Whale of the Month - Bottlenose Dolphin

The Whale of the Month for May is the bottlenose dolphin, a highly intelligent member of thedelphinidae family of oceanic dolphins. The bottlenose dolphin is located in the front room of the exhibition with the other toothed whale species. Different species of bottlenose dolphins live in almost every part of the world with the exception of the poles.

The average life expectancy of a bottlenose dolphin is around 40-45 years. Females typically live 5-10 years longer than their male counterparts. There are records of some females living to be over the age of 60, though this is rare. Their average length is roughly 4 meters, and they can weigh between 300-400kg. They have a short and thick snout called a rostrum and their colour can vary between shades of gray, blue, brown, and black. Offshore bottlenose dolphins are typically larger than those living closer to land in coastal waters. They have an average speed of 5-11 km/hour but can perform high-speed bursts of up to 29-35 km/hour.

Bottlenose dolphins live in pods ranging from a few individuals to over 100 depending on the activity taking place. Adult males usually live in small pods of 2-3 individuals or alone, and then join other pods for short periods of time. Adult females, juveniles, and calves form their own pods, but membership is fluid and group members can and do change often. They communicate using burst pulsed sounds, whistles, and through body language including jumping out of the water, snapping their jaws, slapping their tails, and butting heads with each other.

These dolphins are considered to be extremely intelligent and have been observed to use artificial language and mimicry. They are capable of object categorization and self-recognition, can use tools, and pass cultural knowledge between generations. Bottlenose dolphins in captivity have been trained by military forces to locate sea mines and detect enemy divers. Wild bottlenose dolphins have been recorded cooperating with fishermen by herding fish into their nets, eating the ones that escape. Their diet includes fish, shrimp, squid, mollusks, and cuttlefish. They can hunt alone or as part of groups and can change their strategies to fit the hunting situation. They have been recorded using sea sponges as tools to dig up food from the sea floor and pass this skill-based knowledge between generations.

Natural predators of the bottlenose dolphin include larger shark species, particularly preying on calves. Killer whales are also occasional predators, but less common than sharks. Bottlenose dolphins face a variety of dangers including boat collisions, being caught in fishing nets, pollutants, reduced food availability, habitat degradation, noise pollution, oil spills, and illegal feeding and harassment from humans. They are not endangered overall, but some populations are at higher risk than others.

While not as common in Icelandic waters as the white-beaked dolphin, bottlenose dolphins have been seen in many places around the country. Two bottlenose dolphins made headlines in Iceland when they stranded just off the coast of Reykjavik in 2018 – unfortunately only one of them survived despite the best efforts and hard work from rescue teams. They are most commonly seen off the south coast where the waters are warmer, but have been spotted by whale watching companies in the very north of the country and along the west coast.