Found in all warm and temperate waters in every ocean of the world. Key Identification Features: Body Size: Small, becoming medium-sized in large males; average length, with a maximum of 4.2m. Calves are approx. 1m. Average weight is 200kg. Head Shape: Small, stubby, long, wide, and rounded beak well marked off from exaggerated melon, lower jaw protrudes beyond upper. Soft mouth line curves upwards at back to give familiar, faintly amused, facial expression. Dorsal Fin & Tail Stock: Tall fin, broad at base and curved backwards. Moderately keeled tailstock. Colouration: Medium grey back above, pale or light grey flank and belly. Calves slightly bluish. Animals in the Pacific have distinct pink tinge on underside. Additional Body Markings: Pale line drawn from flipper to eye and some spotting occurs on older animals on the belly; adults may have white callus on tip of lower jaw (additional body markings claimed for some geographical forms). Field Identification: Over-riding impression of the bottlenose in the wild is the height of the fin, bulk of their frame and their strong, deliberate back arch as they dive after breathing. Usually seen in small groups feeding in same area, with. They surface 2-3 times each minute, seldom-showing beak or fluke. Dives usually last for a minute or so but some have been timed at 10 mins. In the absence of ships, they have been observed surf-riding in shore breakers or on storm waves in mid ocean. Status and Distribution: Found in all warm and temperate waters in every ocean of the world. In our waters, the most northerly, known resident population are those of the Moray Firth in the north east of Scotland, this appears to be the northern edge of their range. Most often seen close inshore, even entering estuaries and rivers and very seldom found in the open ocean although they are capable of crossing open water. There is some evidence of co-ordinated migration in several populations of bottlenoses, particularly those found in temperate areas. This movement takes place towards the equator in autumn and back to richer feeding grounds in spring. Bottlenose numbers are unknown but are thought to be common to however, pollution and degradation of fish stocks have led to markedly diminished numbers in some areas. Too large to be captured in nets, they have been and still are, hunted with guns and harpoons. In West Africa, Japan and the Caribbean, small numbers are taken each year in coastal operations to prompted by fears of competition for dwindling fish stocks. Significant numbers are captured and taken alive by the display industry. Where and When Best Seen in Ireland: Can be seen inshore on all Irish coasts. The resident population of c.130 dolphins in Shannon estuary is one of only 4 known resident populations of this species in Europe. Ireland at least three friendly bottlenose dolphins that regularly interact with humans, they are currently in Dingle, Co. Kerry (Fungie) and Fanore, Co. Clare and Inis Oirr on the Aran Islands, Galway. Many sightings are recorded off the coast off Kerry, Clare, Galway Bay and Killary harbour, and Broadhaven/Erris area of Mayo. Species Similar in Appearance: Most likely to be confused in the field with other species which are predominantly blue/grey with tall, curved fins, i.e., rough tooth and the spotted dolphins (neither of which have been recorded in Irish waters) But close-up encounters should present few identification headaches. Bottlenose dolphins readily approach ships to bow ride, wonderfully co-ordinated, never jostling for position, rolling over, diving deeply in formation, twisting back and re-appearing on the surface to they seldom leap high like their smaller, hyperactive cousins, the common dolphin. They have been observed suddenly breaching and hurling themselves 5m or more in the air, which presages the kind of performance they can be persuaded to perform in captivity. Bottlenose dolphins often school with other species, including pilot whales. They are well known for their ability to mimic , thus underlying their value as theme park entertainers. Specimens live for 25-30 years, maturing at the age of 6. Courtship plays a major part in copulation and foreplay in the shape of muzzling, clicking, caressing and stroking, marks out these mammals as truly the Cassanovas of the ocean, which probably goes some way towards explaining their friendly pre-disposition towards man. Food and Feeding: One of the secrets of this species success is its catholic appetite . They eat between 8/15 kg of fish, normally inshore, bottom dwelling fish. They will also take eels, catfish, sharks, rays, hermit crabs, shrimps & mullet. They have also been known to take larger, pelagic fish such as yellowtails. In captivity they have been recorded taking large fish to the bottom, rubbing them on a rock to break the backbone, remove the head for ease of swallowing. They usually hunt in co-operative groups, herding and corralling their prey into shallow water and while 2 stand sentry, they will take turns thrusting into the terrified ball of herring, sprat or mackerel (normal prey off our Irish coasts) and pick them off at their leisure. These feeding frenzies often attract other predators and the bottlenose dolphins intelligent ploy benefits the assembled predators and entire shoals of fish can be wiped out in this way. Dolphins off the West coast of Africa are said to dive to depths of 600m over the continental shelf and to facilitate these incredible dives they have evolved large, strong mid-ear bones to deal with the pressure.
