Twenty Years Ago
As a result of nearly a century of exploitation from the commercial whaling industry, humpback whales were scarce in British Columbia. One could consider themselves lucky to see one anywhere in the province. I remember my first sighting of a humpback whale off northeastern Vancouver Island in the late 1980s. Despite its large blow it was difficult to keep track of in the poor weather as it transited Johnstone Strait. Several years later, in 1994 I saw a pair of humpbacks in the same area. I could hear their huge blows from the Alert Bay marina as they passed offshore. Those of us on the dock that witnessed the sight had never seen or heard anything like it. For most of us, the only baleen whale we had ever seen before was a minke whale and even then we had only had quick glimpses of one.
Unlike the humpback whale, the minke whale was never targeted by commercial whalers in BC. Compared to nearly 5000 humpback whales reported to have been killed in the province, only 3 minke whales were ever taken. Minke whales are small, have no visible blow and are usually solitary. For unknown reasons they appear to be naturally uncommon in the eastern North Pacific. In the 1980s and 1990s they could occasionally be seen in some of the waters around northeastern Vancouver Island feeding on bait balls in summer. If one wanted to see a whale and there were no orcas around the best bet would always be to find a bait ball and hope for a minke to show up.
Today
Humpback whales are a common sight in BC. Just yesterday off northeastern Vancouver Island, Christie and I counted 12 individuals feeding in one spot. They were targeting bait balls in Queen Charlotte Strait and as part of Christie’s Master’s research we were filming and measuring these fish before they were fed on by the whales (see video below and previous blog). To date, we have photo-identified over 160 humpbacks in this area and over 50 this year alone. In comparison, we have only photo-identified 12 minke whales and over 95% of all our encounters have been of the same 6 “resident” animals year after year.
[youtube=http://youtu.be/C51oQd0JRPs]
It is interesting to watch these two species of baleen whale target the same prey resource in these waters. On several occasions, I have witnessed minke whales circle and feed in an area with bait balls for several minutes at a time when no humpbacks were present. Yet, if humpbacks are in the general area and a feeding opportunity for a minke whale arises, they appear to be very business like in their approach. It is difficult or maybe even impossible to quantify but the attitude seems to be to get in – get food – get out! After filming the above bait ball yesterday, minke #001 appeared out of nowhere and fed on it 3 times. We never saw the minke again despite perfect conditions. Although that is not totally uncommon this kind of behaviour makes us wonder if minke whales are adjusting their use of shared prey resources because of the dramatic increase in humpback numbers in the province.
~Jared
