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

Short-tailed Shearweater at sea, photograph by  Kirk Zufelt

Lauren Roman (Marine Debris Research, CSIRO Oceans and Atmosphere, Hobart, Tasmania, Australia) and colleagues have published in the journal Marine Ecology Progress Series on starving Short-tailed Shearwaters Ardenna tenuirostris (Least Concern) feeding on floating pumice on their return to Australian breeding sites from trans-equatorial migration.

The paper’s abstract follows:

“Food deprivation may decrease selectivity in food; however, (1) whether animals can cross a selectivity threshold whereby they ingest non-nutritive items ('non-food') in lieu of food (engaging in pica/lithophagia), (2) their behaviour, or (3) the implications of these behaviours are not documented. By examining carcasses of seabirds that ingested pumice of known provenance prior to death, we provide insights into whether wild animals starve because they have eaten non-food, or whether they eat non-food because they are starving. We investigated ingestion of pumice and plastic in carcasses of short-tailed shearwaters Ardenna tenuirostris following a significant starvation mortality event (also known as seabird wreck), during which millions of shearwaters died along the eastern Australian coastline in 2013. We found that the stomachs of 96.5% of 172 seabirds sampled contained pumice or plastic at the time of death. We used global location sensors to track the 2013 shearwater migration and overlaid these tracks with the dispersing pumice raft from the 2012 Havre underwater volcanic eruption, Kermadec Islands, New Zealand. We determined that shearwaters in a starved state had ingested pumice 12-41 h before death, indicating that starving or food-stressed seabirds exhibit reduced prey discrimination. The provenance of the ingested plastic was not known. Ingestion of non-nutritive items has serious implications for wildlife, particularly long-lived or migrating species. Additional risk to already nutritionally compromised animals includes dietary dilution, gastric foreign body obstruction and toxicity. With a projected changing climate and increased marine pollution and over-exploitation of resources, this study has implications for the interaction of stressors, mass mortalities and exacerbation of existing threats to marine species.”

Read a popular account of the research, and access related papers by the senior author.

Reference:

Roman, L., Bryan, S., Bool, N., Gustafson, L. & Townsend, K. 2021.  Desperate times call for desperate measures: non-food ingestion by starving seabirds.  Marine Ecology Progress Series 662: 157-168.

John Cooper, ACAP Information Officer, 05 April 2021

The young Antipodean Albatross spreads its wings after release, photograph by  Dan Burgin, Wildlife Management International (WMIL)

A young Antipodean Albatross Diomedea antipodensis assigned to the gibsoni subspecies was brought in by the crew two days after landing aboard the fishing vessel Santa Rosa off the West Coast to the EcoWorld Aquarium & Wildlife Rehabilitation Centre in Picton, South Island, New Zealand.  Mike Bell of Wildlife Management International (WMIL) states on the Centre's Facebook page: “She is a young female albatross from this years breeding season. She was obviously very lethargic and weighed only 4.9 kg when she should be at about 7 kg in weight”.  Affectionately named Rosa, the albatross spent three weeks in captivity while it got back to a healthy weight, being fed on donated salmon and squid.  Following banding, the albatross was released on 29 March out at sea off the coast of Kaikoura from an Albatross Encounter Kaikoura tour vessel by Mike Bell and Dan Burgin of WMIL.

According to Wildlife Management International’s Facebook page the globally Endangered and Nationally Critical bird “spent a good amount of time bathing before swimming off.  Here’s hoping we get a band resighting at her breeding colony in years to come, but she has a long way to go still facing a myriad of threats out at sea.”  Read more here.

The Antipodean Albatross gets released at sea, photographs by Tracy McKeown, Albatross Encounter Kaikoura

A similar-looking young Antipodean Albatross “very dehydrated, very hungry and near death” on arrival was treated at New Zealand's South Island Wildlife Hospital, but died while still in care (click here).

John Cooper, ACAP Information Officer, 04 April 2021, updated 05  April 2021