Tim Blackburn - Head of Science
What can you tell me about the kiwi?
The kiwi is a flightless bird native to New Zealand. The problem with birds of New Zealand is that they evolved on the north and south islands without any mammals. The only mammals native to New Zealand are bats, so when the first human settlers arrived they bought pests like rats, ferrets, cats and pigs with them and this was bad news for all the birds there. The new introduced species destroyed the bird populations by eating their eggs and out-competing the birds for their natural food sources. A lot of birds like the moa have gone extinct and many more like the kiwi and the kakapo (a large flightless parrot) are hardly present on the mainland. In fact there are only about 60 kakapo left in the wild, all isolated on 4 small, predator-free islands. There are 3 different types of kiwi: the great-spotted, the little-spotted and the brown kiwi. The kiwi isn’t as critical as the kakapo, but it is endangered none the less.
The kiwi is also a bit of an unusual bird. It is flightless, has very poor eyesight but a good sense of smell.
What noises do bats make?
Bats make high pitched noises that are inaudible to humans. They make clicks that allow them to find their food in a process called echolocation. Other animals like dolphins and some whales can echolocate their food.
Echolocation works like the sonar in a submarine, they make a clicking sound which travels out form the animal and bounces off of things like food items or solid barriers. The echoes from the environment then return to the animal’s ears and they use the time delay of the return to work out where things are.
What is the most endangered bird in the world?
Lots of birds are endangered in the wild like the kakapo, kiwi or Bali starling. However there are some birds like the Socorro dove that are extinct in the wild and can now only be found in captivity.
How do fish breathe underwater?
Fish breathe oxygen like you or me, but the difference is where they get their oxygen from. We breathe oxygen from the air because it is around us as a gas, so we use our lungs to extract oxygen form the air around us. However, in water oxygen exists as a liquid so fish have gills which allow them to extract oxygen from the water around them.
What can we do to preserve animals that are endangered?
Lots of things. You can give money to charity, recycle paper to slow down deforestation, save energy by turning off light switches to prevent global warming. Coming to the zoo is a great way to help conserve animals because you learn all about them and buy buying a zoo ticket you help by giving money directly to a conservation organisation.
How can we save polar bears?
Well we definitely can’t move them to the South Pole! The best thing we can do is try to save their habitat as the northern polar ice caps are melting away very quickly and dramatically reducing the space that polar bears have for living. We can slow down global warming by using less fossil fuels and being energy efficient.
Why can’t we move polar bears to the South Pole?
The polar bear is a land predator and in the South Pole there are no land predators. This means that all the seals and penguins that live in the South Pole have evolved without having to avoid predators on land. If we moved polar bears down there they would decimate the penguin and seal populations because the penguins and seals wouldn’t know how to escape form them. For instance, the emperor penguins stay on land over the Antarctic winter to hatch their eggs and raise the chicks. If polar bears lived down there then they would do terrible damage to all the breeding penguins. In the long term not only would the native species suffer but also the polar bears because food supply would rapidly go down and they’d be left with nothing to eat.