While I can't speak for 17th century British men, in the book Four Against the Arctic by David Roberts, the author chronicles the shipwreck of four Russian sailors in 1743 on a treeless island north of the Arctic circle where they survived for six years.

During an exploratory expedition onto the island of Svalbard, the four men set out from a merchant vessel to determine if an old hunting cabin was still on the island, near some walrus hunting grounds. They were equipped with a musket and 12 shots, a knife, an ax, a kettle, 20 pounds of flour, a tinderbox and a small amount of tinder, a pouch of tobacco, and four pipes. After finding that the cabin was intact they returned to shore to find that the ship was gone (it was thought to have been consumed in an ice flow or destroyed in a gale).

They immediately used their 12 shots to kill reindeer, an animal that freely populated the island. Now, however, without a weapon, they needed to find another way to hunt, preferably a bow and arrow. The problem in making a bow was that they needed animal sinew to make the bowstring and there was only one indigenous animal with strong enough sinew to use: the polar bear.

No trees grow on the island of Svalbard, so the men had to subsist on driftwood for fire. Fortunately for them, in one piece of the driftwood there was a large bolt with a hole through it which they used to fashion a hammer for blacksmithing. After finding two large nails, they smithed two spears and went hunting for a polar bear. One can only guess at the fight that ensued between them, but at the end the men got their sinew (and meat that apparently tastes a bit like hamburger).

They also had a member of their group suffer from scurvy, the only source of vitamin C on the island being lemongrass, which was fairly rare. Three of the members of the group would drink the reindeers' blood after killing them, thereby consuming the vitamin C in the blood, but the fourth one refused to, dying in the fifth year- presumably from scurvy.

They kept the same fire lit for the entire six years they were there. The way they did this was to make a candle-holder out of clay (similar to a lantern), tear strips of linen from their clothes, soak it in reindeer fat and use it like a candle. By the end, none of them had any linen on them; they were entirely garbed in animal skins.

That far north, the sun sets in November and doesn't lighten the sky again till March. Six years these Russian peasants lived this way, five months of night at a time, hunting reindeer by moonlight in winters that hovered around 0 degrees, wrapped in animal skins and staying warm when they were lucky enough to find driftwood. They also ended up killing ten more polar bears, although every time after the first it was in self-defense, when a bear would come sniffing around their hunting cabin, trying to break down the walls.

Interesting side note: the only reason this case was so well documented is because when the men were finally found and rescued, there was a trial in court because the merchant ship's owner believed there had been a mutiny and the ship was stolen.

Edit, compliments of u/avolodin. A small correction: the whole story didn't happen on the island of Svalbard, but on a tiny (4.6 sq miles) island of the Svalbard Archipelago called Half Moon Island.

During the time of Alexander Selkirk, it was very, very common for young single men to travel to the more prosperous coastal cities from the interior of England in order to find work.

At this time, there was a high rate of unemployment and these men did not often have marketable skills for urban life, so they ended up going to sea as common sailors with no experience in order to make a living, or to gain passage to the Americas where they could start a new life.

These men were most often displaced farmers due to the changing agricultural practices of the time which were part of the Enclosures. These men, being basic farmers would have had common experience with animal husbandry, farming, basic leather working, cloth repair, carpentry, masonry, and other tasks found commonly on farms. It's therefore not terribly surprising that someone from Selkirk's background would have been able to not only survive but thrive in a wilderness setting.