Major breakthrough in attempt to unlock secrets of ultra-elusive seabird
An intrepid BirdLife Pacific team has finally managed to capture and tag a Beck’s Petrel – one of the world’s rarest and least-known birds. It’s hoped ‘Pato’ will lead us to its still-unknown breeding grounds, which will provide the essential insight to protect this rare species
Trying to find the breeding grounds of the Critically Endangered Beck’s Petrel Pseudobulweria becki is like trying to find the proverbial needle in a haystack. Except in this analogy, the needle (petrel) is so rare it once went unrecorded for over 70 years, and the haystack (nests) could be situated on any one of the dozens of oceanic islands scattered off the coast of Papua New Guinea.
How to begin such a seemingly impossible search? If we were chasing haystacks, perhaps we’d take a leaf out of a crime drama novel, and attach a satellite transmitter one of the hay bale delivery trucks nearby, to see where they lead us to.
But things get a little more complicated if the target you’re trying to tag is not a huge truck, but rather a Beck’s Petrel – a tiny, agile seabird that roams freely around a vast area of the southern Pacific Ocean.
The Beck’s Petrel is one of the rarest (with an estimated global population of less than 250) and poorly known seabirds going. For the longest time, it was known only from two specimens observed in 1928, until it was rediscovered by Hadoram Shirihai, the Israeli ornithologist, in a remote corner of the Bismarck Archipelago, north-east of mainland Papua New Guinea.
While repeat visits to the region have resulted in further sightings, it's only ever been spotted at sea, and any remaining population is likely to be tiny. But how can we protect it, if we have no idea where it breeds, or what dangers it faces there?
“Ever since the rediscovery, the big question has been: where does it breed?” says Chris Gaskin, who led the BirdLife expedition to satellite tag a Beck’s Petrel. “Finding these breeding sites is key to the future conservation of the petrel. But first we have to live-capture birds, and to do that we aim to capture them at sea”.
Beck's Petrel is one of the rarest and poorly-known birds in all the world. We have no idea where they breed, or what threats they face there.
To aid this BirdLife formed a partnership with the national conservation authority for Papua New Guinea (CEPA), the New Ireland Province, the Auckland Museum of New Zealand and other seabird biologists experienced in seabird capture. Together with the support of funders the Critical Ecosystem Partnership Fund, the Mohamed bin Zayed Species Conservation Fund, the Pacific Development Conservation Trust the Biodiversity Consultancy and BirdLife International a multi-disciplined eight-person team mounted a ten day expedition in April to catch and fit satellite transmitters to Becks Petrels.
Capturing one of these elusive birds in such a way as to render it unharmed, is a task that requires a lot of patience and more than a little luck. (And a high-tech ‘net gun’ too, of which more later). But on 26th April of this year, the team managed to do just that – capturing, tagging and releasing one of these enigmatic seabirds for the first time. It’s a major breakthrough for our hopes of better understanding the land behaviour and nesting patterns of this rare species – which will lay the foundation for future conservation work.
The successful capture was achieved during a ten-day expedition across Silur Bay, a remote corner of the Bismarck Archipelago, not far from the species’ dramatic rediscovery in 2007.
A follow-up BirdLife survey in 2012 discovered that this particular area - a deep-water bay on the coast of the island of New Ireland – was a Beck’s Petrel hotspot, with over 100 birds using the bay’s facilities – nearly half the estimated global population. The discovery led to the formation of an action plan to secure the species’ survival, an integral part of which was to locate the birds’ still unknown breeding grounds.
Gaskin was part of a previous expedition to Silur Bay in 2016, which re-confirmed the area as the hub of all known Beck’s activity. During this voyage, the team trialled numerous at-sea methods to capture and tag a Beck’s Petrel - including a net gun which, as the name suggests, propels a net into the sky in an attempt to snare the bird during flight.
Meet Pato - one of less than 250 Beck's Petrels worldwide.
Great care has been taken in the design of these nets to ensure that no harm comes to the bird during the process, as Gaskin explains: “The net guns we currently use are made from high-pressure plumbing PVC materials and filled with compressed air from a dive tank. They fire four narrow PVC tubes (projectiles) and a four-metre square mist net. The tubes are designed to float. We have captured something like 200 birds in New Zealand, Galapagos, Chile and now Papua New Guinea using this method without injuring any. It’s equipment we continue to improve through the Northern New Zealand Seabird Trust.”
Using these nets, Gaskin and his team came agonisingly close to snagging a Beck’s in 2016, only to be foiled by the petrels’ acrobatics. This follow-up expedition built on the learnings from the previous attempts, using different techniques in a bid to improve their chances. These include the use of kayaks and paddling boards to get closer to the petrels, and shining lights on shore to attract them. (Like many of its sister species, Beck’s Petrel is suspected to be a nocturnal hunter on its breeding grounds).
The bird was captured using a net fired from a high-pressure net gun - it is designed to float, and captures birds in-flight without harming them.
Despite all these measures and the considerable expertise and experience across the team, live-capturing a Beck’s was no sure thing. “To successfully capture a bird using these net guns requires patience, a lot of patience waiting for bird to approach, then quick reactions when a bird finally comes into the ‘capture zone’” says Matt Rayner, Vertebrates Curator of the Auckland Museum of New Zealand.
But with patience comes great rewards. On April 26th, a single Beck’s Petrel, dubbed ‘Pato’ from the local name (pato lonbon – the duck of the sea) – was captured and fitted with a satellite transmitter. “Our team’s reaction to our capturing the bird was classic - yells, laughing, dancing, hugs, high fives, the works!” says Gaskin.
But it is too early to pop the champagne corks – with only one capture, so much rides on both the continued survival of Pato, and its new satellite transmitter, too. Given we know so little about this species, every bit of data we can glean from Pato is invaluable.
Pinpointing the breeding grounds, and the threats they may face there, is a priority. “Petrels only ever go to land to breed, so if we get consistent good quality signals from a location on land we will be able to determine a likely breeding site for a follow up expedition” says Gaskin.
But while we wait for Pato to feel frisky, there is still plenty we can learn from its adventures at sea. “We will be able determine favourite foraging grounds as well as any dispersal outside its known area post-breeding” says Gaskin.
“But as I said, everything rides on that one bird and one transmitter. At the most recent download our bird was approximately 250kms from where it was captured, flying in what appears to be a foraging pattern northeast of Bougainville.”
Capturing Pato was the easy part. Now, the hard part: waiting for Pato's next move.
The project is a collaboration between BirdLife International, the New Ireland Provincial Government, the Conservation and Environment Authority of Papua New Guinea, Ailan Awareness and the Wildlife Conservation Society, funded by the Critical Ecosystem Partnership Fund, the Mohammad bin Zayed Species Conservation Fund, the Pacific Development Conservation Trust, the Biodiversity Consultancy and BirdLife International. With support from the Auckland War Memorial Museum, PNG Surfaris and the Northern New Zealand Seabird Trust
Read more about the Pacific Petrel in Peril initiative.