Category / Birds

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

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

The Hummingbird Festival in Sedona

I just got back from the Hummingbird Festival in Sedona, Arizona. It was an honour to be invited there to present our work on flight.

Sedona Hummingbird Festival, 2017.

Photo by Maria Mahar at www.hummingbirdpictures.net

The audience at the festival had a ton of great questions and I learned a lot. For example, the Anna’s hummingbirds are a fairly recent arrival in Sedona, just as they are in Vancouver, because urbanization has also allowed the species to gradually expand its range east into the desert (as well as north). I wonder how that has affected the hummingbird community there? I also learned that it is pretty easy to set up an outdoor Drosophila colony as a protein source for breeding hummingbirds.

We saw the Grand Canyon and more bats, hummingbirds, and aura photographers than ever before in one place. Arizona has great insects, too. My favourite? The “pleasing fungus beetle” we spotted at Starbucks.

View from the south rim of the Grand Canyon

Photo by Charlie Croskery.

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

A murder and a mutant

I woke up the other day to see this:

A little closer:

Those aren’t leaves covering the trees – they’re crows! There must have been a few thousand of them (the picture only shows part of the flock, which extended to cover several other trees and rooftops). This is the third time this winter that I’ve seen a mega-roost in downtown Ottawa. Each time it has been on days that are much colder than usual. By noon, the flock had dispersed.

We had more bird encounters in Quebec last week where we saw a partial albino black-capped chickadee:

Here’s a black-capped chickadee with regular plumage, for comparison:

In domestic birds, partial albino (pied) mutations are recessive and fairly rare. It took about 100 years of cockatiel breeding before the pied mutation was established in the US, in 1951. I can’t find published numbers for chickadees, but bird banders counting mourning doves have recorded only 1 partial albino among 10,749 individuals. So this was probably a pretty rare bird! And here’s Ada, no longer impressed by a regular old chickadee:

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

Dennis Hlynsky’s small brains en masse

Dennis Hlynsky’s videos are among the best things I’ve seen online recently. Check ’em out:

Hlynsky uses frame-blending to great effect, to give you a sense of overall motion trajectories. When he turns his lens on animals, the results are both beautiful (see fruit flies paint a still life here), and an exciting way to visualize huge amounts of data. It’s got me thinking I could use this method to illustrate the 100s of hummingbird flights in our latest experiment here at UBC in a single animation.

Thanks to Suzanne Amador Kane for pointing these out to me!

by Roslyn

Feel the vibration

In between field work, I’ve been making a lot of videos lately – mostly for my students in the summer course in Ecology and the Environment. But my latest creation is entirely different: it’s for the upcoming American Ornithologists’ Union (read: bird nerd) conference.

It features slow-motion clips of peacocks vibrating their train feathers during their courtship displays. I used a special high-speed camera to film this behaviour at 210 frames per second – it was incredibly difficult to do, because the high-speed camera requires that you get really close, and males only perform the vibration when a female is nearby (and not a human one!). In the end, I was able to coax some hungry peahens practically into my lap by slowly doling out the treats. This allowed me to film males displaying at the females from just a couple of feet away.

From these videos, I estimated that peacocks vibrate their eyespot feathers at a rate of 25 Hz (i.e., the feathers move back and forth a whopping 25 times each second). That’s incredibly fast, but it’s hardly record breaking for birds. For instance, Teresa Feo and Chris Clark recently showed that hummingbirds vibrate their tail feathers at a rate of more than 80 Hz to produce a buzzy trill-like sound during their display dives. However, the hummingbirds do it passively, I believe.

Other birds are also making the news these days for their choreographic skills. Anastasia Dalziell and her coauthors at the Australian National University have shown that superb lyrebirds actually coordinate song and dance during their remarkable courtship displays.

Further Reading

  1. Feo and Clark. 2010. The Auk 127: 787-796.
  2. Dalziell et al. 2013. Current Biology. In press.
by Roslyn

Nest in the city

One of the most incredible things about peafowl is how well these birds thrive in the suburbs. There were hundreds in Arcadia, CA, where I studied them, and every once in a while I hear about some other town where they’ve taken over – Orange County, Palos Verdes, Miami – they even disperse and occasionally pop up somewhere new (like here, or here). I’ve been told that in India (where the species is originally from), flocks also tend to settle down in villages. (And the name for a group of peafowl? A muster!) And peacocks are now on the cover of a book on urban birds1.

So what makes peafowl so much better at urban living than other, similar species?

It could be that they’re catholic about their diets, or that they’re tolerant of a broad range of environmental conditions2. Other research has suggested that, in mammals at least, successful invaders tend to have relatively large brains3 – possibly because a large brain confers the ability to respond flexibly to new situations. American crows fit this theory, as an urban success story with relatively large brains. But peafowl are some of the smallest brained birds out there, when you consider brain size relative to body size – and pigeons, starling and house sparrows aren’t particularly well-endowed, either. So what if it has more to do with how they use their brains to adapt?

A new study points to an intriguing benefit of city life for some birds, and it has me wondering about learning as a mode of urban adaptation. Apparently, some urban birds use cigarette butts to build their nests – and researchers have now shown that the cigarette butts actually improve the living conditions for young birds.

Continue reading →

by Roslyn

Is animal care due for an update?

Canadians will fiercely defend nearly any Canadian-made thing, and we have an uncanny ability to keep track. Insulin? Discovered by a Canadian. The telephone? Also Canadian. Sir Sandford Fleming and his time zones? Canadian too. Tom Cruise? Spent his childhood here.

At the philosophy symposium here in September on ethics and animals, I learned of yet another point of pride: our national body governing the care of animals in research was one of the first in the world. Although the first official law to prevent cruelty to animals was passed in Britain in 1876, and the US had its Animal Welfare Act a few years before Canada’s Council on Animal Care (CCAC) was official, the CCAC had its beginning in the early 1960s – and it was revolutionary at the time.

But is it due for an update?

Continue reading →