Triangle

A dorsal fin with a triangular notch surfaces amid the blows and black backs; the female fin whale Triangle has been spotted several times this summer in dynamic groups off Tadoussac. This regular visitor has been known to make sporadic appearances in the estuary since 1986. Since then, she has been seen three times with a calf, in 1988, 1991, and 2000. However, since 2000, she has not been seen with a young calf. Yet, fin whales give birth every two or three years. What is happening with Triangle?

After a gestation period of 11 to 12 months, fin whale calves are born between November and January. Lactation lasts about six to seven months, and once the calf is weaned, it is independent. The calves seen in the estuary are possibly young whales born late in the season and for whom the nursing period is coming to an end. Otherwise, they may be calves that are already weaned and independent. In fact, researchers must observe the same adult swimming with the calf several times before confirming that it is the mother, as weaned calves are often accompanied by different adults during the course of a single day. Caïman, Capitaine Crochet, Perroquet, Corsaire, and James Bond have been recognized as mothers of calves by the GREMM team since 1988. Of course, a nursing scene or genetic analysis can confirm any doubts surrounding kinship. So perhaps Triangle has taken her calves to other feeding grounds over the past ten years… Or perhaps they were already weaned when she returned to the estuary? The mystery remains.

According to GREMM’s research since the 1980s, none of the fin whale calves photographed in the estuary have been recognized as adults. This may be because they did not return, or because they changed. Indeed, their bodies change significantly during the transition to adulthood, and the chevron, or color pattern behind the head, fades with age.