Sexual Selection

Researchers in Germany have discovered that birds make better parents when they are allowed to choose their own mates.

The researchers organised a ‘speed-dating’ event for 160 zebra finches, allowing the birds to partner up freely. Half of the zebra finch couples were allowed to stay together, while the others were broken up and placed in cages with new partners.

After five months of breeding, the number of living chicks was 37 per cent higher for those birds that were able to mate with their original choice of partner. In the arranged pairs, three times as many eggs were unfertilised, more eggs were buried or lost, and more chicks died after hatching.

The females in this group showed less willingness to mate and the males were less conscientious about looking after the nest while the eggs were hatching. The researchers concluded that zebra finches chose mating partners based on behavioural compatibility – what humans might call falling in love. This compatibility directly affected the birds’ desire to reproduce and be good parents to their chicks.

Watch Sexual Selection to learn more about how animals choose a mate.