00:00:13
Are you familiar with the word symbiosis?
00:00:15
It's a fancy term for a partnership between two different species,
00:00:18
such as bees and flowers.
00:00:21
In a symbiosis, both species depend on each other.
00:00:24
I want to tell you about a remarkable symbiosis
00:00:27
between a little bird, the Clark's Nutcracker,
00:00:30
and a big tree, the Whitebark Pine.
00:00:33
Whitebark grow in the mountains of Wyoming, Montana and other western states.
00:00:36
They have huge canopies and lots of needles,
00:00:39
which provide cover and shelter for other plants and animals,
00:00:42
and Whitebark feed the forest.
00:00:45
Their cones are packed with protein.
00:00:47
Squirrels gnaw the cones from the upper branches
00:00:49
so they fall to the ground,
00:00:51
and then race down to bury them in piles, or middens.
00:00:54
But they don't get to keep all of them;
00:00:57
grizzlies and black bears love finding middens.
00:01:00
But there's more to a symbiosis than one species feeding another.
00:01:03
In the case of the Clark's Nutcracker, this bird gives back.
00:01:06
While gathering its seeds, it also replants the trees.
00:01:09
Here's how it works: using her powerful beak,
00:01:12
the Nutcracker picks apart a cone in a treetop,
00:01:15
pulling out the seeds. She can store up to 80 of them in a pouch in her throat.
00:01:19
Then she flies through the forest, looking for a place to cache the seeds
00:01:22
an inch under the soil in piles of up to eight seeds.
00:01:26
Nutcrackers can gather up to 90,000 seeds in the autumn,
00:01:29
which they return for in the winter and spring.
00:01:32
And these birds are smart. They remember where all those seeds are.
00:01:35
They even use landmarks on the landscape --
00:01:38
trees, stumps, rocks --
00:01:41
to triangulate to caches buried deep under the snow.
00:01:43
What they don't go back and get, those seeds become Whitebark.
00:01:46
This symbiosis is so important to both species
00:01:50
that they've changed, or evolved, to suit each other.
00:01:53
Nutcrackers have developed long, tough beaks
00:01:56
for extracting seeds from cones,
00:01:59
and Whitebarks' branches all sweep upwards
00:02:02
with the cones at the very ends, so they can offer them to the Nutcrackers as they fly by.
00:02:05
Now, that's a symbiosis:
00:02:08
Two species cooperating to help each other for the benefit of all.
русский▼
English
