David Crockett with two Magenta Petrels/Chatham Island Taikos

David Edward Crockett QSO* (25 March 1936 - 24 August 2023) of Whangarei, New Zealand was responsible for rediscovering the globally Critically Endangered and Nationally Critical Magenta Petrel or Chatham Island Taiko Pterodroma magentae in the Tuku Gully in the south west of the main Chatham Island in 1978. The petrel was previously considered to be extinct. David summarized his decade of patient searching in a paper published in the New Zealand journal Notornis in 1994 that covered aspects of the petrel’s behaviour, habitat, morphology and ecology. The population remains tiny with a total estimated population of fewer than 200 birds and 33 breeding pairs that is growing slowly. It is now the subject of active conservation, notably predator control of feral cats and pigs and rodents, fencing, and translocations, by the New Zealand Department of Conservation and the Chatham Island Taiko Trust (watch a four-minute video here).

A Magenta Petrel/Chatham Island Taiko in the hand, photograph by Graeme Taylor, Department of Conservation

I met David only once, at the ICBP Seabird Conservation Symposium held in Cambridge, UK in August 1982, with its proceedings published in 1984. He, along with a large New Zealand contingent, proved to be a convivial group, and added much to the enjoyment of the symposium that was held in King's College. I well remember a magical evening during the symposium with him and the other Kiwis listening to the New Zealand Youth Choir singing in the iconic King’s College Chapel. The closing dinner in the college’s impressive Georgian Gothic Hall was also a grand affair, with what I remember as being madrigals sung from a balcony between each course. I also learnt which way to pass the Port decanter (always to the left) and somewhere still have the menu signed by David and the other symposium attendees.

A 19th Century hand-coloured plate of a Magenta Petrel by Dutch illustrator Johannes Gerardus Keulemans. Not a realistic pose!

Every decent person should leave a legacy. David Crockett left us with a whole species – and a handsome seabird at that. Surely a legacy to be proud of for any marine ornithologist. His funeral and his life of 87 years will be celebrated at Christ Church, Whangarei on 31 August 2023.

Ave atque vale, David.

References:

Crockett, D.E. 1979. Rediscovery of the Chatham Island taiko solved century-old mystery. Forest & Bird 13: 8-13.

Crockett, D.E. 1994. Rediscovery of Chatham Island taiko Pterodroma magentae. Notornis (Supplement) 41: 49-60.

Croxall, J.P., Evans, P.G.H. & Schreiber, R.W. (Eds). 1984. Status and Conservation of the World's Seabirds. International Council for Bird Preservation Technical Publication 2. 778 pp.

Imber, M.J., Crockett, D.E., Gordon, A.H., Best, H.A., Douglas, M.E. & Cotter, R.N. 1994. Finding the burrows of Chatham Island taiko Pterodroma magentae by radio telemetry. Notornis (Supplement) 41: 69-96.

Imber, M.J., Taylor, G.A., Tennyson, A.J.D., Aikman, H.A., Scofield, R.P., Ballantyne, J. & Crockett, D.E. 2005. Non-breeding behaviour of Magenta petrels Pterodroma magentae at Chatham Island, New Zealand. Ibis 147: 758-763.

Lawrence, H.A., Millar, C.D., Imber, M.J., Crockett, D.E., Robins, J.H., Scofield, R.P., Taylor, G.A. & Lambert, D.M. 2009. Molecular evidence for the identity of the Magenta petrel. Molecular Ecology Resources 9: 458-461.

Lawrence, H.A., Scofield, R.P., Crockett, D.E., Millar, C.D. & Lambert, D.M. 2008. Ancient genetic variation in one of the world's rarest seabirds. Heredity 101: 543-547.

Lawrence, H.A., Taylor, G.A., Crockett, D.E., Millar, C.D. & Lambert, D.M. 2008. New genetic approach to detecting individuals of rare and endangered species. Conservation Biology 22: 1267-1276.

*David Crockett was made an Ordinary Companion of the Queen's Service Order for Public Services in 2000 (click here). The order was established by royal warrant of Queen Elizabeth II on 13 March 1975 and is used to recognise "valuable voluntary service to the community or meritorious and faithful services to the Crown or similar services within the public sector, whether in elected or appointed office”.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 29 August 2023.

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