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Coleambally’s Cumbungi Channels to Coastal Coomonderry Swamp

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Demo’s Cumbungi-lined channel of choice for the 2017 winter. Photo: Mark Robb

We have six key messages from winter in this update.

1. Demo has been using a Cumbungi-lined channel in Coleambally for almost three months now. It’s about 12 km from where we caught him in summer. And just yesterday, we received a sighting of five bitterns at another Coleambally rice farm, also using a Cumbungi-lined channel. Once again, this highlights the habitat value of agricultural wetlands, the multi-functional role of irrigation infrastructure and the fact that some bitterns stay local between rice seasons, seeking out wetland habitats. There’s never been a better reason to keep some Cumbungi in irrigation channels.

Demo back in his summer breeding territory when we caught him.

2. MILo remains at Coomonderry Swamp near Shoalhaven Heads. It’s been almost four months now and as the weather warms up we’re anticipating his 600 km return flight to the Deniliquin rice farm where we caught him in summer. Coomonderry Swamp is exceedingly valuable. At 670 hectares, it’s the largest semi-permanent, freshwater wetland on the New South Wales coast. Part of it is gazetted as a nature reserve but the main areas that MILo has been using are on private land. It seems highly unlikely that he is alone or the only bittern there from the Riverina. Last month, we visited Coomonderry and informed local landholders about their special guest. There was much interest in this seemingly unlikely connection between the Shoalhaven and the Riverina. Here’s a short clip of his habitat:

Coomonderry Swamp NSW, home to MILo The Bittern

Coomonderry Swamp and MILo highlight the value of coastal wetlands to bitterns.

3. Coly-Lion caused a buzz again last week. Well, at least we think it’s him. The news comes from seasoned bittern spotters, Cam Brown and Jess Durant, at Tootgarook Swamp on the Mornington Peninsula near Melbourne. They photographed one of our satellite tracked bitterns but because it’s a bird whose transmitter has ceased working, we’re awaiting confirmation of the band colour to figure it out.

4. Sustainable Rice Platform: Sustainability in rice farming is a key global issue. Rice fields cover over 160 million hectares and provide half of world’s population with their daily staple. Have you heard of the Sustainable Rice Platform? Check it out: http://www.sustainablerice.org/ It’s a global initiative established by the UN and IRRI. It promotes best practice in areas such as water use efficiency, pesticide minimisation, improving productivity and livelihoods, greenhouse gas reduction, and biodiversity conservation. Last week we contributed to the standards and performance revision workshop in Bali, thanks to the support of Charles Darwin University. Some of the key challenges surround the trade-offs. For example, what saves water may be bad news for saving wildlife.

Bali’s Subak World Heritage sites were inspiring. This is a rice irrigation system dating back to the 9th century. Subak is also a cooperative social system of 1200 collectives with 50-400 rice farmers each. It’s deeply embedded in nature and local culture. Here, farmers still grow traditional Balinese rice without fertilisers or pesticides. The landscape is considered sacred. Temples abound. There’s plenty of Javan pond-herons too. They love the early part of the season. This rice is planted, weeded and harvested by hand. It’s hard work and profits are low. People seem happy but modernity beckons. For better or worse, some fear this ancient tradition may fade. It’s an amazing system across stunning landscapes.

 

5. A selection of recent media featuring our work:

The Irrigator:

“Riverina’s rice harvest has concluded for another year, but “tonnes per hectare” is not the only measure gaining attention.

Rice growers and conservationists have been working together to maximise the yield of young bitterns.”

The Australian:

In the early days of our project, there was a bunch of rice growers that were central in us gaining serious momentum and John Hand was one of them. Here’s his story.

North-Central CMA:

“In the past five years, there have been fewer than 10 Australian wetlands known to have supported 16 or more Australasian bitterns.”

The discovery of 16 bitterns at Lake Cullen highlights the importance of the Kerang Lakes region for waterbirds. There’s a very good chance that at least some of them are from the Riverina’s rice fields.

6. And finally, for those interested in more depth and global perspective on agriculture and biodiversity conservation, here’s some recommended reading:

First, a great article by Claire Kremen (click link below). Here’s some snippets:

“It is also urgent to understand how specific farm management practices affect species of concern, and whether practices can be adapted to favor either use of agricultural habitats, or movement through them, without negative effects on yields or livelihoods.”

“Finally, conservation organizations should continue to develop innovative programs that can support biodiversity conservation not only in natural areas but in farmlands, such as The Nature Conservancy’s Bird Returns program for migratory birds.”

How to Feed the World Without Killing the Planet?

Second, an excellent bird-friendly farming initiative by Audubon in the U.S.

Third, from last week, the session on food security and biodiversity conservation at the Resilience 2017 conference in Stockholm (click link below).

Now online: our session on food and biodiversity at Resilience 2017

Arnold’s on the move

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Witnessing these insights unfold is a joy. Three weeks ago, Arnold departed the rice field where we found him in April. He’s a young bird, reminiscent of Robbie and only about four months old, presumably born in the rice crop where we caught him. He headed 78 km west to Wargam Swamp near Boorooban, where environmental water had recently been delivered. The landholder was delighted with his VIB (Very Important Bittern) guest and is keen to tweak his management to further benefit bitterns in the future. But Arnold kept moving. He got halfway to Melbourne and we were convinced he was on his way to the coast. Evidently, Victoria wasn’t for him. He returned to his rice field in Coleambally and has since visited several other rice farms, presumably using channels and dams. He’s presently highly mobile and doesn’t seem to have found anywhere that he wants to stay.

Arnold has returned to Coleambally after venturing to Boorooban and northern Victoria.

We’ve come a long way in understanding where the bitterns go when the fields dry up and the rice is harvested. Three years ago we were hatching our plans to satellite-track these secretive birds and preparing to take on the crowdfunding world. We suspected that a large proportion of the population departed the Riverina in autumn and headed to coastal wetlands. Notwithstanding those elusive females, I think it’s now safe to say that we got it right.

The three big movers: Robbie, Coly-Lion and MILo dispersed to the coast.

In most years, outside of the rice-growing season, there is limited bittern habitat in the Riverina. Monitoring by Birdlife Australia at the Edithvale-Seaford wetlands in Melbourne showed larger numbers of bitterns during winter, which seemed to coincide with a post-harvest departure from the Riverina. With these factors in mind, it was a fair prediction. But not all of the bitterns in rice head off to far-flung wetlands on the coast. Prior to any tracking, we undertook winter and spring surveys at wetlands most likely to support bitterns in the Murrumbidgee and Coleambally rice-growing regions. We found a handful of sites – Campbell’s Swamp near Griffith, a dam at Tuckerbil Swamp near Leeton and a Cumbungi-lined drainage channel near Coleambally – that supported four or more bitterns. But none of them had bitterns in summer, so it was a reasonable assumption these sites had acted as non-breeding refuges and their bitterns had moved on to find new rice crops. In November 2015, Fivebough Swamp, also near Leeton, supported at least 34 bitterns but almost all of them dispersed with the onset of summer and the availability of rice crops with sufficient cover. We still get records of bitterns in wheat crops too. The key point is that despite the clear value of coastal wetlands, some bitterns stay. Arguably, providing refuges during the colder months of the year, within and surrounding the Riverina, will give our bitterns more options and mean less of them need to make the arduous journey to the coast.

What’s also becoming clear is that the bitterns that do leave are taking us to the foremost coastal swamps of south-eastern Australia. Robbie showed us Pick Swamp in South Australia and Long Swamp in south-western Victoria, both renowned for their conservation value. Coly-Lion took us to Tootgarook Swamp on the Mornington Peninsula. It’s considered the most important freshwater wetland in the Port Philip and Western Port Bay regions. And more recently, MILo took us straight to Coomonderry, the largest, semi-permanent freshwater swamp in coastal New South Wales. He’s been there for almost a month now. There’s been two other big movers so far; Vin from Coleambally and Neil from Murrami, both of whom we prematurely lost contact with. Vin dispersed almost 200 km and was heading in same direction as MILo before we lost contact, while Neil dispersed 450 km via Swan Hill to Moodie Swamp near Benalla. There’s a good chance they too were on their way to the coast. The extent and quality of large, freshwater coastal wetlands could be a key factor in limiting the bittern population.

The other tracked bitterns, rounding out the ten so far, have been COG, Bidgee, Cumberland and Demo. Last season, COG made local movements around Murrami but never dispersed from the rice fields and then we lost contact. The transmissions from Bidgee and Cumberland, both from rice crops near Barrenbox Swamp this past season, have been perplexing, potentially indicative that their harnesses have fallen off prematurely, the transmitters have been damaged and/or the birds are dead. But we’re not yet ruling out the possibility of dispersal that would confirm they’re in fact alive and well, and being tracked. We are watching Demo closely as well. He is making local movements around Coleambally and could disperse any day now. Will he join the coastal dispersal club, and if so, where? Watch this space …

For anyone in our nation’s capital later this month, you may be interested in heading to the Canberra Ornithologists Group meeting on June 14th at 7:30 pm. It will feature a presentation with all the latest Bitterns in Rice Project news, including population monitoring and our plans to monitor chicks with a thermal drone next season. There are also public presentations being held in Deniliquin (June 15) and Barham (June 16).

 

 

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