Capricornia Cays Survey Holiday – 2. Northwest and Masthead Islands

I forgot to mention that it’s very hot and sweaty in Paradise! And there are no showers or other ablution resources on Northwest Island. So an hour after dawn I gave up trying to doze through the never-ending noddy chorus and wandered down to the beach, past those nesting turtles that hadn’t quite finished concealing their repository of eggs, for a 5:30 am swim. Even at that hour the water was beautifully refreshing, though it did leave its salty stickiness to prickle my skin for the next little while. This would be my routine for the next few days.

The shallow reef waters were just perfect for swimming - or for an early morning bathe before the heat of the day set in; with no facilities for showering, this was virtually a requirement.

The work ethic for the first two to three days was fairly protestant. A 6:00 am start, breakfast over and cleared up by 7:00, surveying from 7:30 until lunchtime, and a few more hours after lunch to finish off for the day. Following this basic schedule, most teams would be done by mid- to late-afternoon. Sometimes, a team might decide to work through lunch and finish their transects for the day by early- to mid-afternoon. Either way, there was usually time at the end of the day for people to relax, chat around camp, go swimming, explore the beaches, or do some birdwatching.

"Camp" was the centre point of our activities - a hub for socialising and of course eating. The catering by Amanda from Wild Mob was excellent and she did a remarkable job given the conditions. 

 

Buff-banded Rails (Gallirallus philippensis) are generally shy and elusive on the mainland but tend to be much more brazen on islands of the Great Barrier Reef and will readily come into camp for free handouts.

It was a hard slog in the hot and humid conditions but, thankfully, there was reasonable cloud cover much of the time, and generally a decent breeze; so not as bad as it could have been. Things were made more difficult by the snowshoes. Yep – snowshoes! Never before, I think, have 17 pairs of snowshoes been taken to a tropical island. Bemusement would turn to amusement as the purpose of the snowshoes was explained to the few campers on the island who were intrigued enough by our activities to ask. But their use, despite being cumbersome and awkward, was worthwhile to minimise the number of burrow collapses we caused as we made our way through the soft sandy breeding grounds under the pisonia trees.

Snowshoes were worn when traipsing across the burrow-ridden sandy expanse of a shearwater colony to minimise the risk of collapsing burrows. Awkward, cumbersome, and ludicrous in appearance, but effective. Other essential equipment included a "waddy" (1 m length of garden hose), a measuring tape, water and a hat.(Photo courtesy of Chris Lloyd)

Feeling for Wedge-tailed Shearwaters in burrows and counting Black Noddy nests in trees - the two key elements to surveying each plot. (Photo courtesy of Chris Lloyd)

Every so often, walking between survey plots, you would come across something a little unexpected. A huge spider on the trunk of a tree you’ve just put your hand on for balance, or an immaculately manicured path (a shearwater runway) in the middle of nowhere. Or your attention might be drawn by a Capricorn Silvereye (the local island subspecies of Silvereye) fossicking in the shrubberies; or yet another species of tiny jumping spider (the islands seemed to be over-run with these) looking at you from a pisonia leaf.

This beautifully manicured pathway over-arched by pisonia boughs leads to - nowhere! - it is not man-made at all. It is a shearwater "runway", that we happened across between survey plots at the eastern end of Northwest Island. It is the result of many thousands of shearwater feet pattering along, night after night, to aid their take off as they head out to feed in the surrounding seas. (Photo courtesy of Jade Fennell)

The islands of the Capricorn Group have their own subspecies of Silvereye known, not surprisingly, as the Capricorn Silvereye (Zosterops lateralis chlorocephala) - more robust and with some differences in life history, it is sometimes regarded as a distinct species, the Capricorn White-eye. 

This huge huntsman spider (Family Sparassidae) was quietly minding her own business on the trunk of a pisonia tree we had just passed. Thanks to Jade for the use of her camera for this photo. 

Jumping spiders (Family Salticidae) seemed to be everywhere on the islands: brown ones, grey ones, starkly black and white ones, and this one beautifully marked in crimson, brown, green and white. At the time I had my 400 mm lens attached and the photo had to be taken from more than 2 m away, so it's unfortunately a bit too blurry to see the immaculate colour scheme. 

This young female St Andrews Cross Spider (Argiope keyserlingi, Family Araneidae) was on Masthead Island.

Late on the afternoon of the second full survey day I was wandering along the beach and came across a high tide wader roost. There were over 150 birds of 14 species all milling about on the beach or perched on the sun-and-salt bleached fallen trees.

High tide wader roost - heaven for a birdwatcher! Species present were Bar-tailed Godwit, Wandering Tattler, Grey-tailed Tattler, Great Knot, Common Greenshank, Ruddy Turnstone, Pacific Golden Plover, Lesser Sand Plover, Greater Sand Plover, Australian Pied Oystercatcher, Silver Gull, Crested Tern, Lesser Crested Tern and Little Tern.

Even with a 400 mm lens I had to approach the birds slowly to get close enough to get enough shots to be sure I could subsequently ID all the species. I took 70 photos of this roost.

Lesser Sand Plovers, a Greater Sand Plover, Pacific Golden Plover, Little Terns, a couple of Lesser Crested Terns, a godwit...

Amongst the 18 Bar-tailed Godwits were five Great Knots - similar in plumage but smaller than the godwits, more portly, and with a shorter all-dark bill.

Two of the trio of Common Greenshanks, with their long legs and long, slightly up-turned bills.

The weathered branches of fallen casuarinas were a favoured perch for these Wandering Tattlers.

After two and a half days of surveying on Northwest Island we had it covered. All 223 survey plots along the 25 transects had been completed. At this point, the “parkies”, the “birdies”, and the film crew left the Wild Mob group and Northwest Island to head down to Heron Island. But we were back again a few days later to pick up the Wild Mob volunteers in order to survey Masthead Island an hour or so to the south-west. Masthead Island (so named by Matthew Flinders in 1802 when it was sighted in the distance “A low island was seen from the mast head, bearing north at the supposed distance of six leagues, of which Captain Cook does not make any mention”) is a smaller version of Northwest Island but with no facilities at all and no campers, and the surveying was completed in a matter of hours. The tide was in when we finished so we had to wade out from the beach to a sandbar at the edge of the reef platform to be picked up by Rod in the Reef Heron’s tender.

Weary surveyors wading across the low tide reef flats to be picked up and taken back to the Reef Heron.

Waiting our turn at the lee edge of Masthead Reef to be picked up in the tender. 

Back at Northwest, we dropped off and farewelled the Wild Mob volunteers for the last time and headed back to Heron Island. It was a pleasure and privilege to meet and work with these guys. Their enthusiasm and commitment to the surveying, which was not always pleasant or easy, made the job enjoyable and fun.

The 2014 survey team. 

Capricornia Cays Survey Holiday - 1. Arrival

In January this year I was lucky enough to be involved in a seabird breeding survey, taking in several of the coral cays of the Capricorn-Bunker Groups that make up the Capricornia Cays National Park and straddle the Tropic of Capricorn at the southern end of the Great Barrier Reef. The survey was organised and run by the Queensland Parks and Wildlife Service (QPWS), with volunteer assistance from four Australasian Seabird Group (ASG) members (including myself) to provide additional seabird and surveying expertise, and a dozen energetic, interested, intelligent young volunteers recruited through Wild Mob, an outfit which facilitates participation in on-ground conservation and environmental management projects.

The beach on Lady Musgrave Island with Fairfax Islands in the distance. This is fairly typical of the conditions we had to put up with for the duration of the surveys, but someone has to do it.

The project was to survey the breeding distribution and density of Wedge-tailed Shearwaters, Black Noddies, and Brown Boobies on several of the larger and more important breeding islands for these species. The islands surveyed were Northwest Island, Masthead Island, Heron Island, and Lady Musgrave Island for the shearwaters and noddies, and Fairfax Island for the Brown Boobies.




View of Lady Musgrave Island from our anchorage outside the reef flats.

This was the 2^nd of three proposed annual surveys to follow up on work done in the late 1990s and 2000 to monitor the populations and levels of breeding of these species. The Capricornia cays support some of the largest remaining stands of pisonia forest, an endangered ecosystem, and consequently harbour some of the largest breeding populations of Wedge-tailed Shearwaters and Black Noddies in the world.

Mature pisonia forest (Pisonia grandis) growing on coral rubble on Lady Musgrave Island. Pisona often dominates mature coral cay vegetation and trees can be up to 20 m tall - way taller than I was expecting prior to arrival. 

Northwest Island, the largest island in the group at almost 1.75 km long and up to 850 m at its widest, is the most important breeding island for the Wedge-tailed Shearwater on the east coast of Australia - it is estimated to support about 300,000 breeding pairs, as well as 100,000 breeding pairs of Black Noddies. The smaller islands support smaller but still significant breeding colonies of these species.



The three main plant species other than pisonia on the coral cays are casuarinas, pandanus and octopus bush, which make up the fringing vegetation on these islands. 

The Wedge-tailed Shearwater Puffinus pacificus (wedgie) is an ocean-going seabird that ranges throughout the tropical Pacific and Indian Oceans. It is a burrow nester, excavating its burrows in sandy soils on islands throughout its range. The eastern Australian population breeds on islands from Montague Island (off Narooma, NSW) in the south to the islands of the Great Barrier Reef, and probably ranges in the non-breeding season to as far north as the Philippines.

Wedge-tailed Shearwater Puffinus pacificus in its more typical habitat - the open ocean. This photo was taken about 30 km east of Wollongong, NSW, in December 2013. 

On land, the Wedge-tailed Shearwater is not quite so graceful; after feeding at sea during the day they tend to sit about on the ground at night, gently wailing to each other.  

Wedge-tailed Shearwater burrows are about 2 m long and are excavated in sandy soil. Roots and fallen branches can help brace the entrance, as well as make it more difficult for surveyors to get their arms down them. 

The Black Noddy Anous minutus is a distinctive bird related to the terns; it is sooty black with a silver-white cap so is also known as the white-capped Noddy. The species has a tropical and subtropical distribution across the Pacific and Atlantic Oceans, including the Caribbean. It is essentially sedentary, is gregarious and strongly colonial in its nesting, building substantial but flimsy nests of leaves glued together with faeces. In the Capricornia cays they have a strong preference for nesting in pisonia trees, but I also saw the occasional nest in the fringing casuarinas, pandanus or even octopus bush. The Bunker Group of the Capricornia cays is the southern limit of their breeding islands along the eastern Australian coast but they also breed (further south) on Lord Howe Island.

Black Noddy in flight - mostly silhouetted but producing a distinctive noddy appearance.

Noddies are highly gregarious and may spend a lot of time sitting together in trees - here they are in an octopus bush (Heliotropium foertherianum, previously Tournefortia argentea).  

Black Noddies are stunning birds with their sooty black plumage and prominent silver-white caps and eye-liner. They nest colonially, building a nest of pisonia leaves glued together with faeces. 

The Brown Booby Sula leucogaster is also a widespread tropical species, occurring in Pacific, Indian and Atlantic Oceans, and in the Caribbean. The Bunker Group of the Capricornia cays is the southern limit of its breeding range in eastern Australia. It nests colonially, essentially in the open on exposed islands, and the nest can be as little as a scrape in the ground depending on what padding or adornments might be available. On Fairfax Island they nest on and amongst the coral rubble, each nest just snapping distance from its neighbours.

Brown Boobies in flight are both majestic and comical.

Booby chicks are pure downy white when young and progressively moult into the smart brown and white adult plumage.

I won’t pre-empt the results of the surveys; that’s the domain of QPWS, and besides I wouldn’t know; but observationally and anecdotally, it appears that the numbers of breeding birds this season may be down on last year.


Anyway, getting back to the trip itself… The ASG contingent (Chris, Mark, Dave and myself) all met up in Gladstone on the 7^th, and then met up with the QPWS participants (Graham, Damon and Julie) at the Parks depot at Gladstone Harbour where the Reef Heron is moored. The Reef Heron is a great boat, customised for QPWS requirements and sleeps up to nine people. Skippered by ‘Congo’ (Andrew) with assistance from Rod, the Reef Heron would be our home away from home for a fair chunk of the trip.

Before spending our first night aboard, Dave, Mark and I got to know each other over a few beers in town, before meeting up with Chris (who I’d met a year previously on a shearwater / storm-petrel / penguin survey of the Tollgate Islands off Batemans Bay) and his partner Nadia at a local Thai restaurant.

We departed Gladstone Harbour under grey skies and encountered frequent heavy squalls on our way out to the islands. The huge catamaran ferry in the left background transports workers to the LNG developments on Curtis Island.  

Next morning dawned grey and very wet, and amongst the clatter and clutter of a heap of gear being loaded on board, we met the hitherto unanticipated (at least by most of us) film crew who would be with us for the first half of the trip. Nick, with Luke, Casper, Dan and John would be filming for a documentary on Life on the Reef to air later this year. Just after 7 am we got underway, powering through the squalls and trying to hear each other talk through our strategy and methodological approach against the constant thrum of the motor and the spatter of rain and spray against the plastic all weather ‘awnings’ that (mostly!) protected the back deck of the boat.

The trip out to Northwest Island, about 80 km north-east of Gladstone, took about 4 hours, most of which, after we gave up trying to talk, was spent testing our resilience against being thrown about a tossing boat and wondering whether we should in fact have taken those Travacalms. But, despite a vague sense of unease for a while, neither I nor anyone else succumbed, either then or at any other time on the trip. And by the time we reached Northwest Island the sun was out, the island literally sparkled against a glittering sea, and we’d seen our first wedgies and noddies on passage, and a Brown Booby and a couple of Great Frigatebirds overhead. A great start.

After waiting a while for the tide to be high enough, and for the Wild Mob group to show up on their catamaran, the Wild Cat (which had taken seven hours since before dawn to come across from Yeppoon), we unloaded a mountain of gear into the Reef Heron’s runabout tender, several times, to be ferried the final 500 m or so across the reef flats to the beach.

Our camp was tucked into the pisonia forest just beyond the beach on Northwest Island. The catamaran on the beach is Wild Mob's Wild Cat, a very nice boat!

After having lunch and meeting the Wild Mob group – Bill, Derek and Amanda from Wild Mob, and the 12 volunteers Brooke, Hannah, Robert, Dylan, Jaime, Sarah, Elizabeth, Karen, William, Morgan, Paulina and Jade - much of the afternoon was spent setting up camp and having a quick run-down of how things would operate over the next few days.

Our campsite amongst the pisonia trees (and shearwater burrows). 

Basically, we would split up into five teams of three or four people. The four teams of four would each take on several of the survey transects that would together cover the whole island. Transects cut across the island north-to-south and were labelled A to Y (the island wasn’t quite long enough to make it to Z based on the predetermined distance between transects), and each transect had from 1 to 13 survey points along it, for a total of 223 survey points. Each survey point would be of 10-m radius and all shearwater burrows and all noddy nests within that 10-m radius would be counted. Then, a sample of 10 shearwater burrows would be tested for any occupants to determine occupancy rates and ultimately give an estimate the size of the breeding population. On the other hand, the team of three (being Graham, the QPWS leader, Jade and myself) would check on several sound recording stations that had been set up by QPWS several months earlier, and assess various methods for determining the occupancy or not of shearwater burrows. (We would also cater to some of the needs of the film crew regarding the footage - what’s the digital equivalent for that? - they might want on this particular and peculiar aspect of “Life on the Reef”.)

The traditional way to determine if a burrow is occupied (i.e. it contains a nesting shearwater or egg) is to prostrate yourself on the ground amongst the grit and guano, stick your arm as far down the burrow as you possibly can (i.e until your cheek is hard up against the burrow mouth and your ear is starting to fill with sand), and if you can’t reach the end (which is most often), use a ‘waddy’ to probe to the end of the burrow and to ‘feel’ or listen (some birds object to being so probed) for the presence of a bird. A ‘waddy’ is often a 1-m length of garden hose, but may be a flexible stick, or indeed a combination of the two. It needs to be flexible enough to negotiate any twists or turns in the burrow, and sensitive enough to be able to feel if a bird is either pecking at it (similar to a ‘nibble’, or sometimes a distinct ‘bite’ in fishing terms) or shuffling away from it.

At arm's length down a wedgie burrow, feeling for occupants with a waddy. Clearly it's very hot work, but it must have still been early in the day as I'm still remarkably clean! (Photo courtesy of Graham Hemson)

Trying to improve on this time-honoured but undoubtedly crude and labour intensive methodology was one of the aims of what my team would be undertaking (though we did do transects S & T on the second day). The sound recorders were in place to detect the calls wedgies and noddies (both are very vocal!) and these would be analysed against the soon-to-be-known densities of the two species based on our 10-m counts. And we also had with us a very expensive piece of equipment called, for our purposes at least, a ‘burrow scope’. This is essentially a tiny camera (infra-red, maybe?) on the end of a long flexible wire hose which sends its signals to a wireless monitor so the images can be viewed in relative comfort. While this worked quite well, and some of the in-burrow images were very cute, its expense and relative difficulty of use is not likely to pose any threat to us traditionalists in the short term!

Graham from QPWS using a burrow scope to ascertain the occupancy of a shearwater burrow - slightly more dignified. 

By comparison, counting noddy nests is a cinch. Stand in the shade under the trees and use a clicker to count all the nests, which are pretty obvious, in a 10-m radius of the specified central point. OK sometimes you had to walk a bit to make sure you could see and count all the nests.

After being thus apprised of the technologies and prepared for what was to come, we had the rest of the afternoon off. I of course spent it roaming the nearby beach with binoculars and camera. And needless to say, I didn’t get very far. At the edge of the water just along from camp there were Pacific Golden Plovers, Pied Oystercatchers, Common Greenshanks, Bar-tailed Godwits, Whimbrel, both Wandering and Grey-tailed Tattlers, Ruddy Turnstones etc, and my bird list grew quickly.

Common Greenshanks Tringa nebularia (and Bar-tailed Godwits Limosa lapponica) on the beach at Northwest Island.

But it was the turtles that captivated me. It was nesting season and Green Sea Turtles Chelonia mydas, better known here as just Green Turtles, were in full swing. Wavering dark shapes cruising the impossibly blue-green waters just offshore would morph into apparently stranded blobs further down the beach, taking stock through bleary eyes of what was ahead before laboriously heaving their way up the beach. The back dunes amongst the casuarinas were littered with the craters of previous nights’ efforts, and every now and again plumes of sand would be thrown into the air as yet another turtle excavated its own nest chamber.

A Green Turtle clearly daunted by the prospect ahead of it as it prepares to ascend the beach.

As they make their way up the beach, the turtles frequently rest for a short while before again dragging themselves up the beach with their front flippers. 

For one turtle the ordeal is almost over, but there seems to be very little acknowledgement as they pass each other on the crest of the dunes. 

The turtles spend hours evacuating a pit before considering it deep enough to lay their eggs.

Some turtles appeared to be more energetic with their excavations than others. This one repeatedly ejected huge plumes of sand, usually one flipper at a time, but occasionally exhibited a massive double-flippered effort. 

Just metres from the water, this turtle is almost home. Its sand encrusted eyes will soon be washed clean and it will return to its much more graceful watery existence. 

Even on that first afternoon I was fortunate to witness the frantic scrabble of half a dozen new hatchlings tumbling down the beach towards the sea, desperate to do what they could to avoid the depredations of the ever-vigilant Silver Gulls that would snaffle them up in an instant. It’s surprising how soft and rubbery young hatchlings are. It’s less surprising just how cute they are!

So cute! but a still photograph cannot do justice to just how cute as they scrabble their way in frantic desperation down to the coralline sand to the water. 

Sometime around 9:30 pm (don’t forget, Queensland doesn’t have daylight saving) we trundled off to our tents. I dossed down on my thermarest – no need for sleeping bag or even sheet here - and drifted off to the 'music' (read cacophony – though some people are said to like it) of a thousand noddies and as many shearwaters cackling and wailing uninterruptedly throughout the night. Tomorrow would be a brand new day in Paradise.