The autumn is the time when the reindeer have their mating season, the rut. The male reindeer, or a reindeer bull, rounds up female reindeer, or does, in its harem. It has to work hard to watch its female reindeer and to keep other bulls away from them. October is in North Sámi golggotmánnu, which means “rut month”.
The first snow falls. All the birds and mammals that stay over the winter in the north have a winter plumage or coat which is thicker than the summer plumage or coat. For example, the willow ptarmigan, the mountain hare and the Arctic fox all blend especially well into the snowy environment after changing their brown summer plumage or coat into their white winter plumage or coat.
In the autumn, before lakes freeze, people catch the fish that they need for the winter. The custom is to fish the fat whitefish of the lakes that lie further away in the woods for the winter.