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Animal Special Abilities
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AnimalsTranscript
00:06Every species has special abilities
00:10Some can regrow lost body parts
00:13Others live in places humans would fear to tread
00:17And many are a lot smarter than you probably think
00:21Even the humble shrew can do something truly extraordinary
00:28Learn what in just one of the exciting stories
00:31Coming up on DW's Science Show
00:33Welcome to Tomorrow Today
00:38Let's have a drum roll please for shrews
00:43Scientific name, Saricidae
00:46A pint-sized animal with some seriously big talents
00:49So she is a super animal
00:52Because she can shrink in size in winter
00:57And then regrow in size
00:59And by size I mean body, brain, bones, everything
01:04That makes the common shrew a fascinating research subject
01:08For behavioral biologists like Cecilia Baldoni
01:12Will any end up in her traps today?
01:15The elusive little critter looks a lot like a mouse
01:19But it's actually more closely related to hedgehogs and moles
01:23Shrews eat insects pretty much non-stop
01:28We have to check them very often
01:30Because the shrews have to eat every two hours, average
01:33And also they don't do well if they are confined
01:37In a very small place for a long time
01:39So what we do, depending on the season
01:42We check them between one and a half and two hours
01:46The little mammals only weigh around eight grams
01:50And they have to eat about that amount of food every day
01:53In summer that's no problem
01:55But winter is a different story
01:57They cannot hibernate
01:59They cannot use torpor like bats, for example
02:02They cannot migrate
02:04They are too tiny to go anywhere
02:05So they have to stick to the place they are born
02:09And they have to survive winter
02:11So what happens is that they shrink in size
02:14To conserve, we think, is to conserve energy
02:18Playing a key role in this process
02:21Is a part of the brain called the hypothalamus
02:23It responds to cold
02:25And sends signals that activate certain genes
02:28Those act like switches
02:30Causing the brain, organs, and even the skeleton to shrink
02:36A smaller body requires less food to survive
02:41In spring, the process is reversed
02:44And the shrew's brain, organs, and bones
02:47Return to almost their original size
02:53During the winter, the shrew's brain can shrink by up to 20%
02:58What does that mean for the animal?
03:01Does having a smaller brain make it slower or less intelligent?
03:04To find out, Cecilia Baldoni built a maze
03:08And tested both small winter shrews and larger summer shrews
03:12As the year progressed
03:13The results are surprising
03:15In the maze that we saw
03:19You cannot distinguish the summer shrew from the winter shrew
03:23Which is very interesting
03:25Because the brain size is different between the two
03:30Despite their shrunken brains
03:32Winter shrews showed little cognitive impairment
03:35It took a different experiment to reveal clear differences between summer and winter specimens
03:43In the past we did Y-Maze
03:46They had to associate food reward with smell
03:51And in that they were not really performing that well
03:55In winter
03:55But maybe they don't need to do that in winter
03:59They don't need that kind of cognitive abilities
04:02But they still need to navigate their environment
04:06But how exactly does the shrew shrink its brain
04:09And more importantly, grow it back?
04:14To find out, Dominik von Elverfeld examines them in an MRI scanner
04:21The crazy thing is, I think, that really, it flattens, right?
04:26It flattens, yeah
04:26And what flattens is the skull
04:30The physicist is helping tackle some unresolved questions
04:36The first question is, what shrinks in the brain?
04:41Which areas and how?
04:43That was our big question
04:45Even more exciting is how it grows back
04:48But first we wanted to know precisely what shrinks
04:52After a comprehensive series of tests
04:55He determined that even though the shrew's brain shrinks
04:58The number of cells in it remains stable
05:01And the axons that connect them remain intact
05:04But there's a crucial difference
05:08We found that the volume inside the cells falls
05:12Compared to the volume outside them
05:14Meaning that compared to the summer
05:15In winter there's more water outside the cells than inside
05:21What's so special about that?
05:25A cell that senses something is wrong
05:27Normally kills itself
05:29But in this case, self-destruction doesn't occur
05:32Even though the cell shrinks
05:34This insight could be incredibly valuable
05:37For many neurological diseases
05:39Like Parkinson's, Huntington's, or Alzheimer's
05:43If we could find a way to trigger renewal in cells
05:47And increase their volume again
05:49That could be a huge breakthrough
05:55Researchers are therefore very interested
05:57In being able to stop programmed cell death
06:01Today, Cecilia Baldoni is talking with her Danish colleague
06:05John-Erik Nieland
06:06The medical researcher was able to show
06:10That cell death doesn't happen
06:12During the shrew's seasonal cycle
06:14How exactly they are doing it
06:17So that's what we now have to try to mimic
06:19In these animal modes
06:21And see if we can find medicine
06:23Or other ways of modulating exactly the proteins
06:26We see happening in the regrowth phase
06:31And if we can redo that in the animal studies
06:35With different brain diseases
06:37And see if we can get the same effects
07:07The common shrew's incredible shrinking brain
07:10The shrew can pass the pathogen on to sheep or horses
07:14It's still not clear how humans get infected
07:16Around half of the roughly 1,500 human pathogens
07:20Originally jumped to us from animals
07:22Researchers estimate
07:24They're now trying to stop these zoonotic diseases
07:27With an approach called One Health
07:34When will the next pandemic begin?
07:37Scientists can't predict the future
07:38But they can study how a disease called a zoonosis
07:41Can jump from animals like chimpanzees to humans
07:44Can the One Health concept help reduce risk?
07:48Simply ignoring the threat is a bad idea
07:51We are so many people on this planet
07:53We are closely connected
07:54We are in contact with nature
07:56And so we are dreaming for every virus
07:58So there will be an next pandemic when?
08:01I don't know
08:02This is Fabian Lehndatz
08:04He's a veterinarian
08:06And the founding director of the Helmholtz Institute for One Health
08:09In Greifswald
08:10In northeast Germany
08:14So One Health is a concept
08:16Which says you need to look at
08:18Humans, animals, environment and climate
08:20The approach views human, animal and environmental health
08:24As parts of a whole
08:25Its goal is to minimize health threats
08:28But it's not like you're solving all problems or questions at once
08:33So you can use this concept to tackle specific questions
08:37Such as how do infectious diseases emerge?
08:41Thai National Park in Ivory Coast
08:44Several decades ago, researchers began monitoring the chimpanzees here
08:48In response to the apes dying prematurely
08:51Teams performed autopsies in the forest to identify and trace the pathogen that was killing the animals
08:57Nowadays, such autopsies are routine
09:01Samples from bats, rodents and other smaller mammals in the park are also taken regularly
09:06Because the apes can catch infections from them
09:11The samples collected in the wild end up in the lab
09:17Where they are stored at minus 80 degrees Celsius
09:20It's a six-hour drive from the park
09:28The lab is located in Buakki, in the heart of Ivory Coast
09:35It's a young city
09:36Though founded only a little over a century ago
09:39It now has a population of 1.5 million people
09:43At its center is the Buakki University Hospital
09:46A scientist from the Helmholtz Institute for One Health is here today
09:53Veterinarian Franziska Stöck
09:55What does she advise when it comes to pandemic prevention?
10:00To prevent a pandemic, there are different approaches
10:05Different ways of doing things
10:09Our approach is to be on-site, collecting data regularly
10:13And collecting it over a long period of time
10:19That way you can spot trends early on, when changes begin to appear
10:24You're not surprised when something happens
10:27Because you have continuous data that's been gathered regularly for some time
10:32And can see the small shifts that have been going on
10:42The researchers from Greifswald have been working with their colleagues in Buakki
10:46For more than 20 years, sometimes providing training, too
10:51Using a range of methods, the scientists analyze samples from humans and animals in the lab
10:58Microbiologist Augustin Etilé-Annaud explains the technology
11:03For example, this portable sequencing device determines DNA sequences in a sample
11:08For identifying particular diseases
11:11Ezoanosis is a disease caused by a pathogen that is transmitted naturally from animals to humans
11:19The infectious microbes can be viruses, bacteria, fungi or other parasites
11:27They might initially infect bats, cattle, chickens or apes
11:31Before jumping to humans in a variety of ways
11:34Via direct contact, a bite from an infected animal
11:38Or eating contaminated meat, but also via mosquitoes
11:43If infected people then pass a pathogen on to others
11:47It can spark an epidemic or even a pandemic
11:51Zoonoses are responsible for most existing and emerging infectious diseases
11:56So studying transmission routes is vital
11:59Even if it's sometimes not very pretty to watch
12:02Chimpanzees, but also other monkeys, are predators
12:06And when they hunt, they don't always do it in the most gentle way
12:11That's part of nature
12:13And it's sometimes hard to see
12:16In this scene from Thay National Park
12:18Isodi Mangabe devours a kind of squirrel that it's caught
12:22Primates mostly eat fruits, seeds and plants
12:25But sometimes consume small animals as well
12:28Along with the Mpox viruses they might carry
12:33Two years ago, four young Manga bees died from the disease
12:38We observed symptoms of Mpox, monkeypox, these monkeys
12:44And so we asked the question, were the squirrels the source of infection?
12:49So we have the video, we knew the monkeys were positive for monkeypox
12:54And so we then went back into the feces, which we collect routinely
12:59In any case, every day, every week we collect
13:02And so we could show genetically that the monkeybees had eaten a squirrel
13:07Because you find the DNA of the squirrel in the feces
13:09And we could also show that the squirrel in the same sample
13:14There was monkeypox DNA
13:15This was the first time that someone has really shown
13:18That there is a transmission caught in the egg, basically
13:24And for almost none of the other pathogens we know about
13:27This has ever been done
13:29Humans can also catch Mpox
13:32A virus that causes painful lesions and swollen lymph nodes
13:35It's been detected in many parts of the world
13:38But originated in the rainforests of Africa
13:40It likely jumped to humans via a direct contact
13:44A bite from an infected animal
13:46Or from infected meat
13:48You cannot tell people that's a risk if they don't perceive it as a risk
13:53So that's where we work a lot with people from colleagues from social science, anthropologists
13:58The One Health approach, researchers from different fields work together
14:03To find out what people think about disease
14:07What do they think about a risk associated with, for example, eating a monkey
14:11You find dead in the forest
14:12And from there you can start and say
14:14You know that in those schools you find Mpox
14:17And remember last week or last year you had a case of Mpox in your village
14:21And connect that
14:22And then together with people you can develop a program
14:26That they become aware of the risks
14:28That they say, okay, let's not do things like that or that
14:32Or let's have a campaign, for example, in the schools or on the radio
14:36To inform people about certain risks
14:41So whether pathogens spread depends, at least in part, on our behavior
14:46Back at Buake University Hospital
14:49They know that Mpox isn't the only infectious disease to crop up in Ivory Coast
14:53Leprosy and anthrax have also made appearances
14:57The key is to detect infection chains early and prevent the respective disease from spreading
15:03His team is prepared, says Obi Waioro
15:06He's a microbiologist who works with the Helmholtz Institute for One Health in Buake
15:12We're all ready to respond to any epidemic, whether Ebola or COVID
15:17If it were to make a comeback, I think we're still prepared to handle it
15:21Because we have a mobile lab
15:23So we don't need to wait for samples to come to us
15:27We can deploy to endemic areas with our equipment and tools
15:31Run our diagnostics and then come back at our leisure
15:34I say the lab is ready for anything and we're prepared for any epidemic
15:39Because here we have resources like reagents to deal with arboviruses, hemorrhagic fever and other diseases
15:50So the lab is well equipped to track pathogens
15:55Franziska Stöck thinks the differences between the Buake lab and the one back in Greifswald are many more
16:05Sometimes we use different reagents
16:08So we need to change the protocols slightly
16:10To make some adjustments and check to make sure everything still works well
16:16Of course it's much hotter here
16:18So that makes it even more important to maintain, what do you call it?
16:23The cold chain
16:24So there are a few small details that are a bit different
16:29We head next to a lake west of Buake
16:32A water treatment plant is located here
16:35But locals also fish, bathe and wash in the lake
16:39The researchers take samples to test for antibiotic-resistant bacteria
16:45The setting illustrates the idea behind the One Health concept
16:49How environment, humans and animals are all interconnected
16:58Here you can clearly see that cattle come here to drink
17:01So it's a good example of the interaction between the animals and the water
17:08And these are the same animals the people here slaughter and eat
17:11And they drink the water here too
17:13So there's a certain amount of interaction between humans, animals and the environment
17:18That means for instance that enterobacteria found in this water could also end up in food
17:24And pose a serious health threat to the general population
17:30Is One Health's approach in Ivory Coast a model for other regions?
17:34The goal is with those One Health observatories to create a template
17:38Which can be copied by others
17:40Or if we have enough money we can also do it in other regions of the world
17:44And many colleagues are interested
17:46From Latin America we have already been contacted
17:49To Asia and further regions in Africa
17:52So the interest is there
17:54And that's the idea
17:55And in the end hopefully there will be like a network
17:58Of these One Health weather stations around the world
18:01Because then that allows us to also identify the bigger trends
18:05Then you're not only focused on one side
18:07You learn from that
18:09You show what works, what doesn't work
18:10But you can also then, you know, look at global trends
18:14That would be the dream
18:16But let's see if I'm still alive when that happens
18:20Utopian dreams can help spur discoveries in science
18:23But this work will help prevent future pandemics in very concrete ways
18:32One reason pandemics are hard to prevent
18:34Is that some animals that carry zoonotic diseases don't stay in one place
18:39Many birds, for instance, are migratory
18:42Crossing continents in flights that cover thousands of kilometres
18:46And all because of a special ability
18:48That we humans have tried to copy over and over again throughout history
18:53A viewer from India wanted to know more
18:56About why they can break the bonds of Earth
18:58And we can't
19:04Why can't humans fly like birds?
19:07It's a dream as old as humanity itself
19:10The ancient Greeks even had a myth about it
19:14But Icarus didn't have a happy end
19:18Still, technology has come a long way since then
19:21We have plenty of different ways to take to the air
19:24So, why can't we just build strap-on wings and fly off?
19:29What have birds got that we don't?
19:33Well, as it turns out, quite a lot
19:37First, they have skeletons that are extremely strong
19:40But also very light
19:42Many of the bones that humans have
19:44Are either fused together in birds for extra strength
19:47Or missing entirely
19:49And in some species, the bones are actually hollow in places
19:55That saves weight
19:56And provides a place to pack in some extra air
20:00Which birds need to fuel their high metabolism
20:04Flying takes so much oxygen
20:06That 15 to 20 percent of the average bird's body
20:09Is devoted to its complicated, spread-out respiratory system
20:13In humans, it accounts for only around 5 percent
20:18Then there are the actual mechanics of flight
20:21Keeping even a tiny bird in the air
20:24Requires some highly specialized body parts
20:27Like the keel
20:29A large breastbone that acts as an anchor
20:32For the animal's huge flight muscles
20:34In hummingbirds, these pectorals
20:37Can make up a staggering 30 percent of total body weight
20:41And there are, of course, the wings themselves
20:44Covered with different kinds of feathers
20:47That birds can adjust and control
20:49By changing the shape of their wings
20:52During upstroke and downstroke
20:54They can generate both the lift
20:56That keeps them in the air
20:57And the thrust that moves them forward
21:00So even though humans have tried
21:02To take to the air for ages
21:04Bird flight is so dependent
21:06On so many specially evolved traits
21:09That we'll never be able to do it like they do
21:12But even knowing that doesn't stop some people from trying
21:16And with a little help from technology
21:18You can get pretty close nowadays
21:20The dream lives on
21:26Having the ability to fly might be cool
21:29But what really counts is having a big brain
21:32Right?
21:33After all, that's what's driven evolutionary success in us humans
21:38But we're far from the only intelligent species out there
21:42And even among birds, a few stand out for their smarts
21:46Like crows, for example
21:48They might have brains only the size of a walnut
21:51But they can use tools
21:53Solve complex puzzles, count
21:55And even recognize and build relationships with humans
21:58At least with those who make it worth their while
22:04A crow on a window ledge
22:06On the campus of Frankfurt University Hospital
22:09At first glance, nothing unusual
22:11Or is it?
22:14The bird is actually letting its human friend inside
22:17Know it's arrived
22:19The crow stops by every day
22:21To enjoy a handful of tasty nuts
22:25We show the footage to ornithologist Bernd Petry
22:29He's surprised, but not overly so
22:36It's really unusual
22:37But it's also yet another example
22:39Of how a crow gets used to someone
22:41And recognizes them
22:43They're good at that
22:44They see eyebrows, eyes, mouth, nose
22:47They know straight away
22:49Whether they're looking at Mr. Schmidt or Mr. Schultz
22:52They're smart, intelligent and fast learners
22:55And this crow realized at some point
22:57That this human was friendly and offered food
23:00Then it lost its fear of them
23:03The man behind the window
23:05Isn't actually named Schmidt or Schultz
23:08He prefers to remain anonymous
23:10But we're still allowed to tell his story in our report
23:17The friendship began at his home near the hospital
23:20He first saw the crow
23:22When it began pulling things out of the compost bin on his terrace
23:26He decided to start feeding it
23:29And before long, something astonishing happened
23:32It showed up at his place of work
23:37The crow must have thought
23:39Hey, that guy is going out
23:41So it followed him
23:42Watched where he went
23:43And saw him going inside
23:45Probably at some point
23:47He opened a window in the building
23:49And the crow recognized him
23:50He fed it again
23:51And that was the connection
23:56Crows have far more talents than you might think
24:00This is a carrion crow
24:04Crows and ravens are at the top of the evolutionary ladder in the bird world
24:08They're highly developed, really intelligent and excellent learners
24:12They can think outside the box
24:15Shift perspectives
24:16Anticipate what another animal might do
24:19Or even what they might be thinking
24:24Bernd Petry knows a lot about crows
24:27He's felt drawn to them for a long time
24:34As a child, I loved spending time outside
24:37Especially in winter
24:38I'd be out with my sled
24:40And suddenly see clouds of black birds
24:43Crows everywhere
24:46I loved watching crows so much
24:48That I became an ornithologist
24:50And studied them
24:55He also led us to this spot
24:58Where huge numbers of the birds gather in the evenings
25:01A spectacular sight
25:07But back to the university hospital crow
25:09How long could the friendship between man and bird last?
25:15As long as this crow lives
25:19It will keep visiting this window
25:21Keep looking for this man
25:22And if he keeps being kind and feeding her
25:25It will last a lifetime
25:27Until one of them dies
25:33So, as long as they both shall live
25:36The bonds of affection can last up to 15 years
25:40A carrion crow's maximum lifespan
25:44Just like in humans
25:45The way to the bird's heart
25:47Is through its stomach
25:52That's all we have time for now
25:54But thanks for joining us
25:55And we look forward to seeing you again soon
25:58On Tomorrow Today
25:59Bye-bye
26:05I'll see you again soon
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