Chronicle

Issue 7, September 2015

Bittern Surveys begin in

September

Matt Herring

Australasian Bittern WHERE WERE THEY AND HOW MANY WERE THERE?

Overall, in the 2014–15 season, 153 Australasian were recorded at 68 throughout , with most records once again emanating from New South Wales. This is the highest number recorded since the Bittern Surveys began in 2008 — indeed, it’s nearly twice as many as were recorded in the first year of surveys, which took place at the height of the Millennium Drought. The number of bitterns was bolstered by many detected in the irrigated rice-growing areas of the Riverina in NSW. Because the supply of water in irrigated rice farms is more reliable, birds may have gravitated towards them, preferring them over wetlands that were drying out elsewhere. It may also reflect the intensive search effort in the Riverina’s ricefields. Numbers were also up by 40 per cent in Victoria, but in Tasmania and South Australia, numbers were generally down on previous years. Bitterns were generally less widespread than last year.

New South Wales: 115 Australasian Bitterns @ 45 wetlands Central Coast 2 birds @ 2 wetlands Riverina 113 birds @ 43 wetlands (including 86 birds on 34 rice farms)

Victoria: 28 Australasian Bitterns @ 18 wetlands Gippsland 2 birds @ 2 wetlands Melbourne 14 birds @ 10 wetlands Western District 6 birds @ 3 wetlands North Central 6 birds @ 3 wetlands

Tasmania: 1 Australasian Bittern @ 1 East Coast 1 @ 1 wetland

South Australia: 2 Australasian Bitterns @ 1 wetland South East 2 birds @ 1 wetland

Western Australia: 7 Australasian Bitterns @ 3 wetlands Esperance 5 birds @ 1 wetland Albany 2 birds @ 2 wetlands

Andrew Silcocks

David Webb David Webb

2008–09 2009–10 2010–11 2011–12 2012–13 2013–14 2014–15

87 birds 94 birds 92 birds 113 birds 129 birds 131 birds 153 birds @ 40 @ 63 @ 54 @ 60 @ 78 @ 67 @ 68 wetlands wetlands wetlands wetlands wetlands wetlands wetlands

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Little Bittern WHERE WERE THEY AND HOW MANY WERE THERE?

With areas inland of the Great Dividing Range in the tightening grip of drought conditions, many wetlands are drying up. Is it any surprise that there were few Little Bitterns reported in 2014–15? Overall, there were just 32 Little Bitterns recorded at 15 wetlands across Australia. This is down slightly on the number of birds recorded last year, and matches the low number recorded in 2008–9, at the height of the Millennium Drought. It is well down — less than half — on the peak of 70 birds recorded after the Millennium Drought broke in 2010–11. Almost certainly reflecting the continuing dry conditions recorded in many parts of eastern Australia, it is difficult to know whether their numbers have decreased dramatically or are they just getting more difficult to find? In some years, Western Australian wetlands have dominated the counts of Little Bitterns, but this year there were no reports at all west of the Nullarbor.

Queensland: 8 Little Bitterns @ 7 wetlands North East 2 birds @ 2 wetlands South East 6 birds @ 5 wetlands

New South Wales: 14 Little Bitterns @ 5 wetlands Central Coast 1 bird @ 1 wetland Riverina 13 birds @ 4 wetlands

Victoria: 10 Little Bitterns @ 3 wetlands Melbourne 1 bird @ 1 wetland North Central 9 birds @ 2 wetlands

Andrew Silcocks Jackie Shepherd

2008–09 2009–10 2010–11 2011–12 2012–13 2013–14 2014–15

32 birds 38 birds 70 birds 38 birds 42 birds 35 birds 32 birds @24 @ 26 @ 31 @ 28 @ 26 @ 26 @ 15 wetlands wetlands wetlands wetlands wetlands wetlands wetlands

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Keeping an eye on Robbie FROM THE RIVERINA’S RICEFIELDS TO THE COAST

Matt Herring

Understanding the movements of a species is vital for its conservation. With the Australasian Bittern officially classified as Endangered in Australia, if we are going to save the species, it is important to know its basic movement patterns. Robbie, an Australasian Bittern that was fitted with a satellite tracking device, has revealed some of his species’ secrets.

We know next to nothing about the movements of Australasian Bitterns in Australia. There have been precious few of them banded, and most of our knowledge has come from inferences based on the presence or absence of birds at particular sites. This can be particularly unreliable with birds that are so cryptic.

Back in 1990, the Handbook of Australian, New Zealand and Antarctic Birds stated that the Australasian Bittern is “Probably sedentary in permanent habitat but possibly regular short-distance movements during winter and occasional irruptions associated with wet years.” It went on to say that there was no overall seasonal pattern to their movements.

In short, we didn’t really understand much about the ecology this species — after all, it had attracted very little study before the Bittern Project was established.

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A crowdfunding campaign was launched early this year to raise funds to buy satellite tracking devices that would allow us to follow the movements of bitterns. Fortunately it was very successful, with over 300 people and 20 community groups contributing funds. Then, with the trackers now in hand, all it needed was to get some bitterns to wear the devices.

In early 2015, a concerted effort was made to catch some bitterns so that they could be fitted with satellite trackers. Rather than try the hit-and- miss method of catching them in mist-nets, it was decided to stalk individual birds and capture them in a net fired from a special net-gun.

Matt Herring The rice fields of the Riverina seemed like a good place to start. After a few unsuccessful attempts — we’ve discovered that Australasian Bitterns are remarkably difficult to catch — we finally had a male bittern in the hand on 21 April. Soon, his satellite-tracking backpack was placed onto his back and he was quickly released (after being christened ‘Robbie’, after Mark Robb, a great supporter of the Bitterns in Rice project). Soon he was lost to view among the rice, but we knew exactly where he was.

For the first week or so he was active around Coleambally, moving no more than a kilometre around his local area, making the local movements that the Handbook had talked about, but on 30 April he set off on a longer journey, heading south-west towards Deniliquin. From there he crossed the Murray and headed directly across western Victoria, not stopping till he’d reached Pick Swamp in the South East of South Australia, a well-known stronghold for the species in winter.

It had been suspected that bitterns moved from the ricefields of the Riverina to spend winter at coastal sites, and now Robbie had provided some proof! After his long flight, he seemed to have itchy feet, and was not content to stay at Pick Swamp for long. After a brief flight out to sea, courtesy of gale-force winds, he headed to Long Swamp in south-western Victoria. His arrival there was a fitting vindication of restoration works at the site, which had been completed just a fortnight before. He’s been at Long Swamp for the rest of winter, again making many local movements (see below).

With the next breeding season under way soon, we’ll be able to continue to follow Robbie’s movements and see whether he returns to the ricefields of the Riverina, stays near the coast, or does something else entirely!

STOP PRESS!! Robbie has just moved back to his old haunts in the Riverina. He recently flew express from Long Swamp to Lake Wyangan, near Griffith, then, on 20 September, headed 70 kilometres south to Coleambally, just 12 kilometres from where we attached his transmitter!

Top: Satellite-tracking device attached to Robbie’s back. Above left: Robbie’s 557 kilometre trip from Coleambally to the coast. Above right: Some of Robbie’s local movements since he arrived at Long Swamp.

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Bitterns in Rice BITTERN BUSINESS IS BOOMING IN THE RIVERINA

By Matthew Herring, Neil Bull, Andrew Silcocks, Mark Robb, Wayne Robinson and Inka Veltheim

Andrew Silcocks

Because the Australasian Bittern is such a secretive and cryptic species, there is much that we don’t know about basic aspects of its ecology. By staying well hidden in the cover among the reeds and other dense wetland vegetation, many facets of the species’ life have remained secret. Until now!

The Bitterns in Rice project is the first time that researchers have been able to get up close and personal to this enigmatic bird, and little by little, its secrets are being revealed. This has been enhanced by advances in technology which have seen clones sent in to scan ricefields for bittern nests, and net-guns which have allowed us to catch wild birds and fit them with special devices to track their movements (see ‘Keeping an eye on Robbie’ on pages 4–5).

With every piece of new information we’ve gained, we have been able to unlock another of the bittern’s secrets.

Australian rice crops provide an extensive area of habitat that is suitable for bitterns to live in, and as it is kept watered by irrigation, the conditions in ricefields are often more reliable than in natural wetlands. Given this, it is hardly surprising that the ricefields in the Riverina of New South Wales support the largest known breeding population of Australasian Bitterns in the world.

Thanks to funding from Riverina Local Land Services, the Bitterns in Rice project recently completed the surveys for its third rice-growing season, and it’s our best sample yet. We surveyed 80 sites covering 2050 hectares of rice on 41 randomly selected farms.

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We have much analysis ahead, but it’s already clear that in most years, between 500 and 1000 bitterns descend on the rice crops of the Riverina district. That’s between a quarter and a third of the entire global population of the species. Last breeding season, we were able to find seven nests, all on randomly selected rice farms, which indicates that breeding activity was widespread in the region. Importantly, we were able to confirm that at least some of the breeding attempts had been successful, as we observed a number of fully young bittern fledglings.

There are two words that usually accompany any summary of the Australasian Bittern’s breeding activities: ‘poorly known’. For example, there are just three records in the Nest Record Scheme, and there is precious little information that has been published on the breeding of the species. And although this situation is still true, they are now slightly less poorly known than they were before our monitoring began.

First of all, we have now confirmed that Australasian Bitterns do actually breed in rice crops. It seems logical, but until this project commenced, it had never been recorded before in Australia. Further, with seven nests discovered in the last breeding season, we are beginning to understand many aspects of bittern breeding ecology, from clutch size and nest design to the survival of nestlings and the movements of fledglings. We’re also discovering information about their social organisation during the breeding season. For example, intensive monitoring of bitterns nesting in the Riverina’s rice crops has revealed that the species is polyandrous, meaning that they have more than one mate at a time. This was shown when three active nests were discovered in a single territory on a farm near Griffith recently.

For more information about the Bitterns in Rice Project check out the Bitterns in Rice website: www.bitternsinrice.com.au.

Reed all about it BITTERNS IN RICE: HOT OFF THE PRESSES

The Bitterns in Rice project has produced a full- colour booklet which tells you all you’ll ever need to know about the project. It includes a summary of the project and what it aims to achieve; it explains the partnership between BirdLife Australia, the Ricegrowers Association of Australia and the Riverina Local Land Services, and tells you everything you could ever want to know about Australasian Bitterns, as well as tips on bittern- friendly rice growing and details of some of the project’s achievements so far.

If you’d like a copy of the Bitterns in Rice booklet, head to www.bitternsinrice.com.au/wp- content/uploads/2015/08/Bitterns_in_rice_summary _booklet_July_2015.pdf to download your copy.

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Introducing the Boom Index

By Andrew Silcocks

The Bittern Project is setting up a long-term monitoring project for Australasian Bitterns that’s easy to take part in and will provide scientifically robust data that will allow us to produce an annual population index. To achieve this we are setting up a network of sites across the bittern’s range where people can record the number of booming birds. The sites are representative of the bittern’s distribution and potential habitat, and are reasonably accessible. Rice crops will not form part of this study, as the area cropped varies considerably, the growing season is late and because they’re being studied separately.

If you would like to participate, please contact us.

Bittern calls In spring and summer, males utter a distinctive, resonant bass booming call, preceded by up to three short, quieter gasps (inaudible at a distance). This call may occur in sets of several booms. Calling is associated with breeding and is most often heard at dawn and dusk, and may continue well into the night. Calls may carry over long distances in still air, and have been likened to a distant foghorn. If heard well, this booming is unlikely to be confused with any other species, though observers should be beware of the first part of the ‘thumping’ call of Purple Swamphens or Black Swans, and cattle making unusual noises.

Site requirements Key bittern sites across the Australasian Bittern’s range need to be surveyed each year, so observers must be committed to surveying them. Someone will have the responsibility of coordinating surveys at each site, which should be visited twice in spring–early summer.

Survey requirements A survey should be conducted during: (i) mid-September to the end of October (ii) early November to mid-December

Surveys could be carried out over a one hour period, either from: • half an hour before dawn to half an hour after • or half an hour before dusk to half an hour after Surveys need to be conducted in good weather conditions — of primary importance is little or no wind.

The number of observers required at each site will depend on the size of the wetland.

Small wetlands Only one observer or survey team should be required. Locate the most suitable site for listening out for bitterns and conduct your survey.

Large wetlands — Triangulation method At large sites, observers should be stationed around the wetland at strategic points to ensure complete coverage, for triangulation of their records.

At each point around the wetland the observer/team will record their position (lat/long). Each calling bird should be given a code (A, B, C, etc.), the direction (compass bearing) to the bird recorded and an estimate of the distance to calling bird (at least ‘close’, ‘far’, ‘very far’). Then the start time of each call- train for each bird is recorded to the nearest minute. The number of calling birds at each wetland will then be calculated by triangulation of the calling birds based on the time of the calls and the distance to the bird in relation to the surveyors around the wetland.

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Booming Bittern Record Sheet

Name/s: Andrew Silcocks Home Phone: Email: [email protected] Survey Date: 30/09/2015 Survey Time Start 19:00 . Survey Time end 21:00

Site Details: Location: Bool Lagoon GPS of your listening site: Lat 37° 07’ 26” Long 140° 41’ 59” Datum: (if known) AUS / WGS 84

Weather Conditions: CLOUD COVER WIND CONDITIONS MOON PHASE Clear Calm If known please note Patchy/Overcast Light breeze moon phase:

Raining Windy Full

Record information for each calling bird: Time calling Compass direction Est. distance to No of ‘OOMs’ in started of calling bird bird (m) sequence Example 20:05 150º 250m 3 Bird A 19:30 140 300 3 Bird B 19:31 130 800 4/2 Bird C 19:31 160 600 3 Bird D 19:32 100 1000 4 Bird E 19:35 180 400 3 Bird F 20:02 10 250 2 Bird G

Record the birds calling each minute, e.g., 20:05 A, B, E Time Birds calling Time Birds calling Time Birds calling Time Birds calling __:00 19:30 A 20:00 A __:30 __:01 __:31 B, C __:01 __:31 __:02 __:32 A, D __:02 __:32 __:03 __:33 __:03 __:33 __:04 __:34 A, B __:04 __:34 __:05 __:35 A, E __:05 F __:35 __:06 __:36 B __:06 A, F __:36 __:07 __:37 __:07 __:37 __:08 __:38 A, C __:08 __:38 __:09 __:39 E, C __:09 F __:39 __:10 __:40 __:10 __:40 __:11 __:41 __:11 __:41 __:12 __:42 A __:12 __:42 __:13 __:43 __:13 F __:43 __:14 __:44 D __:14 __:44 __:15 __:45 __:15 __:45 __:16 __:46 E __:16 __:46 __:17 __:47 __:17 __:47 __:18 __:48 A, C __:18 __:48 __:19 __:49 __:19 __:49 __:20 __:50 B, E __:20 __:50 __:21 __:51 __:21 __:51 __:22 __:52 __:22 __:52 __:23 __:53 A __:23 __:53 __:24 __:54 __:24 __:54 __:25 __:55 __:25 __:55 __:26 __:56 D __:26 __:56 __:27 __:57 __:27 __:57 __:28 __:58 __:28 __:58 __:29 __:59 __:29 __:59

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It’s not just about bitterns

By Matthew Herring

As a threatened species, the Australasian Bittern is not alone in its use of the ricefields in the Riverina. The combination of lush vegetation and a reliable water supply makes the Riverina’s rice crops perfect habitat for other wetland-dependent wildlife. These agricultural wetlands now form part of a network of important habitats for some of our most threatened species. Australian Painted Snipe — classified as Endangered — were recorded among the rice crops during the 2012–13 season. And it wasn’t just one or two of these hard-to-see birds, but hundreds of them.

In addition, several Eastern Grass Owls were also found roosting among the vegetation in the ricefields, while populations of the Southern Bell around Coleambally and in the western Murray

Andrew Silcocks Valley are among the largest known for the species.

Not where you’d expect to see one

By John Peter

Australasian Bitterns are renowned for their preferred habitats — usually dense wetland vegetation, especially beds of reeds or rushes, or among luxuriant rice crops. The structure of these two vegetation types is quite similar from a bittern’s point of view — lots and lots of vertical stems.

They are, however, sometimes spotted in unfamiliar territory. A bittern I saw while I was taking part in an Orange-bellied Parrot survey in the saltmarsh at Lake Connewarre was one such bird.

After an hour or two of sloshing through the saltmarsh, the survey was beginning to become a bit of a chore, especially as I hadn’t seen any Orange-bellied Parrots. However, as I reached the farthest point of my walk, I saw what appeared to be an old hessian sack lying among the low saltmarsh. Then it moved.

A quick glance through my binoculars soon revealed the sack was actually an Australasian Bittern. According to the Handbook of Australian, New Zealand and Antarctic Birds, the species sometimes frequents “beds of rushes or reeds in saltmarsh”, but there were no reedbeds anywhere nearby. Instead, the bird was surrounded by many hectares of low saltmarsh which barely reached part-way up its legs, meaning that the bird was completely in the open, with nowhere to hide.

Apparently aware that adopting its usual ‘bitterning’ posture — with its neck stretched upwards and its bill pointed skyward — would have made it more conspicuous rather than making it disappear into its surroundings, the bird decided to ignore me, and continued creeping about among the Sarcocornia.

What it was doing there was anybody’s guess. Perhaps it had been aiming for nearby Reedy Lake, but was caught short.

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Bitterns in Western Australia

By Deb Sullivan

Last season, Australasian Bitterns proved to be particularly elusive in Western Australia.

There was a distinct silence in the wetlands between Albany and Cape Arid throughout the breeding season — a lone bird was heard giving a half- hearted call on a couple of nights near Albany, but apart from that, nothing!

Australasian Bitterns are classified as Endangered in Western Australia, but despite the species’ undoubted rarity in the state, it is still a mystery why there were so few records of the birds last year. Presumably it is linked to the excessive rainfall which fell in the region in the lead-up to the breeding season (and it continued through it as well), but how it may have influenced the birds is not yet known. Perhaps the bitterns began their breeding cycle much earlier than we’d expected, and so the conspicuous aspects of their breeding activities were over by the time we began to monitor the wetlands. Or did the excessive rainfall ‘wash out’ their breeding season altogether? The answers to these questions will only be revealed by discovering more about the ecology of this elusive species, and that can only happen with increased levels of monitoring.

What a difference a year makes! So far, the 2015 breeding season has been under way for several months, with some of the birds heard calling at three different wetlands since late June.

Over the last 18 months, we have surveyed over 1300 hectares of wetlands between Albany and Cape Arid on the South Coast, but despite this extensive coverage only 14 Australasian Bitterns have been located. The birds are truly a rarity in this part of the world, but the signs suggest that

there may be more activity to report on this time next year. Andrew McCutcheon

Have you taken a great photo of an Australasian Bittern or a Little Bittern lately? If so, we’d love to see it. Send your bittern images to [email protected].

For detailed instructions, identification kits and survey forms, head to the BirdLife Australia website at www.birdlife.org.au/our-projects/bittern-survey.html or contact Andrew Silcocks on (03) 9347 0757.

CONTACT US

BirdLife Australia Suite 2–05, 60 Leicester Street Carlton VIC 3053 T: (03) 9347 0757 E: [email protected]

The Bittern Chronicle was compiled by John Peter Printed on 100% recycled paper

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Searches in spring–summer 2015–16

Varying conditions in various parts of Australia this year may have different effects on people’s efforts to find bitterns. In some areas, many wetlands have been topped up right when bitterns should need them most — bittern breeding conditions are likely to be suitable in many areas, meaning that calling males may be conspicuous, and later in the season, a new generation of juvenile bitterns may bolster the overall population. However, as many wetlands contain water at the moment, it may be akin to searching for a needle in a proverbial haystack. Alternatively, in the areas of Australia that have been experiencing another serious drought, many wetlands are dry, making them easily discounted for bittern searches, and making those which still hold water possibly more likely to attract any bitterns in the vicinity. This spring–summer we need to cover as many wetlands as possible as often as possible. Ideally, searches should begin in early September, with monthly surveys conducted through until March next year. To take part in the Bittern Survey, all you have to do is head off to your local reedbed around sunrise or sunset to listen for the distinctive calls, or walk a transect through the reeds at any time of the day. The more we find out about Australia’s bitterns, the better chance we have of preserving them. For more information, hit the website: www.birdlife.org.au/our-projects/bittern-survey.html.

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The Bittern Chronicle

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