A banded Flesh-footed Shearwater at night on Ohinau Island, photograph by Kaila Ritchie

Patrick Crowe (Wildlife Management International, Blenheim, New Zealand) has reported to the Conservation Service Programme of New Zealand’s Department of Conservation on research conducted on two breeding populations of the globally Near Threatened Flesh-footed Shearwater Ardenna carnepeis

The report’s abstract follows:

“This report covers the findings from the second of three years’ flesh-footed shearwater (Puffinus carneipes) research under Conservation Services Programme project POP2018-04. Here we report on the ongoing population monitoring of flesh-footed shearwaters on Ohinau and Lady Alice Islands and the results of GPS tracking of breeding birds from both islands.

During the 2019/20 breeding seasons we monitored 274 and 288 study burrows on Ohinau and Lady Alice Islands respectively.  A total of 216 study burrows on Ohinau Island were breeding and we were able to identify 408 of the 432 (94%) partners occupying these study burrows.  On Lady Alice Island, 202 study burrows were breeding and 358 of 404 (89%) of partners occupying these study burrows were identified.  We were unable to determine breeding success for the 2019/20 season but the rate of failure during incubation in January was similar to the 2018/19 season.

Breeding flesh-footed shearwaters were tracked simultaneously on Ohinau and Lady Alice Islands during the incubation and chick-rearing stages. On Ohinau Island, GPS devices were deployed on 26 individuals during incubation and 27 individuals during chick-rearing and this yielded 21 tracks and 50 tracks respectively.  On Lady Alice Island, GPS devices were deployed on 29 individuals during incubation and 34 individuals during chick-rearing and this yielded 20 tracks and 55 tracks respectively.

The average length of incubation foraging trips was 11.8 days and 4665 km for Ohinau Island birds and 16.6 days and 4734 km for Lady Alice Island birds. Lady Alice birds undertook significantly longer trips in respect to duration.  The average length of foraging trips during chick-rearing was 3.1 days and 1205 km for Ohinau birds, and was 4.8 days and 1536 km for Lady Alice birds. There was considerable variation in all aspects of foraging trips during chick-rearing which is likely due to a dual-foraging strategy.

There was considerable overlap of foraging areas between Ohinau and Lady Alice birds indicating that birds from different populations mix at sea during the breeding season.  All birds from Ohinau Island foraged either down the East Coast of the North Island or out towards the Louisville Ridge. During incubation, nearly half of Lady Alice birds foraged in the same locations while the remaining birds foraged inshore off the West Coast of the North Island or offshore in the Tasman Sea. During chick-rearing, areas closer to each of the colonies had greater importance but birds still utilised some of the more distant foraging locations identified during incubation in order to maintain their own body weight and condition.”

The Flesh-footed Shearwater has been identified as a potential candidate for ACAP listing (click here).

Reference:

Crowe, P. 2020.  Flesh-footed shearwater population monitoring and at-sea distribution: 2019/20 season.  Blenheim: Wildlife Management International Ltd.  39 pp.

John Cooper, ACAP Information Officer, 22 October 2020

Balearic Shearwater at sea, photograph by Pep Arcos

R. Costa (Departamento de Biologia, Universidade de Aveiro, Portugal) and colleagues have published in the journal Marine Pollution Bulletin on entangled seabirds received by a rehabilitation centre in Portugal, including six out of 77 Critically Endangered Balearic Shearwaters Puffinus mauretanicus.

The paper’s abstract follows:

“Plastic pollution and the subsequent entanglement of marine animals is a global and increasing problem.  In this study we present an analysis of the seabirds recorded as entangled by a rehabilitation centre and an associated marine animal stranding network, along the central coast of Portugal, between 2008 and 2018.  Results show a high annual rate of entangled seabirds (average 6.9%) compared to other studies and fisheries related materials are a relevant cause of seabird entanglement (82%) compared to other debris.  When comparing age classes, juveniles were more vulnerable to entanglement than other age classes in the species studied.  Regarding the rehabilitation of entangled seabirds, the release rate was higher in non-fishing material entanglement cases.  In conclusion, this study highlights the impact of fisheries related material on marine fauna and the need for reinforcement of the existing legislation for protecting seabirds and the implementation of mitigation measures associated with fishing activities.”

Reference:

Costa, R.A., Sá, S., Pereira, A.T., Ângelo, A.R., Vaqueiro, J., Ferreira, M. & Eira, C. 2020.  Prevalence of entanglements of seabirds in marine debris in the central Portuguese coast.  Marine Pollution Bulletin doi.org/10.1016/j.marpolbul.2020.111746.

John Cooper, ACAP Information Officer, 21 October 2020

A Hawaiian Petrel chick is placed in a carrying box ready for its helicoper flight down the mountain, photograph by Jennifer Rothe, Kaua'i Endangered Seabird Recovery Project

Following “a hike, a quick helicopter ride and a road trip” and despite some challenges with the weather, the first day of translocating globally Endangered Hawaiian Petrel Pterodroma sandwichensis from the mountainous Hono o Na Pali Natural Area Reserve on the Hawaiian island of Kauai last week was declared a success by the Kaua'i Endangered Seabird Recovery Project.  Twelve downy chicks were transferred to their new home within the predator-proof fence at the coastal Nihoku Ecosystem Restoration Project site with a further eight chicks collected the next day and placed in artificial burrows.  For the next 30-60 days the chicks will be hand fed and cared for by the Pacific Rim Conservation’s translocation team.  The 20 petrel chicks form the sixth and final instalment of translocations aimed at creating a new seabird colony at Nihoku within the Kilauea Point National Wildlife Refuge.

“Keeping Hawai’i Wild”

“Artificial Burrows: Technology for Conservation”

“First Flight: Hawaiian Petrels Journey to Safety”- videos produced by the American Bird Conservancy

Another Hawaiian endemic, the globally Critically Endangered Newell’s Shearwaters Puffinus newelli, has also been the target of chick translocations to the Nihoku site each year since 2016.  Over half of the 20 shearwaters translocated this year have now fledged.  Which of the two threatened seabird species will be the first to breed within the fence – perhaps the petrel as already several fledglings of the 2017 cohort have been seen back in their “childhood” burrows as returning adults?  But maybe both will be pipped by the three Kermadec Petrels P. neglecta which were unexpectedly filmed a few months ago exhibiting breeding behaviour on the ground inside the fenced area.  If they do this itwill be “the first breeding record for not only Hawai’i but the entire Northern Hemisphere” for this southern hemisphere gadfly petrel.

The Nihoku Ecosystem Restoration Projectis a multi-partner effort of the Kaua‘i Endangered Seabird Recovery Project, Pacific Rim Conservation, Hono O Nā Pali Natural Area Reserve, Hawaii Department of Land and Natural Resources, Hawaii Division of Forestry & Wildlife, University of Hawaii at Manoa, The Pacific Cooperative Studies Unit, Pacific Islands: U.S. Fish and Wildlife Service, Kilauea Point National Wildlife Refuge,  American Bird Conservancy and the National Fish and Wildlife Foundation.

Information from the Kaua‘i Endangered Seabird Recovery Project and Pacific Rim Conservation Facebook pages.  With thanks to Andre Raine and Lindsay Young.

John Cooper, ACAP Information Officer, 20 October 2020

Salvin’s Albatrosses on Proclamation Island, Bounty Islands, from a drone photograph in the report

Graham Parker & Kalinka Rexer-Huber (Parker Conservation, Dunedin, New Zealand) have produced a final report for the Conservation Service Programme (CSP) of the New Zealand Department of Conservation on the use of drone photographs to count breeding albatrosses at the sub-Antarctic Bounty Islands.

A CSP summary separate to the report follows:

“Salvin’s albatross Thalassarche salvini are a Nationally Critical seabird endemic to New Zealand. They breed at two sites, predominantly at the Bounty Islands, and are one of the New Zealand seabird species most at risk from fisheries bycatch. The population status at the Bounty Islands is poorly known due to logistical difficulties in conducting research at this remote location, and differences and inherent uncertainties in methods previously used to assess population status. By extrapolating densities from one island, population sizes of 76,000 and 31,000 pairs across the group were estimated in 1978 and 1997, respectively. Method differences, including in how densities and areas were estimated, led to targeted repeat censuses of marked areas that over time gave worrying data on trends (30% decline in breeding pairs between 1997 and 2011). Repeat counts for trend assessment, however, need to be complemented by whole-population size estimates because a small count site may or may not remain representative of changes in the whole population over time.

Because many of the islands are inaccessible to boat-based landings, aerial photographs appear to be the best way to estimate population numbers across the whole Bounty Island group and assess trends over time. Aerial photographs taken from fixed-wing aircraft have been used to count Salvin’s albatross in the past. Estimates ranged between 42,800 and 60,400 birds, although not all birds counted in photographs will have been breeding. However, surveys involving aeroplane charter or helicopters are logistically demanding and expensive, so other methods for aerial surveys are being explored. Population monitoring by drones hold promise as an alternative way to obtain aerial photographs suitable for estimating albatross numbers at reduced effort and cost. Also known as unmanned aerial vehicles (UAV), drones are increasingly used for seabird population assessment and monitoring worldwide. In the New Zealand subantarctic, drones have been used successfully for a range of wildlife monitoring at the Antipodes and Auckland Islands. Relative to piloted aerial surveys, drone surveys have low operational costs, simple logistical requirements, and are relatively low risk for operators, while providing data that are systematic, repeatable, and accurate. Some constraints are similar, particularly the impact of wind, rain, and haze on image acquisition. As with any survey method drones also have limitations, notably in battery life and potential for wildlife disturbance.

Effects on animals are becoming better documented as drone use for wildlife surveys becomes more common. To date, drones have been used at the Bounty Islands primarily to assess the potential for wildlife disturbance. The islands are densely populated with fur seals Arctocephalus forsteri, erect-crested penguins Eudyptes sclateri and smaller seabirds as well as the Salvin’s albatrosses, so the potential for disturbance by drones was assessed carefully. Disturbance of animals on the ground or in the air was minimal provided the drone was flown with due caution (avoiding seal clusters near launch site, flight height assessed relative to flying bird density but not below 20m flight height).

We discuss the implications of data quality in this report for future potential drone-based estimates of the population size of Salvin’s albatross at the Bounty Islands, and provide recommendations for how best to deal with some of the uncertainties inherent in aerial count data. To assess if drone-image counts are comparable with existing data (photo counts from aircraft, ground counts), we then do whole-island counts of Salvin’s albatross on all islands that have had drone overflight (Proclamation, Spider, Tunnel and Ranfurly Islands). We document baseline drone counts, compare results to those from other methods, and discuss the relative utility of survey methods.”

Reference:

Parker, G.C. & Rexer-Huber, K. 2020.  Drone-based Salvin’s albatross population assessment: feasibility at the Bounty Islands. Final report to Department of Conservation, Marine Species and Threats July 2020.  Dunedin: Parker Conservation.  18 pp.

John Cooper, ACAP Information Officer, 19 October 2020