Adult males are 7 to 10 metres long and weigh 4 to 10 tonnes: females are 5 and a half to 8 and a half metres long and 2 to 8 tonnes. The head is large and the flippers are paddle like. The large dorsal fin of the males can be up 2 metres long. The upper body is black, the underside is white, and they have white patches behind the eyes. Life expectancy is up to 50 years.
The killer whale is the largest member of the dolphin family. Unlike the baleen whales, orcas are ‘toothed’ whales, with true teeth rather than fibrous plates for filter-feeding. They catch single prey ranging from fish, squid, penguins, seals, dolphins, porpoises and even whales, including the largest whale of all, the blue whale. Their usual migrating speed is 10 to 15 km/hour, but they can easily reach 50 km/hour.
Orcas are highly social animals that travel in groups called pods. Pods usually consist of 5 to 30 whales, although some pods may combine to form a group of 100 or more. Orcas establish social hierarchies and pods are led by females. The animals have a complex form of communication with different dialects from one pod to another.
Like dolphins, orcas use echolocation - bouncing sound off objects to determine their location - to hunt and use a series of high-pitched clicks to stun prey. Orcas feed on fish, squid, birds and marine mammals.
Orca pods often work together to catch a meal: pods sometimes will force many fish into one area and take turns feeding or will beach (slide out of the water onto the shore) themselves to scare seals or penguins into the water where other whales are waiting to feed.
Gestation is 13 to 16 months: a calf is born in autumn weighing almost 400 pounds and measuring up to 7ft in length. A calf will remain with its mother for at least 2 years.
The minke is the smallest of the baleen (filter-feeding) whales and is found throughout the world's oceans, from the Arctic to the Antarctic. The minke is most likely to be seen from the shore in the UK and Ireland, especially in Scotland, the Northern Isles and Western Ireland. They have become resident in the area around the Isle of May in the Firth of Forth in the last few years and regular sightings have been reported.
Most of the baleen whales undergo seasonal migrations and in many cases these are over vast distances. The minke whale is unusual in apparently not conforming to this pattern, although they seem to move further away from the shore in the autumn, perhaps for breeding purposes. They also appear to be more solitary than other baleens and are usually seen singly or in pairs, although larger groups can gather.
Minke whales are very adaptable and eat a wide range of fish and squid, as well as krill and other plankton. They feed in a variety of different ways, depending on the prey concerned and often trap shoals of fish against the water surface.
Births occur in mid-winter, after a pregnancy of 10 months. The new born calf is only about 2 and a half metres long. It stays with its mother for about 2 years and reaches sexual maturity at about 7. The natural life span of minke whales is 50 years.
The story of this whale's name illustrates its blighted history: Minke was an 18th-century Norwegian whaler, infamous for regularly breaking the rules concerning the sizes (and therefore species) of whales that he was permitted at that time to hunt. Soon all the small whales became known as Minke's whales. Eventually, it was formally adopted as the general name for this small species.
The fin whale is a baleen whale and comes a close second to the world's largest whale, the blue whale and they are known to grow to more than 26 metres.
They are large, long and streamlined with smooth silvery grey, dark grey or brownish black skin with asymmetrical pigmentation on their heads. On their right sides, their lower lip, mouth cavity and baleen plates are white, whilst the left side is dark. Their backward sloping dorsal fins, which give fin whales their name, are more pronounced than in other baleen whales and are set far behind the centre of the body. Fin whales have baleen with fine bristles which are brownish grey to grey-white: their baleen can be up to 70cm long.
They weigh around 2 tonnes when they are born and fully grown adults can weigh from 30 tonnes to as much as 80 tonnes. They eat fish, krill and/or other crustaceans and are normally in small groups or alone.
Fin whales neither avoid nor approach boats: they are fast swimmers and can be seen to breach, re-entering the water with a big splash. When fin whales eat they often turn on their sides with the right side facing downward, and in this position the lighter colouration of the head makes it less visible to the intended prey.
They blow a few times at intervals of 10 to 20 seconds before diving for 5 to 15 minutes (though they are capable of much longer dives). They can dive to depths of 230 metres (755ft).
Humpback whales are 40 to 50ft in length and weigh 35 to 40 tonnes (equal to the weight of 500 people!) and travel at a maximum speed of around 16mph.
They have a distinctive pigmentation pattern on the underside of their tail or fluke: this black and white pattern can be seen when the whale lifts its fluke out of the water when it dives. The pattern is different for each humpback, allowing researchers to identify individuals without the use of synthetic markers. The pattern also helps researchers to estimate population, life expectancy and migration patterns.
Humpback flippers make them very distinctive as they are up to a third of the total length of the whale, at about 15ft long.
They are also famous for their songs: these songs are structurally similar to the songs of birds. In the winter, when the whales are on their breeding grounds, the male humpbacks will hold their breath and sing for up to an hour. All the males of the same population sing the same song, and that song changes a little each year, as if they are changing a verse. Most commonly, it is believed that these songs are used to attract a female, though other theories exist. One such theory is that the songs are used to establish a territory.
Humpbacks are baleen whales, meaning they have no teeth. Instead they have hundreds of hard, flexible plates of baleen inside their mouth and each plate has a hair-like fringe on the inner edge. The baleen acts like a strainer to help the whale collect its food.
The whale finds a school of small fish, such as sand eels, herring or krill, opens its mouth and engulfs the school or cloud. Then it pushes all the water out of its mouth and past the baleen plates. As this happens, all the small fish or krill get trapped on the inner hairy edge. The whale then scoops off the food with its tongue and swallows it whole.