Graeme Elliott delivers a paper on a long-term study of Antipodean Albatrosses

The 2024 Birds New Zealand Annual Conference was held in Nelson, South Island from 1-2 June.  Several talks and posters were given on procellariiform seabirds.  Four abstracts on ACAP-listed species follow.  See an earlier article in ACAP Latest News on two presentations at the conference on the subspecies of Antipodean Albatrosses Diomedea antipodensis.

Graeme Elliott OZNM and Kath Walker OZNM talk is entitled ‘33 years of monitoring wandering albatrosses on Antipodes and Adams Islands’.  Their abstract follows:

“Monitoring of Gibson’s wandering albatrosses on Adams Island started in 1991 and an almost identical programme of monitoring of Antipodean wandering albatrosses started on Antipodes Island in 1994. Both programmes have continued annually, except for one missed year on each island.  Both programmes have involved estimating survival by banding and re-sighting birds, monitoring nesting success, tracking birds at sea using satellite and geolocator tags, estimating the size of the population by undertaking whole island censuses, and tracking population change by annual counting of nesting birds in representative portions of the islands. Both populations increased up until 2005 but then crashed with numbers continuing to fall for about 15 years, until Antipodean albatrosses were about 42% and Gibson’s about 47% of their pre-crash levels. Satellite and geolocator tracking of both taxa have enabled accurate description of their foraging ranges and identified that a large number of birds have been killed by tuna long-liners, particularly in the waters to the northeast of New Zealand. Tracking has revealed that although their foraging ranges overlap, Gibson’s mostly forage in the Tasman Sea while Antipodean mostly forage in the eastern Pacific. Such long-term monitoring programmes have involved half of our lives’ summers and several hundred days of sea-sickness, but we now know exactly what the two albatross populations are doing in good detail and we’ve had the joy of interacting with a wide range of rarely seen subantarctic birds.”

Black-browed Albatross by Lois Davis, Artists and Biologists Unite for Nature for ACAP

Jonathan Rutter and colleagues presented on “Immersion regularity predicts vessel following by albatrosses”. Their abstract follows:

“Many oceanic seabird species are threatened by bycatch in fisheries. Bycatch risk assessments benefit from quantifying individual seabird interactions with fishing vessels, including their frequency, duration, and impacts on seabird behaviour. However, interaction analyses are often limited by low-resolution seabird tracking data and incomplete fisheries tracking data. Here we examine the potential of leg-borne GLS-immersion loggers to detect seabird-fishery interactions from simple wet-dry patterns when tracking data are lacking or incomplete. We first identified 46 discrete seabird-vessel interactions by spatiotemporally matching high-resolution GPS data (0.0024-1 Hz) from 45 black-browed albatrosses (Thalassarche melanophris) breeding in the Falkland Islands to Automatic Identification System (AIS) data from vessels near their trajectories. We subsequently observed highly stereotypical patterns of immersion (i.e., regular landing and taking off) when birds were following trawler vessels. Then, using only wet and dry durations derived from immersion data (0.1667 Hz), we developed a temporal metric to identify these periods of behavioural regularity. This metric alone successfully identified one-third of vessel following events, with no false positive detections. Thus, we demonstrate the potential of immersion loggers to detect vessel following by seabirds, even in the absence of tracking data for both seabirds and vessels. This result provides a foundation for more comprehensive seabird bycatch risk assessments that quantify previously hidden seabird-vessel interactions, such as those involving migratory life history stages and illegal, unreported, or unregulated (IUU) fishing vessels.”

“Towards understanding tākoketai/Black Petrel recruitment on Aotea/Great Barrier Island” delivered by Elizabeth ‘Biz’ Bell

Biz and her co-authors’ abstract follows:

“Monitoring of tākoketai/black petrels (Procellaria parkinsoni) has been undertaken at their breeding colony on Hirakimata/Mt Hobson, Aotea/Great Barrier Island since 1995. Over this period, the population trend suggests a stable or slightly declining population, which appears to be related to low juvenile survival and recruitment into the population.  As these low rates may be related to recapture effort at the colony, recent expeditions focused on increased nocturnal surveys to capture as many tākoketai on the surface as possible, as well as capturing individuals at-sea. Comparison between on-land and at-sea ‘returned chick’ recapture rates indicate that on-land effort is more effective in resighting ‘returned chicks’. Over 28 years of tākoketai monitoring on Aotea, 141 ‘returned chicks’ have been recaptured over 228 night surveys with an average 0.62 returned chicks caught each night. The recent focused effort in 2021/2022 and 2022/2023 (22 nights surveys) increased that rate to an average of 2.3 returned chicks recaptured per night. In comparison, from six at-sea capture expeditions extending over three years and 15 days cumulatively, 3 tākoketai originally banded as chicks were recaptured (average 0.2 per day). Continued effort to recapture ‘returned chicks’ at the Hirakimata study colony is recommended to enhance population trend models and risk analyses”.

Black Petrel, PanPastels by Rosana Venturini, Artists and Biologists Unite for Nature for ACAP

Maria Düssler and colleagues gave a talk entitled “Comparative study of the diving behaviour of three Procellaria petrel species”.  Their abstract follows.

“The ongoing impact of fishery bycatch on seabird populations suggests bycatch mitigation measures are insufficient or ill-informed. For these measures to be appropriately revised, a thorough understanding of seabird foraging behaviour is necessary. My thesis aims to examine and compare the foraging behaviour of three Procellaria petrel species, all of which are vulnerable to bycatch in longline fisheries. Using data from time-depth recorders (TDRs) deployed on 23 Westland (Procellaria westlandica), 10 white-chinned (P. aequinoctialis), and 9 black petrels (P. parkinsoni), we retrieved dive depths, durations, descent rates, and dive profiles. Preliminary results show white-chinned petrels dive less frequently but deeper than Westland petrels, with maximum depths of 17.31 m and 21.72 m, respectively. Further results will have the potential to inform the necessary sink rates of hooks and the depths to which hooks must be protected. Additionally, we deployed global positioning system (GPS) tags alongside the TDRs on 7 black petrels.  Pairing GPS data from birds and fishing vessels will allow us to investigate whether petrel diving behaviour differs around fishing vessels. Should behaviours differ, previous mitigation measures based on undefined diving behaviour may need to be revised. By employing a comparative approach across three species, we begin to understand potential parameters influencing the foraging behaviour, and thus the bycatch risk, of different seabird species.”

A number of talks and posters were given on other procellariiform seabirds not listed by ACAP.  Information comes from the Facebook page and website of Birds New Zealand.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 02 July 2024

Kath Walker presenting at the 2024 Birds New Zealand Annual Conference

At the recent 2024 Birds New Zealand Annual Conference held in Nelson, South Island from 1-2 June, Kath Walker ONZM gave a co-authored presentation entitled “Comparative analysis of plumage, morphology and biology of Antipodean and Gibson’s wandering albatrosses”. She concluded by saying that the two subspecies should be accorded specific status as Antipodean Albatross Diomedea antipodensis and Gibson’s Albatross D. gibsoni.

Kath and colleagues' abstract follows:

“Identification of Antipodean and Gibson’s wandering albatrosses (Diomedea antipodensis antipodensis and D. a. gibsoni) at sea has been difficult due to a lack of quantitative comparative morphometric and plumage data on subadults and adults on their breeding grounds, respectively the Antipodes and Auckland Islands. Since 1994 annual banding of chicks produced and adults mating and breeding in study areas on both islands has allowed the collection of photographic records of plumage changes in known age, sex, and origin individuals over their lifetimes. The presence (in female Gibson’s) or absence (in female Antipodean) of white feathers on the upper wings at the “elbow” was found to reliably distinguish the two taxa. For both sexes, the combination of wing and toe length measurement correctly identified taxa 85% of the time, with longer wings and shorter toes in Antipodean than Gibson’s albatrosses. The biggest change in plumage of Antipodean females comes not with age as in most wandering albatrosses, but after a successful breeding season when extensive wear of brown-tipped body feathers exposes white feathers below, giving the birds a spotty appearance, and causing taxon confusion at sea. Median lay date for the 2 taxa differed by 15 days (Gibson’s albatross 10 Jan [26 Dec–7 Feb]; Antipodean albatross 25 Jan [6 Jan–15 Feb]). No Gibson’s albatrosses foraged in the south-eastern Pacific and off Chile, whereas Antipodean albatrosses of both sexes regularly did. Given the diagnosability of female Gibson’s and Antipodean albatrosses, restoration of their former taxonomic status as species would be appropriate.”

Watch a brief video of Kath’s presentation.

A colour-banded Antipodean Albatross, photograph by Kath Walker

Imogen Foote and colleagues' presentation was entitled “Whole-genome analyses reveal genetic structure in the highly threatened Antipodean and Gibson’s albatrosses.” They conclude that their study will  help define species taxonomy and inform updated conservation management for the two taxa.

Their abstract follows:

"The Antipodean and Gibson’s albatrosses (Diomedea antipodensis antipodensis and D. a. gibsoni) are highly threatened NZ taxa whose conservation management has been hindered by ongoing taxonomic uncertainty. Single locus genetic studies revealed low levels of genetic differentiation informing the current taxonomy of subspecies, but the potential of genomic data to reveal population structure in these taxa has not previously been explored. Here, we present whole-genome data for these two taxa to examine population genetic structure and genomic differentiation. We produced whole genome sequence data for 86 individuals across both populations and aligned to high quality reference genomes to generate a dataset of 60,488 high-quality neutrally evolving Single Nucleotide Polymorphisms (SNPs).  Assignment tests and Principal Component Analyses (PCA) revealed two distinct clusters relating to the subspecies groupings. Analysis of Molecular Variance (AMOVA) showed these two groupings to be significantly differentiated. A genome-wide scan for loci putatively under selection also provide (sic) evidence of adaptive divergence between the taxa.  These results indicate that genetic differentiation between these albatross taxa is higher than was previously estimated using single locus genetic markers and reveal the potential for genomics to identify structure in closely related albatross taxa. Given the high level of threat these birds face and the continued population declines, particularly of the Antipodean subspecies, these results should be used to help define species taxonomy and inform updated conservation management.”

Four more papers on ACAP-listed-procellariiforms given at the conference will be covered in a following news post.  A number of talks and posters was given on other procellariiform seabirds (petrels, prions and shearwaters) not listed by ACAP.  Information comes from the Facebook page and website of Birds New Zealand. 

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 27 June 2024

A Short-tailed Albatross chick on Midway Atoll, photograph by Narongkorn Thatsanangkun

George and Geraldine, the well-known pair of Vulnerable Short-tailed Albatrosses Phoebastria albatrus on Midway Atoll’s Sand Island fledged their latest chick around late May this year – it was last seen when it was videoed, on 23 May.

The chick was given its metal and colour bands on 17 April.  This is the fifth chick to be reared successfully (out of six breeding attempts) by the atoll’s lone Short-tail pair.  George and Geraldine are the only Short-tailed Albatrosses breeding outside of Japan’s Torishima and Ogasawara Islands and the disputed Senkaku Islands.

Short-tailed Albatrosses George (at back) and Geraldine, artwork by Flávia F. Barreto after a photograph by Jonathan Plissner

News from the Friends of Midway Atoll National Wildlife Refuge.  Access previous posts in ACAP Latest News about George and Geraldine here.

j26 June 2024

The recent Iceland sighting of a Black-browed Albatross, photograph by Tom Collier

An adult Black-browed Albatross Thalassarche melanophris was photographed at sea off Húsavík, northern Iceland on 09 June 2024 from a whale-watching vessel.  According to comments posted to Facebook there have been at least three previous records of Black-browed Albatrosses sighted off Iceland.

Single Black-browed Albatrosses have been recorded in the Northern Hemisphere on numerous occasions, as has been reported in ACAP Latest News from time to time.  It seems likely that more than one at-sea sighting is of the same individual.  Birds have been seen ashore in Northern Gannet Morus  bassanus colonies in the United Kingdom, most recently at Bempton Cliffs, Yorkshire (click here).  It has been suggested that the latest Iceland record could be of the Bempton Cliffs bird.

25 June 2024