Thursday, February 18, 2010

Common dolphins, bottlenose dolphins and pilot whales

Today the weather was surprisingly sunny and, allowing us to really enjoy even our sightings of  common dolphins, bottlenose dolphins and pilot whales!

Montanha do Fogo (Fogo mountain) seen by sea. As usual, covered with clouds!!

The common dolphin (Delphinus delphis) is the most common species of Odontoceti (cetaceans with teeth) in the Azores. They can be seen year-round and therefore are designated as a resident species.
They dive up to 300 m and for a duration of up to 4 minutes. The species is characterised by a cross pattern on their sides,which goes from a yellow region to a light grey region further back. Their maximum length is about 2.6 m and they can weigh up to 130 kg.

Common dolphins

Common dolphins live in groups which can reach up to hundreds of individuals, especially during the summer. As for the boats, they are very fond of playing and jumping near them and can put on quite a show! Maybe you can come next time and see it yourself!!

Here you can see how well defined is the pale yellow pattern on the side is

Our second species sighted were the bottlenose dolphins (Tursiops truncatus). You may recognise these from the flipper movies. Bottlenose dolphins are very social and often very friendly towards the boats. The males can reach up to 4. 5 m in length and 600 kg in weight. When they show off, jumping curiously around the boat, it can be quite overwhelming!

Bottlenose dolphin

We stayed with the group of bottlenose dolphins for a while and then our lookout told us he had seen some bigger bottlenose dolphins a few miles further.

Saying bye bye to the bottlenose dolphins!!

And then we were moving again!!

Surprisingly, the big dolphins we out to be pilot whales. At least 15 of them!! And what a thrill!!! They can be sighted in the Azores through the entire year, butt in the period between April and October we see them more frequently, and often in bigger groups!

Pilot whale

Pilot whales are grouped into two different species; short-finned pilot whale (Globicephala macrorhynchus) and long-finned pilot whale (Globicephala melas). Both species can be seen in the Azores, although the short-finned is more common to see here. Despite the name, pilot whales are actually dolphins. They can reach up to 7 m in length and weigh up to 4 tonnes. One of their most remarkable characteristics is the wide dorsal fin that varies in shape depending on how old the whale is and whether it's male or female.

Notice the wide dorsal fin!

Pilot whales are very social animals that live in pods of up to 60 individuals and are known for having a well defined social structure. Pilot whales are also frequently seen together with other species such as bottlenose dolphins and Risso's dolphins.

Pilot whale - notice how the head is round and it has no beak like some other species of big dolphins (the killer whale is one of them).

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