In winter, when the cold weather sets in, Japanese macaques descend from the mountains to the thermal springs

In winter, when the cold weather sets in, Japanese macaques descend from the mountains to the thermal springs, where they bask in warm water for a long time. Indicate the form of animal fitness. What is her character?

1) the form of fitness – ethological (behavioral) fitness;
2) this form of behavior of Japanese macaques is acquired and plays an essential role in the life of these animals (Japanese macaques are the northernmost species of monkeys).