BBC Wildlife - UK (2019-12)

BBC Wildlife December 2019 Seven Worlds, One Planet

W LRUSES

25

NORTH AMERICA

FIELD NOTES

T

Po

arbears:

BBC

NHU

Whilefilmingpolarbearshijackingbeluga

whalesinHudsonBay,theteamhada day

whenthingsdidnotgotoplan.A polarbearhad

pickeduptheanchoroftheirboatandwas

reelingtheminwhentheboatsnaggedona

rock.JohnShierwasoneofthecrew.

“Askyourselfthis:what’stheworstthingthat

canhappentoa smallboat,surroundedby

swimmingpolarbears,withfourguysand

about$800,000worthoffilmequipmenton

board?I wouldsayit’srunningagroundona

rock,withthetidedroppingrapidlyanda polar

bearswimminga coupleofhundredmetres

away.And,that’sexactlywhathappened.

Gunningthemotordidn’tbudgetheboat,and

pushingothebottomwithoarsdidn’thelp.

Therewasnothingelseforit,I hadtojumpinto

thecoldwater.Withmeunderthebowpushing

andtheskipperpullingonthestern,wewere

freeagain.Therewasbarelyenoughwaterfor

ustomakeourescape.It wasonlyafterI

clamberedbackonboardthatit dawnedon

me:I hadswamwitha polarbear!”

CameramanJohnShier

hadtothinkfastwhena bear

grabbed his boat’s anchor.

he third largest continent

is North America. It occupies about

16.5 per cent of the world’s landmass

and, like Asia, it extends from the

Arctic to the tropics. The big difference

is its especially extreme weather, which

is all down to its geography.

In Asia, the major mountain

chains run in an east–west direction,

but in North America, the Rockies

and Appalachians are aligned

north–south. In between are the vast

grasslands of the Great Plains and

a complex of very different wildlife

habitats, from steppe in the north

and hot deserts in the southwest to

swamps and bayous in the south

and southeast. It means that, with

nothing to impede it, cold polar air

can barrel down towards the Gulf

of Mexico, where it meets warm

air from the tropics.

The result is tornadoes.

The USA experiences up to 1,717

major tornadoes a year: more than

anywhere else in the world. And,

if that’s not enough, the southern

and southeastern parts of North

America, including the Caribbean,

are regularly slammed by particularly

powerful hurricanes that swing

in from the tropical Atlantic.

The regular occurrence of these

extreme weather systems makes

the continent unique.

Rainforest bears

On the coast to the west of the

Rockies, the Pacific Ocean ensures

that the climate is mild and damp,

both summer and winter. There

are no extremes here. As a result,

it supports the largest tracts of

temperate rainforest in the world.

They stretch from southern Alaska

to northern California, where they

are home to the American black bear

and, on Canada’s Vancouver Island,