staff, and he set up a video camera to record for several hours before and after we attached the transmitters. Also luckily, the enclosure contained five birds that received transmitters and four that didn't, making this a perfect setup for a before-after-control-impact study. We could compare the behavior of the GPS-tagged birds before and after tagging to the behavior of control birds during both periods, eliminating the influence of underlying differences between the groups of birds and things like time of day that affect the behavior of both groups.

Of course, that also meant that someone (me) had to actually watch the videos. Each video was a little over 33 minutes long and had to be watched nine times (for nine different birds). There were ten videos, five pre- and five post-tagging. You can do the math... or I will. That's about 3000 minutes, a.k.a. 50 hours, of watching a bunch of pelicans move around an enclosure not much bigger than-- well, my bunker office. Luckily, I am starved for pelican viewing in winter, so it wasn't as much of a pain as you might imagine.

For about a week, my world looked something like this:

The screen on the left is the video; the screen on the right is a coding program called EthoLog. Every time a pelican does something different, I enter a time-stamped code, and at the end EthoLog tallies up the statistics for me. I know how many times each pelican stretched, how long (on average) it was in the air each time it flew, when it ate... the list goes on.

I also got to observe some interesting things about pelicans. For one thing, the rehab birds spent more time standing with their wings stretched out than we're used to seeing in the field. For another, they really like to go back to their favorite spots along the edge of the tub. This made my job (following the same pelican around the enclosure for 30 minutes at a time) a lot easier. There were some pelicans that had established dominance, while others were trying not to be noticed.

But what about behaviors? In the end, there wasn't a lot of difference. The tagged birds spent more time preening and less time resting after tagging than the controls, but critical behaviors like perching, swimming, and flying didn't seem to be affected. The preening behavior lines up well with what we saw in the field, and based on observations we made several days afterward, this difference doesn't seem to last. That's good news for the GPS data (means that our tracked birds are behaving like normal birds!) as well as for the pelicans. For the rest of the details, you'll have to wait for the paper :-)

Anyway, if you ever feel like watching some riveting pelican cinema, let me know. I can hook you up.