Our trips to sea are not just to see whales and dolphins they are also trips into the open ocean where we seek other pelagic marine life of interest. Often we encounter sea turtles, especially Loggerhead turtles Caretta caretta but very occasionally Leatherback turtles Dermochelys coriacea too. Both these species are pelagic. Once they have hatched and left their nesting beaches they spend the rest of their lives at sea. Only the females will return to land to lay their eggs, often on the very same beachwhere they were hatched. 

A Leatherback turtle surfaces close to a whale watching boat. 

Humpback whales (Megaptera novaeangliae) are perhaps the best known and most easily recognised of the great whales. They are charismatic and acrobatic animals, often breaching, lob-tailing, spy-hopping and flippering. They are also the most social of the baleen whales. Not surprisingly they make frequent subjects for wildlife film makers.  Their highly variable under-tail markings, ranging from pure white to pure black, differ between individuals and therefore also make them good subjects for photo-identification and research. Here in the Azores they are quite rare, usually just one or two sightings occur each year and their presence always causes great excitement among the whale watching community. This year has been good with six animals seen from three sightings so far. 

Humpbacks are migratory. Some of their documented movements represent the longest known migrations of any mammal covering 5000 miles one way. Recent estimates suggest there are around 11,500 Humpbacks in the North Atlantic.  In the northern Spring these whales all return to specific feeding grounds in the Gulf of Maine, Gulf of St. Lawrence, Newfoundland, Labrador, Greenland, Iceland and Norway. Studies suggest that the whales faithfully return to these sites each year. In the winter whales from all these feeding grounds return to a common breeding ground in the West Indies to mate and calve. Just like the Blue, Fin and Sei whales, the Humpbacks that pass by Pico are on-passage. We usually see them in Spring when they are heading North.

Interestingly genetic data suggests the existence of a second breeding population composed of animals that spend the summer feeding in Norwegian and Icelandic waters. The location of this breeding site is still unknown. Small numbers of Humpbacks are also known to breed in the south-east Carribean and Cape Verde Islands and recent photo-ID has positively identified a Cape Verde breeding Humpback feeding in Icelandic waters. Perhaps the Cape Verdes are the location of the second breeding ground.

Cw Azores are submitting all it's sighting data (including photos) to the North Atlantic Humpback Whale Catalogue and the researchers studying the Cape Verde population. In so doing we hope to contribute to a greater understanding of the Humpback whale's migration. Perhaps too, we can help locate the mysterious second breeding ground as well as help identify the migration routes of endangered populations such as found around the Cape Verde Islands.    

Krill + Fish = Seabirds + Whales. 

I love the maths here. In truth, as any modeller of ocean ecosystems will tell you, the relationships between each trophic level are more complex than I state above. Nevertheless sometimes the outcome of these relationships are plain to see. In the last few weeks we have had a super abundance of krill. We have also had an abundance of their predators; fish such as sardines, baleen whales and seabirds, particularly Cory's shearwaters Calonectris diomedea. Day after day regular sightings of Blue whales Balaenoptera musculus, Fin whales Balaenoptera physalus and Sei whales Balaenoptera borealis have been thrilling our clients. So far six Humpback whales Megaptera novaeangliae have also been seen. These whales are particularly rare here, this side of the Atlantic.

Have you ever wanted to see a Blue whale; to hear it blow and smell its breathe?

Follow this sequence of photographs; observe, watch and wonder...

Identification of Fin whales Balaenoptera physalus and Sei whales Balaenoptera borealis, the two baleen species we see most frequently, is not always easy. Separating individuals of the two species travelling together is not straight forward. The largest Fin whales are always bigger than the largest Sei whales but we do not always encounter full grown animals or the largest individuals. Males of both species are appreciably smaller than the females too. We may therefore encounter individuals of either species in a variety of sizes depending on their age and sex. For example it is very possible to encounter a large female Sei whale travelling in loose association or even close proximity to a small male Fin whale.

So how do we recognise each species? Well this is partly down to picking out one key feature of Fin whales that is never shown by Sei whales and, when this cannot be detected, using something many birdwatchers will be familiar with - something called 'jizz'. This is actually an acronym for General Impression of Size and Shape. 'Jizz' can be a very useful tool as each species shows a variety of traits and behaviours shown less or very infrequently by the other. Picking out these features in an animal can be sufficient to identify the species. There are, however, sightings that we can never be sure of their identity.

The key feature of Fin whales that is not shown by Sei whales is the colour of their lower jaw on the right hand side. This is always white in Fin whales and black/dark in Sei whales (see photos below). It has to be the right side too. The lower jaw on the left side of Fin whales is also dark.