Surprises in the Bear World

by Ranger Michael Fitz

Katmai’s female bears go through a somewhat predictable cycle. They go to the den in the fall, hibernate in winter, and emerge in the spring. They mate in late spring and very early summer. They keep their cubs for 2-3 summers, den with them for one more winter and drive their cubs away in the spring. They nurse their offspring while caring for them and don’t go into estrus while nursing. These behaviors happen with regularity and are the “norm.” However, bear behavior is full of surprises.

The behavior of bear 402 is illustrating this now. As of yesterday (July 10, 2014) she still had one yearling cub. If 402 was following the “normal” pattern for bears, she would still be nursing that yearling and would not go into estrus. However, bear 856 (a very dominant male bear at Brooks River) seems to think otherwise. Over the past few days, he has been following her incessantly—just like he would if she were in estrus. I must note, that I have no evidence she is in estrus, only that the behavior of the two animals suggests she is.

Male bears can gauge a female bear’s receptivity to mating through scent. It appears that 402 may smell “right” to 856 even though she still has a cub. 856 has been following her non-stop for more than two days as 402 wanders the river and occasionally fishes. 402 has not been especially receptive to 856’s advances.

This isn’t good news for the yearling cub. 856 is not a bear that the yearling will want to get close to, even with its mother’s protective services. Last night, the cub was in a tree about 100 meters behind the viewing platform at Brooks Falls. The cub was seen in that tree on the night of the July 9, it was there on the morning of July 10, and was still there at 9 PM that evening. From what I have observed, 856 has not shown interest in the yearling cub, but this morning it was not there. Bears are very tolerant of physical discomfort, but eventually dehydration and hunger will force the cub to leave the tree.

Meanwhile, 856 is still following 402 and the yearling cub’s whereabouts are unknown. According to the “norm” 856 should be ignoring 402. She shouldn’t be in estrus. It is easy to stereotype bears, but the ongoing story of 402, her yearling, and 856 demonstrates that bear behavior is quite variable and full of surprises. Not everything you see on the bearcams will fit the norm.