A fledgling Black Petrel; photograph by Elizabeth (Biz) Bell, WMIL

A report by Elizabeth Bell (Wildlife Management International Ltd, New Zealand) and colleagues on the tākoketai/Black Petrel, Procellaria parkinsoni of Aotea/Great Barrier Island has been released by New Zealand’s Department of Conservation (NZDOC). Research for the report, Key demographic parameters and population trends of black petrels (Procellaria parkinsoni) – 2022/23, was carried out over the 2022/2023 breeding season.

The summary from the NZDOC website follows: 

"During the 2022/23 breeding season 480 tākoketai/black petrel study burrows were intensively monitored within the Mt Hobson/Hirakimata study area on Aotea/Great Barrier Island. 

There were 313 (65.2%) burrows occupied by breeding pairs, 64 (13.3%) occupied by non-breeding birds, and 103 (21.5%) were unoccupied. Overall, 191 chicks were produced from the study burrows representing a fledgling success rate of 61%, but 13 chicks were found to be below weight and smaller in size during the May chick banding trip, and most of these chicks were not expected to survive to fledging. This would further reduce breeding success to 56.9%. 

Breeding success was impacted by weather events, specifically the Auckland flood event on 27 January 2023 and Cyclone Gabrielle between 12-16 February 2023. A number of burrows flooded, causing eggs to fail and small chicks to drown or chill and die, and foraging success of parents appeared to be reduced with 13 chicks being in poor condition by May prior to fledging. 

Nine census grids were monitored within the study area and accounted for 197 of the inspected study burrows. Of these, 119 were occupied by breeding pairs (60.4%) and 68 chicks were produced representing a fledging success rate of 57.1%. Again 7 of these chicks were in poor condition and were not expected to fledge, reducing breeding success to 52.1%. 

A total of 664 adults and 129 fledgling chicks were captured during the 2022/23 field season with 174 adults banded this season (including 52 from study burrows). Of the 129 fledgling chicks banded during the 2022/23 field season, 119 were banded in study burrows; 72 could not be banded due to torrential rain over the chick banding trip, and one had already fledged prior to the banding visit in May 2023. 

There have been a total of 420 returned chicks recaptured at the colony since they were banded prior to fledging. Of these, 117 returned chicks were identified during the 2022/23 breeding season; 28 of which were caught for the first time at the colony. The majority of all 420 returned chicks were from the 2016/17 breeding season, followed by the 2013/14 cohort. Not all cohorts were represented as no returned chicks from the 1995/96, 1996/97 and 1997/98 cohorts were recaptured this season. Understanding the factors affecting return rates of chicks within the 35-ha study site is vital. It is important to determine whether it is related to low juvenile survival and/or recruitment or if it is simply due to a lack of detection. Understanding juvenile survival and recruitment is necessary for accurate demographic modelling and for species risk assessment modelling. Therefore, it is recommended that effort to obtain this data is completed with urgency. 

Additional monitoring of pig and other predator occurrence and impact on black petrels on Cooper’s Castle was undertaken this season. Eighteen black petrel burrows were identified within the boundaries of this study area; three were breeding sites and four sites were being visited by non- breeding birds. All other burrows were empty. Trail cameras were placed along pig pathways, walking tracks and outside active black petrel burrows. Footage confirmed feral pig, rat, and feral cat presence. While no interactions with black petrels were caught on camera at Cooper’s Castle, there was one cat predation of an unbanded adult and one chick from a random, non-monitored burrow. There was one rat predation event at the study colony on Hirakimata this season. Introduced species still pose a threat to the black petrel population and it is imperative pest control measures continue."

Reference:

Bell, E.A., Lamb, S. & Maclean, C. 2023. Key demographic parameters and population trends of tākoketai/black petrels (Procellaria parkinsoni) on Aotea/Great Barrier Island: 2022/23. POP2022-01 final report prepared by Wildlife Management International Ltd for the Conservation Services Programme, Department of Conservation, Wellington. 41 p.

07 September 2023

Southern Buller's Albatross, Snares Islands, April 2007, photograph by Paul Sagar

The Albatross and Petrel Agreement recognizes 22 species of albatrosses, all of which it lists under its Annex 1. Distinct breeding populations of two of these species continue to be variously treated in the professional and popular literature (and on social media) either at the subspecific or specific level; a third albatross, hitherto thought not to vary taxonomically (“monophyletic”) has recently been proposed to consist of two species. The question thus arises should there be 22 or 25 species of albatrosses? In this Monthly Missive I consider the taxonomic status of these three albatross species, primarily based on reviews summarized by ACAP’s Taxonomy Working Group (TWG) in its reports to meetings of the ACAP Advisory Committee.

Buller’s Albatross

New Zealand’s endemic Buller’s Albatross Thalassarche bulleri occurs in two distinct populations. These have been treated either as subspecies or as distinct species in the literature. The northern population T. (b.) platei (sometimes referred to as the Pacific Albatross) breeds in the Chatham Island group (Rangitatahi/Three Sisters and Motuhara/Forty-Fours) and on Rosemary Rock, Manawatāwhi/Three Kings Islands. The southern population T. (b.) bulleri breeds on the Solander and Snares Islands. The two populations breed around two months apart with the northern population laying eggs in October-November and the southern birds over January and February. At least some field guides consider they can be identified by plumage and other differences. According to New Zealand Birds Online “the two subspecies are separated by bill size and colour and head plumage. Southern Buller’s mollymawk has a silvery-white forehead with black extending over about 70% of the sides of the bill. Northern Buller’s mollymawk has a silvery-grey forehead with black extending over about 80% of the sides of the bill. In addition, the bill of northern Buller’s mollymawk is more robust (longer and deeper) than that of the southern Buller’s mollymawk”.

In 2006 the TWG evaluated the taxonomic status of Buller’s Albatross and in its report (AC2 Doc 11 to the 2nd Meeting of the ACAP Advisory Committee, recommended the northern and southern populations be recognized as subspecies, this then being supported by the committee. This year the TWG reevaluated the situation following new genetic evidence, recommending to the 13th Meeting of the Advisory Committee that the two populations’ subspecific status should be retained (AC13 Doc 10 Rev 1). It commented that “no statistical analyses of morphometric data have been published for these taxa”, suggesting the need for a study. MSc anyone?

Antipodean Albatross

The Albatross and Petrel Agreement recognizes four species within the “wandering” group of great albatrosses in the genus Diomedea. These are the Amsterdam D. amsterdamensis, the Tristan D. dabbenena, the Wandering D. exulans and the Antipodean D. antipodensis. The first three species are regarded as monophyletic by ACAP and most authorities. The Antipodean Albatross, a New Zealand endemic, is recognized by ACAP as having two subspecies, the nominate D. a. antipodensis, which breeds on Antipodes Island, and the “Gibson’s” race D. a. gibsoni, which breeds on the Auckland Islands. However, this view is not held by all authorities, with some awarding full species status to the two subspecies, as set out in detail on the TWG’s 2006 Report (AC2 Doc 11) to the Second Meeting of the ACAP Advisory Committee. Following its literature review the working group recommended that the two subspecies did not warrant specific status. It did, however, recognize that little or no gene flow occurs between the two taxa; that D. a. antipodensis tends to be darker than D. a. gibsoni, and that it is likely D. a. antipodensis forages more frequently in the eastern Pacific whereas D. a. gibsoni tends to forage in the Tasman Sea. The TWG concluded that these two taxa be recognised as subspecies, which accords with the current situation within the Agreement.

Short-tailed Albatross

Males of the two proposed cryptic species of the Short-tailed Albatross, photographs by Satoshi Konno

The Short-tailed Albatross Phoebastria albatrus breeds primarily on two island groups in the North Pacific: Japan’s Torishima and to the west on the disputed Senkaku/Tiaoyutai/Diaoyu Islands. The species has long been considered monophyletic, but recent research by Masaki Eda and colleagues has shown genetic and mensural differences between the populations breeding on the two island groups, leading to their proposal that they constitute two cryptic species – but not providing scientific or common names for them (click here). Hybridisation between the two populations is thought to occur.

The TWG considered the available evidence this year and noted that there “were some significant differences in morphological characteristics between males of the two taxa. In general, Torishima-type birds were larger than western-most current breeding site-type birds, whereas western-most current breeding site -type birds had relatively longer beaks. Sample sizes were small however and insufficient to analyse female differences statistically.” The TWG went on to say “Assessment of the two types of Short-tailed Albatross is undoubtedly hampered by low sample sizes and the inability to visit the [disputed] western-most current breeding site. It remains possible that further research might demonstrate that the two types represent two sub-species, but the morphometric discrimination is not great and the assortative mating is incomplete and likely reflects the known differences in timing of courtship/breeding in the two populations.” The working group therefore recommended that these taxa do not warrant specific status. Collecting new evidence will surely need a ground visit to the disputed islands, but this seems to be unlikely any time soon, given the geopolitical tensions that exist in the region (click here).

Considerations by the 13th Meeting of the Advisory Committee

Following the report from the TWG, the Advisory Committee at its meeting in 2023 stated in its own report that:

“10.1.3 Based on recommendations from the TWG, AC13 agreed that the taxonomic treatment of both Buller’s Thalassarche bulleri and Short-tailed Phoebastria albatrus Albatrosses should not change despite additions to the evidence on the taxonomy of the two species.

10.1.4 New Zealand advised that data had been collected on the morphometrics of T. bulleri and on the plumage of Antipodean Albatross Diomedea antipodensis breeding on the Antipodean and Auckland Islands. A whole-genome analysis for Antipodean Albatross was also reported to be underway. This information will further inform the taxonomic treatment of these species.”

So, for the time being, and until new evidence is to hand, there remain 22 species of albatrosses, at least from the perspective of the Albatross and Petrel Agreement.

References:

Brothers, N., Bone, C. & Wellbelove, A. 2022. Albatross population monitoring using satellite imagery, a case study. Marine Ornithology 50: 7-12.

Eda, M., Yamasaki, T., Izumi, H., Tomita, N., Konno, S., Konno, M., Murakami, H. & Sato, F. 2020. Cryptic species in a Vulnerable seabird: short-tailed albatross consists of two species. Endangered Species Research 43: 375-386.

Taxonomy Working Group 2006. Taxonomy Working Group Report to the Second Advisory Committee Meeting - Annex 5 to AC2 Meeting Report. AC2 Doc 11. 21 pp.

Taxonomy Working Group 2023. Report of the Taxonomy Working Group.  Thirteenth Meeting of the Advisory Committee, Edinburgh, United Kingdom, 22 – 26 May 2023.  AC13 Doc 10 Rev 1. 12 pp.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 07 September 2023

The New Island Restoration Project’s schematic for an artificial burrow for White-chinned Petrels

The New Island Restoration Project (NIRP) aims to remove introduced mammals from New Island in the Falkland Islands/Islas Malvinas* (click here). The island supports a small population (one of the very few in the island group) of ACAP-listed White-chinned Petrels Procellaria aequinoctialis. As recently reported by ACAP Latest News this population of a globally Vulnerable species has been having a very poor to zero breeding success attributed to the deleterious effects of feral cats and introduced rodents and European Rabbits, coupled with an eroding habitat.

The NIRP now intends to install artificial burrows with the intention of improving breeding success and via its Facebook page has made a request for local help in securing spare offcuts of pipe, roughly 250-500 mm in diameter and up to a metre long, to use as entrance tunnels to the artificial burrows as illustrated above. In its appeal the project states “The White-chinned Petrels on New Island are facing tough times. Not only are they threatened by invasive mammals, but their burrows are drying up and eroding away. [We will] create artificial nest burrows to help these birds by ensuring a secure breeding ground on New Island.” It is also intended to commence the control of cats in the vicinity of the burrows. A response to its appeal has led to the donation of leftover ducting.

A White-chinned Petrel in its burrow on New Island, photograph from the New Island Restoration Project

Artificial burrows are commonly used both as an aid to allow the study of burrowing petrels and shearwaters (by providing an inspection lid as here) and to facilitate or encourage breeding at translocation sites, as well as on New Island to improve breeding in situ in otherwise sub-optimal conditions.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 05 September 2023

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.

Successful 2022 ACAP Secondment Applicant, Cristián Suazo, from Chile. ACAP Party, Argentina is hosting Cristián for his Secondment, titled: Multi-fishery interactions of sympatric black-browed and grey-headed albatrosses from the Diego Ramírez Islands: An isotopic and tracking approach

The Agreement on the Conservation of Albatrosses and Petrels invites applications for the 2023 round of its Small Grants and Secondment Programmes. 

Both programmes provide funding towards proposals that progress the Agreement’s objective to achieve and maintain a favourable conservation status for albatrosses and petrels. Additionally, Secondment proposals should aim to promote capacity-building within Parties.

At the recent Thirteenth Meeting of the Advisory Committee (AC13), the Committee identified several opportunities for small grants and secondments. Applicants are encouraged to put forward proposals clearly addressing tasks contained within the work programmes of the Advisory Committee (see Annex 4, AC13 Report) and Secretariat (see Annex 5, AC13 Report) as relevant.

The Agreement’s Working Group Convenors, the Advisory Committee Chair or Vice-chair, or the This email address is being protected from spambots. You need JavaScript enabled to view it. can be contacted to assist in determining ACAP priority areas for proposals.

Applications will only be accepted from ACAP Parties, but can involve collaboration with institutions or individuals based elsewhere. Applications can be completed in English, French or Spanish and should be submitted to relevant ACAP National Contact Points.

Applications close at 5pm on 3 October for Small Grant applications and on 17 October for Secondment applications.

The 2023 application forms, in all three ACAP official languages, are available to download here.

Find articles about previous ACAP Secondments, here.

04 September 2023