More than 1,600 kangaroos due to be shot in Australia for eating too much grass

The annual cull in Canberra has been delayed by animal rights groups

Eastern grey kangaroos grazing near Canberra (AFP/Getty)

More than 1,600 kangaroos are due to be killed in Australia because they eat too much grass.

The annual cull in the capital, Canberra, has been delayed amid continued protests by animal charities but is still expected to go ahead.

Adult kangaroos are shot by marksmen but baby joeys still in the pouch are often killed by a blow to the head.

Conditions in the Australian Capital Territory have been perfect for the marsupials this year and parts of the region now have the highest density of kangaroos in Australia - over 500 per square kilometre in some places.

They are regularly seen hopping around parks and reserves and the lush grass of golf courses, as well as the manicured lawns of Government House, are a favourite spot for grazing.

But encounters with kangaroos, which can be up to 7ft tall, are not always friendly for local residents.

In 2009, one reportedly crashed through a window into a family home and ripped furniture to shreds, and in 2010 a jogger was knocked unconscious after he was allegedly hit in the face by an angry marsupial.

Queen Elizabeth II and Prince Philip view grey kangaroos in the grounds of Government House, Canberra, in 2011. (Getty)

According to authorities, the cull is necessary to reduce the population of eastern grey kangaroos because they damage grassland habitats, threatening the survival of some species.

Large numbers of kangaroos can eat down the ground layer vegetation so there is no food and shelter for reptiles, insects and birds., they said.

The government is looking into an alternative to the controversial cull – contraception.

A sample of 500 kangaroos is being used this year to test fertility control, which animal rights groups argue is a more humane and cost-effective way of reducing the population.

Scientists have been studying the effects of a vaccine that stops the animals breeding for three seasons.

Animal charity Alphadog has been working with the local government to implement fertility control.

A spokesman claimed it can be delivered at “one fifth of the cost” of a cull, when the government pays thousands of dollars to marksmen.

“We prefer not to interfere with kangaroos in any way,” he added.

“We acknowledge however, the only way to successfully advocate for the immediate end to unnecessary, brutal annual culls is by presenting non-lethal solutions and alternatives.”

After a legal challenge by animal rights groups, a tribunal has ordered a temporary stay to the killing until a hearing on Thursday.

Representatives from Animal Liberation ACT argued that the government's data does not support the supposed benefits of a cull.