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Speaker 1: Hey, welcome to Stuff to Blow Your Mind. My name

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Speaker 1: is Robert Lamb. It's Saturday. We have a vault episode

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Speaker 1: for you. This one originally published six six, twenty twenty five.

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Speaker 1: It is the Extreme Maneuverability of Hummingbirds with Rosalind Dakin.

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Speaker 1: So this is another interview episode and I really enjoyed

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Speaker 1: this one. Hummingbirds are such an important part of my summer,

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Speaker 1: getting to look out the window and see these amazing

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Speaker 1: organisms darting around and feeding, and so it was a

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Speaker 1: real pleasure to get to talk to an actual hummingbird

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Speaker 1: researcher about these amazing creatures. Let's jump right in.

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Speaker 2: Welcome to Stuff to Blow Your Mind, production of iHeartRadio.

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Speaker 1: Hey, welcome to Stuff to Blow your Mind. Robert Lamb.

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Speaker 1: Here in today's episode, I'm going to be chatting with

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Speaker 1: Oslyn Dakin, Associate professor at Carlton University in Ottawa and

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Speaker 1: principal investigator at the Dynamic Behavior Lab. We're going to

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Speaker 1: be chatting about hummingbirds, as she and her co authors

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Speaker 1: just had a new paper published in the Journal of

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Speaker 1: Zoology Turning trade offs. Hummingbird power reserves are used to

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Speaker 1: decrease turning radius or increase turning velocity. So without further ado,

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Speaker 1: let's jump right into the interview. Hi, Rosalind, Welcome to

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Speaker 1: the show.

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Speaker 3: Hi, thanks for having me.

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Speaker 1: So we're going to be talking about hummingbirds today. We're

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Speaker 1: already really enjoying the company of hummingbirds down here in Atlanta.

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Speaker 1: Have they arrived up there where you are? You're in Ontario?

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Speaker 3: Correct, Yes, exactly, I'm in Ottawa, Ontario. And they arrive

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Speaker 3: the first week of May the ruby started. Hummingbirds show

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Speaker 3: up almost like clockwork every year.

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Speaker 1: It's always a joyous occasion here at my house when

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Speaker 1: we finally see the first hummingbirds of the season appear

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Speaker 1: at our feeders and flowers. And I think, you know,

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Speaker 1: at first it's the magic of them being here, the

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Speaker 1: way they move and all. But as you begin to

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Speaker 1: observe them, you really begin to notice how intensely territorial

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Speaker 1: they are about their flowers or about the cute little

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Speaker 1: feeder we've put out for them. Can you tell us, like,

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Speaker 1: why are they so territorial about this? As sometimes as

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Speaker 1: humans putting out feeders, we want to tell them like no, no,

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Speaker 1: there's plenty you can share, and they're generally not having

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Speaker 1: any of that.

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Speaker 3: Yeah, that's right. They have super competitive behaviors and that's

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Speaker 3: something that we've been studying in my lab. Why they're

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Speaker 3: like that, I think it all comes down to their

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Speaker 3: super high metabolic rates. Their lifestyle relies on having a

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Speaker 3: steady stream of calories throughout the day, and if they

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Speaker 3: go even an hour without feeding, depending on how much

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Speaker 3: energy fest do are they have in their body, that

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Speaker 3: can mean death an hour without a meal. So those

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Speaker 3: food sources are really really valuable to them, and their

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Speaker 3: metabolic rates are so high. If you could scale a

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Speaker 3: hummingbird's body up to the size of the average adult human,

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Speaker 3: it would be like if you or I had to

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Speaker 3: eat one hundred and fifty large pizzas in a day. Wow.

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Speaker 1: Now, how can their wings that move so fast to

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Speaker 1: repel thems of the air.

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Speaker 3: Yeah, So in order to be able to hover, hummingbirds

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Speaker 3: have to beat their wings, depending on the species, between

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Speaker 3: thirty to eighty times per second. So if you think

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Speaker 3: about a full wing stroke, that's your arm being fully

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Speaker 3: extended back, coming forward and then back again and repeating

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Speaker 3: that cycle. For species like ruby throated hummingbirds fifty times

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Speaker 3: every second. It's incredibly fast. So they have, so that's

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Speaker 3: why they have such high metabolic rates, the highest of

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Speaker 3: any vertebrate animal per unit body mass. But they have

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Speaker 3: a lot of anatomical adaptations that are required tired to

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Speaker 3: be able to do that. So, for example, they're pectoral

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Speaker 3: muscles that draw the wings down that activate the downstroke

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Speaker 3: are hyperchase feed. They're really really large. But similarly, they

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Speaker 3: have another muscle, the super corecoidous muscle that draws the

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Speaker 3: wing back up and it's also hypercha feed. It's also

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Speaker 3: extra large. In hummingbirds, they have skeletal adaptations as well,

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Speaker 3: so the muscle that the bones that those muscles attached

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Speaker 3: to have to be larger and more robust than they

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Speaker 3: are in other birds that have more typical wing beat frequencies.

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Speaker 3: And they also have dramatically modified anatomy to the bones

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Speaker 3: of their wing. These are the bones that we can't see.

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Speaker 3: We just see the feathered part of the wing, but

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Speaker 3: inside the hummingbird's wing they're humorous, is really really short.

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Speaker 3: It's so short, it's almost like a little dot, you know.

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Speaker 3: It's just a couple of millimeters in length, and their

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Speaker 3: wing is mostly and what that does is it means

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Speaker 3: that the heavy parts of their arm bones are drawn

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Speaker 3: in close to the body to make it easier to

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Speaker 3: beat those wings so fast. But it also means that

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Speaker 3: those muscles that are activating those wingstrokes are working over

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Speaker 3: a shorter distance, and so that makes it physically possible

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Speaker 3: for them to beat their ways at this incredibly high frequency.

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Speaker 1: So what evolutionarily has driven this development this arms race

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Speaker 1: of hummingbirds. Is it just their diet and how they

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Speaker 1: need to feed it, is it predators, is it other hummingbirds? Like,

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Speaker 1: how does it all come together?

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Speaker 3: Yeah, that's a super interesting question and one that we

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Speaker 3: have hypotheses, but it's still an active area of research.

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Speaker 3: If we go back, well, let's start with looking at

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Speaker 3: what we have today. The hummingbird family is extraordinarily diverse.

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Speaker 3: There's three hundred and sixty six different species and they

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Speaker 3: live in the America, so South America, Central America, the Caribbean,

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Speaker 3: and some species here in North America. That's incredibly diverse,

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Speaker 3: and they've radiated, they've diversified into all of these species

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Speaker 3: over the past twenty five million years. And if we

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Speaker 3: look at their closest relatives in the evolutionary tree, the

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Speaker 3: family tree of all birds, those are swifts, which are

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Speaker 3: also super agile birds. They're distributed across the globe. We

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Speaker 3: have swifts in North America. We also have swifts in

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Speaker 3: Europe and Asia that are aerial insectivores. So swifts spent

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Speaker 3: almost all of their time in the air catching flying insects,

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Speaker 3: so they have to be like little fighter pilots to

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Speaker 3: be able to chase down their prey. So the first

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Speaker 3: hummingbirds evolved around thirty million years ago from an ancestor

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Speaker 3: that was a really really acrobatic predator in the air,

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Speaker 3: and swifts have some of the same skeletal adaptations that

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Speaker 3: we see in hummingbirds. They have an enlarged keel that's

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Speaker 3: the part of the bone on the breastbone where those

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Speaker 3: pectoral muscles attach, and swifts also have changes in their

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Speaker 3: wing bones that we see in hummingbirds as well. So

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Speaker 3: that's part of how we know where the hummingbirds fit

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Speaker 3: in anatomically, but also genetic studies have established what those

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Speaker 3: relationships are. So, yeah, the first hummingbird or something something

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Speaker 3: like an insective war chasing down insects and somehow, you know,

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Speaker 3: maybe they started to prefer insects that were associated with

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Speaker 3: the flowers and maybe that led to them consuming some nectar.

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Speaker 3: We don't know exactly what happened to produce this fifth

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Speaker 3: towards being so specialized on flower nectar. But the other

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Speaker 3: mysterious part is that the earliest ancestor, the earliest fossil

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Speaker 3: ancestor we have of hummingbirds is not at all in

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Speaker 3: the same part of the world where we have all

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Speaker 3: of the species that we can observe today. The closest

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Speaker 3: fossil ancestor of hummingbirds they come from Europe, So fossils

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Speaker 3: with a lot of those hummingbird typical features, a long bill,

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Speaker 3: an exaggerated keel, and different wing proportions. Those have been

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Speaker 3: found in Poland and in France and multiple places. So

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Speaker 3: they arose in Europe we think, and at some point

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Speaker 3: made their way over to the Americas thirty twenty five

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Speaker 3: million years ago and from there diversified into very many

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Speaker 3: species day and a lot of that is the diversification

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Speaker 3: is probably due to specializing into different areas in the

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Speaker 3: Americas and.

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Speaker 1: In the Caribbean, so they're enhanced maneuverability in their power reserves,

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Speaker 1: which we're going to get into when we start talking

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Speaker 1: about your study here. This is largely for inter hummingbird

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Speaker 1: competition or do they have aerial predators they need to

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Speaker 1: worry about as well.

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Speaker 3: They may have some effective predators, that's not something that

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Speaker 3: we have very often, but we see a lot of

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Speaker 3: competition both between species and also within species, so especially

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Speaker 3: among males within a species, competing for a territory, competing

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Speaker 3: for a food resource. The other area where we see

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Speaker 3: them using their acrobatic skills is when they're courting mates.

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Speaker 3: So in very many species, the males will try to

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Speaker 3: impress females by doing an elaborate display in the air,

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Speaker 3: and the way that display goes will differ in different species,

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Speaker 3: but often they're zooming back and forth, reaching really high

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Speaker 3: speeds and turning quickly as part of that display, all

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Speaker 3: at the same time as they show the female their

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Speaker 3: colorful plumage and sometimes like make certain sounds while they're

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Speaker 3: doing those displays as well.

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Speaker 1: So getting into your research a bit more here, tell

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Speaker 1: us a little bit about the Dynamic behavior lab and

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Speaker 1: how humming birds factor into your work there.

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Speaker 3: Yeah, so we are interested in differences between individuals and

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Speaker 3: differences between species, and when performance is such an important

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Speaker 3: part of how they survive. How is it that, Like,

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Speaker 3: what determines which individuals are dominant over which others, who's

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Speaker 3: winning those competitions, what traits determine who wins? But also

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Speaker 3: for individuals that are subordinate, what options do they have?

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Speaker 3: How do the subdominant individuals make a living? Those are

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Speaker 3: some of the questions we're studying in my lab. So

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Speaker 3: we measure things like they're an individual bird's ability to

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Speaker 3: generate power in flight, and we also measure their behavior

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Speaker 3: in big arenas where we can pit multiple birds against

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Speaker 3: each other competing over a food resource and seeing both

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Speaker 3: who's dominant, but also how are they using flight maneuvers

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Speaker 3: to outdo each other?

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Speaker 1: Now, how do you go about stuff something like this

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Speaker 1: because hummingbirds, i imagine, are not easy creatures to study anyway,

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Speaker 1: and then you're dealing with some difficult to measure properties here.

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Speaker 3: Right, Yeah, it takes a lot of patience. And one

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Speaker 3: of the nicest assays that's possible to do with hummingbirds

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Speaker 3: is a load lifting assay where we can measure the

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Speaker 3: maximum power they're able to generate with their flight apparatus,

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Speaker 3: with those muscles that are activating the wings. And we

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Speaker 3: do that assay in a chamber that's think of like

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Speaker 3: a vertical cylinder with kind of an open bright light

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Speaker 3: at the top, and a hummingbird at the bottom of

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Speaker 3: that chamber is going to be highly motivated to fly

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Speaker 3: upwards try to escape, and we use an assay that

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Speaker 3: was developed decades ago by other scientists where we put

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Speaker 3: a little ring around the bird's neck that's attached to

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Speaker 3: a string of beads, and when we know the weight

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Speaker 3: of the beads along that chain, we can record what's

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Speaker 3: opening when the hummingbird gets released from the bottom of

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Speaker 3: the chamber, and if everything is set up suitably for

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Speaker 3: the bird as they try to escape upward with everything

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Speaker 3: they've got, we're able to measure exactly how many weights

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Speaker 3: or how many exact weight of the beads on that

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Speaker 3: chain that they're able to lift. The higher they go,

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Speaker 3: they're lifting more and more weight until they hit a

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Speaker 3: maximum and return back to the bottom of the chamber.

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Speaker 3: So we're able to develop an essay that just fits

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Speaker 3: with their capabilities their motivations to measure their maximum weightlifting ability.

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Speaker 1: So essentially the tiny necklaces on hummingbirds is a part

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Speaker 1: of the study exactly.

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Speaker 3: Yeah, yeah, So we have to make those necklaces. Yeah.

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Speaker 1: Oh wow. So this latest study published in the Journal

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Speaker 1: of Zoology really gets into their maneuverability and their power reserves.

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Speaker 1: Can you lay out how these two aspects are linked.

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Speaker 1: As I was reading the paper, I can't. I really

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Speaker 1: kept thinking of hummingbirds in like video game terms and

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Speaker 1: imagining like little meters at the time the screen.

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Speaker 3: Yeah. So a couple of questions motivated this study, and

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Speaker 3: it was led by my colleague Paulo Segre and my

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Speaker 3: co author Doug Altuler. So one of the questions was,

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Speaker 3: when we're measuring their maneuvering performance, which includes lots of

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Speaker 3: complex behaviors that have a lot of degrees of freedom,

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Speaker 3: how tightly can they turn, How fast can they move

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Speaker 3: when they're turning, How fast can they accelerate decelerate? When

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Speaker 3: we're measuring those maneuvers, it's really hard to capture what

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Speaker 3: is a bird's maximum ability. The more freedom you give

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Speaker 3: them in a space where you're capturing what they do,

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Speaker 3: the less well defined maximum is because there's so many

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Speaker 3: different ways to move in a completely open environment. So

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Speaker 3: we've been studying maneuvering ability in across different hummingbird species

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Speaker 3: for some years, but we wanted to know is the

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Speaker 3: power they're able to generate in a more constrained assay

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Speaker 3: like our low lifting assay, is it predictive of some

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Speaker 3: maximum that we're able to capture in this free flight assay.

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Speaker 3: That was the motivation for that study, so led by Pollow.

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Speaker 3: What Pollow did was he reasoned using fundamental physics that

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Speaker 3: one of the basic maneuvers that they use very frequently

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Speaker 3: to turn, which we're calling an arcing turn, which is

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Speaker 3: basically just a level turn that if you look at

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Speaker 3: it from above, you follows a smooth arc. He reasoned

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Speaker 3: that those arcing urns, that we can build a physical

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Speaker 3: model of the forces that they need to to produce

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Speaker 3: those arcing turns, and we can test whether the maximum

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Speaker 3: load that a bird is able to lift in our

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Speaker 3: low lifting assay does that correspond with the maximum that

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Speaker 3: they're hitting up against as they read aroun forces during

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Speaker 3: those arcing turns.

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Speaker 1: So one of these arcing terns you're describing here, would

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Speaker 1: this perhaps be one of these maneuvers we see when

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Speaker 1: one hummingbird chases another hummingbird away from a feeder or

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Speaker 1: flowers in our yard.

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Speaker 3: Yes, absolutely, Yeah, and yeah, definitely. They'll they'll use arcing

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Speaker 3: terns during chases. They'll also use arcing turns during obstacle avoidance,

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Speaker 3: which is really important to a fast moving animal. Those

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Speaker 3: collisions could be deadly.

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Speaker 1: Yeah, these are the the collision avoidance turns. I guess

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Speaker 1: I don't notice as much because if they're avoiding collision

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Speaker 1: with my head, it's all happening so quickly. But yeah,

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Speaker 1: but sometimes we'll be watching them. Often we'll be watching

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Speaker 1: them and we'll see one chase the other off, and

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Speaker 1: it sounds it sounds like, yeah, that's what you're talking

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Speaker 1: about here.

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Speaker 3: Yeah, exactly.

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Speaker 1: I'm sorry, but I got us off topic here. You

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Speaker 1: were describing your analysis of these turns, right, Yeah.

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Speaker 3: So, so in those free flight essays, we are telling

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Speaker 3: birds what to do. They're performing at a sort of

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Speaker 3: routine flight level of performance as they're trying to avoid

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Speaker 3: the threatening experimenters avoid collisions with the size of the

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Speaker 3: flight chamber. But we can capture thousands of maneuvers from

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Speaker 3: each individual over a relatively short span of time because

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Speaker 3: everything humming birds do just happens on a much faster

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Speaker 3: timescale than other species or than their own lives. So

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Speaker 3: if you record a hummingbird for two hours, you might

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Speaker 3: capture two thousand arcing turns, for example. And so we

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Speaker 3: can computationally pull out the segments of flight that represent

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Speaker 3: the arcing turns that we're limited to a level plane,

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Speaker 3: and we can apply the physical model that Paolo built

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Speaker 3: to say, okay, the redirection of forces as the bird

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Speaker 3: is banking its body to execute that turn. What's the

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Speaker 3: kind of space of what that looks like for the many,

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Speaker 3: many thousands of turns that we captured from the different

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Speaker 3: hummingbirds in our study. We studied about twenty individual hummingbirds

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Speaker 3: in that study, and does the limit of that distribution,

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Speaker 3: how does that align with our predicted limit from how

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Speaker 3: much weight those birds could lift in our highly constrained

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Speaker 3: load lifting assay. And what we found was that overall, collectively,

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Speaker 3: the model predicts really well the maximum turning performance of

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Speaker 3: the birds in that chamber. So the Anna's hummingbirds that

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Speaker 3: we study either from the West coast of North America

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Speaker 3: slightly larger species than we have here in Ottawa or

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Speaker 3: where you are, but they have in our low lifting

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Speaker 3: assay they can lift about two and a half times

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Speaker 3: their body weight on average, and we can model what

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Speaker 3: that would translate to in terms of being able to

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Speaker 3: redirect forces to execute that turn. And the birds in

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Speaker 3: our free flight experiment, their peak performance matches that peak

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Speaker 3: of what we would predict based on their maximum ability.

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Speaker 3: So it's really satisfying. It It aligns with our hypothesis

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Speaker 3: that in order to be maneuverable, that power has to

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Speaker 3: come from their muscle capacity and flight and their kind

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Speaker 3: of excess muscle capacity, their ability to just lift weights

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Speaker 3: vertically is going to determine how well they can execute

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Speaker 3: these high performance acrobatic maneuvers.

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Speaker 1: So as they're flying about during the day, like, how

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Speaker 1: often are they like absolutely using up their powers?

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Speaker 3: Yeah, that's a really good question that we don't know

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Speaker 3: the answer to yet. And how often are they hitting

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Speaker 3: their maximum out in nature? Probably not that often compared

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Speaker 3: to you know, when you think of like the lifespan

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Speaker 3: of a hummingbird and how much they do during it

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Speaker 3: during the day, I would estimate, I would hypothesize that

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Speaker 3: it's it's pretty rare that they're executing maneuvers that are

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Speaker 3: that are hitting their max. But in our flight chamber,

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Speaker 3: you know, it was a pretty small proportion maybe one

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Speaker 3: percent of the turns are kind of hitting that maximum

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Speaker 3: envelope and and maybe it's similar out in the wild,

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Speaker 3: but that's something that we'll be able to test in

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Speaker 3: the future, for example, by having sensors small enough to

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Speaker 3: put on a really small bird. That's kind of the

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Speaker 3: challenge there. But a lot at the time of the

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Speaker 3: like you know, a lot of their time of the

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Speaker 3: day they spend perching and and probably one of the

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Speaker 3: biggest challenges for them is maintaining the muscle mass that

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Speaker 3: they would need to execute those rare, super high performance maneuvers.

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Speaker 1: That's absolutely fascinating. Now I have I have another question

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Speaker 1: or two about just studying the hummingbird, Like we as

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Speaker 1: we observe them, you know, we we obviously pick up

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Speaker 1: that they are they're very powerful creatures in their own right,

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Speaker 1: but we also get the sense of fragility about them.

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Speaker 1: Are they are they fragile to deal with?

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Speaker 3: Like?

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Speaker 1: What, how is it different dealing with hummingbirds versus other

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Speaker 1: birds you might be studying in your in your work.

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Speaker 3: Yeah, I would say in the lab, they're they're relatives

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Speaker 3: are easy to deal with compared to other species. And

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Speaker 3: part of that might be they're they're so specialized. If

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Speaker 3: you kind of know the conditions they need. They're relatively

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Speaker 3: easy to keep healthy. The main point of fragility is

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Speaker 3: that super high metabolic rate. If they run out of food,

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Speaker 3: that's catastrophic. But if you've got the right conditions for them,

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Speaker 3: kind of unlimited food, the right physical space, they're pretty

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Speaker 3: easy to deal with in the lab. But we have

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Speaker 3: to cows them separately, and that's different than other birds because, yeah,

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Speaker 3: they're so aggressive they they would exclude each other from feeding,

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Speaker 3: for example, and their bills can be a weapon. So

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Speaker 3: when when they're kind of housed in captivity, we keep

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Speaker 3: each individual on its own. And you don't see it

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Speaker 3: that often in the wild, but if you have video footage,

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Speaker 3: high speed video footage of birds interacting and fighting at

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Speaker 3: a feeder, you'll see how that bill is really like

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Speaker 3: a long dagger, and that they're when they're facing off,

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Speaker 3: they're making sure they orient their bills towards each towards

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Speaker 3: each other. You can imagine a collision with those long

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Speaker 3: bills would be really catastrophic for an animal that only

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Speaker 3: weighs two and a half grams.

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Speaker 1: Oh wow, Yeah, that was going to be one of

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Speaker 1: my questions, like what, like, what is the we see

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Speaker 1: them chasing each other, like, what are they actually doing

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Speaker 1: to each other? If they catch it, it kind of

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Speaker 1: sounds like it's like a joust in a sense, right, yeah.

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Speaker 3: And it's really hard for us to capture what that like,

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Speaker 3: what are the consequences of that in the wild. The

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Speaker 3: best examples we have are footage that people can capture

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Speaker 3: at a feeder and when birds really get into it

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Speaker 3: close to a feeder, what happens and you see them

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Speaker 3: grabbing each other's feathers and using their bills to defend

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Speaker 3: that space to displace another bird. And there's still a

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Speaker 3: lot of open research questions about you know, exactly how

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Speaker 3: like what signals or outcomes are determining who wins those competitions,

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Speaker 3: And that's an active area of work that we're studying

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Speaker 3: now in my lab. But even in the lab, we'll

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Speaker 3: see them rarely make physical contact with each other. So

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Speaker 3: if one bird wants to displace another from a perch,

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Speaker 3: sometimes they'll get into little scuffles where they're making contact,

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Speaker 3: and I think at high speeds those kinds of scuffles

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Speaker 3: would be dangerous to both individuals. So it's a real

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Speaker 3: game of chicken.

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Speaker 1: Now when you're studying hummingbirds, do you is it completely seasonal?

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Speaker 1: Is it seasonal availability very much a part of this,

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Speaker 1: or do you have hummingbirds like in captivity that you

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Speaker 1: can study year round.

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Speaker 3: Yeah. So in my lab here in Oddwell, we're studying

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Speaker 3: ruby throarted hummingbirds and they are migratory, and so we've

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Speaker 3: been catching birds here since the beginning of May, and

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Speaker 3: we've got a group of males in the lab now

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Speaker 3: that will release again prior to their autumn southward migration.

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Speaker 3: So we're only working with them within the breeding season

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Speaker 3: here and only studying the males, and remarkably many individuals,

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Speaker 3: many of the migratory species, an individual hummingbird will come

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Speaker 3: back to the very same feeder. So one of the

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Speaker 3: birds in my lab now is a bird that we

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Speaker 3: caught and released on campus last year, attached a little

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Speaker 3: band to his leg with an identifying number, and he

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Speaker 3: would have migrated all the way to Mexico. And then

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Speaker 3: this spring, the first two weeks of May, like clockwork,

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Speaker 3: he showed up at the exact same feeder. We captured

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Speaker 3: him again this year. So it really is remarkable not

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Speaker 3: only the physical feats that they do, but also they

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Speaker 3: have remarkable memories, and so they're and that's all part

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Speaker 3: of their high metabolic rate. They need to know where

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Speaker 3: those reliable food sources are. So this male we're be

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Speaker 3: throwed hummingbird came back to the exact same feeder after

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Speaker 3: this cross continental journey.

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Speaker 1: That was going to be one of my follow up

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Speaker 1: questions about the what's going on in the mind of

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Speaker 1: a hummingbird, And it's because again they just there's such

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Speaker 1: drastically different creatures they're living on this this time frame,

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Speaker 1: you know, that's so different from from ours, and then

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Speaker 1: vast distances in addition to vast speeds, So we have

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Speaker 1: what else do we know about their about the way

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Speaker 1: their little brains work.

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Speaker 3: Yeah, it's really fascinating. So there's a lot of excellent

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Speaker 3: research coming out of my co author dug Altuler's lab

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Speaker 3: on how their brains work and how the visual system works.

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Speaker 3: And we also have studies of their spatial memory. And

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Speaker 3: so a really beautiful study from about twenty years ago

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Speaker 3: now on a species of hummingbird that lives in the

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Speaker 3: Rocky Mountains looked at their ability to learn flowers that

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Speaker 3: change in nectar availability through time. So real flowers are

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Speaker 3: not like feeders, real flowers will be depleted and will

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Speaker 3: replenish themselves over some seasonal period. And hummingbirds that have

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Speaker 3: a territory with lots of flowers in them, they need

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Speaker 3: to know where their next meal is coming from, and

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Speaker 3: they're able to learn the locations of many flowers. As

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Speaker 3: an example, this bird that came all the way back

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Speaker 3: to my feeder from Mexico, you know, he would have

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Speaker 3: remembered other places along that route, we hypothesize. So what

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Speaker 3: the researchers did in Alberta, Canada, was create an experiment

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Speaker 3: where they could track one male in the wild who

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Speaker 3: had a territory and they had dynamic feeders in that

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Speaker 3: territory that went on different time schedules. Maybe some feeders

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Speaker 3: would replenish on five minute intervals, others on ten minute intervals,

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Speaker 3: others on twenty minute intervals. And if a bird had

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Speaker 3: multiple of those variable timed feeders available, would they be

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Speaker 3: able to learn those different time schedules. And they found

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Speaker 3: that indeed they could. So not only can they remember

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Speaker 3: where the food resources are, but they can keep track

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Speaker 3: of multiple variable schedules within their territory like all in

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Speaker 3: their head. Right, So they've brought like a calendar in

433
00:26:54,840 --> 00:27:00,000
Speaker 3: their head to determine where, like which resources have food,

434
00:27:00,240 --> 00:27:02,560
Speaker 3: where are they and when are they going to become

435
00:27:02,600 --> 00:27:07,200
Speaker 3: profitable again? And their brains are really really small, remember,

436
00:27:07,240 --> 00:27:09,719
Speaker 3: because their whole bodies are miniaturized, so their brains are

437
00:27:09,840 --> 00:27:12,879
Speaker 3: much much smaller than the brains of other birds. So

438
00:27:12,880 --> 00:27:14,760
Speaker 3: it's really quite incredible that they can do that.

439
00:27:14,920 --> 00:27:16,919
Speaker 1: Yeah, I'm really impressed by their ability to map all

440
00:27:16,960 --> 00:27:18,760
Speaker 1: that out. And then I feel a little I can't

441
00:27:18,800 --> 00:27:23,399
Speaker 1: help but feel guilty by how like if I forget

442
00:27:23,440 --> 00:27:26,159
Speaker 1: to refill the feeder or to change out the nectar

443
00:27:26,200 --> 00:27:29,600
Speaker 1: and a feeder, I just now I'm going to feel

444
00:27:29,600 --> 00:27:33,280
Speaker 1: even worse because I'm messing with their finely tuned like

445
00:27:33,400 --> 00:27:36,960
Speaker 1: mental map of where all the flowers and the feeders are.

446
00:27:37,359 --> 00:27:40,520
Speaker 3: Yeah, it is important if you're maintaining a feeder, is

447
00:27:40,520 --> 00:27:44,160
Speaker 3: important to keep it going. But you know they're they're

448
00:27:44,200 --> 00:27:48,320
Speaker 3: really resilient as well. They've been around for millions of

449
00:27:48,400 --> 00:27:52,960
Speaker 3: years before we started providing feeders, and so the birds

450
00:27:53,000 --> 00:27:56,520
Speaker 3: that are in your yard, in your neighborhood, they're going

451
00:27:56,560 --> 00:28:01,880
Speaker 3: to have other food sources mapped out. So yeah, it's important,

452
00:28:01,960 --> 00:28:07,359
Speaker 3: but it's unlikely to be catastrophic if one person forgets

453
00:28:07,440 --> 00:28:11,720
Speaker 3: to refill their feeder. But what's also fascinating is that

454
00:28:11,760 --> 00:28:16,800
Speaker 3: we're learning how those feeders are changing are causing contemporary

455
00:28:16,800 --> 00:28:24,600
Speaker 3: evolution in hummingbirds. The species that we have on the

456
00:28:24,640 --> 00:28:28,520
Speaker 3: eastern North America here ruby throt hummingbirds, their populations are

457
00:28:28,520 --> 00:28:33,640
Speaker 3: doing quite well despite lots of threats that humans are

458
00:28:33,640 --> 00:28:36,120
Speaker 3: creating for other bird species, and probably a big part

459
00:28:36,119 --> 00:28:40,560
Speaker 3: of that is humans providing food to them. On the

460
00:28:40,600 --> 00:28:44,880
Speaker 3: West Coast, the Anna's hummingbird is a species that has

461
00:28:44,960 --> 00:28:47,840
Speaker 3: expanded its range, so it used to only live in

462
00:28:48,120 --> 00:28:52,320
Speaker 3: kind of warmer states in the southwest of the US,

463
00:28:52,960 --> 00:28:55,360
Speaker 3: and now we find that species and as hummingbird as

464
00:28:55,400 --> 00:28:59,640
Speaker 3: far north is as Vancouver, Canada, where we conducted our research.

465
00:29:01,600 --> 00:29:05,080
Speaker 3: They've expanded over the past century with people providing food

466
00:29:06,120 --> 00:29:10,440
Speaker 3: both ornamental flowers but also feeders, and we're learning that

467
00:29:10,480 --> 00:29:12,440
Speaker 3: there's a study that just came out this year. We're

468
00:29:12,520 --> 00:29:17,800
Speaker 3: learning how providing feeders is causing measurable changes to the

469
00:29:17,880 --> 00:29:21,320
Speaker 3: morphology of their beaks. Their beaks are changing in size

470
00:29:21,360 --> 00:29:25,760
Speaker 3: as they've been expanding. So it's really really neat because

471
00:29:26,800 --> 00:29:31,080
Speaker 3: beak shape evolution is kind of this classic case where

472
00:29:32,360 --> 00:29:36,040
Speaker 3: that led Darwin to come to appreciate how natural selection works,

473
00:29:36,960 --> 00:29:40,920
Speaker 3: and we humans are now causing that to happen on

474
00:29:41,400 --> 00:29:43,200
Speaker 3: a rapid timescale.

475
00:29:43,480 --> 00:29:46,880
Speaker 1: Wow, so what sort of changes are taking place here?

476
00:29:46,920 --> 00:29:48,640
Speaker 1: Are the beaks getting shorter longer?

477
00:29:49,480 --> 00:29:52,280
Speaker 3: Yeah, so their beaks are getting longer to be able

478
00:29:52,320 --> 00:29:57,000
Speaker 3: to extract food from feeders and their way. Researchers have

479
00:29:57,040 --> 00:29:59,880
Speaker 3: been able to discover that is by measuring the beaks

480
00:30:00,080 --> 00:30:03,560
Speaker 3: of museum specimens that were collected over the past century

481
00:30:03,560 --> 00:30:07,160
Speaker 3: and kind of building up a time series of specimens

482
00:30:07,200 --> 00:30:09,240
Speaker 3: from you know, one hundred years ago, fifty years ago

483
00:30:09,040 --> 00:30:10,120
Speaker 3: to present.

484
00:30:10,560 --> 00:30:15,000
Speaker 1: Wow, that's impressive. So you're spending all this time studying hummingbirds,

485
00:30:15,920 --> 00:30:18,840
Speaker 1: do they retain their magic for you? Or did they

486
00:30:18,840 --> 00:30:22,640
Speaker 1: become like just a little every day? Are they still exciting?

487
00:30:22,840 --> 00:30:26,760
Speaker 3: They are still exciting. One of my favorite moments from

488
00:30:27,040 --> 00:30:30,400
Speaker 3: going out into the field at the sites where we

489
00:30:30,600 --> 00:30:34,560
Speaker 3: find our hummingbirds is getting to see courtship displays, getting

490
00:30:34,600 --> 00:30:37,560
Speaker 3: to see a male court a female and rub throw it.

491
00:30:37,640 --> 00:30:41,480
Speaker 3: Hummingbirds they do the shuttle display where they're zooming back

492
00:30:41,520 --> 00:30:43,920
Speaker 3: and forth and they start, you know, with a small

493
00:30:44,160 --> 00:30:47,080
Speaker 3: arc and they're flaring their colorful feathers in front of

494
00:30:47,080 --> 00:30:50,280
Speaker 3: the female and their shuttle gets bigger and bigger, faster

495
00:30:50,360 --> 00:30:55,200
Speaker 3: and faster. It's still really magical, even after handling lots

496
00:30:55,200 --> 00:30:59,720
Speaker 3: of hummingbirds in the lab. And the other thing I

497
00:30:59,720 --> 00:31:03,400
Speaker 3: find really exciting about them is seeing their behavior slowed down.

498
00:31:03,960 --> 00:31:08,600
Speaker 3: When if you capture interactions with high speed video and

499
00:31:08,640 --> 00:31:14,680
Speaker 3: then watch them slow speed, it really looks like you

500
00:31:14,800 --> 00:31:17,200
Speaker 3: get an even greater appreciation for what they can do

501
00:31:17,240 --> 00:31:19,920
Speaker 3: because it looks like they're swimming in the air. It

502
00:31:19,960 --> 00:31:25,080
Speaker 3: looks like like they're moving in the air as definitely

503
00:31:25,280 --> 00:31:28,800
Speaker 3: as we do kind of on the ground, and you

504
00:31:28,840 --> 00:31:31,320
Speaker 3: get a real impression for things that they can do

505
00:31:31,480 --> 00:31:33,360
Speaker 3: that you know, they just whiz by you when you're

506
00:31:33,360 --> 00:31:36,760
Speaker 3: seeing it in real life, but there's a lot happening there.

507
00:31:36,960 --> 00:31:39,440
Speaker 1: Yeah, I know just from this was several years back,

508
00:31:39,440 --> 00:31:42,040
Speaker 1: but I went with my family to Costa Rica and

509
00:31:42,080 --> 00:31:44,440
Speaker 1: we got to see some hummingbirds there at some feeders,

510
00:31:45,000 --> 00:31:47,880
Speaker 1: and just with whatever sort of iPhone we had at

511
00:31:47,920 --> 00:31:51,160
Speaker 1: the time, you know, you could take a to take

512
00:31:51,400 --> 00:31:55,640
Speaker 1: pretty decent video and slow it down and gets this

513
00:31:55,800 --> 00:31:58,040
Speaker 1: enhanced appreciation for what they were doing. And so I

514
00:31:58,080 --> 00:32:02,600
Speaker 1: can only imagine what's possible with today's iPhones and smartphones

515
00:32:02,640 --> 00:32:07,160
Speaker 1: and with like serious of film film equipment.

516
00:32:07,680 --> 00:32:11,160
Speaker 3: Yeah, yeah, that's right. And Costa Rica has like a

517
00:32:11,400 --> 00:32:15,440
Speaker 3: huge diversity of species, and different locations that you'll visit

518
00:32:15,520 --> 00:32:19,320
Speaker 3: will have different species. And that's another question that continues

519
00:32:19,360 --> 00:32:23,720
Speaker 3: to fascinate me. The smallest hummingbirds we have are just

520
00:32:24,040 --> 00:32:27,479
Speaker 3: you know, two grams, which is the mass of a penny.

521
00:32:27,920 --> 00:32:28,160
Speaker 1: Wow.

522
00:32:28,160 --> 00:32:30,800
Speaker 3: And then the largest species we have is twenty grams.

523
00:32:30,840 --> 00:32:35,800
Speaker 3: That's ten times bigger. And then we've got three hundred

524
00:32:35,800 --> 00:32:39,600
Speaker 3: and sixty six species that span that range, most of

525
00:32:39,640 --> 00:32:42,320
Speaker 3: them kind of between the two to ten gram size,

526
00:32:42,320 --> 00:32:44,840
Speaker 3: which is still a big range. Why is it that

527
00:32:44,880 --> 00:32:47,560
Speaker 3: there's so many different ways to be a hummingbird? How

528
00:32:47,600 --> 00:32:50,880
Speaker 3: do all of these like this one kind of overall strategy,

529
00:32:50,880 --> 00:32:54,320
Speaker 3: How does it lead to this diversification? And how do

530
00:32:54,400 --> 00:32:57,080
Speaker 3: they all coexist? Is another really fascinating question.

531
00:32:57,640 --> 00:32:59,520
Speaker 1: All right, well, Rossland, thanks for coming on the show

532
00:32:59,520 --> 00:33:01,560
Speaker 1: and chatting with me today about hummingbirds.

533
00:33:01,840 --> 00:33:02,640
Speaker 3: Thank you very much.

534
00:33:06,240 --> 00:33:09,000
Speaker 1: Thanks once again to Rosalind Dacon for taking time out

535
00:33:09,040 --> 00:33:10,880
Speaker 1: of her day to chat with me again. The paper

536
00:33:11,040 --> 00:33:15,200
Speaker 1: is turning trade offs hummingbird power reserves are used to

537
00:33:15,240 --> 00:33:19,240
Speaker 1: decrease turning radius or increase turning velocity out now in

538
00:33:19,280 --> 00:33:22,320
Speaker 1: the Journal of Zoology, and you can learn more about

539
00:33:22,360 --> 00:33:25,640
Speaker 1: her work with the Dynamic Behavior Lab by visiting our

540
00:33:25,640 --> 00:33:29,760
Speaker 1: website at Rosalindacin dot com. That's r O s l

541
00:33:30,000 --> 00:33:35,000
Speaker 1: y N da ki n dot com. Just a reminder

542
00:33:35,040 --> 00:33:36,800
Speaker 1: to everyone out there, the Stuff to Blow Your Mind

543
00:33:36,880 --> 00:33:39,680
Speaker 1: is primarily a science and culture podcast, with core episodes

544
00:33:39,720 --> 00:33:42,760
Speaker 1: on Tuesdays and Thursdays, but on Fridays we set aside

545
00:33:42,800 --> 00:33:45,080
Speaker 1: most serious concerns to just talk about a weird film

546
00:33:45,160 --> 00:33:48,440
Speaker 1: on Weird House Cinema. Thanks as always to the excellent

547
00:33:48,520 --> 00:33:50,840
Speaker 1: JJ Possway for producing the show, and if you would

548
00:33:50,880 --> 00:33:53,000
Speaker 1: like to reach out to us, you can email us

549
00:33:53,160 --> 00:34:03,480
Speaker 1: at contact at stuff to Blow your Mind dot com.

550
00:34:03,640 --> 00:34:06,560
Speaker 2: Stuff to Blow Your Mind is production of iHeartRadio. For

551
00:34:06,680 --> 00:34:10,480
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552
00:34:10,560 --> 00:34:25,920
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