STATE OF PLAY NORTHERN RIVERS SPRING-SUMMER 2024: Fires and La Niña years have helped cane toads accelerate their spread in northern New South Wales

 

Atlasof Living Australia, Cane Toad Occurrence records map, Family Bufonidae, est 38,038 records 1990-2024

ABCNews, 23 November 2024:

When Rick Ensby spotted cane toads on his Woodford Island property, he was quick to call the local Clarence Landcare group.

The Woodford cattle grazier said a control officer spent nine days removing adults and metamorphs from the area.

"It had a massive effect on the number of cane toads for quite some time after," he said.

But several years later the notorious invasive pests are back in "huge numbers", despite the best efforts of Mr Nesby and his wife.

"We both work and we work the farm as well and it's quite time-consuming to go on an emu parade every night," he said.

"We definitely will do that because cane toads are quite [poisonous] to native animals and birds that we're a little bit attached to that live around the place.

"We grow hay and we don't want [cane toads] getting wrapped up in our bales of hay and possibly transported elsewhere."

But this time Clarence Landcare was only able to offer Mr Ensby collection buckets and handbooks as Local Land Services NSW (LLS) has discontinued control funding.

Funding redirected to studies

The NSW Cane Toad Biosecurity Zone shows areas in green where cane toads have become established. (Supplied: NSW Department of Primary Industries)

The Ensbys' property was previously in a DPI Cane Toad Biosecurity Zone, which meant all cane toad sightings had to be reported.

But that classification, made in 2017, has now expired.

LLS team leader for invasive pests, Dean Chamberlain, said field surveys were being conducted to determine the cane toad's range.

"We know from where the initial biosecurity line was when it was set up that they've moved considerable distances to the west and in reasonable distances to the south," he said.

"We could spend money now where control has been done in the past, but if it is 10 or 15 kilometres off the front line, then it's not really effective management of incursion."

The Ensbys' property was previously in a DPI Cane Toad Biosecurity Zone, which meant all cane toad sightings had to be reported.

But that classification, made in 2017, has now expired.

LLS team leader for invasive pests, Dean Chamberlain, said field surveys were being conducted to determine the cane toad's range.

"We know from where the initial biosecurity line was when it was set up that they've moved considerable distances to the west and in reasonable distances to the south," he said.

"We could spend money now where control has been done in the past, but if it is 10 or 15 kilometres off the front line, then it's not really effective management of incursion."

While cane toads have been spreading west at a rate of up to 60 kilometres a year in the tropical north of Australia, their spread south has generally been much slower.

But Charles Sturt University herpetologist Matthew Greenlees said that was changing.

"They were introduced around the Byron Bay area in the 1960s and they've spread relatively slowly compared to the expansion that we've seen in northern Australia," Dr Greenlees said.

"Since the bushfires and consecutive La Niña events and wet seasons, they just seem to be spreading more rapidly, particularly over the past three or four years.

"So from Angourie to Brooms Head [18km] it took them almost 30 years, but now from Brooms Head down to Diggers Camp [slightly further] we're talking five to six years."

Early signs this season

Clarence Landcare invasive species officer Matthew Morris said conditions had been perfect for breeding this season.

Bureau of Meteorology weather data shows Yamba received 615 millimetres of rain between May and August this year, almost double the seasonal average, and temperatures were also warmer than the median.

"I think the toads have done a little bit better during the winter," Mr Morris said.

"Coming out of winter we had that massive heatwave for a week and a half and that triggered a number of breeding events, which we saw very early in the season being reported to us."......

Cane Toad Calls

>https://www.pir.sa.gov.au/__data/assets/file/0011/232004/cane_toads_call.mp3

RSPSA Knowledgebase, 17 January 2024:

Whatis the most humane way to kill a cane toad?

What killing methods are being recommended?

In 2011, the Australian Government released the Standard Operating Procedure for the Humane Field Euthanasia of Cane Toads (SOP) which was based on a comparative study of the humaneness of a range of different cane toad killing methods [1]. However, this SOP has not been updated and so omits some recently developed and evaluated methods, but it still contains some useful information. No methods are listed in the SOP as unconditionally acceptable, thus highlighting the need for more research to develop a humane killing method for cane toads.

The following method is the most humane currently available to the general public:

Cooling and then freezing – one study has shown that this method may be more humane than other methods [2, 3]. It involves placing the toad in a plastic bag or container ensuring that there is sufficient cool air around each individual toad to allow for uniform cooling and freezing (e.g. place toads individually in containers). Place the container(s) in the fridge at 4°C for 12 hours, and then after ensuring the toad is not moving (it is effectively anaesthetised), transferring it to a freezer (-20°C) for at least 24 hours to painlessly kill the toad.

Gloves must always be worn when handling toads. Toads must be confirmed dead before disposal.....

How do I know when a cane toad is dead?

When using any killing method, it is essential to confirm that the animal has died before disposing of its body. Determining death can be difficult with amphibians as their heart rate is difficult to detect and respiration can occur through the skin as well as the lungs. Absence of all of the following signs will confirm that the cane toad is dead (remember to wear thick plastic gloves when handling cane toads):

• Loss of righting reflex – the toad cannot turn itself over when placed onto its back

• Loss of withdrawal reflex – no response to a light squeezing of the skin in between the toes

• Loss of deep pain reflex – no response to moderate squeezing of the toes

• No respiratory movement – no throat movements that indicate breathing

• No heart activity – no chest movement or visible pulse

Always check for these signs and do not assume an animal is dead just because it is not moving or apparently not breathing. If death cannot be confirmed, then the killing procedure must be repeated.

Locals need to keep an eye out - cane toads are on the march again in the Clarence Valley

 

Clarence Valley Independent, 24 March 2021:

They’re ugly, they’re poisonous, they’re invasive.

And they’re here, in the Clarence Valley.

Since their introduction into Australia 86 years ago, the cane toad has thrived and rapidly expanded its distribution since the first 3000 hopped into the cane fields of North Queensland after being released by the Bureau of Sugar Experiment Stations in an attempt to control the native grey-backed cane beetles which were decimating sugarcane crops and subsequently, impacting the Australian sugar cane industry.

With no natural predators or diseases which affect their population in the country, cane toad numbers exploded at an alarming rate and their presence has had devastating consequences for several native species including the northern quoll and red-bellied black snake, which often mistakes the cane toad for native frogs, only to succumb to their toxins after eating them.

After the first reports of cane toads in the Clarence Valley made headlines when the invasive species was discovered in Yamba in 2003, the recent devastating bushfires around Whiporie and Rappville, north of Grafton, have resulted in the creation of favourable travel routes for the ground-dwelling predator.

With areas of bushland and forestation cleared following the bushfires, cane toads have hopped their way south along the Summerland Way and breeched the southern containment line, the Clarence River, within the past 12 months.

In late 2020, a new population of cane toads was discovered at Mountainview, close to Grafton, when local landholders first became

aware of the recent arrivals after hearing them calling to one another across the paddocks.

A report was made to the Department of Primary Industries (DPI) who alerted local organisation Clarence Landcare to the huge biosecurity risk on their doorstep.

Clarence Landcare Educational Officer Kelly McRae, along with coordinator Debbie Repschlager, attended properties in Mountainview and confirmed the presence of cane toads, prompting them to take evasive action.

Funded and supported by the New South Wales Government through its Environmental Trust, the Clarence Cane Toad Education Project in partnership with the DPI Invasive Species Unit, Clarence Valley Conservation in Action (CVCIA), Clarence Valley Council (CVC), Yaegl Traditional Owners Aboriginal Corporation and Office of Environment and Heritage (OHE) and National Parks and Wildlife Services, aims to raise community awareness of the invasive species and educate Clarence Valley residents of the importance of correctly identifying cane toads and managing their numbers on their properties.

“The number of cane toads is significantly growing in the Clarence Valley, especially considering the wet weather the area is currently experiencing, and we want to get the community actively involved so together, we can help to stop them spreading,” Ms McRae said.

“A lot of people don’t realise cane toads are in the Clarence Valley.

“We’ve had outbreaks at Brooms Head, Shark Creek and Gulmarrad, and it’s really important people become aware of them because they pose a huge biosecurity risk, not only to native animals within the Clarence Valley, but also to the environment and people’s pets as well.”

Utilising their funding, Clarence Landcare is enabling cane toad controllers to be on the ground throughout the Clarence Valley, speaking with community members and liaising with local landholders to encourage people to do their own cane toad control……..

Describing cane toads as quite easy to catch, Ms McRae recommends people use gloves or place their hand inside a plastic bag when picking up cane toads, therefore avoiding contact with the toxin produced by the bulging glands on their shoulders. 

Once caught and secured in the plastic bag, the cane toad can then be placed into the fridge for up to 24 hours before being removed and put into the freezer for 48 hours. 

Ms McRae said the cold temperatures lull the cane toads into a sleep state and therefore, they are humanely euthanised before they can be disposed into the red bin. 

“It’s important that people ensure they are dead prior to being placed into the bin to reduce the risk of them escaping and subsequently, breeding again,” Ms McRae said. 

“Our aim is to stop the cane toads before they damage our local environment and unique ecosystem.

“We all need to work together to prevent them spreading further.”......