How long will we let deadly roadside grass slaughter kangaroos before we DO something?

Victoria’s kangaroo rescuers are facing a crisis unlike anything they had seen in years.

A silent roadside threat was leaving mobs of kangaroos stumbling, disoriented, and doomed.

For many volunteers, every rescue ended in the hardest decision of all—humane euthanasia.

The cause was Phalaris aquatica, a tall, blue-green grass introduced to Australia in 1884 and once hailed as an agricultural hero.

Originally brought from the United States and later developed into the ‘Australian’ variety in Toowoomba in 1906, phalaris became a cornerstone of livestock grazing.

Between 1990 and 2020, 4.4 million kilograms of certified CSIRO phalaris seed were sold, covering about 1.48 million hectares across the country.

Its resilience and rapid growth made it valuable to farmers but also a relentless invader.

Professor Bhagirath Chauhan from the University of Queensland described it as a fast-growing weed with seeds that could take years to germinate.

‘Even if you can stop the seed production in this season, you will get these plants in the next three to four years, definitely,’ he said.

Understanding phalaris staggers

When kangaroos grazed on phalaris in autumn and winter, they risked developing ‘phalaris staggers’.

Wildlife veterinarian Dr Tian Chen explained the grass produced neurotoxins called tryptamine alkaloids during these seasons.

Symptoms began with head wobbles and ears pointing downwards, then progressed to zigzag hopping, tail swaying, circling, and repeated falls.

In the final stages, kangaroos suffered muscle tremors, severe incoordination, and reduced awareness.

‘They may allow people to get very close to them due to their reduced awareness of surroundings, but can still be incredibly dangerous when agitated,’ Dr Chen warned.

The staggering rise in cases

The scale of the problem was unprecedented.

In July, Wildlife Victoria recorded a 433 per cent increase in cases compared to the same month in the previous year, totalling 485 incidents.

Many involved entire mobs, with few successful rescues—though four young joeys were recently saved from their mothers’ pouches.

Why a livestock cure can’t reach wild kangaroos

A solution existed for livestock—oral cobalt treatments that allowed gut bacteria to destroy the toxins—but wild kangaroos could not be treated in the same way.

Cobalt sprays, bullets, and pellets protected sheep and cattle for months or years, but these methods were impossible for free-roaming wildlife.

The human toll on rescuers

Rescuers were emotionally and financially exhausted.

‘Most cases are untreatable. Humane euthanasia is often the only option to prevent suffering which is a heavy burden for our rescuers, both emotionally and physically,’ Wildlife Victoria stated.

In just two months, the organisation had spent $100,000 on sedation and euthanasia, and called on the state government for urgent support.

Leonie, a rescuer, described the grim reality: ‘Practically everyone we attend to, we have to euthanise. It’s horrific. It’s a shocking way to die.’

She added that affected kangaroos often became aggressive: ‘They’re just very sensitive to touch. They growl a lot more.’

Managing the spread

Controlling phalaris was a long and complex process.

DEECA worked with agencies like VicRoads, Parks Victoria, and local councils, using methods such as herbicide spraying, slashing, and ecological burning.

James Todd, DEECA’s Chief Biodiversity Officer, stressed there was ‘no one-size-fits-all approach’ due to the sensitivity of native species.

Wildlife Victoria suggested replacing grazing grass with non-toxic species and eradicating phalaris where possible, but Chauhan believed it could never be fully removed.

Instead, he urged focusing on preventing its spread, given that seeds could be carried by water, animals, and machinery.

Dr Chen recommended exclusion fencing for high-risk areas like golf courses, as well as signage to warn visitors and encourage reporting during the high-risk season.

He estimated the danger period could last three to four months each year.

How you can help

What seniors could do included identifying phalaris on their property, replacing it with native grasses, reporting sick kangaroos, donating to rescue groups, and advocating for native plantings in parks.

They were also urged to keep children and pets away from sick wildlife and drive cautiously in affected areas at dawn and dusk.

While phalaris poisoning is a hidden danger along our roadsides, other threats to kangaroos can come directly from human interaction.

Feeding wild animals, even with the best intentions, can lead to injuries, illness, and distressing rescue situations.

One recent case revealed just how dangerous this can be when kangaroos became trapped after seeking out food.