Kalinka Rexer-Huber (Department of Zoology, Otago University, Dunedin, New Zealand) has been awarded a PhD for her study of the ACAP-listed White-chinned Petrel Procellaria aequinoctialis following field work conducted on New Zealand’s sub-Antarctic Auckland and Campbell Islands.

Kalinka on Adams Island in the Auckland Islands group, holding a White-chinned Petrel in front of its burrow

The thesis abstract follows:

“Albatrosses and petrels are a group of oceanic seabirds that spend most of their lives at sea. The Southern Ocean, which rings Antarctica in a continuous belt of wind and currents, supports most of the world’s albatrosses and petrels. The conservation status of many oceanic seabirds has deteriorated dramatically over the last two decades, due to mortality from incidental bycatch in fisheries and depredation by introduced mammals at breeding sites. Globally, seabird bycatch is highest in Southern Ocean waters and introduced mammals occur on a third of sub-polar and high-latitude seabird islands.

The seabird species most frequently killed in Southern Hemisphere fisheries bycatch is the white-chinned petrel Procellaria aequinoctialis. Almost three decades after substantial white-chinned petrel mortality in fisheries was first recorded, capture rates remain high despite substantial global efforts to reduce bycatch rates. Population impacts are exacerbated by introduced mammals at some breeding sites, yet some island populations are still virtually unstudied. White-chinned petrels breed on eight subantarctic island groups around the Southern Ocean. Key steps toward targeted conservation are obtaining robust estimates of abundance and at-sea distribution, and defining the scale of genetic conservation units within the species. Population-level questions in these key areas limit the ability to gauge the impact of current threats locally and around the Southern Ocean, and hinder informed conservation, management action and policy development.

This thesis broadly asks at what scale(s) processes affect species distribution, abundance and connectivity in the Southern Ocean ecosystem, with the white-chinned petrel as the focal species. It evaluates status and connectedness of white-chinned petrels breeding on subantarctic islands around the Southern Ocean via three broad approaches:

- Population size estimates for the Auckland Island and Campbell Island breeding populations, the last two island groups lacking estimates of white-chinned petrel numbers (Chapter 2);

- Tracking devices follow the at-sea movements and distribution of 150 white-chinned petrels year-round, from all major breeding islands (Chapter 3); and

- Molecular genetics tests connectedness within the white-chinned petrel metapopulation, using sequences from mitochondrial and nuclear genes as well as genomic data from every island population (Chapter 4).

This thesis provides the first robust population size estimates for white-chinned petrels at the Auckland Island and Campbell Island groups, including 11 islands (Chapter 2). Burrow numbers were sampled widely to capture spatial variability (33–241 randomised sampling sites per island). Estimated burrow numbers were corrected with detection rates and occupancy rates to estimate numbers of breeding birds. The Auckland Island group has an estimated 186,000 (95% CI: 136,000–237,000) white-chinned petrel breeding pairs, and the breeding population of the Campbell group is estimated ~ 22,000 (15,000–29,000) pairs. The New Zealand region supports almost a third of white-chinned petrels globally, substantially more than suspected. Importantly, the estimates establish repeatable population baselines. Tracking data from all major island populations except Campbell Island were analysed together, giving the first metapopulation-scale picture of the at-sea distribution of adult white-chinned petrels (Chapter 3). The movements of 150 adult petrels (9–33 petrels per island group) were tracked for an average of 369 days with light-level geolocation GLS loggers. Quantitative density estimates for white-chinned petrels show key global density hotspots (off South America, New Zealand, and southern Africa). Island population-specific distributions highlight areas used only by adults from a given island population. Island-specific distributions also show spatial segregation between island populations varying across the year to an extent unusual for seabirds, so the implications for resource partitioning are explored (Chapter 3). Using comprehensive sampling from every island population, high-resolution genomic data (60,709 genotyping-by-sequencing loci) was compared with data from widely-used mitochondrial genes (entire cytochrome b gene and the highly variable 1st domain of control region) (Chapter 4). Genomic data revealed genetic structure in white-chinned petrels at very fine scale (among islands) and at broad oceanic scales (between Atlantic and Indian Ocean regions) that was not detected in analyses of single genes. Three ocean-basin scale evolutionarily significant units, ESUs, were identified. There is promise that some island populations are sufficiently unique to link mortality in a specific fishery to a given island (Chapter 4). The results of the thesis are synthesised (Chapter 5) to explore the implications for conservation and the broader biogeographic context.”

In 2014 ACAP made a grant to New Zealand’s National Institute of Water and Atmospheric Research (NIWA) to undertake a population estimate of the Whie-chinned Petrel Procellaria aequinoctialis on Disappointment Island, Auckland Islands. The field work was carried out over the 2014/15 summer by Kalinka Rexer-Huber click here).

With thanks to Kalinka Rexer-Huber, whose PhD is being formally conferred today with her graduation to take place next year in May.

Reference:

Rexer-Huber, K. 2017. White-chinned petrel distribution, abundance and connectivity have circumpolar conservation implications.  PhD thesis.  Dunedin: University of Otago. 166 pp.

See also:

Rexer-Huber, K., Parker, G.C., Sagar, P. & Thompson, D. 2015. White-chinned Petrel Population Estimate, Disappointment Island (Auckland Islands). Report to the Agreement for [sic] the Conservation of Albatrosses and Petrels. Dunedin: Parker Conservation. 14 pp.

Rexer-Huber, K., Parker, G.C., Sagar, P.M. & Thompson, D.R. 2016. White-chinned petrel population estimate, Disappointment Island (Auckland Islands).  Polar Biology 40: 1053-1061.

John Cooper, ACAP Information Officer, 13 December 2017

On 22 June 2012 domestic dogs entered a Laysan Albatross Phoebastria immutabilis colony on private but unfenced land in Moloa'a on the Hawaiian island of Kauai, killing eight chicks and injuring five more a few days before they were expected to fledge (click here). The chicks had only been banded on the previous day.

The five wounded birds were rescued by Kim Steutermann Rogers, Hob Osterlund and Jeanine Meyers of the Kauai Albatross Network which monitors albatrosses on Kauai rural lands. They were then taken into care by Tracy Anderson of the Save our Shearwaters (SOS) programme of the Kauai Humane Society. One chick had to be euthanized but four, once they had recovered from their injuries and had been deemed waterproof following washing, were transferred to the Kilauea Point National Wildlife Refuge in July from where they all successfully fledged after hand feeding within the fenced site.

So far, two of the four colour-banded birds, A432 and A441, have been resighted ashore. A441 was first recorded post-release at Kaena Point National Wildlife Reserve (KPNWR) on the nearby island of Oahu in October 2015 as a three-year old by Lindsay Young of Pacific Rim Conservation. It was next seen back on Kauai in the 2016/17 breeding season by Hob Osterlund, but is yet to be recorded breeding.

A432 is the second from the 2012 incident to be re-sighted post-release. It had several injuries that required suturing and was in shock at arrival at SOS. In January 2017 during the previous breeding season it was photographed by Hob Osterlund displaying as a four-year old on Kauai’s north shore. On the first of this month the rehabilitated bird, considered to be a female, was photographed on Kauai by Hob incubating as a five-year old. Since then a changeover has occurred at the nest with an assumed male, K855, taking over incubating duties. This bird hatched out in 2010 and is believed to be a first-time breeder like its rehabilitated partner. Fortunately their chosen breeding site is fenced so they should not be at risk to predators.

No definite attacks on Laysan Albatrosses by dogs on the north shore of Kauai have been reported since the last known incident in 2013 (click here), although an attack by a free-ranging dog causing an injury to an albatross occured in the Pacific Missile Range Facility Barking Sands (PMRF) on the west side of the island in 2015.  Fortunately this bird was successfully rehabilitated by SOS and has been sighted subsequently several times within the KPNWR.  In addition to Laysan Albatrosses, breeding Wedge-tailed Shearwaters Ardenna pacifica on Kauai are reported regularly as being attacked by dogs; click here for a report of an attack that killed 33 birds in the PMRF in August this year.  Tracy Anderson of Save our Shearwaters advises ACAP: "we get orphaned [shearwater] chicks and mangled adults from colonies all over the island every year due to dog attacks".

Kim Rogers, who monitors rural properties where Laysan Albatrosses breed on Kauai, writes to ACAP: "we’ve had confirmed [feral] pig attacks on Laysan Albatross, sadly, over the past four years - approximately a dozen [incidents] of suspected pig predation. Either the birds are completely obliterated - nothing left but feathers; killed outright, their bodies found in fairly gruesome condition; or massively injured but subsequently euthanized."

 PHOTO PORTFOLIO

A432 is anaesthetized and sutured...

 ... and washed to help restore waterproofing

A432 swims in the SOS conditioning pool to assess waterproofing

A432 on the day of release in the Kilauea Point National Wildlife Refuge after 19 days in care

About to fledge the day after release: A432 in the Kilauea Point National Wildlife Refuge

Photographs above from Tracy Anderson of Save our Shearwaters

A432 on the left in January 2017 as a courting pre-breeder, its future mate (K855) is on the right

A432 crouches over its egg on 1 December 2017

K855 takes over incubation duties

Above three photographs by Hob Osterlund, Kauai Albatross Network

Read more about the discovery of A432 breeding here.

With thanks to Tracy Anderson of Save our Shearwaters, and Hob Osterlund (Founder) and Kim Steutermann Rogers of the Kauai Albatross Network for information and photographs.

John Cooper, ACAP Information Officer, 12 December 2017

An international conference to assess the status and trends of habitats, key species and ecosystems in the Southern Ocean will be held in Hobart, Tasmania, Australia over 9-13 April 2018.

Abstracts are due by 15 December on any of the four main conference themes:

1. Assessments of status and trends in habitats, species and ecosystems, and the causes of change

2. Responses of species to changing habitats, including ocean acidification, sea ice and temperature

3. Modelling and analytical methods to assess status and trends

4. Implementation of observing systems to estimate dynamics and change

Light-mantled Sooty Albatrosses: a Southern Ocean species; photograph by Aleks Terauds

The conference will be co-hosted by the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Centre.

Read more on the conference website.

John Cooper, ACAP Information Officer, 11 December 2017

The 27th International Ornithological Congress (IOC) under the direction of the International Ornithologists' Union will be held in Vancouver, British Columbia on Canada’s Pacific Coast from 19 to 26 August 2018. IOCs have been held at generally four-year intervals since the first was held in Vienna, Austria in 1884.

Events planned to accompany the scientific programme include field tours and the Vancouver International Birding Festival. The Congress will be held in the Vancouver Convention Centre.

Registration and abstract submissions are now open; the abstract deadline is 31 Jan 2018. Click here to access the planned symposia and their co-convenors.

Read more at the IOC27’s website.

Short-tailed Albatrosses occur in Canadian Pacific waters, photograph by Aleks Terauds

John Cooper, ACAP Information Officer, 08 December 2017