Hello, my name's Lindsay Turnbull and I'm an associate professor in the Department of Plant Sciences
at the University of Oxford, and we're right in the middle of this very serious corona virus crisis right
now. And my students are all stuck at home and we want to keep them in touch with biology
and keep in touch with us. And so we're going to make a new series of videos and they're going to be called back
garden biology.
Hello and welcome to the 16th episode of Back Garden Biology. And it's going to be
about garden birds. Well, it's going to expand out a little bit beyond garden birds because the famous
really about foraging. So how do birds go about feeding, getting the energy they need?
And what are the risks they run when they're doing that? And most of it is going to be about garden birds. Of course, a bit weird if it
wasn't. And we're going to hear from Fredi, who is a pitch to student just finished in zoology.
She's been studying some of the foraging tactics that garden birds use,
particularly polluted. And great tips. She's been working up a while to Woods. We're going to hear a bit from her.
But right at the end, we're going to hear from Annette Fire. She's a junior research fellow and she works
on puffins with probably the world's best job. Right. And she looks at their foraging. They also
have to grazi, find fish, feed their chicks and themselves. And that can be quite a complicated
business. And she's got some great footage of them going about their fishing. So that's
at the end to look forward to. And most of us have garden birds. Obviously, we don't live by the sea
and we feed them food. Lots of us do. I've got some different kinds of food here. This is one of the foods
that I feed my birds. These are sunflower seeds. They've had all the shells taken off them. And the birds much
prefer that because they don't have to put so much energy in to two feedings.
So energy is really important to birds. And if they have to spend a lot of time processing food, that makes
it a lot less attractive to them. What's amazing is I also have these seeds. These are Niger
seeds, and you can see they're really, really tiny. And you might imagine that that's not a
good food for a bird. If you've got to pick up each one individually, that's going to be very time consuming.
But goldfinches in particular, really love those those seeds. And I think they just sort of move them up
in quite large quantities rather than picking them up one at a time. And certainly I see them sitting on my feet
through the winter for hours on end, just gorging away on those. I mean, if you're a bit more adventurous as well as
these more normal kinds of food, you might also want to consider buying something like this.
These are freeze dried mealworms, but horrible looking. But Robins
in particular really love them. And lots of gardens have a tame Robin My Robins,
not very time. I was a bit disappointed. It comes out and sort of makes itself known to and it wants some food. But as
soon as I come out to give it food, it disappears off. But a bit later in the programme, I want to show some footage
from my mum's garden. And my mom has been feeding the birds for a long time and
they have become incredibly tame. And she's built up generations of birds that have become incredibly time
to put out mealworms in her garden. You aren't going to sit around long for things, come and get them. And actually,
she doesn't just feed dried mealworms. She also feeds life worms
and the birds go nuts for them. Okay, so we're gonna start off with Freddy talking a little bit about foraging,
then coming back to my mum's garden and seeing the amazing birds there and then ending with Annette Fi
and her puffins.
One of the many ways we study somebody in White and Watts is we clip each individual
with a little lacquering in which we put a trained
tech. So to have a bird comes to a bird feeder. We get a record of its I.D.
and a timestamp to feed a visit. And this allows us to analyse the forging behaviour
and really great data. And so one of the things we found out is that birds differ
in the way they use these features. They are binge eaters and grazes. The Bingy does other birds
that come to the beach to eat as much as they possibly can and leave and come back at a later time
with the other individuals rising throughout the day. And the grazing
strategy is considered more risky because the birds repeatedly exposing themselves to
potential predators. So if competition determines
who can use the feeder and which way, then you would expect that individual to try to to
reduce competition and basically spread out these multiple resources.
We don't find evidence for this for individuals disputing themselves in such a way.
Instead, we actually find that they move between food patches and more honest, coherent
ways and tried to maintain cohesion with their members. And
my own research actually showed that individuals would actively recruit other members
to a food source when they have just discovered one. So you might ask why? Why would they
recruit a potential competitor to a food source? So
stretching the group brings benefits to each individual member by reducing
the predation risk. So by just foraging with one other individuals and groups of two,
I am already reducing my risk of being predated in case of a predation by 50 percent
and a group of five. I my personal risk of being tonight is only a six.
But you don't want to recruit too many other individuals because then
competition again increases.
So great. Thanks, Freddy. So a couple of weeks ago, when the lockdown eased and we were allowed to
go and visit our parents again, I went up to Macclesfield, to my mom's gone, and you can see that
her bird feeders are much bigger, more impressive than mine. There's two wonderful sunflower
seed feeders here together. And these birds on those feeders are goldfinches.
They're very distinctive with those red heads and those gold wing bars that give them the name.
They've become quite common in gardens. They're one of those birds are doing better in gardens now near the Twittering,
often as they go over. You can see they're also together and they often go around in flocks, especially
in winter with other finches, too. That's what Fred he was talking about. It's reducing the risk of predation.
Small birds are quite likely to get eaten by Svara Hawks. And Sparrowhawk comes to my mum's garden
at least once a week to pick off one of those small birds. Now, this bird arriving
at the sunflower seeds is something I never see in my garden, and that is a nuthatch. It almost
looks a bit like a kingfisher, the build of the bird, a big head and a long, sharp beak.
But it lives in woodlands and it loves to eat seeds and nuts and it can walk vertically down trees,
which is a pretty impressive feat when you think about it. And speaking of woodpeckers, one of the other things my
mum puts out to feed the birds is fat. It's plants fat. It's either coconut oil or peanut
fat. And this is a great spotted woodpecker. They nest nearby. They bring their
young every year to my mum's guard and the younger feeding on the fat as well. They're a bit nervous
and causes before they start feeding. And you see this jackdaw arrives and scare's they are
and it does this amazing defensive posture, but it's decided it doesn't want to fight with a jackdaw
and it leaves know if the adult may have taken the Dardar on, but the baby wasn't prepared to. Now, remember, I told
you that what's special about what my mum feeds as well as the life food. So here's me putting out some white
wax worms and some mealworms all alive, the same number of eat. I was kind of interested
in what the birds preferred. So I put them all out on the ground like this, waited for a couple of customers.
Here's the first Robin arriving. You can see it does seem to further wax MS. That doesn't take very many, but it eats.
Wanted to tie and eat them, swallows. It takes another one and then it disappears, mounts a bird feeding
itself rather than taking food for its young. Little while later, a second Robin appeared.
It does something different because it's trying to pick up every worm that it can see and it's sort of driving itself, Max.
It keeps dropping them because it speaks for. But it just can't resist trying to pick up every one that it can see. And eventually
a blue it just gets fed up of watching it and sweeps down just takes one from it. And my dad said he sometimes
watch the Blackbird literally trying to stuff 20 of these worms into its beak
and driving itself mad because it can't fit them all in. Now, finally, what I did is I put
out a little bit, a little part, and I just filmed it empty and it took about three minutes. That's all for a huge
part of these live worms to be totally emptied. I'm going to show you speeded up. My challenge is to ask
you how many birds come, what species can you see? Can you even manage to count them? SPED
up quite a lot. So I'll be impressed if you get this right.
How did you get on? Well, I counted seven blue [INAUDIBLE]. Fifteen great [INAUDIBLE].
Three robins. Four dunnarts. Just checking a map and a blackbird. Was
that a partridge in a pear tree? I didn't say one of those. And if you enjoyed that music, that is the genuine
sound of Prince Edward Island in Canada, where one of my peers, these students, Kristen Howard
Norton, is comes from and he's there at the moment. He had to go back there during the lockdown. So
thank you so much to him for doing that brilliant piece of fiddling. It's a piece called St. Anne's Skrill.
If you thought you were seeing how sparrows, by the way, you weren't a Dunnock. It does look a little bit like
a female house sparrow anyway. But they do kind of have a different way of walking and holding themselves.
And they're not a sparrow at all, although they used to sometimes be called heads sparrows.
Hello, I'm Annette Fay and I'm a seabird biologist. And today I'm going to tell you a little
bit about sea birds and how they feed seabirds. A very different mother, birds,
because they spend most of their lives at sea. And actually that means they have to feed on fish.
Some of them will catch the fish from the surface just flying above the water and catching it as it appears.
But others will actually dive sometimes very deep to catch prey.
Now, feeding can be a challenge for seabirds, especially during the breeding season, because that's the
moment where birds have to be on land to build a nest and where a cheque.
But the fish remains at sea. So what they have to do is travel between the land and the sea
to find fish for themselves and for the hungry chick. So how did they do this?
Well, the first thing is that most of them are very good flyers. And so that means they can fly very long distances
pretty quickly at a minimum cost. But another thing is that that chicks grow actually very
slowly compared to garden birds whose chicks might stay in the nest for
a couple of weeks. Seabird chicks might take months before they can leave the nest.
And that's because they only fed maybe once or twice a day, sometimes actually less than once a day.
And the parents have to make quite complex decisions when they want to decide what to feed
because often near the breeding colonies where they are, they're not actually that much good
food around. And usually the good feeding patches are further away. So imagine you have a small
supermarket with not very well stocked shelves nearby, maybe five minutes away from your house
or a much better, bigger supermarket with loads of choice in your food. But it's an hour's drive away.
You can't always go to the one very far. It would just take too much time, especially if you have one hungry
chick that you need to feed as often as you can. And so seabirds solve this problem
by alternating very short trips to the local area, which is not
so good. And that's to feed that chick as often as possible with occasional
longer trips farther out where they get better food. And that's usually for themselves.
And that is called dual foraging. Now, what's interesting is that actually
both parents feed the chicks together. And we have noticed that the parents seem to alternate
who's on which duty. So while one parents will be on short trips feeding the chick, the other one will go
on a long trip to feed itself and then they'll swap. And that way, then once the chick is never not fed
for a very long period of time. Now I see loads of different seabird
species, but my favourite and the one I know most is the Atlantic Puffin. That's not
hunting for food here. The very beautiful seabirds with a big, colourful beak. And you can find them
all around the North Atlantic, including in the U.K. But we don't know very much
about their feeding ecology by feeding ecology. I mean, everything has to do with feeding where
they feed, what type of fish they eat and so on. So to try and find out more about
this, I did a study where we use these really, really, really small trackers here. They only
wear a couple of grams and we put these on the back of a fence and they'll measure for about a week
whether birds are going to feed. And I also put some camera traps on the colony tops of the bird behaviour.
When am I coming back to the nest to feed that chick? Now I'm going to share a few videos with you
to show you what we found. So the first video illustrates the trips of a few puffins
from Schoeman Islands in Wales going out to feed at sea. And every point on it, on the video
is a different bird. And you can see these birds actually good feed quite far, even up to 75
kilometres away. That's 150 kilometres and a single trip to get food either for themselves
or for the chick. Now, the next video actually shows you a bird coming back to its nest
with some fish in its big voice chick. And you can see it looks around and then it zooms into the bow very quickly.
And you might wonder why that is. Well, the answer is on the next video, because actually there are goals around
the colony and they're just waiting for the puffins to come back to scare them off and steal their fish.
So the puffins when to come in, in their nests before the girls can get to them. And it's not just the big birds
like those that do this. The next video I recorded in Iceland and actually there it was
the very small Arctic tern. They were mobbing the puffins to try and steal their fish.
And as you see on this video, they succeeded. Now, this really helped us understand more about
the fitting ecology of puffins. But they will say one thing we do know, and that was what the adults who actually eating
because we can only see were they carrying back to the chick. And to do this, we actually collecting some
of their poop. And you can see on this video, that's how it works. And essentially what we did with this poop is we could
look at the DNA in the faeces and identify what prey these were. And
that's called DNA barcoding. And we could actually work out what the adult puffin had
eaten based on this. And actually what we found was that mostly the adults were eating the same thing
as that chicks. And so by combining all these techniques, the tracking
with the camera traps and the DNA barcoding, we could finally get insight
into the feeding behaviour of these seabirds. Okay.
A huge thanks to Freddie. And to our net for sharing their research with us. I hope you enjoyed learning
about that. And I hope you will be feeding the birds in your garden. You can still put food
at all times of year. And the RSPB say that's okay. The parent birds know what they're
doing and they generally won't feed their chicks anything inappropriate. I still have birds coming
to my feeders. The young birds especially. They're fattening up around August time. You see
them really drop off. And I don't quite know where they go if they go off to the countryside to law and feed on other foods
and the gardens seem to be empty, but of course, they'll be back come autumn and winter. So get
stocking up on food. So that's it from back garden biology this week. I'm not quite sure how many more of
these I'm going to make now that lockdown's finished, but I do hope you've enjoyed watching them. If you've
been a regular viewer.