Azores: Cetaceans galore

We had a full day out on the catamaran on 24 July.

The lookout to the north had seen a couple of sei whales, while the lookout to the south had only seen dolphin. By the time we got to the north, the sei whales had disappeared. But there were hundreds of spotted dolphin feeding on horse mackerel along with Cory’s shearwaters. After watching for a while, we carried on a bit further offshore to one of the areas that is usually good for finding sperm whales. Just after hearing some sperm whale clicks on the hydrophone, we came across a loggerhead turtle eating a piece of squid! That squid was probably vomited by a sperm whale, so we knew we were on the right track. When sperm whales eat squid, they do not digest the beaks. After a time, the beaks become uncomfortable and the whale will vomit to get rid off them. By default, anything they have recently eaten will also come up, so we sometimes see chunks of squid or deep sea octopus at the surface when sperm whales have passed by.

At the end of the squid crumb trail we found a group of socialising sperm whales. One individual did four breaches and the juveniles and a calf were lobtailing and throwing their tails around in a social group. Unfortunately, when the whales are socialising, they do not usually show their flukes, since they aren’t diving. I managed to get one fluke of one individual that did make a deep dive at the very start of the encounter and then got the same fluke as she dived in preparation for a breach. It appears that she could be pregnant, looking at the size of her belly visible in one of the breaches. Sperm whales breed all year, since they do not depend on migrating to warm waters to have their calves. I guess if she is around later this year or next year, we may have our answer, if there is a small calf with her. She was accompanied by a calf in the suckling position before she dived the first time. Sperm whale females will suckle another female’s calf, since they live together their whole life, the favour will be repaid sometime in the future.

We also had a group of over 500 spotted dolphin feeding on mackerel along with 1000 or so Cory’s shearwaters. One individual had a lot of barnacles attached around its mouth. I have seen this occasionally on bottlenose dolphin and do not know if they have an impact on the dolphin’s ability to feed; this one certainly did not look skinny. This seems to happen when there is an injury to the jaw and the teeth become exposed for the barnacles to attach to.

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On 25 July we managed to avoid most of the rain showers and followed the lookout’s directions to four feeding sei whales accompanied by spotted dolphin. There is a lot of bait fish around for the sei whales to eat, which is why they are hanging around. Then it was out to the area where the sperm whales were. Out there, we also found another sei whale and striped dolphin too. The sperm whales have been seen before, one in 2015, another last year and the third one on 7 July. I thought I recognised one of the sei whales from the other day, but although the dorsal fins are similar, they are not the same. We also stumbled across a small group of Risso’s dolphin on the way to the whales, but were not able to spend much time with them, since the lookout kept telling us to get a move on!

The weather did not co-operate for a full day on 26 July, but we had a fantastic morning.

We started with a small group of spotted dolphin on the way to sperm whales. We just missed two flukes by 10 minutes, so we had to wait a bit to get our first whale. It turned out to be “2578” one of the “Whitehead” group. We saw another individual, but it fluked in a wave, so no ID on the second individual. It was quite bouncy out where the sperm whales were and they were heading into the waves, so we headed back towards shore where the lookout spotted a sei whale with some dolphin.

It turned into an incredible sighting of three individuals, including a mother & calf. The calf showed a bit of interest in the boat, with the mother patiently waiting for it to go back to her! There was a sighting of a mother & calf sei whale a couple of days ago in São Miguel, about 125 nm away from Horta. I have sent the dorsal fin ID photos of one of the biologists over there to see if these are the same individuals. Most sei whales passing through the Azores are headed towards Labrador, based on some tagging done by the University of the Azores, but there seem to be some individuals that do not make the long trip, instead preferring to find fish further south. At the moment, there is quite a lot of baitfish around here. They were seen feeding on snipe fish a couple days ago and we saw some mackerel bait balls in the north of the island two days ago.

There is a bit of wind arriving later this week, but until it arrives, I will be going out to see what is around. There are a few whale watching tourists around at the moment, which means that the support from Biosphere Expeditions will last a bit longer, if I can hitch rides with them.