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Ecosystem dynamics: Clark’s nutcrackers and the white bark pine
Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations. Created by Khan Academy.
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- how will this help me in the real world ?(25 votes)
- facts Tho I don't think it will(9 votes)
- how will this help me ?(5 votes)
- This will help you understand the dynamics of ecosystems in general, every ecosystem has a dynamic.(14 votes)
- The climate in alpine ecosystems is too harsh to support tree growth then how come pine trees seem to be present in this particular ecosystem? Or is it only a small number of tree species that are allowed to grow?(7 votes)
- I am not a hundred percent sure, but I imagine certain kinds of trees can grow in that environment.(1 vote)
- lol i'm a dancer and i'm doing the nutcracker soon... am i the only one who thought the nutcracker bird is super fascinating?(3 votes)
- How will this help me outside of school ?(3 votes)
- if you decide to become a biologist than this would be good on your collage application.(2 votes)
- But wouldn't all the seeds that the Nutcrackers put in there cache be turned into trees?(2 votes)
- No, some of the seeds will be eaten by the Nutcracker or other animals that find the cache such as squirrels or other birds. The seeds that don't get eaten might sprout but there is also a chance they might not recieve enough water or sunlight to germinate.(4 votes)
- whats the point of this vid?(2 votes)
- the point Is for the other tests and quizzes.(2 votes)
- So what if a person can't hear it ←_←
😂(2 votes)- They can imagine what it sounds like.(2 votes)
- If the pines disappear, will the other species decline in population or will they adapt and find a new food source?(2 votes)
- The other populations would decline but survive.(1 vote)
- CLARK's nutcracker is beutiful(2 votes)
Video transcript
(bird caws) - [Instructor] What's that? That sound? (bird caws) That call sounds like
something a crow would make, but not quite. That's actually the call of
a really interesting bird called Clark's nutcracker. These birds are cousins
of the American crow, which you might see and
hear around where you live, except that the Clark's
nutcrackers like to live up in the mountains in alpine ecosystems in the Western United States, where the winters are pretty
harsh with lots of snow and there are lots of evergreen
trees, like pine trees, which keep their leaves
all throughout the year. But what would this bird possibly eat in this kind of ecosystem? I'll give you a hint.
It's in the bird's name. Turns out that Clark's
nutcrackers love eating seeds, and not just any seeds, but mainly the seeds of
pine trees, like this one, the whitebark pine. And it's actually good for the trees that nutcrackers eat those seeds. Wait. What? Let's take a look at the whitebark pine. These trees have cones,
which hold their seeds. Other pine-tree species
have cones that will open when the temperature is warm enough or if the air is especially dry or when the cone is exposed to fire, but for the whitebark pine, their cones don't open on their own. Instead, the cones have to be pried open, and the Clark's nutcracker that does this as it looks for seeds to eat. But the nutcracker doesn't
just eat the seeds. It stores them in what's called
a cache, or a safe place, where they store the
seeds to eat them later. Remember, these birds live
in an alpine ecosystem, where the spring and
summer are pretty warm and there's lots to eat, but the winters are cold and
long with very little to eat. So the nutcrackers have to stock up. In fact, the nutcrackers will
cache up to 100,000 seeds in a single year. I can't remember where I
put my phone half the time. But the nutcrackers don't
retrieve all of these seeds. Many of the caches won't
be used by the nutcrackers, so those seed germinate and
grow into new whitebark pines, and the cycle continues. Nutcrackers rely on whitebark pines as an important food source, and the whitebark pines
rely on nutcrackers to plant their seeds. And on top of that, more
than 100 other alpine species of plants and animals benefit
from that relationship between the Clark's nutcracker
and the whitebark pine. For example, Douglas
squirrels will also eat seeds from whitebark pine cones
and mountain bluebirds and northern flickers may nest
in the whitebark pine, too. When you look at it, all
of these interactions that occur in this all pine
ecosystem are like a web. Each population interacts
with many other populations, and each population is affected by non-living parts of the environment like temperature and snowfall. So a change in any one
part of an ecosystem can lead to changes in many of
the ecosystem's populations. For example, if something
happens to the nutcrackers and their population starts to decline, that could cause some big
problems for the pines that need these birds
to plant their seeds. In turn, if the whitebark
pine starts to decline, too, that can have negative impacts on all the other species
that rely on this tree, like squirrels, bluebirds, and flickers. Even though it seems like
a perfect relationship between the nutcracker and the
pine in the alpine ecosystem, every ecosystem is dynamic, meaning that parts of the ecosystem, both living and non-living, can and probably will change over time. Sometimes, ecosystems might
experience a negative change, like a disruption. Maybe it's a particularly
harsh and cold spring, and there aren't as many cones and seeds for the nutcrackers to cache. Changes like that can make it harder for individual nutcrackers
to survive and raise chicks, which can cause nutcracker
populations to get smaller. But on the other hand,
other types of changes can help individuals in a population. For example, if the ecosystem experienced
a particularly warm spring after a wet winter, there would
be lots of available food. These types of changes
can cause more individuals to survive, have offspring,
and increase their population. Clark's nutcrackers and their relationship to the hard-to-open cones
of the whitebark pine are just one example of
the kind of relationships that drive many different ecosystems. Just like how a decrease
in nutcracker populations could cause problems
for the whitebark pine and other species in the ecosystem, a change to one species in any ecosystem can impact a whole web of
interconnected organisms. So next time you're outside
and hear the call of a bird, think about all of the
interactions that bird has with other parts of its ecosystem. These relationships are all
part of the complicated web that is life on Earth. (bird caws)