Filling data gaps for the population of Wandering Albatrosses on New Zealand's Disappointment Island (pictured) was one of the aims of the research

A report by Kath Walker (Department of Conservation, New Zealand) and colleagues on the population of Antipodean albatrosses Diomedea antipodensis on New Zealand’s Auckland Islands has been released by the Department of Conservation. Researchers carried out a census and considered the capacity for drone-based whole-island surveys. 

The report’s summary follows: 

“Gibson’s wandering albatross (Diomedea antipodensis gibsoni) has been in decline since 2005. Research into the causes of and solutions to the falling numbers of Gibson’s wandering albatross includes an annual visit to the main breeding grounds on Adams Island, and this report describes the results of the field programme in the 2022/2023 breeding season.

The survival and productivity of Gibson’s wandering albatross has recovered from the dramatically low rates recorded during 2006–08, but the average survival rate for both sexes remain lower than before the population crash in 2005, and nest success has only just recovered to pre-crash levels. Recent increases in the number of nesting birds are almost certainly attributable to a higher proportion of the population choosing to breed and mark-recapture models estimates of population size still show a decline. The data missed because of the late cancellation of the 2021 season field trip precludes better estimates of population size until next year.

Twenty-two juvenile Gibson’s wandering albatrosses were fitted with satellite transmitters and dataloggers before they fledged in late December 2022. In the subsequent seven months juveniles spent more time foraging north-east of New Zealand than previously tracked adult birds. No information has previously been collected on the at-sea distribution of juvenile Gibson’s wandering albatross, so this data filled a major data gap.

For investigation into diet and mercury pollution in Gibson’s wandering albatross, work additional to the CSP annual plan, feather and blood samples were collected from 20 juvenile and 58 adult birds outside the main albatross study area.

Drone census techniques were refined, allowing a more reliable estimate of the effort required for a whole-island drone-assisted count of the number of Gibson’s wandering albatross nesting on Adams Island. High variability in the number of birds sitting on nests but not incubating eggs (loafing birds) is a large source of error when trying to count breeding birds from the air, which would require substantial concurrent ground-truthing to ameliorate. The costs and benefits of undertaking whole-island nest counts using a variety of methods including drones are explored. The island’s large size, height and persistent bad weather mean a large amount of time and resources are required to obtain a reliable whole-island count using any method. It would be a major undertaking, requiring its own dedicated effort, best done after the regular field programme to ensure the vital mark-recapture trend monitoring dataset is not compromised.”

Reference:

Walker K, Elliott G, Parker GC, Rexer-Huber K. 2023. Gibson’s wandering albatross: population study and potential for drone-based whole-island census. POP2022-08 final report prepared for New Zealand Department of Conservation. 28 p.

POP2022-08 Gibson's wandering albatross: population study and assessment of potential for drone-based whole-island census (PDF, 2,242K) 

28 August 2023

Figure 5. from the paper which presents vulnerability of seabirds to marine heatwaves (MHWs) is related to the spatial overlap/proximity of the event to breeding and foraging areas, and to the duration of the temporal overlap. Vulnerability is indicated by warmer colours, and the dashed lines are representative of equiva- lent vulnerability. For example, an extended MHW with low spatial overlap will have a similar impact to a brief MHW that has high overlap

Eric J. Woehler (Australasian Seabird Group, Hobart, Tasmania, Australia) and Alistair J. Hobday have published open access in the journal Marine Ecology Progress Series, on how a seabird’s life experience could play a role in moderating the effects of marine heatwaves.

The paper’s abstract follows,

“Marine heatwaves (MHWs) are periods of anomalously warm water associated with changes in ocean structure, based on the horizontal advection of water masses and atmospheric exchange of heat. The longest MHWs persist for many months, and dramatic effects on marine life have been reported from around the world. As top-order predators, seabirds are particularly sensitive to MHWs, with high levels of mortality associated with some events, but not with others. Thus, prediction of impacts is not straightforward, as mortality is not linearly related to simple measures of MHW intensity, persistence, and areal coverage. We describe biological responses expected for seabirds, based on demographic parameters and the geographic proximity and phenological timing of MHWs with respect to seabirds. The expected interactions between seabirds and MHWs will be complex (with some responses likely to be unpredictable) and will extend over broad spatial and temporal scales. The spatial proximity of anomalous marine conditions to breeding colonies, their overlap with foraging areas, and the degree to which MHWs coincide with pre-breeding and breeding seasons presently generate the greatest pressures on seabird populations. We posit that area-restricted seabird species, in terms of movement and breeding strategies, are at greater risk from MHWs, but that non-linear effects complicate prediction. The impacts of MHWs on seabirds may be mediated by their life history strategies.”

Reference: 

Woehler, E.J., Hobday, A.J. 2023. Impacts of marine heatwaves may be mediated by seabird life history strategies. Marine Ecology Progress Series. https://doi.org/10.3354/meps14333

25 August 2023

Mouse-infested Sand Island, with smaller mouse-free Eastern Island upper right, photograph by Jon Brack, USFWS

The Midway Seabird Protection Project aimed to eradicate House Mice Mus musculus that have taken to attacking albatrosses on Sand Island, the larger of the two islands that make up USA’s Midway Atoll in the North Pacific.

“Using a new hopper [filled via an excavator] specially constructed for this project, we safely and efficiently filled the bucket while reducing risk to crew and equipment. Affectionately called Dennis and standing roughly 10-feet [three-metres] tall, the hopper is made of heavy steel and able to stand securely despite the helicopter’s strong downwash”, photograph by Jon Brack, USFWS

Aerial bait applications were completed in July, but subsequently mice have been found to be still present, as recently reported on the Facebook page of the Pacific Islands: U.S. Fish and Wildlife Service.

“In 2015 attacks by invasive mice on albatross at Midway Atoll spurred the U.S. Fish and Wildlife Service and our partners working in Papahānaumokuākea Marine National Monument to initiate the Midway Seabird Protection Project, with a goal to eradicate non-native mice from Sand Island. After years of planning and preparation with top rodent control experts from the U.S. and internationally, the project was implemented this year.

However, after safely and effectively completing bait applications across Sand Island this summer, mice are still present in many areas of the island, and a root cause is not immediately evident.

We are ceasing current eradication efforts and transitioning to continue to care for native species and gathering data to help inform this project and similar projects around the world. Learn more about the project implementation, where we are now with the project, and [find] upcoming updates here.”

Evidence of mouse attacks on Midway’s Laysan Albatrosses, from USFWS

The project reports in its latest update, dated 15 August:

“There are theories, and questions, as to why mice persist on Sand Island. As the team transitions to a Mitigation and Learning Phase, we will continue to gather data to try to find answers. Environmental Monitoring, begun before the application of any bait and continuing throughout the project, can help us understand conditions on the ground. Additional studies can provide knowledge of Sand Island mouse foraging behaviors and food preferences, habitat anomalies, factors of weather and bait, and more. We will also continue to monitor the native wildlife for impacts from mice and take efforts to minimize predation on seabirds when we find it is occurring. The outcome of every rodent eradication effort is uncertain, and every project is an opportunity to learn more about rodents, rodent behavior, toxicants, mitigation of risk to non-target species, and other factors that can influence future restoration projects. Lessons learned on Midway will help inform this project and similar projects around the world”.

The Midway Atoll failure follows that of the Gough Island Restoration Project that failed to eradicate House Mice that also attack that island’s albatrosses (and other seabirds) in 2021.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 24 August 2023

Monitoring the population of Northern Royal Albatrosses (pictured) was one area of focus for the research on New Zealand's Chatham Islands. Photograph by David Brooks

A collection of reports on albatross research conducted on the Chatham Islands has been published by New Zealand’s Department of Conservation.

The Publications:

Motuhara seabird research field trip December 2022 (PDF, 182K)

Trail-camera assessment of the fates of Northern Royal Albatross and Northern Buller’s Mollymawk chicks: 2021 breeding season, Motuhara (PDF, 3,132K)

POP2022-05 Northern Buller’s albatross GLS tracking and comparison with Southern Buller’s albatross (PDF, 5,392K)

POP2022-06 Northern Royal Albatross tracking from Motuhara, Chatham Islands, and Taiaroa Head in 2021 (1,364K) 

A summary of each report follows:

“The field work has been undertaken on Motuhara Island, a privately owned island east of Chatham Island with some of the most significant albatross colonies in New Zealand. Mike Bell (Toroa Consulting Ltd) visited the colony in December 2022 to collect tracking tags of northern Buller’s albatross/mollymawk (Thalassarche bulleri platei), download trail camera footage from cameras left out over the previous 12 months, carry out banding of birds for demographic studies and conduct counts of albatrosses and northern giant petrels (Macronectes halli).

The trail camera footage from 2021 for northern royal albatross (Diomedea sanfordi) and northern Buller’s albatross was analysed by Peter Frost (Science Support Services). This was looking at breeding success at monitored nests, timing and causes of nest failures, activity levels across the daily cycle to inform aerial survey techniques and other observations relevant to the behaviour of the birds across the nesting cycle. Dates of departure of chicks are provided. Climate related issues on the colony are assessed in the report.

Global location sensing tags (GLS) were applied to northern Buller’s albatross as well as southern Buller’s albatross (Thalassarche bulleri) on the Snares Island (Tini Heke). Johannes Fischer has analysed the tracking datasets (n=69 from northerns and n=28 from southerns) to show patterns of annual movements, migration routes and core foraging zones both within the New Zealand EEZ and the high seas and when the birds reach South American waters off Chile and Peru. There are temporal differences in the timing of breeding with a four month difference in peak breeding: northerns departing earlier and returning earlier than southerns, reducing spatial and temporal overlap in their foraging ranges here and off South America. Northerns largely remain north and east of the Chatham Rise whereas southerns are common off southern and western South Island, and off Otago and Canterbury. Some birds reach the seas off Australia.

The satellite tracking of northern royal albatross in 2021 is reported by Samhita Bose. This species had tags applied on Motuhara and the birds stayed exclusively within the New Zealand EEZ during chick rearing. After breeding failure or at the end of the season the birds migrated to the seas off western and eastern South America (Chile, Patagonia and Argentina). Issues with the loss of aerials on tags on some tags were identified with this project. Also a pair of northern royals and their chick from Taiaroa Head were tracked in 2021 and the results presented in this report. The male from this pair made the only visit to the Tasman Sea of the 33 birds involved in this study.”

Publication information

Bell, M. 2023. Motuhara seabird research: field trip report December 2022. Report prepared by Toroa Consulting Limited for the Conservation Services Programme, Department of Conservation. 4 p.  

Frost, P., Bell, M., Taylor, G. 2023.  Trail-camera assessment of the fates of Northern Royal Albatross and Northern Buller’s Mollymawk chicks: 2021 breeding season, Motuhara. Report prepared for the Conservation Services Programme, Department of Conservation. 25 p. 

Bose, S., Bell, M., Taylor, G. 2023.  Northern Royal Albatross tracking from Motuhara, Chatham Islands, and Taiaroa Head in 2021. POP2022-06 final report prepared for the Conservation Services Programme, Department of Conservation. 9 p.  

Fischer, J.H., Bell, M., Frost, P., Sagar, P.M., Thompson, D.R, Middlemiss, K.L., Debski, I., Taylor, G. 2023. Year-round GLS tracking of Northern Buller’s albatross and comparison with Southern Buller’s albatross. POP2022-05 final report prepared for the Conservation Services Programme, Department of Conservation. 16 p.

23 August 2023