Ruth Scatter, of Rangiora New Life School, asks :-

Can birds detect colour?

Andrew Grant, a zoologist with the Department of Conservation, responded.

All the evidence suggests that they can.

Birds are the most colourful of all the animal groups and it is difficult to imagine why they need to be so colourful if other birds could not recognise these colours. Most male birds are more colourful than their female counterparts and use their coloured feathers for courtship displays so without them they would not be able to find a mate and successfully breed. Colour enhancement actually improves the breeding success of some species. It has been shown that Zebra finches with the brightest red bills and legs are the most successful. Scientists studying the finches put various different colour bands on the bird's legs so that they could identify individuals. By accident, they found that the birds which had red colour bands on were more successful at breeding than those with other colours and even birds with no colour bands.

Other studies have been done to see if colouring poison baits will stop birds from eating them. It has been found that birds are less likely to eat green coloured baits.

Probably the easiest experiment to do in the classroom to investigate a bird's ability to see colours is using food. I suggest using a sparrow on normal wheat for a few days to get it used to eating it. Present the sparrow with a number of different bowls of variously coloured wheat at the same time (use the same type of dye - food colouring should do). Count the number of wheat grains in each bowl before presenting it to the bird. At the end of each day count how many of each colour have been eaten. Do this for a number of days and see if the bird is selecting specific colours. You could try mixing different coloured grains in the same bowl too. This experiment would be best done in a cage but using wild birds might work just as well.