Friday, 23 July 2021
Green Tree-Frogs in Queensland & NSW - Death by Chytrid Fungus
The dreaded chytrid fungus is believed to be responsible for the mysterious deaths of growing numbers of Green Tree-Frogs in Queensland and NSW. Dead and dying frogs have been reported from as far north as Yeppoon in Queensland to south of Sydney. While the fungus is known to favour colder weather, a substantial concentration of deaths have not been noted previously in this species, a favourite of Australian frog enthusiasts.
The frog in the image above was found this morning in the driveway of a friend at Marcoola on Queensland’s Sunshine Coast. Like many other reported casualties, it was in the open during the day, its legs slightly splayed, and close to death. Underneath it was bright pinkish-red, a feature being noted consistently in dead frogs reported elsewhere.
Chytrid fungus attacks parts of a frog's skin that have keratin in them; frogs breath through their skin so they are effectively suffocated. The fungus also damages the nervous system. It is widespread around the world and believed to be native in Australia, but what factors trigger deadly outbreaks from time to time are not known. Chytrid wiped out several species of frog in the late-1970s that lived in mountain rainforest streams in Queensland, including the remarkable Gastric-brooding Frog (below). Hundreds of frog species around the world have been impacted.
Australian Museum biologist Jodi Rowley told the ABC this week: "We're hoping this is just a temporary thing and as soon as the weather warms up the frogs will be able to bounce back, but we are pretty alarmed. This is particularly alarming because you don't often see a dead frog – they decompose pretty quickly - so when you do see them you know that there's probably more of them around and we're very worried."
Last week, the Queensland Frog Society posted an alert on its Facebook page of reports of sick and dead Green Tree-Frogs. Within 24 hours, the society had received 50 reports from Queensland and NSW, like the one above from Scotts Head, NSW. The following are samples:
“Found one on my verandah at Nana Glen near Coffs Harbour NSW. He was red and stiff and could barely breathe. Very sad." /
“One in my shower drain looked brown on his back. I tried saving one on the patio, put him in the [frog] hotel and was dead by morning.” /
“We've also been finding dead frogs on our property. We are located in Junction Hill just north of Grafton NSW. We've noticed that it is all ages of frogs from young ones to some of our oldest that we've had here for approx 8yrs. “ /
“Emptied a half dozen at least out of tank strainer.” /
“I found 2 dead in Casino NSW. Thought it was so weird they were red in colour.” /
“I lost one of my frogs… red legs splayed out in my Moss pot. Poor fella. Yeppoon. Central Queensland. July.” Below is what a healthy Green Tree-Frog looks like.
Tuesday, 20 July 2021
1000 Hectares of Sunshine Coast Wetland Protected
Combined efforts by the Sunshine Coast Council, statutory authority Unitywater and the Queensland Government have led to almost 1000 hectares of wetland and associated woodland being protected as environmental reserve in the centre of Australia’s tenth largest city.
More property acquisitions are expected to be added to reserves as government authorities make good on promises to protect the Sunshine Coast’s so-called “Blue Heart” – 5000 hectares of the environmentally rich and diverse Maroochy River floodplain (protected areas shown in the map above). The designated Blue Heart area is described as an "innovative partnership" including the Sunshine Coast Council, Unitywater and the state Environment Department. Its aim is to "build future economic and environmental resilience, while retaining a focus on flood hazard management and climate change adaptation". However, the good news is tempered by the continuing subdivision of sugarcane farmland in the designated Blue Heart area south of the Maroochy River.
The Sunshine Coast Council recently acquired three parcels of land totalling 38 hectares in the vicinity of River Road, expanding its Coolum Creek Environment Reserve to 433 hectares. The council reserve provides important buffer zone protection for Unitywater’s 191-hectare Yandina Creek Wetland (first image in post, captured this week). Part of the buffer area is pictured above.
The protected areas includes extensive areas of grassland and wetland that provide habitat for scarce birds such as King Quail, Eastern Grass-Owl (below) and Lewin’s Rail. Together with the Queensland Government’s 342-hectare Coolum Creek Conservation Park, a total of 966 hectares is now protected in the area surrounding Coolum Creek and Yandina Creek in interconnected reserves.
Included in the council’s Coolum Creek Environment Reserve is the 90-hectare “West Coolum Wetland” (below), a diverse and bird-rich wetland sanctuary east of Coolum Creek that I proposed be protected as a reserve in 2016 (for further information see http://sunshinecoastbirds.blogspot.com/2016/09/newly-discovered-wetland-on-sunshine.html - note that Blogger no longer provides hyperlinks; URLs need to be copied and pasted to search engines).
Another part of the council reserve is a River Road property I first suggested be acquired and protected in a submission to the council in 2012 (see http://sunshinecoastbirds.blogspot.com/2012/12/wetlands-destruction.html). The council rejected the submission at the time, saying the area was not of significant environmental value and was not in a “highly strategic” location. The property adjoins Yandina Creek Wetland. The present owners will be able to continue current land uses for a further five years under a lease agreement.
Later, the council used similar arguments to reject my submission to purchase Yandina Creek Wetland (above) for a reserve. It was ultimately acquired by Unitywater in 2018 - following a concerted campaign backed by BirdLife Australia and others - and has been restored as a wetland (see http://sunshinecoastbirds.blogspot.com/2018/05/yandina-creek-wetland-back-from-brink.html). A 1.7 kilometre walking trail which was opened last year by then Unitywater chairman Jim Soorley (pictured with me below at the trail opening) has proved popular with birders and more broadly the general public.
The council has clearly turned full circle in a substantial and welcome change of heart, having now spent more than what Unitywater paid for Yandina Creek Wetland on conservation property acquisitions in the area. Following the most recent land purchases, mayor Mark Jameson (below) acknowledged that the Blue Heart area had “significant environmental and natural flood plain characteristics”, adding: “It’s an area where responsible land and water management will showcase – and deliver – exemplary environmental, social and economic outcomes.” The acquisitions by the council in the Blue Heart are a substantial contribution to protecting biodiversity and increasingly threatened habitats and wildlife in the Sunshine Coast region.
Across the Maroochy River from River Road, the story is not so rosy. The floodplains adjoining Burtons Road and smaller roads south of the river host a variety of grasslands and woodland habitat that attract vagrant shorebirds such as Pectoral Sandpiper and Wood Sandpiper (below), as well as infrequent avian visitors from the inland like Brown Songlark and Stubble Quail.
A small number of large cane farms in the area have been allowed to subdivide and much of the grassland has been bulldozed and filled for home sites in what is surely a highly flood-prone area. Earlier this year I took these images of some of the subdivided properties (below) following heavy rainfall in the region.
The area is also being used as an unofficial rubbish dump for all manner of debris (below).
These subdivisions are well within the boundaries of the designated Blue Heart conservation hotspot and stand in stark contrast to the positive developments north of the river.
Tuesday, 13 July 2021
On the Paradise Parrot, the Golden-shouldered Parrot, and fire mismanagement in Australia's tropical savanna
TRANSCRIPT OF MY FEATURE IN TODAY'S EDITION OF THE AUSTRALIAN NEWSPAPER: Eric Zillmann’s eyes twinkle as he recalls when, 86 years ago, he spotted a pair of paradise parrots while riding his horse as a young station hand on a property near the south-east Queensland town of Gin Gin.
“I remember them still, feeding on the ground and flying up into trees,” says the 98-year-old from his Bundaberg retirement village home. “I could see the lovely colours on the birds. We’d ride up there to dip the cattle once a month and I’d see them every time.”
He observed the parrots for a further three years until 1938, when he left the area. Zillmann (below) was likely the last person to see a paradise parrot, and is the only individual alive to have had the fortune to lay eyes on one.
One of Australia’s most beautiful animals, the paradise parrot is the only bird on the nation’s mainland to become extinct. It was thought to have been lost before the turn of the 19th Century but was rediscovered in 1921 near Gayndah, not far from Gin Gin, by pastoralist Cyril Jerrard.
Ornithologists this year are marking the 100th anniversary of what was regarded at the time as a natural history find of great significance for the country.
The joy was short-lived. Jerrard (below) photographed the parrot for the first time; his grainy images of birds at a nest are the only ones existing (above). Parrots were seen sporadically for a while longer, until Zillmann’s encounters. Then the paradise parrot was lost again, this time forever.
Now, the fate of the paradise parrot’s closest relative, the equally resplendent golden-shouldered parrot, is in the balance. The two species share the unusual habit of digging tunnels in termite mounds to build nests. (The mound housing the nest that Jerrard famously photographed remained intact until collapsing half a century later in 1974.) Both birds favour lightly wooded country with a plentiful supply of grass seed.
The paradise parrot (below) was restricted to a small area of southern Queensland. Its demise followed the extensive modification of its habitat for cattle pasture and the widespread destruction of termite mounds, which were highly valued as base for tennis court construction.
The golden-shouldered parrot (first image in post and below) is similarly confined to a small area of woodland but further north, in southern Cape York Peninsula. A 125,000ha cattle station, Artemis, is the epicentre of the parrot’s territory. Fourth generation grazier Susan Shepherd has been observing golden-shouldered parrots on the property for 30 years.
In that time, Shepherd says, the parrot population has crashed from as many as 2000 to 50 today. In woodland not far from the station homestead, she points to a small hole in a “witch’s hat” termite mound a metre above the ground that leads to a parrot nesting chamber used last season. “Once I’d find 100 nests or more in a season. Now it’s a struggle to find three or four. Birds are gone from many places where you could find them before.”
Shepherd (below, at a parrot nest) is battling to protect her 50 parrots and hopes to grow the population. Cattle grazing has reduced the supply of seed favoured by the birds; seed is now purchased and left out for them. A bigger challenge facing the parrots is one afflicting the vast tropical savanna woodlands that cover the northern quarter of Australia: the mismanagement of fire on an epic scale.
On Cape York, traditional light burning by indigenous people was replaced by tighter restrictions on fire after European settlement. Open grassy areas were invaded by thick scrub not suitable for parrots and other woodland animals. The vegetation provides cover for feral cats, butcherbirds and other predators which kill golden-shouldered parrots. Some cats have learned how to track down and pillage the termite mound nests.
Bush Heritage Australia estimates the total surviving parrot population is as few as 780. The conservation group is helping Shepherd to rehabilitate Artemis. A 2000ha plot has been destocked and other areas are being cleared or thinned to restore open woodlands and reduce cover for predators. A new fire regime will be implemented and feral pests controlled. “Hopefully there’s a brighter future,’ Shepherd says.
Elsewhere across the savanna belt (map below) the mismanagement of fire is wreaking havoc in a different way. The horrendous bushfires of the 2019-2020 summer in south-east Australia captured the world’s attention, but massive and frequent fires of great intensity are a common feature of the tropical north.
Data collected through LANDSAT satellite imagery estimates 20 per cent of the 1.9 million square kilometres of savanna woodland in northern Australia burns each year. Savanna fires account for 70 per cent of the area burned in Australia annually; most of the rest is in the arid inland, with just two per cent in the country’s heavily populated south-east.
Mismanagement of fire in Australia’s savanna – the most extensive area of that landscape in the world – has far-reaching consequences for biodiversity. Several threatened species have been wiped out in the rugged escarpments of the Borroloola region of the Northern Territory by fires lit by landholders. Among them was the entire NT population of a rare small songbird, the carpentarian grasswren.
Says an environmental consultant working in the area, who asked not to be identified: “Planes went up each season dropping hundreds of incendiary devices across huge areas. Everything burned. Pockets of vegetation high up in the escarpments that normally provide refuge for animals from fire were incinerated. It’s a moonscape.” Charles Darwin University researchers confirm that recent surveys have failed to find rare animals known previously from the region.
While natural open woodland in some parts of the savanna belt, like Artemis Station (below during my visit last year) on Cape York, is replaced by thick vegetation because fire is restricted, elsewhere fires for pasture improvement or control burns are lit too often or at the wrong time of year, resulting in the widespread torching of the countryside. The most fire-prone part of the most fire-prone continent is poorly managed.
Northern Australia’s 60,000-year history of fire management by indigenous people centred on fires lit throughout the year, particularly early in the dry season. Many fires today occur late in the dry season, when they are more intense due to greater fuel loads and higher temperatures.
Says Charles Darwin University professor Alan Andersen (below): “Recent decades have witnessed precipitous declines in populations of small mammals across northern Australia and changed fire regimes are implicated as an important factor.” For instance, the unusual brush-tailed rabbit-rat has been pushed to the brink of extinction on the NT mainland.
Andersen says fire is “not inherently bad”; savanna is well adapted to fire every two to five years. The severity and frequency of fire is the issue. Mammals and reptiles are vulnerable to increased predation by feral cats (below) when protective vegetation is removed.
That’s an ironic variation of the cat threat to golden-shouldered parrots: fire mismanagement threatens the survival of native wildlife in different areas in different circumstances.
Australia is the only country to include emissions from savanna fires in its national greenhouse gas accounts, with landholders earning carbon credits by reducing emissions through changed fire management. The program rewards burning early in the dry season to reduce the frequency of hot fires.
The scheme has had limited impacts on curbing the extent and intensity of damaging fires, however, and perversely creates new hurdles. Over at Artemis, carbon credits are an important money earner for Susan Shepherd, like many landholders, but they mean she can’t burn the hot fires late in the year needed to restore open woodlands. “It’s a big bad circle that keeps going round and round,” Shepherd says.
Large areas of savanna are under public stewardship. Kakadu in the NT, managed jointly by traditional owners and Parks Australia, is widely regarded as the jewel in the crown of Australia’s national park estate. Satellite imagery shows a third of Kakadu’s 20,000 square kilometres burns annually (above).
Charles Darwin University ecologist Stephen Garnett, who has conducted detailed research on fire impacts, says of Kakadu National Park: “There is a legacy of loss in Kakadu from very poor fire management that’s extended over many years. A whole lot of animals are gone.”
Another songbird, the white-throated grasswren, is found nowhere in the world but atop the sandstone cliffs of Kadadu. The bird’s population was estimated to be as high as 182,000 in 1992; today it is about 1100, perhaps fewer. Says Garnett: “It’s going to take years and a good deal of investment to turn things around. It’s been a big wet season and I fear we’re going to see big fires later in the year.”
Leading fire research scientists John Woinarski and Sarah Legge, referring to the savanna generally, conclude: “There is evidence that many species of birds and other vertebrates and plants are declining across substantial parts of this region and that current fire regimes are contributing to that decline and in some cases are the major driver of it.”
Legge says carbon emissions abatement has helped improve fire management, but climate change is making control burns more difficult because of the increasing variability of the duration and quantity of rain in the wet season.
Meanwhile, introduced grasses such as buffle and gamba are running riot across the savanna as well as over much of inland Australia. Prolific growth of exotic grasses is fuelling the intensity of fires (gamba grass alight above) and allowing them to reach previously protected areas of spinifex and other native vegetation.
The CSIRO’s Historical Records of Australian Science has published an essay by James Cook University historian Russell McGregor marking the 100th anniversary of the paradise parrot’s rediscovery. McGregor says: “Rediscovery of the paradise parrot in 1921 failed to inspire sufficient action to save the species. We can’t afford similar inaction towards endangered species today. Experts had scant scientific information on wildlife extinctions 100 years ago and even less on how to avert them. That is no longer the case.”