A new species of diving bird was discovered near the coast of Stewart Island, New Zealand.
The native birds living on sand dunes on the island were identified through a joint research project between Victoria University of Wellington, the Department of Conservation (DoC), the Museum of New Zealand Te Papa Tongarewa and the Chizé Centre for Biological Studies in France.
These birds which resemble fluffy penguins has been discovered near a 1km strip of sand on Whenua Hou (Codfish Island) just south of New Zealand.
They have been named the Whenua Hou diving petrel (Pelecanoides whenuahouensis) and the population is believed to be only around 250. Diving-petrel species feed on crustaceans such as amphipods while also consuming small fish, squid and other mammals like rats.
Codfish Island, off the southern coast of Stewart island, might be small, but it’s of tremendous importance to the country’s multitude of seabirds. The five-square-mile isle, known as Whenua Hou to the Māori people, is probably best known as the epicenter of Kakapo conservation. The largest population of the imperiled flightless parrots survives in the island’s forest alongside Mottled Petrels (some 350,000 pairs, more than anywhere in the world), Cook’s Petrels, and Sooty Shearwaters during the seabirds’ breeding season.
The birds used to be considered South Georgia Diving-Petrels, a species numbering in the millions that breed on islands in or near the Southern Ocean. However, scientists suspect that these may be a different one.
Graeme Taylor, a seabird scientist, has been with New Zealand’s Department of Conservation since it was formed in 1987. For decades, he’s thought that the Codfish Island colony could be a different species. He hadn’t heard of South Georgia Diving-Petrels nesting in sand dunes before. Then, he noted that these birds had forked tails—an “odd” finding considering that no South Georgia Diving-Petrels in museums had the same.
Some preliminary genetic data also suggested they were unique, but it wasn’t entirely conclusive.
Finally, a few years ago, a graduate student showed up with the interest and time to work with the birds. After Johannes Fischer’s first research project, on Bornean Peacock-pheasants, fell through, he immediately contacted the Department of Conservation which led him to Codfish Island. “I realized: I’m in the seabird capital of the world in New Zealand,” he recalls.
Of course, they didn’t yet know for certain that it was one of their rarest species. Fischer spent two months living at the research station on Codfish Island during the 2015-2016 breeding season, during which time he caught and measured 127 live diving-petrels. About the size of a human hand, the “tiny potatoes,” as Fischer describes them, zoom right above the sea’s surface—and when a big wave comes, they fly right through it. (The birds have an unusual nostril structure that “presumably deals with this massive wall of water they smash themselves into on a daily basis,” he says.) Their wings are more like a penguin’s flippers which they might have used spending most of their time underwater, yet they can still fly with them, resulting in diving-petrels having “the highest wing loads of almost any bird,” he says.
The seabirds are also fiercely loyal. They come back to the same burrow and the same partner every year—and you don’t want to get in between a diving-petrel and its chick. “I’ve had birds try to push me out of the way because I was in the way of its baby,” Fischer says.
To confirm whether the Codfish Island birds differed from other South Georgia Diving-Petrels, he caught and measured live South Georgia Diving-Petrels on Kerguelen Island. He found that the Codfish Island birds were quite different from the rest of the species, having longer wings, deeper bills, longer heads, and different coloring. With these information, Fischer named the birds Whenua Hou Diving-Petrels, after the Māori name for the island.
It will take some time for taxonomic committees to decide whether they agree with the new species designation. But in the meantime, the new description is enough to convince the Department of Conservation to take active measures to protect the colony.
Codfish Island has a long history of destructive invasives: Weka, a large flightless rail that wreaks havoc on nesting seabirds, were removed by 1984; and then possums were removed by 1987. Fischer suspects the diving-petrels survived on the island only because the other seabirds nesting in the forest provided a distraction. “Several million seabirds on top of the hill were more attractive than the small colony in the dunes,” he speculates.
Now that the species has been officially described, Taylor can devote DOC resources to protecting the birds. The first step is to try to convince diving-petrels currently nesting in the dunes to move farther away from the ocean. “A lot of them are literally on the edge of the dunes” facing the sea, he says. (Biologically, it’s understandable: They can shoot out of the sea and straight into their burrows, and vice versa, without attracting too much attention from predators.)
The colony then has to grow before they take Kress’s methods to the next level: physically relocating chicks to a new island to create a second colony. (The birds return to nest in the same place they were raised.) Fischer is already strategizing about how to best do that, but the population “numbers are so low, you couldn’t consider it at the moment,” Taylor says. “You’d have to double or triple the number before we consider moving chicks,” an effort he suspects will take 20 or 30 years. But all this toil will be worth it if it means preserving these tiny potatoes, the last relicts of New Zealand’s own diving-petrel species.
While not so many predators exist in the island, a few threats are involved in the efforts in conserving this bird species.
Sand dunes are particularly vulnerable to erosion and turbulent seas have destroyed much of their habitat. In addition, climate change and storm surges also affect the limited numbers of the population.
The critically endangered population of Whenua Hou Diving-Petrels isn’t yet safe to recover. Taylor recalls a major storm in 2003 sent waves on the island that ripped out 10 meters of sand dune— and the birds nesting inside. “Birds washed up dead on the beach that had been caught up inside the burrows when the dunes collapsed. That’s when we realized they were a lot more vulnerable than we thought,” he says. “With climate change, there is a real risk that these storm frequencies and severities are only going to increase over time.” Also, with all these sand that envelops near these winged creatures, chances are they could end up being covered with sand and then buried completely.
What happens next?
The Whenua Hou population uncovered differences as they compared them with museum specimens obtained from around the world.
“Until now, it was assumed this was a population of South Georgian diving petrels. However, we discovered differences in the birds’ size, shape, and colour. They’re also the only diving petrel known to breed entirely within a sand dune environment. Together, these differences are enough to identify them as a separate species based on the IUCN Red List of Threatened Species criteria,” says Johannes Fischer.
Johannes worked with Kaitiaki Roopu, a group made up of representatives from Southland’s four Ngāi Tahu rūnanga, to come up with a name for this new species and an abstract has been provided in the publication. His Master’s thesis was supervised by Victoria University Associate Professor Heiko Wittmer.
DOC seabird researchers Dr. Igor Debski and Graeme Taylor were heavily involved in the research and are now working with Johannes on a conservation plan.
“Discovering this last remnant population of consummate survivors is exciting news for conservationists, scientists, and all who value New Zealand’s unique biological heritage,” Mr. Taylor says.
These birds were already recognized as a threatened population even before the official discovery of the new species.
He further stated that the species’ survival will depend on maintaining high levels of biosecurity and pest surveillance on the island, limiting any non-essential human activity on the fragile sand dune environment and supporting the research and monitoring programme.
“As we gain more detailed knowledge of the species over time we can look to more proactive management, including translocations to suitable places to help the species thrive,” Mr. Taylor says.
Local officials especially the Congress urges these researches to take action and promote ways on how to conserve these critically endangered bird species even if they were just been recently discovered.
The researchers believe that the species survival will depend on vigilant biosecurity that would eventually prevent invasive species from reaching the island. Limiting human activity will also help preserve the fragile sand dune ecosystem. Hopefully, as detailed knowledge is gained, conservationists will be able to establish effective protection measures that will help the species thrive.