Every plant and animal needs food to survive, but sometimes there just isn't enough to go around! This means that all organisms have to compete with others for the things they need - food, as well as sunlight, water, and a good place to live.

Have you ever entered a competition or a contest where the winner got a prize for beating everyone else? This is essentially what competition in nature is like too. Plants and animals fight against others to try to win the prize: a piece of food, a sunny nest, or an empty patch of ground to grow on.

Possums compete for the same food as  tui

The organism may have to compete with other individuals of the same species, or it may compete with other species. For example, tui have to compete with each other for fruit and nectar, as well as with bellbirds and possums.

Competition is greatest if there is not much of the resource around, or if a lot of organisms want that particular resource. For example, if we gave your class 2 chocolate bars, there would be much more competition for the chocolate than if we gave your class 20 bars. If everyone in your whole school wanted to eat the chocolate then there would really be a lot of competition!

What animals does the tui compete with?

The tastiest foods, like nectar from flowers and juicy fruits, are always in high demand from the many birds and other animals that live in New Zealand's forests. Every tui has to compete with other birds-including other tui-and with wasps, possums and rats for their food.

A growling tummy can make a tui aggressive, even towards other tui that are smaller or younger. Usually, tui that are male, older, and have lived in the area for a long time are dominant over the other tui. To advertise how strong and dominant they are, tui often make a distinctive whirring noise when they fly. This noise is made by a notch in one feather of each wing.

Tui are especially competitive with the other honeyeater species, stitchbirds and bellbirds, because they feed on the same plants. Because the tui is bigger than either of these birds, the tui usually can chase the other birds off and get the best flowers with the richest nectar.

Tui have even been known to attack large birds like long-tailed cuckoos, moreporks, harriers and New Zealand falcons. However, if the fight is between them and a rat or possum, they usually can't compete.

Introduced wasps compete with tui for honeydew

Another predator that humans have introduced is the wasp, which loves honeydew as much as tui do. In some forests, wasps have eaten so much of the honeydew that they've forced many birds to move to other places for food.