Nature: Ireland (5 of 19)

Nature: Ireland

Pups first take the plunge when they're around 2 1/2 months old.
They stay with their mother for around a year, until they've learned enough hunting and social skills to strike out on their own.
Fish are the otters' main prey, but crabs are always a tasty alternative.
In the chilly Atlantic waters, plenty of play and a well-groomed, waterproof fur coat keep the otters warm.
Like the peregrine falcon, the otter would have been part of Ireland's post-Ice Age landscape.
But just how they and all the plants and animals we see today got here once the ice had gone is still a mystery.
Some may have survived in ice-free areas.
Some probably migrated from Europe.

But among the first to enter this new world was a fish with a head start-- the salmon.
Able to survive in both salt- and freshwater meant that as the glaciers retreated north, salmon cruising around the coastline could make their way up the new rivers that now flowed into the sea.
Since then-- for 10,000 years or more-- salmon have been making the same trip.
These fish have spent one or more winters feeding at sea, building up enough bulk to return to the place they were spawned to breed themselves.
It 's a long, often treacherous journey, but the salmon are following an instinct impossible to resist.
Once they enter freshwater, the salmon stop feeding.
Their only source of energy now is the body mass they gained at sea.
Deep river pools give them a chance to rest along the way.