Armed with some amazing senses and skills, animals can communicate in many different conditions, some of them extreme and challenging. On this page we have picked out some fascinating examples from the environment featured in the programme Crowded Worlds.
Crowds of animals can form a bewildering spectacle, and create an overwhelming noise, making communication with any particular individual difficult. When crowds co-operate, communication is needed to co-ordinate the masses.
In some animals, like fur seals, parents need to leave their babies in order to hunt. On their return, finding their offspring amongst a million teaming bodies is no mean feat. Fur seals use voice to recognise their offspring. They are 'tuned in' to a particular voice, so can pick it out from the crowd, in a similar way that we pick out our name at a noisy party.
Flamingos also need to recognise their young, who are left in creches, but they have another problem - they mate with the same individual each year, so need to locate their mates at the start of the breeding season. They have distinctive calls, which are low in frequency, allowing them to travel better through the flamingo's bodies. Their calls are in two frequencies which combine to form 'pulses' of amplitude which are distinctive for the individual birds.
When crowds co-operate, they need to ensure that individuals pull their weight. White-winged choughs in Australia have found a good way to do this. The choughs live in a harsh, dry environment, and it takes a large group of co-operating birds to feed a nest of chicks enough to survive. Young from the previous year stay at home to help their parents, but the helpers get hungry themselves, and are sometimes reluctant to give food to the chicks. They will sit by the nest waiting until no-one is watching, then greedily eat the food intended for the chick. If they are spotted doing this, the whole group will surround the guilty individual, boggling their eyes, flapping their wings and screeching.
Ants also need to co-ordinate large crowds. They commonly use scent trails to communicate the location of food, but fire ants have a more unusual way of sending a message. They use an 'alarm call' to alert others when they are disturbed, and the ants respond by all stinging at exactly the same instant - a good deterrent to any intruder!
Humans are the best communicators on the planet, and many of the latest new technologies, e.g. WAP phones, the internet and satellite links have been invented to help us communicate even more effectively.
