This video explores the various marine mammals that inhabit the world's oceans, including seals, sea lions, dolphins, and whales. It describes their physical characteristics, social structures, mating and breeding behaviours, and roles within the broader marine ecosystem. Key points include:

• Seals and sea lions are semi-aquatic pinnipeds that spend most of their lives in the water, coming ashore for mating, moulting, and resting. They exhibit a range of social behaviours, from solitary hunting to large breeding colonies.

• Dolphins are highly intelligent, social cetaceans that live in complex, fluid pod structures. They use a variety of vocalisations for communication and echolocation, and engage in cooperative hunting strategies.

• Whales, the largest marine mammals, are divided into two main groups - baleen whales that filter-feed on small prey, and toothed whales that actively hunt other marine animals. Whales are largely solitary but highly vocal, with some species known for their complex 'songs'.

All marine mammals play crucial roles within the ocean's ecosystems, contributing to the growth of phytoplankton, providing food sources for other predators, and forming unique microhabitats after death. Their diverse behaviours, social structures, and adaptations are a testament to the richness and complexity of life in the world's oceans.

Animal Society is a documentary series about the different social behaviors of various animal groups and individual species, from seabirds to insects, schooling fish to great cats.