Rationale
(Changed due to Not applicable)
The status of the global population of Light-mantled Albatross Phoebetria palpebrata is poorly known. Due to the impact on breeding colonies by invasive predators and mortalities experienced in longline bycatch, the global population is thought to be in decline justifying its global Near Threatened status. Within the region, Light-mantled Albatross is restricted to the Prince Edward Islands, satisfying the Near Threatened criterion under D2 (population with a very restricted area of occupancy or number of locations (typically five or fewer) such that it is prone to the effects of human activities or stochastic events within a very short time period in an uncertain future, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period). However, it was felt that it was unlikely that stochastic events or human activities at the Prince Edward Islands would lead to this species becoming Extinct or even Critically Endangered within one to two generations, although there is a possibility that such activities could result in the Light-mantled Albatross being listed as Vulnerable or Endangered during that period.
Distribution
The Light-mantled Albatross breeds on the Prince Edward Islands as well as Iles de Kerguelen, Iles Crozet (France), Heard and Macquarie islands, (Australia), South Georgia, and the Auckland, Campbell and Antipodes islands (New Zealand) (ACAP 2011). Although little is known regarding its at-sea movements (Ryan 2005), it is believed to range widely across the Southern Ocean, seldom venturing into continental shelf waters (Ryan 1997). It has a much more southerly distribution than its sister species, the Sooty Albatross, and is associated with the edge of the pack ice and Antarctic waters.
Population
The global annual breeding population has been quantified at c. 20 500 breeding pairs (ACAP 2011). Ryan et al. (2009) estimated there to be 120 pairs and 600 pairs on Prince Edward and Marion islands, respectively, giving a regional population of c. 720 pairs. Light-mantled Albatrosses are difficult to count due to their dark plumage and cliff nesting habits (Ryan et al. 2009), lowering the confidence in this regional population estimate to medium.
Population trend
Limited information is available to determine global population trends for the species but declines have been reported at all sites where repeated surveys have been carried out (ACAP 2011). The Marion Island population decreased by 25% between 1990 and 1998 or at about 2.6% per year (Crawford et al. 2003), increased by 5% per year up to 2005 (Ryan et al. 2009), undergoing a further slight decrease until 2008. The decline over three generations is less than30%. Confidence in this population trend estimate is medium.
Threats
The primary threat at sea is from bycatch in tuna longline fishing (Nel et al. 2002). Trawling on sea-mounts in the south-west Indian Ocean is a potential threat but data are lacking. Population decreases are considered to be due to at sea mortality associated with fisheries, particularly longline fishing vessels (Delord et al. 2008). Introduced House Mice Mus musculus have been reported to have preyed on a single chick of the closely related Sooty Albatross at Marion Island (Jones and Ryan 2010), and more widespread attacks occurred in 2015 (PG Ryan in litt.). This may pose a serious threat and should be investigated as a matter of urgency.
Conservation
Underway
Internationally, the Light-mantled Albatross is protected by the Agreement on the Conservation of Albatrosses and Petrels - Annex 1 and by the Convention on the Conservation of Migratory Species - Appendix II. Within the region it is protected under the Sea Birds and Seals Protection Act, 1973 (Act No. 46 of 1973), Marine Living Resources Act (Act No. 18 of 1998): Publication of Policy on the Management of Seals, Seabirds and Shorebirds: 2007 and the National Plan of Action (NPOA) for Reducing the Incidental Catch on Seabirds in Longline Fisheries (2008). The Prince Edward Islands are listed as a Ramsar Wetland of International Importance, and a Special Nature Reserve under the Environment Conservation Act (No 73 of 1989) and are managed through the Prince Edward Islands Management Plan 1996. The Prince Edward Islands Marine Protected Area was proclaimed in 2013.
Proposed
Ongoing efforts by BirdLife International, as well as BirdLife South Africa, to reduce incidental mortality of seabirds in fisheries industries, should be supported. Observer programmes, essential for the reporting of the scale of incidental mortality and potential effectiveness of mitigation measures, must be continued. The eradication of introduced mice on Marion Island should be considered based upon results of research into the patterns and scale of mouse predation on the chicks of Light-mantled Albatross and other pelagic seabirds.
Research
The following research questions, mostly related to demography and population dynamics are proposed:
* What is the nature, scale and spatio-temporal pattern of predation by introduced House Mice on Light-mantled Albatross chicks?
* What are the sex-, stage- and age-specific foraging distributions at sea?
* Is this species genuinely less at risk from longline bycatch, or is this an overlooked threat?
* At what age do Phoebetria albatrosses at the Prince Edward Islands recruit?
* Are Phoebetria albatrosses serially monogamous and how common is extra-pair paternity?
* Under what conditions do pairs breed every year?
* What is the population-level frequency distribution of one, two or three-year sabbaticals?
