when the (resident) orcas are away
It’s been rather uncanny over the years, to note how often the space left by absent resident orcas is filled by transient orcas, who somehow manage to show up and save a thin whale watching day. It is difficult to know whether this is a real phenomenon, or an observational artifact. One might reasonably suppose that it relates to the intensity of scrutiny that accompanies straining eyes out on the water, when there is nary a sign of an orca fin to be seen clear to the horizon. When fins are sighted on these empty days, more often than not, it seems, they turn out to be transients. If there is some statistical truth to be found here, perhaps the thought deserves investigation.
What we do think we know, is that resident and transient orcas generally avoid one another. They occupy the same ocean spaces, but have different enough habits and needs that they don’t often come into direct contact. Generally, transients pass through an area, residents stick around (hence the labels). After 40 years of listening, we can count on the fingers of one hand, the number of times residents and transients have been vocal at the same time in the same acoustic space we are monitoring. We have seen dramatic examples of the reluctance of transients to occupy the same space as residents, e.g. moving out of the way by going behind a rocky reef while residents were passing, and then emerging when the residents were gone. We have also seen dogged persistence by transients who wanted to travel from one space to another, but found their way blocked by residents. Quite clearly, the two communities prefer their own company, and their own spaces, but they are sometimes obliged to share, and they do so with caution.
It may well come as a relief to transient orcas, then, to find that a favourite ocean space is all theirs, with no hint of a resident orca clear to and beyond the horizon. Such may have been the case 2 nights ago, when a group of transient orcas sang the night away in Johnstone Strait. They were constantly vocal for over 4 hours, from 11:10pm to 3:30am, as they moved between Blackney Pass and Robson Bight. Their calls went on and on, with great variety, including whistles, for hour after hour, despite constant boat noise that was happening around them from dozens of boats involved in a commercial fishing “opening”. We did not know who was calling, only that what we were listening to was remarkable.
Transient orcas are generally much quieter than residents, who come across as rowdy in comparison. It is thought that transients mostly become vocal after they have killed a prey, and eaten their fill. What happened the night of September 1-2 had a very different flavour. It sounded like party time for transients, maybe a little like what was going on around the camp fire at the annual Boat Bay party next door. We had no idea who was singing, but the next morning a small group of transient orcas made their way northwards through Blackney Pass, quietly and silently, and then circumnavigated Hanson Island before heading east. Probably, they were involved. Nor will we ever know what the songs represented. Perhaps they were part of an ancient ritual. Sheer speculation. About the only thing we do know is that this wonderful acoustic performance occurred in the total absence of resident orcas. It does tend to make one think.
Also interesting in this vein, was the sudden appearance of around 1,000 Pacific white-sided dolphins in Blackfish Sound today. They rushed about together for hours, this way & that, leaping and cavorting, and judging by the birds flying around them, grabbing a bite on the fly too. It looked like great fun for them, and was certainly great fun for the people watching them (they saved a pretty empty whale watching day). It’s been years since we saw so many of them together. Probably just a coincidence that this happened to be a day that no orcas were around, resident or transient.