[INTRO MUSIC] So last time, we put a polar bear in the
desert, and I still feel bad about that. The good news is that in real life, a polar bear
probably won’t just wander into the Sahara. But not everything stays in the same habitat all the time. A new species might come into a
habitat, a species might die off. Even the habitats themselves can change
as a result of things like floods and droughts. The point is, habitats, and the food webs they support, can get out of whack and sometimes, it’s not pretty. Let’s look at what happens when
an ecosystem gets out of balance. Last week, we learned that a habitat is home
to a tangle of food chains called food webs. The animals depend on each other for food,
but they don’t just need each other; they rely on the nonliving things in the habitat too. This interaction of living and nonliving
things in a habitat is called an ecosystem. The things in an ecosystem are all connected, just like when you touch one part of a
spiderweb and the whole thing vibrates. When one link in the food web is threatened,
it can shake up the whole ecosystem. Let’s see what might happen, for example,
if an ecosystem loses a species. Since we’re talking about food webs, I
think we should look at spider monkeys. They’re called spider monkeys because they hang
upside down from their tails with their arms and legs dangling – this is somehow completely adorable. These primates live in a tropical rainforest habitat, which is just bursting with some of the coolest
creatures out there; toucans, jaguars, sloths… As we learned last time, these
animals need each other to survive. And spider monkeys happen to play a particularly
important role in the rainforest food web: they eat mostly fruit, which contains seeds, and we know that seeds are how plants make more plants. When a spider monkey snacks on a
berry, he gets to enjoy the tasty fruit while also doing the plant a solid favor. When the monkey moves on to another part of the forest
and, um, passes the fruit, he leaves the seeds behind. Wait a while and then, voila! You have a new plant. Imagine thousands of monkeys eating
thousands of fruits every day. More monkeys equals more plants and trees. Those trees support lots of other animals:
insects and sloths eat those plants too. And more spider monkeys, insects and
sloths mean more food for carnivores. Leopards dine on the sloths and spider
monkeys, while frogs eat the insects, and of course our decomposers like fungi and
bacteria break down leftover plant and animal matter, so we’re talking around 50,000 plant and
animal species that rely on these plants. Now imagine the spider monkey
population starts to decline; maybe they’re hit with a strange new disease,
or maybe humans over-hunt them. If the monkeys aren’t around to eat the
fruit, then the seeds aren’t scattered around, and the forest stops growing,
leaving fewer fruits for fewer monkeys. Not only that – fewer plants means less food for
other animals, like insects and our sloth friends. That means the insect and
sloth numbers start to decline, and that means less food for the animals that eat them. All of a sudden, none of the animals
in our ecosystem have enough to eat, all because of the loss of one species. Do you see how this could get really bad? Remove one piece of the food web, and
you might knock down the whole thing. That’s bad news for us, too. The good news is that
ecosystems WANT to be in balance. After a natural disaster like a forest fire or
a flood, things might be wacky for a while, but habitats can usually get back to normal. But, if things get really bad, the
habitat might change forever: the old species will leave, searching for a
better place to live, new species will come in. Life will keep going, but it won’t look the same. In every ecosystem, the plants
and animals are connected; you can’t mess with one species
without affecting all the others. Food webs are delicate, like spiderwebs. We don’t want
to be all crazy pants and just go knocking them down. [OUTRO MUSIC ]
what if the top predator's species die off, would the whole food chain be affected?
Well that's good to know. π
crash course kids is amazing i love it . your amazing
i live in hawaii and i,m 8 years old
I used this video for an FQR
Ur good but u kind of talk too fast
I can't stop looking at her hands.
Here. Here and so on and so on and back there. There and back. Kind of mix them. Hold the bottom and slice off the top.
My class teacher totally lives on crash course
Need to learn about food: crash course
Need to learn how to recycle : crash course
Crash course this and crash that
But its true
wow it's amazing. I have my exams after 2 days and your chanel is helping me a lot
Jones ka Dallas kun he dos..
I'm here from Diana fisher my 3rd grade student teacher (my worst enemy) I knew I could read minds i knew she was Diana. So chances are this is her considering all of the 3rd grade videos in her playlists so by chance this could be her
Holy shiz this channel is helping me sm
love your vids so much im six year old need to learn
thank you for the info
thank you
shut up
is she Filipino? she kinda looks like my teacher in chemistry. they both have the same hair π
shuddup penis head
awsome
awsome foxygirl forever
thank you for making this vioe
nice video
good video i'm learning that !
lol
why why why!
Thank u
I β€οΈ these videos of Crash Course
hi
Teacher Here, Your videos are good but you talk wayyyy to fast for kids. Your animations seem based on a young audience K-8th grade but you are incomprehensible to them.
huh well done its fuuuuuuuuuuuuuuuuuuuuuunnnnnnnnnnnnnnnnnnnnnnnn!!!!!!!!!!!!!!!!!!
The first 56 seconds was really all I needed
why is there adventure time references and mario?
Shelby and the mushroom with fin
why did you put the polar bear in the dessert and i subscribed
boiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
I saw Finn haha
Had to watch on .75 speed
i love ucrash cours ekids
thanks it helped alot! πππ
my teacher showed this to me…and how dare u hurt the polar bear? XD
U talk to fast!
I CANT KEEP UP AAH!!!?
This is so cool π
thanks to help me get the maximum grade XD
XDDDDDDDDDDDDDDDDDD
My teacher showed us this and i forgot about ut so then i watched it again. π
XD
make more vidoes
you are so bad
dis cool
nice
I like the video yet you talk very fast for kids to follow along.
tiny tardis <3
pls talk slower
But good ep
I found the hiden things.
THIS DIDNT HELP ME >:0
I only watch this video to study for an exam
why do i love this so much this video helped me with my project. thanks
ough this was posted on 2015 now its 2018 hmph sorry
i love her vidioes
shut your mouth
The food web the end with decomposer …she say rain forest ecosystem …
Desert ecosystem.
WHY DID YOU STOP POSTING VIDEOS YOUR VIDEOS HELPED MR IN SCHOOL SO MUCH
I did not understand this
youε·
Hi teacher
Why does she talk so fast,Iβm a teenager and I canβt keep up
Wish Sabrina was my teacher
I showed teacher my science trivia which is this and she said very nice trivia we all listened to your video. Btw i love your intro!!
Great for kids
My classroom loves your channel do more videos
Very interesting and exciting to learn about.
I use these with my students. We love them. The kids like the surprise of characters in the background. I wish you had 3rd grade and 4th grade aligned videos for science. I have a special education classroom for 3-5th grade.
im i n the middle of class right now
hello
Im in connors guy class
L
Mario mushroom
LMAO I'M DYING XD DAB DAB YEET SKRRT LOL RELATABLE!!!!
I LOVE YOUR VIDEOS SABRINA πππ
I will sub to whoever subbs to my channle
not that coooooooooooooooooooooooooooooooooooooooooooooooooool boring!!!!!!!!!!!!!!!!!!!!!!!!!!
You talk to much
yes
YOU ARE SO GOOD AT THIS.
Your videos make learning so much easier!
Gayest shit ever seeen
you suck
i am in 6 bro
#watchingthisat2019
Your cute
2:04 lol
You saved me from my science project
Meeeeeeep
ur eyebrows be buggin' me for no reason ana ou-
im not cool and neither is anyone in this world
did you see plankton from spongebob
Eating a peanut butter and onion sandwich to calm the mind whilst watching this.
https://chrome.google.com/webstore/detail/threelly-ai-for-youtube/dfohlnjmjiipcppekkbhbabjbnikkibo
Thank you for helping me pass 5th grade π
My science exam is tomorrow and I was literally freaking out…
until now :):)
dgf=]i pim-9
Make more videos
hey this is perfect for my class thanks