You never know what might go bump in the night. Early in the morning of September 24, just before 4am, a humpback began to bubble net feed. And boy! did this whale ever find a good spot! The feeding event went on for close to two hours, in the same place and pretty much with the same intensity throughout. We have heard bubble net feeding throughout this season but only for short durations. Last year we did not hear much activity. Bubble net feeding is well known further north. In Alaska, the humpbacks there were the first to be documented and because most efforts are a group effort the events tend to be very dramatic. As humpbacks came into the inner coast they did so from north to south. Once well established on British Columbia’s north coast they began to vocalise and adopt bubble net behaviours. Making their way into other parts of the coast, including the Johnstone Strait area, they were at first “shy” and did not immediately vocalise. Over a short period of time, as they became comfortable about their choice of locale they found their voices. Simple at first, a few social and feeding calls, then more elaborate song trials performed by the male humpbacks as summer turned into autumn. We have become quite used to spending hours recording the humpbacks. This season there does not seem to be as many humpbacks here as in previous years although several of the most familiar returnees have shown up, including Guardian with her new baby. So far they have not been very vocally expressive either. A rather delayed and subdued season all round. The resident orcas came a month late and left a month later. The sea lions have yet to haul out on the Hanson Island rocks although they have done so across the way and in the Plumper Islands. Even our famous sea gull, Uni, came late. With all these delays the surprise increase in bubble net feeding has grabbed our attention. Has this unique feeding strategy finally arrived here?
From what we understand a humpback or a group of humpbacks begin low and deep and as they circle towards the surface they create bubbles which act as a trap for the small fish. The final “nail” is the piercing moan they emit before coming to the top and devouring their catch.
Usually we have heard and seen the bubble net efforts during the day, so to hear such an extended effort in the dark of the night of the 24th felt exceptional. The first big storm hit the coast the next night. The wind and the waves made hearing the distinctive sound of the bubbles breaking was lost, but even so, distinctive distant moans were heard briefly in the night and then around 7am.
The last few days have also been punctuated by sightings (no vocals) of two orca brothers T060D and T060E. Bigg’s orcas began to proclaim their presence on September 19 just before 6pm. Heard but not seen, these orcas were in Johnstone Strait and vocal until about 6:30pm. On September 21, there was the first sighting of the two brothers. Till and Carla were at the Cracroft Point camp and saw them heading toward Blackney Pass at 6:44pm. Amazingly it was still light enough to see them as they came into view of the Lab. They made long dives as they headed into Blackfish Sound.
In the intervening three days before the next sighting ,Emily, who has just completed her Masters studying the complexities of humpback vocalisations at St Andrew’s in Scotland, was staying up at night annotating the live humpback vocals which were now happening on a more regular basis. Emily shared her thesis findings with the rest of the group the evening before Barbara and Paulo left. Barbara followed Emily’s presentation by showing us a comparison of the scan data from here and the Fin Island Research station. Each location is tasked with scanning the waterways in front of their station nine times per day. During the 15 minute scans boats, cetaceans, weather, sea state are all entered onto a tablet. It was remarkable how similar the findings were at the two locations month by month.
On September 24 the two brothers were back at 6:30 am heading south. Just under two hours later they were seen yet again, this time heading north. They were gone by 9:22am. At4pm they were back going the other way again. This time they shifted into Parson Bay. Lots of seals were over there, but at such a distance it was unclear if they found a target. They kind of disappeared after a long dive and into the late afternoon gloom. They were back going south once more at 8:13am on the 25th. This passing was quite close to Hanson which afforded us a much better look at their dorsal fin distinctions.
The storm which had raged through the night settled down quite a bit during the rest of the 25th but the forecast promises us to expect another blow. We had already battened down the hatches so we are braced and ready. In the afternoon two sea lions occupied one of the Hanson Island rocks. A bit later there were 7. Hmm this might be the start of something after all.
During this time we said good-bye to Gloria, Barbara, Paulo, Till, Carla and Juliette. We would like to thank them for all their hard work especially during the busy part of the summer. Through it all, each was cheerful and willing. We could not ask for more. We wish each safe travels. Thank you!
