Australian_Geographic_-_February_2016_

January. February 79

B

RUMBIES GENERALLY belong to

one of two social groups in

the wild. The first is a harem that

usually comprises one dominant

stallion and three or more mares

and their offspring, which tend to

live near reliable water.

The second is the more change-

able bachelor group: generally

1–3 males of two years or older,

including retired males, who have

dispersed from a harem and tend

to range further afield.

In northern Queensland, horse

mobs have been found to have

home ranges of up to 10,000ha;

in Central Australia that range

may be 7000ha, and in south-

eastern Queensland 2000ha.

Wild horses can travel vast

distances to water or feed. “Some

of our collared horses went five

days without water and travelled

55km, with a foal at foot, to graze,”

says the University of Queensland’s

Dr Brian Hampson, who radio-

tracks horses in Central Australia.

“Up to 75 per cent of the horses

in the desert die in a bad drought,

so the 25 per cent that breed on

are real survivors and benefit from

30 generations of adaptation to

this harsh environment.”

In contrast, wild horses in

south-eastern Queensland seem to

enjoy a more sedentary lifestyle

due to the availability of good

pasture, water and shelter. High

horse density coupled with steady

population growth has seen horses

expand into new areas and survive

well, says ecologist Dr Magdalena

Zabek, who has studied wild horses

extensively in Central Australia and

southern Queensland.

“I think it is the ability to adapt

to different environments, temper-

atures and food availability that has

allowed horses to spread across

the country,” she says.

WILD HORSE DYNAMICS

Australia’s brumbies are known for their keen

eyesight and hearing, and have slightly shorter

necks and backs than domestic breeds.

LOUISA KELLAND