The X-pert Files: Mary Foster

Mary Foster works on communicating with hens in her research laboratory. Picture / Amos Chapple

University of Waikato psychologist Mary Foster specialises in asking hens questions and measuring their response. And gallus gallus domesticus, she says, is not quite as stupid as you might think.

The hens Professor Foster and her team have studied can indicate what they most prefer for dust-bathing (in general, damp peat over sand or feathers). They prefer eating whole wheat to puffed wheat and would rather be near another hen, even a domineering one, than be left alone.

They communicate their preferences by pecking certain keys, or certain keys a number of times, to achieve something.

"They have to learn to peck the key. It's not a reflex. It's learning more like the learning we do," says Professor Foster.

For example, to find out what dust bath material they prefer - dust-bathing removes excess oil from feathers - the hens are placed in a floorless cage that, according to a certain number of pecks, moves mechanically to areas of different materials.

Each hen learns to demonstrate what she wants. Even if the required number of pecks to get the peat keeps rising, says Professor Foster, they will "work quite hard" for damp peat.

"We look at the point at which it will stop pecking to get access," she says. "So the question is: How much effort are you prepared to put in?"

Professor Foster knows her work can seem quite absurd - she has heard every pun in the world about her research being chicken feed - but laughs easily about it.

However, the wider applications are profound: not just animal welfare, but communication with intellectually disabled people unable to speak.

Just because you like something, she says, doesn't mean that a person or animal will too; you have to develop ways of finding out.

But why use hens? Two reasons: "It's a behaving organism; it has things it likes and doesn't like," she says. And chooks are also relatively cheap to keep, compared with horses, possums and cows, the other animals her team has studied.

There are around 72 hens in the team's lab in rural Waikato. Some of the behavioural experiments they are involved in are computer-controlled, running 24 hours a day.

New students often assume that hens are thick, she says, but are usually "amazed" how quickly they can be trained.

"Mind you," says Professor Foster, laughing, "they always say 'I had a really bright hen'."

Like humans, some hens learn faster than others.

"What we usually learn for ourselves is if we can't get an answer that makes sense, we aren't asking the question properly."

Professor Foster also works with cows, horses and brushtail possums. Her team has assessed the food preferences of all three. In one study, possums called Ziggy, Egor, Gladwrap, Astra, Oscar and Silkie told researchers that they preferred steam-flaked barley with sunflower seeds over rolled oats or bran.