02.10.2025 – Two social systems in comparison

Short-finned pilot whales (Globicephala macrorhynchus) and Sperm whales (Physeter macrocephalus) are clearly matriarchal. The social groups of these species usually consist of females and their offspring. An experienced older female takes on the role of leader. She decides on migrations, dives and hunting grounds. The matriarch’s knowledge of food and dangers is essential for survival. Young males remain in the mother group until they reach sexual maturity. They then leave the group and join loose bachelor groups. Females, on the other hand, remain in the maternal line for the rest of their lives. This creates stable social units that often last for decades. Matriarchy ensures strong bonds and cross-generational learning.

The structure is different in Atlantic spotted dolphins (Stenella frontalis) and Bottlenose dolphins (Tursiops truncatus). Here, complex hierarchies exist that are based more on dominance and alliances. Males in particular often form coalitions to secure access to females. The hierarchy is based on strength, experience and social alliances. Although there are close mother-child bonds, there is no permanent matriarchal structure. Groups can often break up and reassemble. This ‘fission-fusion system’ makes the community very flexible. Friendships and co-operation are crucial for social status. Some males work together to court or defend females. There are also hierarchies among females, albeit less pronounced.

So while cetaceans such as Sperm whales and Pilot whales rely on stable, matriarchal lineages, dolphins such as Spotted dolphins and Bottlenose dolphins display a dynamic ranking system. The knowledge of older females is less dominant in dolphins than in cetaceans. Instead, social intelligence, flexibility and alliances are decisive. Both systems have proven to be evolutionarily successful. Matriarchy ensures long-term stability and traditions. The hierarchy of dolphins allows them to adapt quickly to changing situations. Thus the different social structures also reflect the way of life. Whales are often deep-sea orientated foragers with fixed routes. Dolphins tend to utilise dynamic coastal and deep-sea habitats with changing resources.

By Fatima Kutzschbach

Sightings of the day

Ribeira Brava

09:00 Pilot whales, Bottelnose dolphins

13:00 Pilot whales

Stenella

09:30 Atlantic spotted dolphins, Pilot whales, Bottelnose dolphins

13:30 Atlantic spotted dolphins, Pilot whales, Bottelnose dolphins, Sperm whale

16:30 Atlantic spotted dolphins, Sperm whale