Taketo Komura (Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan) and colleague have published open access in the online journal PLoS One on diet of the Wedge-tailed Shearwaters Ardenna pacifica from Minamijima Island in the Ogasawaras revealed by DNA metabarcoding.

The paper’s abstract follows:

“The foraging ecology of pelagic seabirds is difficult to characterize because of their large foraging areas. In the face of this difficulty, DNA metabarcoding may be a useful approach to analyze diet compositions and foraging behaviors. Using this approach, we investigated the diet composition and its seasonal variation of a common seabird species on the Ogasawara Islands, Japan: the wedge-tailed shearwater Ardenna pacifica. We collected fecal samples during the prebreeding (N = 73) and rearing (N = 96) periods. The diet composition of wedge-tailed shearwater was analyzed by Ion Torrent sequencing using two universal polymerase chain reaction primers for the 12S and 16S mitochondrial DNA regions that targeted vertebrates and mollusks, respectively. The results of a BLAST search of obtained sequences detected 31 and 1 vertebrate and mollusk taxa, respectively. The results of the diet composition analysis showed that wedge-tailed shearwaters frequently consumed deep-sea fishes throughout the sampling season, indicating the importance of these fishes as a stable food resource. However, there was a marked seasonal shift in diet, which may reflect seasonal changes in food resource availability and wedge-tailed shearwater foraging behavior. The collected data regarding the shearwater diet may be useful for in situ conservation efforts. Future research that combines DNA metabarcoding with other tools, such as data logging, may provide further insight into the foraging ecology of pelagic seabirds.”

Wedge-tailed Shearwater, photograph by Alan Burger

Reference:

Komura , T., Ando, H., Horikoshi, K., Suzuki, H. &Isagi, Y. 2018. DNA barcoding reveals seasonal shifts in diet and consumption of deep-sea fishes in wedge-tailed shearwaters. PLoS One doi.org/10.1371/journal.pone.0195385.

John Cooper, ACAP Information Officer, 03 May 2018

Susan Waugh (Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand) and colleagues have published in the journal The Condor: Ornithological Applications on overlaps between foraging ACAP-listed and globally Endangered Westland Petrel Procellaria westlandica and trawl fisheries.

The paper’s abstract follows:

“Environmental and anthropogenic influences in the marine environment are primary drivers of behavior and demographic outcomes for marine birds. We examined factors influencing the foraging patterns of the Westland Petrel (Procellaria westlandica), a highly threatened, endemic petrel that inhabits subtropical water masses primarily in the Tasman Sea, with a poorly known at-sea distribution. Risk assessments place the species at moderate risk of population impacts from fisheries-related mortality. Studies in the 1990s indicated that trawl fisheries would have an important influence on the Westland Petrel's foraging behavior. We investigated the influence of climatic conditions, marine productivity, bathymetry, the core fishery zone, concurrent fishing activity, light conditions, sex, and breeding stage on Westland Petrel foraging patterns. We analyzed the stable isotopes of carbon and nitrogen from blood sampled during the incubation period and examined changes in isotopic niche width over a 6-yr period. We found that the Westland Petrel's foraging zone varied only slightly between years and that the location of intensively used areas was strongly influenced by bathymetric slope and latitude, and negatively influenced by chlorophyll-a. The core fishery zone had a secondary influence, suggesting that these petrels co-occur with fisheries, but are not dependent on waste for food. Trophic niche width was significantly wider during strong El Niño conditions, indicating that food type, rather than location, was most affected by climatic variation. Consistent use of one marine area across varying times and conditions increases the risk of adverse effects of climate or human-induced impacts on the species. However, marine spatial management tools become viable in these conditions. Further, with rapid increases in sea surface temperatures and extreme values recorded in the region in recent periods, changes to fisheries zones and distributions of natural prey of the species are likely to occur and may change the population's sustainability."

Westland Petrel, photograph by Raja Stephenson

For a popular account of the publication click here.

With thanks to Robert Vagg.

Reference:

Waugh, S.M., Griffiths, J.W., Poupart, T.A., Filippi, D.P., Rogers, K. & Arnould, J.Y.P. 2018. Environmental factors and fisheries influence the foraging patterns of a subtropical seabird, the Westland Petrel (Procellaria westlandica), in the Tasman Sea. The Condor 120 (2): 371 DOI: 10.1650/CONDOR-17-179.1.

John Cooper, ACAP Information Officer, 02 May 2018

On 15 April the Hawaiian island of Kauai was hit by a massive storm that caused extensive flooding and damage in the northern part of the island (click here and here). Rainfall in the 24-hour period of the storm was measured at 48 inches [1.2 m], and is being reviewed as the most rainfall in one day ever recorded anywhere in the U.S.A. (click here).

After the storm: washed-away vehicles and a public rest room building in a river bed

ACAP Latest News reached out to its Hawaiian contacts to ask how the island’s north-shore breeding Laysan Albatrosses Phoebastria immutabilis had fared through the downpour.

Cathy Granholm of Princeville in the north of Kauai wrote to ACAP Latest News:

“All of the 24 Princeville chicks made it safely through the storms. We all tend to give these birds our human qualities, but even surrounded by “civilization,” they lead the albatross life. MK, the chick in my yard, had access to shelter, yet she chose to sit totally unprotected as thunder and lightning shook my house, and while the heaviest rain I can ever remember formed rivers through my yard. She sits alone most of the time, with the occasional visit by a pesky non-nester. She has no reason to be afraid of anything.  It is not a question of courage, she is a part of the natural world, she meets challenges as they arise; she has no time to waste in the human activity of anticipating problems. MK spent the day after the storm grooming her feathers, having lost more of her baby fluff to the rain” (click here).

Laysan Albatross MK, a little bedraggled after the storm, photograph by Cathy Granholm

Kauai’s Hob Osterlund of Kauai also wrote to ALN: “I do not know of any Moli [Laysan Albatross] injuries or deaths related to the storms and floods. All the Moli chicks at the Cornell cam site are fine [the cameras were down but are now active again]. Since LAAL prefer to nest on bluffs, they are usually safe from floods. The KPNWR [Kīlauea Point National Wildlife Refuge] reports that all the Moli chicks there are OK after the storms. One chick came very close to being nailed by a falling tree, but got lucky. As Kauai gradually recovers from massive rains and subsequent life-altering floods, Mōlī parents keep right on feeding their football-sized chicks.”

It seems the albatrosses’ habit of breeding on bluffs above the island’s coastline made them less at risk from the flooding that occurred in lower-lying areas along the north shore, such as occurred in the town of Hanalei close to the higher ground of the Princeville community where albatrosses breed in private gardens. Good to know that the current cohort of 162 chicks (72 within the refuge, the rest on private lands, including Princeville) along Kauai’s northern shore all survived the storm and that Laysan Albatrosses on Kauai continue to have their human guardians. Mahalo to them all!

According to a posting today on the Pacific Rim Conservation's Facebook page the Nihoku predator-proof fence on Kauai wasn’t badly damaged by the storm despite sediment piling up. The fenced area where translocations have occurred of globally Vulnerable Hawaiian Petrels Pterodroma sandwichensis and globally Endangered Newell’s Shearwaters Puffinus newelli over the last three seasons still appears to be pest free.

With thanks to Cathy Granholm (My Albatross Diary) and Hob Osterlund (Kauaʻi Albatross Network).

John Cooper, ACAP Information Officer, 01 May 2018

The Museum of New Zealand – Te Papa Tongarewa in Wellington supports an active ornithological research programme that extends beyond the classic museum studies of taxonomy and osteology to active field work on seabirds at their mainly island breeding sites.

The museum posts a series of biodiversity blogs on its website, a number of which reports on field trips after seabirds that have been taken by staff members. The most recent blog, by regular contributor Colin Miskelly, describes how he joined a Department of Conservation team to study the globally Vulnerable Chatham Petrel Pterodroma axillaris and other burrowing seabirds on introduced predator-free Rangatira Island, a 219-ha designated nature reserve in the Chatham Group. Rangatira’s fragile ground requires the wearing of “petrel boards” to reduce the chances of collapsing burrows when checking the contents of over 200 nest boxes installed from the mid 1990s.  The boxes have been provided with flaps over their entrances to deter entrance by Broad-billed Prions Pachyptila vittata.

A downy Chatham Petrel chick held by Graeme Taylor, photograph by Helen Gummer

 Earlier blogs by Colin Miskelly this year describe Te Papa involvement in field trips to the Auckland Islands studying albatrosses and burrowing petrels. Other species reported on include the globally Endangered and ACAP-listed Westland Petrel Procellaria westlandica, studied by Te Papa scientist Susan Waugh and colleagues (click here).

Te Papa has partnered with Birds New Zealand and the Department of Conservation to develop NZ Birds Online, a digital encyclopaedia of New Zealand birds, which, inter alia includes images, sound files and information for many of the 31 ACAP-listed albatrosses, petrels and shearwaters.

Read more about New Zealand's conservation work with Chatham Petrels here.

With thanks to Colin Miskelly.

Selected Literature on Rangatira's Chatham Petrels:

Gummer, H., Taylor, G., Wilson, K.-J. & Rayner, M.J. 2015. Recovery of the endangered Chatham petrel (Pterodroma axillaris): a review of conservation management techniques from 1990 to 2010. Global Ecology and Conservation 3: 310-323.

Nilsson, R.J., Kennedy, E.S. & West, J.A. 1994. The birdlife of South East Island (Rangatira), Chatham Islands, New Zealand. Notornis (Supplement) 41: 27-37.

Rayner, M.J, Taylor, G.A., Gummer, H.D., Phillips, R.A., Sagar, P.M., Shaffer, S.A. & Thompson, D.R. 2012. The breeding cycle, year-round distribution and activity patterns of the endangered Chatham petrel (Pterodroma axillaris). Emu 112: 107-116.

West, J. A. & Nilsson, R. J. 1994. Habitat use and burrow densities of burrow-nesting seabirds on South East Island, Chatham Islands, New Zealand.  Notornis (Supplement) 41: 27-37.

John Cooper, ACAP Information Officer, 30 April 2018