Tag Archives: Seabird

Life in the Burrow

3 May 2012 – 4.07pm
By Alison Burnett and Susan Waugh

The austral summer is the peak breeding season for seabirds in New Zealand. Te Papa is undertaking research into the impacts of seabird mortality in fisheries on shearwater populations over the next 2 summers. We began the study in January 2012, surveying islands to assess changes in the numbers of breeding birds. We combined transect surveys (measuring density of birds nesting in burrows), with studies of the foraging ecology of two species of native shearwater, the flesh-footed shearwater and the sooty shearwater.

During the summer season the shearwaters are nesting in their burrows, they take turns sitting on the egg, one parent waiting patiently in the dark whilst the other is at sea feeding for around five days. Shearwaters fly huge distances, the Sooty Shearwater can cover up to 64,000 km annually and can fly at over 64 mph. Part of this work was to try and establish the exact movements of these birds during the nesting period by fitting them with tracking devices for several days. The loggers were taped under the feathers on the back of the bird and double secured with mini cable ties. The fixing had to be ultra secure as, incredibly, these birds can dive to depths of 60 m for their food – and we wanted the data back. This work is being done in collaboration with Associate Professor John Arnould, Deakin University, Australia.

Te Papa shearwater research team preparing GPS loggers for deployment prior to departing for the island in Marlborough. We programmed the loggers (green and white electronic devices) and encased them in black heat-shrink tubing to keep them watertight. Dr Susan Waugh, Senior Curator Natural Environment (front left) with volunteers Alison Burnett (centre) and Simon Hayward (right) Photo: Jean-Claude Stahl.

Attaching the locational logger to a flesh-footed shearwater at Titi Island, Marlborough, by taping the small electronic device to the birds’ back feathers. Photo: Simon Hayward.

Flesh-footed shearwater after its logger was attached. White marking on its forehead enables the research team to confirm visually if this bird returns after feeding at sea, without the need to handle it. Photo: Simon Hayward.

Shearwaters are active at night, shortly after dusk the birds return to the island, this is signified by a sudden loud whump, followed by rustling as they make their way through the foliage and into their burrows. Recognising the shape of the trees and bushes from the air is how they locate their burrow, and then they drop through the tree canopy, land with a thud and walk the rest of the way home. They start the day with their version of the dawn chorus before heading out to sea to feed.

Flesh-footed shearwater track from a bird loggered during incubation at Titi Island in January 2012. The bird flew to the east of Cook Strait and to the base of the Chatham Rise,and returned to Cook Strait, where the logger battery failed. The bird then returned to its nest, where we recovered the logger and it continued raising its chick.

Titi Island has sheer cliffs to one side with barely any vegetation, the south side is steep sided and has gullies interspersed by stony ridges. The birds make burrows in the deep soil of the gullies, these are used for many many seasons, often by the same breeding pair. Our job was to estimate the size the seabird population and track the changes through time. Our results are being compared with a similar study undertaken in 2006 – 2011

Finding the burrows on the steep slopes, hidden under the vegetation and fallen trees was the first task, even on the bare earth slopes, leaves and twigs could fill the indent which was all that indicated an entrance. We had to crawl around carefully and check out each possibility, the earth above each burrow was fragile and the roof could be very thin.

Transect locations on Titi Island, Marlborough surveyed by the Te Papa team in January 2012. Each tiny flag marks the beginning or end of a sample transect to count burrows. Areas not sampled had few or no shearwater burrows.

We also had to define the nesting areas within each gully as seabird populations tend to expand outwards from the existing colony and we wanted to establish what changes had occurred since the last survey. There were eight colonies on Titi and the perimeter of each had to be established with GPS reference points created at frequent intervals so the dots could be joined and the outline would be known, any future change in this would show population increase. We did this work on two other islands over the 2011/12 shearwater breeding season; Ohinau Island, off Whitianga in Coromandel, and Lady Alice Island in the Hen and Chickens group off Whangarei were our other survey sites.

Bycatch in fisheries is a pervasive problem for long-lived species such as shearwaters. Fishing deaths occur when birds get hooked on longline hooks, or entangled in trolling lines, trawl nets and setnets in both recreational and commercial fishing in New Zealand.  The level of bycatch for some species is of concern nationally and internationally. Our research is helping to clarify whether species such as the flesh-footed shearwater are holding their own at breeding sites in spite of persistent deaths through bycatch.

Loggers deployed, recovered, and over 500 burrows inspected by burrowscope, we headed home after our exertions, enjoying a gourmet meal of mussels at Havelock – after much needed showers. This study is funded by the Conservation Services Programme of the Department of Conservation. Thanks to the team at DOC in Havelock and Nelson for assistance with the study, and much needed weather reports.

By Susan Waugh | Posted in Biodiversity, Field trips | Also tagged , , | Comments (4)

One step forward after three steps back – slow progress with restoring populations of New Zealand seabirds

13 January 2012 – 8.05am

Fairy prion chick being banded on Mana Island, January 2012. Photo: Kate McAlpine & Colin Miskelly

2011 was a grim year for New Zealand seabirds. They suffered the triple-whammy of nuclear-fallout from the crippled Fukushima Daiichi power plant affecting the North Pacific non-breeding grounds of at least four species, a severe winter storm that killed up to half a million prions, then the Rena oil spill believed to have killed several thousand birds. Compared to the scale of these disasters, attempts to restore seabird populations appear almost futile.

Storm-wrecked prions at Paekakariki, Wellington west coast, July 2011. Photo: Colin Miskelly

Diving petrels and fluttering shearwaters killed by the Rena oil spill, Bay of Plenty, October 2011. Photo: Colin Miskelly

For the past two decades, New Zealand conservationists have been developing techniques for restoring burrow-nesting petrels (including shearwaters and prions) to sites safe from predators. This required overcoming the birds’ strong homing instincts by translocating then hand-feeding young chicks until they completed their feather development and flew out to sea. This method has now been tried on more than ten species of petrels, but progress is glacially slow. All petrel species lay only a single egg per year, and many do not start breeding (or even return to land) until they are four or more years old.

Translocated fluttering shearwater chick being fed a sardine smoothy, Mana Island, January 2007. Photo: David Cornick

Mana Island, off the Wellington west coast, has been the single site where the greatest effort has been made to restore burrow-nesting petrels. Between 1997 and 2008, over 700 chicks of three species were translocated to the island, and cared for by teams of contractors and volunteers organised by the Department of Conservation and the Friends of Mana Island (a community conservation group). The younger birds are still returning, but over 60 have been recorded back so far.

All three species are now nesting on the island, with increasing numbers of chicks being recorded each year. During the 2011/12 breeding season, 19 chicks are known to have survived to fledging – 8 common diving petrels, 7 fluttering shearwaters and 4 fairy prions. Other chicks are likely to have been produced in undetected or unmonitored burrows (some of the latter are located at inaccessible cliff sites).

In addition to the translocated chicks that returned as adults, a few unmarked birds of each species have been attracted by loudspeakers broadcasting petrel calls each night, and perhaps also by the birds that have returned to the island.

Colin Miskelly holding a fluttering shearwater chick, Mana Island, January 2012. Photo: Kate McAlpine & Colin Miskelly

Restoring seabirds takes time and requires a lot of effort. Understanding how to proceed, at what cost, and the likely outcomes, is essential as we consider how to offset the impacts of disasters caused directly or indirectly by humans.

Further information
Te Papa prion wreck blogs
Te Papa Rena oil spill blogs
Miskelly, C.M.; Taylor, G.A.; Gummer, H.; Williams, R. 2009. Translocations of eight species of burrow-nesting seabirds (genera Pterodroma, Pelecanoides, Pachyptila and Puffinus: Family Procellariidae). Biological conservation 142: 1965-1980.

By Colin Miskelly | Posted in Bay of Plenty oil spill, Biodiversity, Birds, Field trips | Also tagged , | Comments (3)

What bird is that? The grim task of identifying seabirds killed by the M.V. Rena oil spill

14 October 2011 – 3.53pm

Fluttering shearwaters coated in oil from the M.V. Rena. Photo: Colin Miskelly, Te Papa

Te Papa bird staff are providing expert assistance to Maritime New Zealand and Massey University veterinary staff in the form of identifying birds affected by the oil spill. Three current and one former staff member have been a ‘tag team’ since 12 October, identifying the hundreds of corpses recovered by the teams patrolling the beaches, plus any picked up at sea. There are many seabird species potentially present in the Bay of Plenty at this time of year. Making sure that each bird is correctly identified is essential for understanding the impacts of the spill. This information will be crucial if there is any potential for environmental mitigation after the clean-up is complete.

Colin Miskelly (Te Papa's Curator Terrestrial Vertebrates) with a heavily oiled northern giant petrel. Photo: Colin Miskelly, Te Papa

Identifying heavily oiled birds is a challenge, especially when the oil is thick and tar-like. Not only are all plumage markings, bill and leg colour concealed, but it can even be difficult to determine the shape of the bill, which is otherwise diagnostic for many species. For some birds it is necessary to use body structure – the relative length of the tail separates the similarly-sized Buller’s and sooty shearwaters. For others, knowing the one crucial identification character to check (e.g. leg colour) to separate species pairs means that a bird can be identified more rapidly.

Karen and Lucy with oiled seabirds inside the pathology tent. Photo: Colin Miskelly, Te Papa

The work is dirty, smelly, frustrating, and deeply saddening for anyone who knows the beauty of these birds in their prime. Over 20 species of seabird have been identified dead and coated with oil so far, ranging in size from tiny white-faced storm petrels to an enormous wandering albatross. The three main species affected (common diving petrel, fluttering shearwater and Buller’s shearwater) are not threatened species, but their populations will take decades to recover from a mortality event of this scale. All lay a maximum of one egg per pair each year, and the two shearwaters do not start to breed until they are about 5 years old.

 
By Colin Miskelly | Posted in Bay of Plenty oil spill, Biodiversity, Birds, Disasters, Field trips | Also tagged , | Comments (3)

Riders of the storm – thousands of seabirds perish on New Zealand shores

18 July 2011 – 2.24pm

It started as a trickle and soon developed into a flood of devastating proportions. On 11 July 2011 I received an email enquiry from a family at Waikanae seeking help with identifying an unusual seabird that they had found dead on their driveway. It was a Salvin’s prion, a not-too-unexpected discovery near the coast during a winter storm. But the next day a Department of Conservation colleague phoned from Masterton reporting a dozen live prions found scattered inland in the Wairarapa, on the sheltered (eastern) side of the Tararua Range. If that number had reached the leeside, what was happening of the exposed western coast? It didn’t take long to find out.

By 14 July over a thousand live prions had been handed in to wildlife care centres in Wellington and Manawatu, an alarming number given that during prion ‘wrecks’, only a tiny fraction of the birds are still alive by the time they reach land. But what is a prion? and why do they wreck?

Fig. 1. Some of the 660+ stranded prions delivered to Wellington Zoo. These are all broad-billed prions. Photo: Colin Miskelly. Copyright Te Papa

Prions (the singular is pronounced ‘pry-on’) are a group of six small closely-related seabirds that are hugely abundant in southern oceans. They are petrels, and like most petrels, typically breed in enormous colonies on remote islands free of introduced predators. They should not be confused with the other use of the word (in this case pronounced ‘pree-on’) used for a particularly nasty group of infectious proteins that cause the brain-wasting Creutzfeldt–Jakob disease in humans, plus mad-cow disease, and scrapie in sheep.

All prion (bird) species are very similar in size and plumage markings, with the most obvious difference being bill shape, which varies from broad through to narrow or chunky. Within this continuum of variation, some pairs of species are very difficult to distinguish from each other. 

Fig. 2. Bill shapes of four species of prions. Left to right: broad-billed prion, Salvin’s prion, Antarctic prion and fairy prion. Photo: Colin Miskelly. Copyright Te Papa.

The three species with the widest bills have prominent lamellae (comb-like structures) along the edge of the upper mandible, used to filter tiny crustaceans and other small animals and their eggs from sea-water. When combined with a muscular tongue and an extendible pouch below the bill, these adaptations recall those of baleen whales, which feed in a similar way. Perhaps this is why prions are sometimes referred to as ‘whale-birds’. 

Fig. 3. Lamellae (comb-like filters on the edge of the upper mandible) on a broad-billed prion. Photo: Colin Miskelly. Copyright Te Papa.

Prions are well known to New Zealand birdwatchers, even if they are frustratingly difficult to distinguish at sea. Members of the Ornithological Society of New Zealand have for many years patrolled the New Zealand coastline recording the numbers and identities of birds cast ashore. For many, this is the only way to become familiar with prions, particularly in those years when large multi-species wrecks occur. The results of these ‘beach patrols’ are occasionally published in the OSNZ’s journal Notornis. Between 1960 and 1996, over 86,000 prions were found dead on New Zealand beaches; large wrecks occurred in 1961, 1970, 1974, 1975, 1984-86 and 2002, with over 10,000 birds cast ashore in 1974, 1985 and 2002. Earlier wrecks occurred in 1878, 1918 and 1932.

Like all petrels, prions are true seabirds, spending their entire lives at sea apart from the 4 months when they are tied to a nesting burrow and the care of their single egg and resultant chick. At other times they are constantly on the move, often in vast flocks, skimming the waves of the southern oceans in search of productive upwellings. Although frail-looking, they thrive in a part of the globe renown for strong winds. Until they encounter land… 

Fig. 4. A flock of Antarctic prions near South Georgia in the South Atlantic Ocean. Photo: Colin Miskelly. Copyright Colin Miskelly.

Prions move with the wind, using the varying airspeeds on the windward and leeward sides of waves to fly long distances with great energetic efficiency. There are few land masses in the southern ocean, and it is usually easy for flocks of prions to slide around the few obstacles that present. Except, that is, for the 1500 km coast of New Zealand. For ten consecutive days in July 2011, persistent westerly gales in the Tasman Sea pushed prions against New Zealand’s western shores. To start with, the birds moved effortlessly with the wind. Then as land loomed, they started to fight the wind, trying to stay offshore. But the relentless gale continued, consuming the birds’ energy until they were exhausted and driven ashore in tens of thousands.

Although there is a long history of prion wrecks on New Zealand beaches, the scale of the 2011 wreck is unprecedented. Far more prions have been killed in this single event than the 37-year total recorded by the OSNZ. Details are still being collected and collated, but large numbers have been found from at least Dargaville to Okarito, 900 km apart. In places they have stranded at rates over 400 birds per kilometre of coast. And that ignores the birds blown inland.

Even more alarming is that nearly all the birds are broad-billed prions (91% estimated), a locally-breeding species. The two previous largest wrecks of broad-billed prions were between 1100 and 1400 birds. It will be difficult to estimate the full extent of the 2011 wreck, but it is likely to be up to 250 times larger than either the 1961 or 1974 events. 

Fig. 5. Beach-wrecked broad-billed prions, Paekakariki (Wellington west coast), 16 July 2011. Photo: Colin Miskelly. Copyright Te Papa.

Desperate efforts are being made to save some of the birds, including a combined total of over 1000 being hand-fed at Wellington Zoo and Massey University. As the birds are exhausted and emaciated from their struggle against the gale, it is terribly difficult to revive them, and hundreds of those delivered have since died.  

Fig. 6. A rescued broad-billed prion being fed at Wellington Zoo. Photo: Colin Miskelly. Copyright Te Papa.

The 2011 prion wreck will have wreaked a terrible toll on the New Zealand broad-billed prion population. The species also occurs in the South Atlantic, but the birds in New Zealand waters are thought to come from the breeding populations on the Chatham Islands, Snares Islands, and islands around Stewart Island and off the Fiordland coast. Apart from the 330,000 pairs estimated on Rangatira Island in the Chatham Islands, none of these other populations are thought to number more than a few thousand pairs. The total New Zealand population is likely to be little more than a million birds, and so the tragic deaths of (probably) several hundred thousand of them will have a huge impact, especially if the birds in the Tasman Sea were mainly from the less numerous southern (non-Chatham) populations. 

Fig. 7. The calm before the storm – healthy broad-billed prions on Kundy Island, off Stewart Island, March 2011. Photo: Colin Miskelly. Copyright Te Papa.
Other blogs on this topic:
http://birdsnews.com/?p=264
Riders of the storm – the severely depleted next generation
 
By Colin Miskelly | Posted in Biodiversity, Birds, Disasters, Field trips | Also tagged , , , | Comments (24)

Magnificent petrels, and pina coladas on the beach

18 March 2011 – 1.29pm

Two of Te Papa’s Natural Environment staff recently returned from two weeks seabird research in northern Vanuatu. Colin Miskelly (Curator Terrestrial Vertebrates) here recounts some of the adventures he had with Alan Tennyson (Curator Fossil Vertebrates) during early March 2011.

Back in 2001 New Zealanders Mike Imber and Alan Tennyson proposed a new species of gadfly petrel, the Vanuatu petrel (Pterodroma occulta), based on 6 specimens collected at sea in northern Vanuatu in 1927, plus one storm-wrecked in Australia in the 1980s. The breeding site for the birds remained a mystery until Australian-based naturalist Stephen Totterman followed up stories related to him by villagers on Vanua Lava (in the Banks Islands), and found two nests on the slopes of the volcano Mt Sereama in early 2009.

Stephen invited Alan and Colin to return to Vanua Lava with him this year, to survey the extent of the colony, and to collect measurements and DNA samples to compare with the closely related (larger) white-naped petrel from the Kermadec Islands.

After leaving Auckland, we island hopped from Port Vila to Espiritu Santo to Gaua and then to Vanua Lava. From Santo we were accompanied by government representative Anaclet Philip. Stephen met us at Sola airport, and a couple of hours later we were on a small boat heading 5 km or so along the coast to the village of Lalngetak, where we were the guests of honour at a kava ceremony.

We were introduced to our local guides Manman and Ala, and the following morning the six of us plus three hired porters set off on the 4 hour tramp inland through wet tropical forest to the camp at the Qwelrakrak solfatara field at the base of Mt Sereama. It was the wet season, hence few tourists, and hordes of malaria and dengue-fever bearing mosquitos. They were intolerable at Lalngetak, but were scarce after we gained altitude heading inland, and almost absent at Qwelrakrak.

Qwelrakrak solfatara looking east towards Mota Lava

Qwelrakrak solfatara looking east towards Mota Lava

The camp was very basic – three 2-man tents, a palm-leaf-covered cooking shelter over the cooking fire, and a larger dining shelter that we covered with polythene. The shelters were all made from materials at hand, with Manman and Ala using their bush knives (machetes) with great skill and effectiveness. The cuisine was even more basic – anyone for boiled white rice with a dollop of tinned tuna on top three times a day for 6 days? I exaggerate, as three of us spent three of the five nights on the summit of the nearest peak of Mt Sereama, 300 vertical metres above us, where we enjoyed a more exotic picnic dinner of peanut putter on cabin bread. Three nights in a row.

Anaclet, Manaman and Ala drying firewood

Anaclet, Manman and Ala drying firewood

Stephen, Manman and Ala had located five burrows of Vanuatu petrel in about 2 weeks of searching, but had not handled any birds, as none was at all keen to put their hand into a hole containing a stroppy sharp-beaked petrel. Alan and I had no such qualms, and with our high-tech petrel locating tool (i.e. the palm of the hand and exhaled breath to make a first nation war-whoop), we set about locating nests and attracting flying birds in. The war-whoop is equally effective at attracting gadfly petrels – one flew into my midriff the first night (and bit me through my shirt) – and encouraging birds inside burrows to call, to facilitate locating burrows, and determining if they are occupied. In this way we located a total of 16 nests with eggs during our five nights at the colony, extended its known boundaries, and handled 27 adult birds.

Alan Tennyson holding a Vanuatu petrel and egg

Alan Tennyson holding a Vanuatu petrel and egg

But the real intrigue started when Manman, Ala and Anaclet completed cutting a track to the summit of the 800 metre peak above Qwelrakrak. We had been puzzled by the variety of petrel calls we were hearing at night, and we soon discovered that this was because there were two species present – Vanuatu petrel, and the even more poorly known ‘magnificent petrel’Pterodroma brevipes magnificens, named only in 2010 based on six specimens shot at sea at the same time and location as the original Vanuatu petrels in 1927, and more recent observations (2009) at sea off Vanua Lava. As the name suggests, these are spectacular looking birds (coal black with white faces and parts of the underwing), and are the smallest members of the genus.

Manman, one of our guides from Lalngetak village

Manman, one of our guides from Lalngetak village

On our first night at the summit we saw several in flight, and figured out that they were the source of an unusual call coming from the dense umbrella fern and wild cane grass around us. Alan eventually succeeded in catching one, which was duly photographed, measured, bled, and photographed again. We returned to camp elated, and based on the number of calls around us were confident that we could catch many more, and perhaps find nests.

Colin Miskelly holding a magnificent petrel (a subspecies of collared petrel). Photo: Alan Tennyson

Colin Miskelly holding a magnificent petrel (a subspecies of collared petrel). Photo: Alan Tennyson

The next day we instructed Manman and Ala to cut four 4 metre long poles and to carry them to the summit, where they set to cutting a 20 metre long mistnet site along the cliff edge. We eventually got both nets up, but by then the wind had got up and the nets were billowing like sails on a galleon, rendering them all but useless. There were very few birds calling that second night, but either despite or because of the nets, we did catch one more bird, just beyond the nets. Somewhat to our surprise, it was a pale bird, which contradicted the description for the subspecies.

Our visit was in the wet season, which meant a lot of rain. We had 8 hours of continuous torrential rain one day, turning our camp into a quagmire. Along with the heat and sweat whenever the sun came out, we had two states of being for the six days – wet or damp. This affected people, electronics and other equipment, as well as the general discomfort of living in mud. The one redeeming feature of the site was the thermally-heated water, and we soon constructed a luxurious bath in the outflow from the solfatara.

Water-logged campsite at Qwelrakrak

Water-logged campsite at Qwelrakrak

On our second night at the summit we were caught by one of these torrential downpours, and beat a sodden retreat to camp. We only had one more shot at catching further collared petrels, as we were due to depart the summit on 10 March. Neither Alan nor I give up easily when there are rare birds to catch at night, so we packed our peanut butter crackers and gave it one last shot. But it was not to be. The winds were even stronger, and though we saw a few birds in flight, we did not catch any, and the only ground calls we could trace were in dense vegetation on the lip of a 300 m cliff.

Vanuatu green tree skink Emoia sanfordi – a visitor to our camp

Vanuatu green tree skink Emoia sanfordi – a visitor to our camp

It was time to retrace our footsteps (slowly, due to trench foot in some cases, and diarrhoea in others) and head back home via another kava ceremony, mosquitos and tsunami warning.

No one has offered us a pina colada yet. Perhaps it is time to find one…

By Colin Miskelly, Curator Terrestrial Vertebrates

By Colin Miskelly | Posted in Birds, Field trips, Reptiles | Also tagged , | Comments (1)
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