Thanks Grandad!  Rosie Brothers proudly holds her “Sponsor a Hectare” certificate of appreciation received for her 10th birthday from the Mouse-Free Marion Project

At the last meeting of Albatross and Petrel Agreement’s Population and Conservation Working Group (PaCSWG5), held near two years ago in Florianópolis, Brazil, South Africa reported on progress with plans to eradicate the introduced albatross-killing House Mice Mus musculus on its sub-Antarctic Marion Island.  COVID-19 then got in the way with planning over the course of 2020 but now it’s all go again with a Mouse-Free Marion Project Manager, Anton Wolfaardt, appointed earlier this year, a revitalized sponsorship campaign and the intention to undertake the eradication during the austral winter of 2023.

Immediately following South Africa’s report in Brazil, ACAP Seabird Bycatch Working Group expert member Nigel Brothers of Australia spontaneously contributed to the M-FM’s crowd-funding “Sponsor a Hectare” initiative, entrusting ACAP’s Information Officer to carry the donation back to his home in Cape Town.  Now Nigel and his partner Catherine Bone have sponsored a second hectare of Marion Island’s 29 000 ha, this time in the name of his granddaughter, Rosie Brothers, on the occasion of her 10th birthday last month.  Nigel writes to ACAP Latest News: “we think a sponsorship gift is a fabulous idea as clearly evident in Rosie’s thrilled look of pride.”

Nigel Brothers (left) is thanked by ACAP's Information Officer for his Mouse-Free Marion sponsorship made at the 2019 ACAP meeting in Brazil

Nigel Brothers has worked on albatross conservation for a number of decades, including initiating and continuing for 20 years a study of the then little-known Australian endemic Shy Albatross Thalassarche cauta on Albatross Island, a study which continues to this day by others.  From his early days surveying and studying seabirds on Macquarie Island and on the many islands around the coast of Tasmania, he moved to address the problem of seabird bycatch by longline vessels, a hitherto overlooked threat.  It is fair to say that his 1991 paper in the journal Biological Conservation was the first to alert the scientific and conservation communities to the scale of the problem.  This has led to Nigel writing several handbooks that describe how longline fishers can reduce their seabird bycatch.  He has been actively involved with working groups and allied bodies of such international organizations as the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the Food and Agriculture Organization of the United Nations (FAO), the various Regional Fisheries Management Organizations that deal with tunas (t-RFMOs) and of course ACAP itself.  His support of an eradication effort that, if successful, will save many albatross chicks from grisly deaths on Marion is thus particularly welcomed.

Eaten alive: a Grey-headed Albatross chick is attacked by a mouse at night on Marion Island; photograph from the FitzPatrick Institute, University of Cape Town

Nigel is not the only ACAP stalwart who has sponsored hectares, witness the recent contribution by the United Kingdom’s Mark Tasker.  Further sponsorships by other members of the ACAP community will surely be well received by Mouse-Free Marion!

Selected References:

Brothers, N. 1991.  Albatross mortality and associated bait loss in the Japanese longline fishery in the Southern Ocean.  Biological Conservation  55: 255-268.

Brothers, N. & Robertson, G. 1996.  Fish the Sea, not the Sky.  How to avoid by-catch of seabirds when fishing with Bottom Long-lines.  Hobart: Commission for the Conservation of Antarctic Marine Living Resources.  46 pp.

Brothers, N.P., Cooper, J. & Løkkeborg, S. 1999.  The incidental catch of seabirds by longline fisheries: worldwide review and technical guidelines for mitigation.  FAO Fisheries Circular 937: 1-100.

Brothers, N., Pemberton, D., Pryor, H. & Halley, V. 2001.  Tasmania’s Offshore Islands: Seabirds and other Natural Features.  Hobart: Tasmanian Museum and Art Gallery.  643 pp.

Note: photographs of minors in ACAP Latest News are posted with the express approval of their parents or guardians.

John Cooper, ACAP Information Officer, 09 April 2021

The Northern Giant Petrel after release at sea, photograph by Andy Cunningham

A recently fledged Northern Giant Petrel Macronectes halli (Least Concern) was found “in a paddock” in Washdyke, an industrial suburb north of Timaru, South Island, New Zealand early in the evening on 8 March. After overnight care, it was transferred next day to the Wildlife Hospital - Dunedin, where it was found to be in an “emaciated and weak state, similar to that of birds battered in a storm”.

The young bird showed signs of renal failure and blood tests confirmed it was severely anaemic.  However, following regurgitation of “chunks of plastic” the bird has showed signs of recovery, feeding on its own (see video) and swimming in a rehabilitation pool (video). 

Following health assessments (“repeat tests all came back normal and he was beautiful and waterproof and had gained some good weight eating lots of salmon”) the giant petrel was successfully released at sea on 1 April by Wildlife Vet Nurse, Emily Brewer aboard the mv Sootychaser during a wildlife cruise of Dunedin's Port to Port Wildlife Cruises out of Otago Harbour and past Taiaroa Head to the open sea (see video).

Read more here and view a video clip of a similar giant petrel release from the wildlife hospital by the Sootychaser last November.  These are not the first Northern Giant Petrels the hospital has treated.  Last year during July a bird brought the hospital with an injured wing was released on a beach (click here).

John Cooper, ACAP Information Officer, 08 April 2021

A daytime attack: more details below

A night-time attack: more details below

Christophe Barbraud (Centre d'Etudes Biologiques de Chizé, Villiers en Bois, France) and colleagues have published in the journal Biological Invasions demonstrating that feral cats have negative impacts on breeding success and population growth rate of Vulnerable Wandering Albatrosses on the Courbet Peninsula, Kerguelen Island.

Images from camera traps showing the different behaviours of feral cats when interacting with Wandering Albatross chicks at Kerguelen Island.  Top row left: passing; top row right: approach; second row and third row left: attack by daytime; third row right: attack by three individuals; bottom row: attacks during the night (taken from the publication)

The paper’s abstract follows:

“Feral cats (Felis catus) are a potential threat for several seabird species including medium sized albatrosses, but studies documenting predation behavior, demographic impacts and effects of predator control are scarce. Here, we present data on feral cat predation behavior on one of the world’s largest seabirds, the wandering albatross (Diomedea exulans) at Kerguelen Island, and show how it affects breeding success and rate of population growth. We assess the effect of a feral cat control experiment on breeding success and population viability. Using 32 camera traps we monitored 25 nests of albatross and detected 295 events showing a potential predator. Of these, 75.2% and 24.8% involved feral cats and giant petrels, respectively. Giant petrels were never implicated in direct predation. We recorded 17 attacks of feral cats on 13 albatross chicks. Attacks lasted in average 52.1 ± 72.9 min, and resulted in the death of 10 of the 13 (76.9%) monitored chicks. Breeding success where attacks were recorded was low (12%) compared to areas with no attack (86%). Mean breeding success during 3 years before cat control was 26% and increased to 80% during the 3 years following the experiment. According to predation scenarios, population modelling showed that the albatross population would decline by 2.7–4.5% per year without cat control. Following cat control the population would increase at 1.8% per year. Our results demonstrate that feral cats predate and have negative impacts on breeding success and population growth rate of wandering albatrosses at Kerguelen Island. We provide recommendations on feral cat control and eradication to mitigate the risk of population decline or local extinction of large albatrosses.”

Three feral cats attack a Wandering Albatross chick on Kerguelen Island

With thanks to Christophe Barbraud for information and photographs

Reference:

Barbraud, C., des Monstiers, B., Chaigne, A., Marteau, C., Weimerskirch, H. & Delord, K. 2021.  Predation by feral cats threatens great albatrosses.  Biological Invasions doi.org/10.1007/s10530-021-02512-9.

John Cooper, ACAP Information Officer, 07 April 2021

Balearic Shearwater at sea, photograph by Pep Arcos

Andrés de la Cruz (University Institute of Marine Research, Cádiz University, Spain) and colleagues have published in the journal Aquatic Conservation: Marine and Freshwater Ecosystems on using spatial modelling as a tool to define the at-sea distribution of Critically Endangered Balearic Shearwaters Puffinus mauretanicus in the Gulf of Cádiz.

The paper’s abstract follows:

“1. Spatial modelling is an important research tool to improve our knowledge about the distribution of wildlife in the ocean. Using different modelling techniques (MaxEnt and a generalized linear mixed model), a predictive habitat suitability model was developed for one of the most threatened seabirds in the world: the Balearic shearwater, Puffinus mauretanicus.
2. Models were developed using a 10-year dataset from the Gulf of Cádiz (on the south-western Iberian Peninsula), a key foraging area for Balearic shearwaters during migration and the non-breeding season.
3. Predictive habitat maps strongly matched the observed distribution patterns, pointing to bathymetric features as the main modelling drivers. The species was concentrated on shallow areas (up to approximately 100 m in depth) of the continental shelf, very close to the mouth of the Guadalquivir River. In contrast with previous studies, Balearic shearwater distribution in the highly dynamic Gulf of Cádiz was not correlated with areas of high chlorophyll a concentration.
4. This lack of spatial correlation probably arises from the delay between the phytoplankton bloom and the response of the zooplankton and small fish that are preyed upon by Balearic shearwaters, which may result in important displacements of this trophic chain across the Gulf of Cádiz.
5. The analysis presented contributes to a better understanding of the spatial distribution and ecology of the critically endangered top predator in the Gulf of Cádiz and offers important information to improve management plans.”

With thanks to Barry Baker.

Reference:

de la Cruz, A., Ramos, F., Navarro, G., Cózar, A., Bécares, J. & Arroyo, G.M. 2021.  Drivers for spatial modelling of a critically endangered seabird on a dynamic ocean area: Balearic shearwaters are non-vegetarian.  Aquatic Conservation: Marine and Freshwater Ecosystems doi.org/10.1002/aqc.3542.

John Cooper, ACAP Information Officer, 06 April 2021