Social life has its benefits. Animals that live in groups are better protected from predators, allowing them more time to feed and care for their offspring. But each individual within the group has different needs. For example, some may need more time to digest, while others may want to move to a new area with food or water.

To keep the group together, most social species need to make collective decisions, which is why they each have their own voting systems. Sometimes, the opinions of all individuals count equally, while for other species, only part of the group can vote. In still others, the leader holds all the power. Below are five cases in point.

Buffalo: females decide where to graze

Tanzania’s Lake Manyara National Park offers several places for buffalo to graze. In the afternoon, the herd is often found resting on the lake shore. Most lie down, but now and then a buffalo will stand up, shake a little as if to stretch its legs, and lie down again. When the sun touches the horizon, it’s time to look for a place with good grass to eat. The herd rises and starts walking in the same direction. Somehow, they all know where to go.

In the 1990s, Herbert Prins, a professor of ecology at Wageningen University in the Netherlands, noticed that when females stood up to stretch their legs, they were actually voting. After shaking and before lying down, they “looked” in one direction for a minute, holding their heads higher than when resting but lower than when alert. Once the females had expressed their preferences, the herd would move in the direction with the most votes.

Bees: scouts choose the new nest site

When a hive grows too large, the queen and half the colony leave to find a new home, while a young queen continues to rule the old nest. Selecting a new nest begins with the departure of hundreds of scout bees that go from tree to tree to inspect each cavity for the right place. They consider factors such as size, light, humidity, and temperature.

When the search ends, the scouts return to the hive and voting begins. In a kind of dance, each bee communicates the site that it likes the most, providing information about its location and its quality. The decision is made when many bees agree through their dances. A minute later, the bees are on their way to their new home.

[…]

Read more: https://english.elpais.com/science-tech/2023-05-22/this-how-animals-make-collective-decisions-bees-dance-and-the-elephant-matriarchs-decide.html