Jack Roxborough, of Balclutha Primary School, asks :-

Why do short-tailed New Zealand bats eat nectar?

Brett Gartrell, a veterinarian at Massey University, responded.

Throughout the world there are many hundreds of species of bats and they have evolved to feed on many different foods. Some eat mainly fruits, some eat insects and there are even some bats in South America that feed on blood. There really are vampire bats, but we don't have any bats like this here.

In New Zealand, we have only two species of bats left, the long-tailed bat and the short tailed bat. The short tailed bat or peka peka is a very special animal because it is one of the only bats in the world that feeds on the ground in the leaf litter as well as by hunting insects while flying which is known as "hawking". When they hunt in the air they use sound waves (sonar) to find their prey. The short tail bat can also fold up its wings and scurry around on the ground like a mouse, which is a good way of finding insects in the leaves and dirt but it also means that the bats can get caught and eaten by stoats, ferrets and cats.

But your question was about nectar. Nectar from plants is very rich in sugars and therefore has lots of energy. Bats, and other animals such as tui, feed on nectar because it gives them lots of energy to move and hunt and keep warm. Bats are very small animals so they need lots of energy to stay alive. However nectar doesn't have many of the other nutrients like protein, vitamins and minerals that bats need so they also have to eat other food such as pollen, insects and fruit. Its like people can't live on raspberry cordial on its own, they also have to eat other things like vegetables, meat and fruit. Eating a number of different things is a good way to keep you, and the bats healthy.

Plants deliberately make nectar because it attracts animals like bats, birds and insects to their flowers. The plants can then place pollen on the head and fur or feathers of these animals while they are eating their nectar reward. When the animal visits another flower from the same type of plant the pollen is transferred across to help make a new plant. So nectar is the reward plants make for getting animals to carry their pollen for them.

You can find out more information on short tail bats at the Department of Conservation's website, http://www.doc.govt.nz/conservation/native-animals/bats/

You can find out more information on pollination at http://www.doc.govt.nz/conservation-week-home/teachers/ruud-kleinpaste-bees-bugs-birds-and-breakfast/