Category / Science

by Roslyn

New lab paper: weather drivers of bird collision risk

yellow-rumped warbler in flight

Photo by Hugh Sansom, Wikimedia Commons

A new paper led by undergraduate student Kara Scott is published now in the journal Ecology and Evolution!

In this paper, we looked at the conditions that drive bird collisions with buildings in two major cities, Toronto and Chicago. We were able to do this thanks to data from programs like FLAP Canada and Chicago Bird Collision Monitors, where hundreds of volunteers survey the city each day to collect birds that have been killed or injured in collisions. Within a 10-year period, volunteers in Chicago and Toronto had counted more than 60,000 collisions.

We found that most bird collisions with buildings occur during a relatively small number of days within the peak migration seasons (the first days of May, and first days of October, respectively). In a typical season, more than 50% of the collisions occur in just the 12 worst days.

The high risk days have fair weather, with clear skies, high visibility, a lack of precipitation, and favourable winds for migration — all conditions that increase the amount of migration traffic.

Our results also indicate that window reflections may be especially hazardous during fall migration, when many first-time migrants are on the move.

Kara worked on this project during her iCureus award in 2020, then co-wrote the manuscript with me for an independent study in BIOL 4901. She is moving on to start her MSc in Steve Cooke’s lab this year. Congratulations, Kara!

by Roslyn

Caitlin Menzies nails her 3-minute thesis!

Caitlin Menzies gave an excellent 3-minute thesis at Carleton’s annual 3MT competition.

Caitlin's 3MT slide

Fitting your entire MSc thesis into one slide

by Roslyn

First paper from a lab member is out!

suet feeder with three birds

Birds at a suet feeder (Wikimedia commons)

Very proud to say that the first lab paper led by student Ilias Berberi is out now in the journal Proceedings B!

Some bird species flock in winter, whereas others are highly solitary. How does the evolution of flockiness in birds influence a bird’s ability to dominate others in the competition for food? Ilias investigated this along with our coauthor Dr. Eliot Miller. 

We were able to look at this quesiton thanks to Project FeederWatch, a program led by the Cornell Lab of Ornithology. FeederWatch participants are volunteers across North American who submit sightings from their backyard bird feeders. There are thousands of FeederWatch volunteers and millions of sightings, including hundreds of thousands of instances when one bird evicts another from the feeder. The tremendous scale of these observations made it possible for us to figure out who dominates whom in winter bird communities.

We expected to find that flockier bird species (those that group with their conspecifics) would have a competitive advantage.

To our surprise, we found the opposite – on average, more social bird species are wimpier when facing size-matched opponents. But their competitive ability is also sensitive to the immediate social environment. When more social bird species are in the presence of conspecifics, they tend to gain a boost in their dominance status.

This indicates that the evolution of sociality is associated with reduced dominance as individuals, but increased dominance in groups.

This research was covered in Audubon and BirdWatching magazines and Calgary QR 107.3 radio.

by Roslyn

Winter field work with chickadees

In November, Emil and Ru flew off to wild rose country to snoop around the social lives of black-capped chickadees, in collaboration with Prof. Kim Mathot’s research group at the University of Alberta. This research is part of Ru’s MSc and Emil’s PhD projects.

Here’s a short account of their trip, written by Ru Ratnayake:

trees and snow

The University of Alberta Botanic Garden in winter

The forests surrounding the U of A botanic garden were magnificent in the winter. Most mornings we would spot blue jays, nuthatches, chickadees, woodpeckers, or waxwings the moment we stepped into the forest. In a few days, Kim and Jan had us fully trained on setting up mist nets, handling chickadees, and banding them. Captured chickadees were fitted with a unique passive-integrated transponder (PIT) that allows us to detect each tagged bird as it visits the seed feeders at the site.

Emil with a chickadee

PhD student Emil Isaksson

Holding the nearly 12 g birds was a magical feeling. Emil would go on to say, “I felt like a Disney princess”. Unfortunately, this moment was understandably less magical for the chickadees, who relentlessly pecked at our fingers as we took measurements and fitted bands.

setting up the video camera

Recording video at the feeders

Emil and I also set up cameras at each feeder so we could covertly observe social interactions. The cameras recorded over an hour of footage per feeder, despite the frigid temperatures drastically reducing their battery life. Each video was full of interactions, and it was fascinating to see the way chickadees lined up at the feeder for a seed. Rude nuthatches would cut said lines and we captured many chases between birds. My favourite moment? Whenever a plump chickadee (I call him Gus gus) refused to take a seed and leave, and would hold up the line while casually eating seeds before getting ousted.

group of researchers in the field

Emil and Ru (left) with Kim Mathot (right) and Jan Wijmenga (centre-right) from U of A

We are super grateful to Roz, Kim and Jan for this research trip and its experiences, the skills we developed, and the opportunity to see where the data in our projects come from. And we can’t wait to see what our data reveals about the learning and social behaviour of this chickadee community.

Photos by Ru Ratnayake

by Roslyn

Visiting the LSU Museum of Natural Sciences

This month, lab members Ilias Berberi, Lauren Miner and I travelled to Baton Rouge, Louisiana for a research trip to the LSU Museum of Natural Sciences.

Ilias with hummingbirds

Ilias serves up a tray of hummingbird skins

LSU is renowned for its tremendous collection of tropical birds from South and Central America. We were there to collect measures of skeletal traits related to flight. This project will allow us to study the evolution of flight performance and how it is shaped by social behaviour.

Lauren with condor wing

Lauren with a California condor, a species with a 10-foot wingspan

Lauren, Ilias and I were an amazing team! We measured 589 hummingbirds in just a few days. Once we got up to speed, our record was churning through 167 hummingbird skeletons in a single day. This has to be a world record – I don’t think anyone else has measured that many hummingbird skeletons ever, let alone in a single day.

sword-billed hummingbird skull

A kkull of a sword-billed hummingbird, Ensifera ensifera. Their bills are 10-12 cm, longer than the rest of their body!

We easily reached our goal of measuring all of the hummingbird species in the collection, and had enough time to collect data from their manakin collection (Pipridae) as well.

Very excited about these projects! We are very grateful to Steve Cardiff and curator Nick Mason at LSU for their warm welcome and all of their help in the collection.

bee hummingbird

The bee hummingbird from Cuba is the smallest bird in the world

Photos by Lauren Miner, Ilias Berberi and Roz Dakin.

by Roslyn

What to Read for new graduate students

Ilias and I have been talking about papers each week. Most recently, we read Platt’s Strong Inference paper about the scientific method and Doug Fudge’s engaging 50-year anniversary essay about it.

What are some articles that are great for new graduate students should read? This is a rough list-in-progress…

Stephen C. Stearns “Designs for Learning” (and “Some Modest Advice for Graduate Students”)

Platt (1964) “Strong Inference” (and Fudge’s 2014 essay “50 Years of JR Platt’s Strong Inference”)

Tinbergen (1963) “On Aims and Methods in Ethology”

Srinivasan et al. (1996) “Honeybee Navigation en route to the Goal: Visual Flight Control and Odometry”

Esch et al. (2001) “Honeybee Dances Communicate Distances Measured by Optic Flow”

Gould and Lewontin (1979) “The Spandrels of San Marco and the Panglossian paradigm…”

Ducrest et al. (2008) “Pleiotropy in the melanocortin system, coloration and behavioural syndromes”

Ioannidis (2005) “Why Most Published Research Findings are False”

Burnham and Anderson “Model Selection and Multimodel Inference”

Gelman and Stern “The Difference Between ‘Significant’ and ‘Not Significant’ is Not Itself Statistically Significant”

Gelman “The Problems with P-values are not just with P-values”

Gelman and Loken “The Garden of Forking Paths…”

Loken and Gelman (2017) “Measurement Error and the Replication Crisis”

Gopen and Swan (1990) “The Science of Scientific Writing”

by Roslyn

Does biology explain the sex ratio in tech?

Here’s what bugs me about James Damore’s recent anti-Google screed: it’s a terrible misuse of biology.

The question he addresses is: Why are there so few women in tech and tech leadership? In his memo to Google, Damore offered an explanation (note: I added the numbers):

On average, men and women biologically differ in many ways. These differences aren’t just socially constructed because:

(1) They’re universal across human cultures

(2) They often have clear biological causes and links to prenatal testosterone

(3) Biological males that were castrated at birth and raised as females often still identify and act like males

(4) The underlying traits are highly heritable

(5) They’re exactly what we would predict from an evolutionary psychology perspective

I’ll assume, for the sake of argument, that points (1)-(4) are more or less true.

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by Roslyn

Data sharing, reproducibility and peer review

I just reviewed my first manuscript where the authors provided a reproducible analysis (i.e., they shared their data and analysis script with the reviewers). This is something my coauthors and I have tried to provide with our recent studies, but it was my first time experiencing it as a referee.

I think it really helped, but it also raised new questions about traditional peer review.

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by Roslyn

Flight school

Our research on hummingbird flight is featured in the July 2017 National Geographic!

The article is all about hummingbird science, and how new techniques are allowing us to see aspects of their behaviour that aren’t available to the unaided eye. You can read the print article here, see a beautiful video summary here, and another one here. Here’s one of an Anna’s hummingbird in a wind tunnel. He’s remarkably good at keeping his head steady as the wind ramps up:

The photographer, Anand Varma, took a great shot of my vision experiments at UBC that shows a bird perching in a strange, Tron-like environment of glowing green stripes:

Hummingbird in the virtual reality flight tunnel

Photography and video by Anand Varma in National Geographic.

Between getting the scene right, adjusting the lighting, and then waiting for the bird to act in just the right way, this one photograph took an entire week of work (hands on work that is, no photoshop!). Given all the other complex shorts in the article, it’s easy to see how the whole endeavour took a couple of years – much like a scientific study. Working with Anand that week, it was interesting to see how many other parallels there are between what he does and our research. A lot of trial and error, a lot of patience, and a lot of coping with the quirks and surprises of animal behaviour.

The article ends with a scene from the summer when the writer, Brendan Borrell, spent a couple of days with me in the lab. I have the honour of being described as emerging from the lab with a “sheen of sweat” on my forehead. It is embarrassing, but true! It was a hot day and we were working hard in that room.

There is also a nice editorial about the project here.

by Roslyn

Troubleshooting and iteration in science

The scientific method is taught as far back as elementary school. But students almost never get to experience what I think is the best part: what you do when something goes wrong. That’s too bad because self-correction is a hallmark of science.

In ecology and evolution, most graduate students don’t get to experience iteration firsthand, because they are often collecting data right up until the end of their degree. I didn’t experience it until my postdoc, when we failed to repeat a previous experiment. It took several experiments and a lot of time  – two years! – to figure out why. In the end, it was one of the most rewarding things I’ve done.

Wouldn’t it be great if undergraduate students actually got to do this as part of their lab courses (i.e., revise and repeat an experiment), rather than just writing about it?

One thing that can come close – teaching you how to revise and repeat when something doesn’t work – is learning to code.

by Roslyn

Bird-inspired drones

This Christmas the strong winds decorated the trees with shiny new drones:

(photo by Rod Croskery)

Drones of the future are going to get a lot more maneuverable.

A group at Imperial College London has now built an aquatic diving drone with wings that can tuck in for protection during rapid plunges, inspired by the hunting behaviour of seabirds in the family Sulidae (gannets and boobies).

And a Swiss team has developed a drone with feather-like elements that allow the wing to fold into a range of configurations, analogous to the way birds can overlap their wing feathers. This allows the drone’s wings to be adjusted to suit the conditions – reducing wing area in strong winds, for example.

These advances should make it possible for drones to maneuver in a greater range of tough-to-access environments, just like birds.

Both studies are published in a new issue of Royal Society Interface Focus:

Siddall et al. Wind and water tunnel testing of a morphing aquatic micro air vehicle.

Di Luca et al. Bioinspired morphing wings for extended flight envelope and roll control of small drones.

by Roslyn

How hummingbirds control flight

We have a new study out on how birds use visual cues in flight. Here is a summary:

Thanks to Charlie for helping to capture the video footage! The study is a collaboration with Tyee Fellows and Doug Altshuler at UBC.

For the experiments, we used eight high-speed black & white cameras to capture the entire length of the 5.5 metre-long flight tunnel (I only had space to show two in the Youtube video above). The cameras were part of an automated tracking system that tracked the birds’ motion, and determined the birds’ 3D flight paths from the different camera views. This works similar to the way multiple cameras are used to make 3D movies.

Hummingbirds were great subjects, not only because they are incredible fliers, but also because they are sugar fiends! They have to feed every 10-15 minutes throughout the day. This meant that we were able to design big experiments and test a wide range of visual conditions.

Here are two other clips that illustrate the data from the tracking system:

The best part about this project was that we started with a pilot study that seemed like a failure, at first. We tried to repeat what had been previously shown for other birds (based on a pioneering study of budgies), but we did not see the same results. At first, that can be pretty disappointing. But it also gives you the chance to think of new ideas, and then figure out ways to test them. I think this evolution from failed experiments to ones that work is the most exciting part of science! The catch is that it can take years to get there. I really started to appreciate this once I began working with birds in the lab.

Dakin, Fellows & Altshuer. 2016. Visual guidance of forward flight in hummingbirds reveals control based on image features instead of pattern velocity. PNAS, in press.

by Roslyn

Peacock physics

We have a new paper out!

Biomechanics of the peacock’s display: how feather structure and resonance influence multimodal signaling

In this study we describe the rapid feather vibrations that peacocks use during courtship. These vibrations – at a rate of about 26 Hz on average – represent a substantial mechanical and metabolic challenge for the birds, especially given that they are performed using a massive array of feathers with widely varying lengths.

IMG_3139

A peacock shows his stuff. His train feathers range from 10 cm to > 150 cm in length, and the whole thing weighs about 300 g. Photo by Roslyn Dakin.

We recorded high speed videos of peacocks displaying in the field. We also used lab experiments to test whether the peacocks move their feathers at resonance (which would be an efficient strategy), and to understand how the colourful eyespots can remain so steady during these vibrations. One surprising result was that the peacocks with the longest trains actually used slightly higher vibration frequencies overall – making their displays a greater challenge to perform. The next step is to understand how these feather motions influence the iridescent colour patterns as viewed by the peahens (the females), and ultimately, the hens’ choice of a mate.

Media coverage has been great – here are a few of my favourites:

…and Suzanne reports that her husband met a couple in the Netherlands who had just read about our study in that newspaper. Pretty gratifying to hear that!

The videos associated with the paper are available here.

by Roslyn

Science is flawed. So what?

The results of the Reproducibility Project – a very cool endeavour to repeat a bunch of published studies in psychology – came out this week [1]. 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.

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