Earlier in the year, whilst out surveying the cliffs for breeding birds, one of the team spotted the carcass of a whale in a remote bay on The Oa reserve on Islay. A couple of days later I ventured down the cliffs to take a closer look at what I presumed would be the remains of a Minke Whale, the commonest whale seen in nearby waters.
The creature had been dead some time, so identification wasn't straight forward. The grey and rotting carcass was about 7 metres long, but with no fins, tail or discernible markings remaining. Whilst looking at the head end I noticed the jawbones appeared to have tooth sockets (although no teeth). This along with it's size ruled out most possibilities and I was left wondering if I was looking at the remains of a killer whale.
Upon sending a few photos to experts at The Scottish Marine Animal Stranding Scheme (SMASS), it was quickly confirmed as a killer whale, a remarkable occurrence. These whales are rarely seen around Islay, with only a handful of sightings in recent decades. A small group known as the 'west coast community' are seen further North around Mull and the Outer Hebrides, with sightings of other groups more commonly seen around Shetland.
Over the next couple of days we took muscle and blubber samples for SMASS, and were asked not to publicise the location of the carcass, as further samples and the skeletal remains would be required for research purposes. Just last week, three strong-stomached scientists from National Museums Scotland spent two days recovering the skeleton from amongst the rotting remains. This is not a job for the faint hearted or even for anyone with a sense of smell really!
On the third day they asked for help from the RSPB team carrying the bones out of the steep sided bay. Strangely only 4 of us agreed to help, with others missing out on a once in a lifetime experience. After several hours of hard and smelly slog, we managed to drag, haul and struggle our ways up the cliffs. The skull alone weighed around 10 stone and took three of us to haul it up the slope.
The research that will now follow will contribute to our understanding of the health and ecology of these difficult to study animals. The post mortem work could give information on age, sex, body condition, cause of death, pollutant levels, reproductive patterns, diet, disease burden and pathology, helping to build a picture of what is happening to these iconic animals. If the carcass turns out to be from one of the west coast community, then these samples will be even more important. This population is currently thought to be only 8 strong, and incapable of breeding, possibly due to the extremely high levels of PCB toxicity burden they carry.
We'll post a further blog with any results later in the year.