Here is the poster we presented at SICB Portland last week on the biomechanics of peacock displays (click to enlarge):
I think it turned out pretty well, although I’m not sure it could stand alone without an interpreter.
We had a constant stream of awesome visitors. My coauthor Suzanne brought feathers and a model peacock to demonstrate what we were talking about – brilliant! We also had a touchscreen mounted to the left of the poster to display the supplemental videos, but to my surprise we didn’t use it much. It was too slow to load for every new visitor, although it did come in handy for people who wanted an in-depth look. I realize now that videos should really be integrated spatially with the poster content. This could be done if whole display was a touchscreen, for example.
One of the highlights of the meeting was seeing how folks in Stacey Combes’ lab are tracking the movements of individual bees by gluing tiny QR codes onto the bees’ backs (the codes are automatically recognized on video of the bees entering and exiting their hives by tracking software). Another highlight was Ken Dial’s talk about the influence of predation on the development of flight in nestling birds. Overall I had a lot of good food, good drink, and an exciting view of 1000s of roosting crows late at night in downtown Portland.
Thanks to Owen, Suzanne, Jim and Bob for such a fun project!
June 2013 was bad for tree swallows. At the Queen’s University Biological Station, over 90% of nests failed as a result of persistent cold, rainy weather.
This happened to be the same year we were conducting an experiment on the hormonal mechanisms of parental care in these birds. The bad weather made for a disastrous field season. Just a couple of weeks in, and we were turning up cold lifeless chicks in nearly every nest. The upside was that it led to some potential insights into the way stress hormones and tough weather conditions interact. My coauthors Jenny Ouyang and Ádám Lendvai have written an excellent blog post about it here:
It was remarkable how closely the nest failure rates tracked the fluctuating air temperature. This could be caused by a couple of factors, with a major one being that tree swallows rely on flying insects to feed their young, and the ability of insects to fly depends on temperature. Persistent cold weather means that parent tree swallows cannot find enough food to support their offspring.
The corticosterone hormone implants made the treatment birds more susceptible to faster brood mortality, even during benign weather. It should be noted that the implants were deployed before the bad weather struck, and we would not have performed this experiment if we had known in advance that this would be such a tough year! Hopefully, though, the results provide some insight into the role of stress hormones as mediators of a sensitive period in the life history of these birds.
Read the study here:
My friend Terry Beech is running for parliament in the Burnaby North-Seymour riding. Charlie and I are helping with his campaign – Charlie is his campaign manager, and I’m part of his team of volunteers. It’s shaping up to be an exciting three-way race between Terry (the Liberal), Mike Little (Conservative), and Carol Baird-Ellan (NDP). The press has highlighted Burnaby North-Seymour as a “riding to watch”. Go Terry!
One of the highlights was attending a local candidates debate last week.
The results of the Reproducibility Project – a very cool endeavour to repeat a bunch of published studies in psychology – came out this week . The authors (a team of psychologists from around to world) found that they were able to successfully replicate the results of 39 out of 100 studies, leaving 61% unreplicated. This seems like an awful lot of negatives, but the authors argue that it’s more or less what you’d expect. A good chunk of published research is wrong, because of sampling error, experimenter bias, an emphasis on publishing surprising findings that turn out to be false, or more than one of the above. No one study can ever represent the truth – nor is it intended to. The idea is that with time and collective effort, scientific knowledge progresses towards certainty.
So science crowd-sources certainty.
This is from a session I did with the UBC R group. Loops can be convenient for applying the same steps to big/distributed datasets, running simulations, and writing your own resampling/bootstrapping analyses. Here are some ways to make them faster.
1. Don’t grow things in your loops.
2. Vectorize where possible. i.e. pull things out of the loop.
3. Do less work in the loop if you can.
Frame-blending is a great way to illustrate animal behaviour and other things that change over time. This got me thinking about ways to animate time series data. In R, the animation package has lots of options, but you can also build your own just by plotting over the same device window. If you save each iteration in a loop, the resulting images can be used as frames in a video or gif.
Click the image to see a larger version
Here is an example using recordings that track hummingbirds flying in our tunnel here at UBC. This animation shows a bird’s eye view of 50 flights by 10 birds. In half of the flights (the red ones), the birds had horizontal stripes on their left side and vertical stripes on their right, and the other half (blue) had the reverse. The subtle difference between the red and blue trajectories (red ones tend to have more positive y values) shows that on average, birds tend to deviate away from vertical stripes, and towards horizontal ones. The histogram that builds up on the right side of the figure shows the mean lateral (y) position for each trajectory as it finishe
The Los Angeles Arboretum is one of the most beautiful places I have been. Where else can you see six species of hummingbird zooming from perch to flower, an Asian red-whiskered bulbul nesting beside a dancing peacock, with noisy flocks of parakeets commuting overhead? Even the introduced species (on this list, all but the hummingbirds) are beautiful.
So it was fitting right after I got back from LA to read the news that 30 new, never-before-seen species of flies were just discovered in the city. Read more about it here. And how did the discoverers identify these flies as unique? By the gnarly shapes and bristles of their genitalia. These traits can help define species in other groups too, like bats and primates.
Photo by Kelsey Bailey, LA Natural History Museum BioSCAN project.
It was a rainy day here at the Los Angeles Arboretum in Arcadia, California, and the peafowl were hunkered down. The hummingbirds were out though!
A male Selasphorus hummingbird stretches and shakes in the rain. Filmed at 240 fps, played back at 1/8 real speed.