Not all of this, obviously, is hard fact. Sorry about that. For the number-loving: the mammoths migrated to the islands around 20,000 B.C. or so; by 15,000 B.C.,they'd shrunk. Around 13,000 B.C., they encountered Man. And by 10,000 B.C., they were gone.

In the Channel Islands off the coast of California, there was a species of pygmy mammoths. This was something like the Shetland Pony of mammoths; about the size of a Percheron with severe glandular problems. They stood about six feet tall at the shoulder, and weighed about two tons. They could hear branches rubbing against each other in the wind from ten miles away. Their trunks could snap good sized saplings, or handle an orchid without bruising its petals. They could smell fruit ripening on the bough across the thirty mile channel separating them from the mainland. When calves or old matriarchs died, they'd gather about the corpse one by one, touching the body with their trunks, stroking the hide, as if to say goodbye.

--They hadn't always been living oxymorons; once they had been mammoths that were actually mammoth. Full-sized (i.e., about fourteen feet tall at the shoulder), the pachyderm Cortez stood stout and silent on a peak in Darien, gazing out at the peaceful ocean. And smelled the apples of Santarosae, then only five miles offshore.

For a few millenia, their only neighbors were: sundry lizards and turtles (regular size). Assorted seagulls, albatrosses, pelicans, cormorants; the odd wind-swept sparrow or crow (regular size). Flies, beetles, bees (regular size). And deer mice. Giant deer mice (as in, up to a foot long).

--Then one day a new animal arrived.

Yep, you guessed it.

People tamed the mammoths, and loved them and groomed them and rode them and ate them for lunch. Such abundance! Steamed mammoth feet for breakfast; mammoth hide fritters for lunch; stuffed mammoth heart for dinner. Later, smoked mammoth sausage (in natural casing). Pickled mammoth ham. Mammoth tendons boiled for ten days with wild garlic and guava juice. Polished spear blades made of mammoth ivory. Divination on mammoth shoulder blades, thrust into a mammoth-dung fire.

--the mammoths went extinct; the people suffered first from endemic heart failure, and (later on) from malnutrition. Their inbred descendants, some of them still clad in stinking mammoth hides, were overrun by the Chumash tribe. And some days or months or years or centuries later, the Spanish brought chicken pox to America.

JudyT says: They also survived on Wrangel Island off Siberia until about 4000 years ago. Coincidentally this is also when you-know-who arrived.