H859, a.k.a. “Yvon”

This season, the humpback whale H859—known locally as “Yvon” in the estuary region—was first spotted on June 17. Seen almost every week since then, it was still in the Saguenay–St. Lawrence Marine Park as of August 27! Easily recognizable by its sizable dorsal fin, which features a half-moon-shaped scar at its top, it also has a rather dark tail fin. With this persistent presence in the marine park—in addition to visiting every year since 2018, except in 2024—H859 has become a real star! Can we say that it is now faithful to this feeding ground? The fidelity of whales to the St. Lawrence has been extensively studied in fin whales, allowing researchers to classify individuals into three categories. Drawing on the methodology used for fin whales, scientists can also classify humpback whales. The interannual return rate and the seasonal visitation rate are the two descriptive variables used to categorize them. Seasonal residents are whales that return every year—or nearly so—and whose presence is sustained throughout a season. Regular visitors, as their name suggests, return regularly to the area, but their presence within a given season is less sustained than that of seasonal residents. Finally, occasional visitors return infrequently from one year to the next, and their presence during the season resembles that of regular visitors. As for H859, its sustained presence in 2026 and in previous years, combined with its high return rate from year to year, grants it the status of a seasonal resident! This status could, however, change in the future if H859 were to alter the frequency and duration of its visits to the marine park.