|Scientific Name:||Phoebastria irrorata|
|Species Authority:||(Salvin, 1883)|
|Red List Category & Criteria:||Critically Endangered B2ab(v) ver 3.1|
|Reviewer/s:||Butchart, S. & Taylor, J.|
|Contributor/s:||Allport, G., Anderson, D., Croxall, J., Cruz, F., McClellan, R. & Vargas, H.|
This species is classified as Critically Endangered because it has an extremely small breeding range, essentially confined to one island, and evidence suggests that it has experienced a substantial recent population decline.
|Range Description:||Phoebastria irrorata breeds on south Española Island in the Galápagos Islands, and (perhaps) on Isla de la Plata off Manabí province, Ecuador (Croxall and Gales 1998). Breeding adults travel to the Peruvian upwelling region to feed (Anderson and Cruz 1998, H. Vargas and F. Cruz in litt. 2000), and in the non-breeding season birds move mainly east and south-east into the waters of the Ecuadorian and Peruvian continental shelf (Tickell 1996, Anderson and Cruz 1998, BirdLife International 2004). Rarely seen north of the equator, they are occasionally sighted off the coasts of Columbia and Panama (Jahncke 2007). On Española, the overall breeding population was considered to have been stable until recently. It was estimated at c.12,000 pairs in 1970-1971 (Harris 1973), 15,600-18,200 pairs in 1994 (Croxall and Gales 1998, Douglas 1998) and at least 34,694 adults in 2001 (Anderson et al. 2002). Although there has not been a global population estimate since 2001, surveys at two principal breeding sites on Española in 2007 demonstrated a decrease in the number of breeding birds since 2001, an overall population decrease (including non-breeders) at these sites since 1994 (Anderson et al. 2008). The breeding distribution has changed owing in part to vegetation regrowth following the eradication of goats (Anderson et al. 2002). Breeding no longer occurs at two inland sites, perhaps through redistribution to the coast (Anderson and Cruz 1998, Douglas 1998). On Isla de la Plata, there are probably fewer than 10-20 pairs (Anderson and Cruz 1998), and long-term data are too sketchy to assess population trends (Croxall and Gales 1998). In 2001, three adults were seen there with no evidence of breeding and a further 11 non-breeding adults were found on Isla Genovesa (Anderson et al. 2002). Recent evidence has shown a 2-3% reduction in annual adult survival compared with that in the 1960s, which is thought to have driven recent dramatic declines in the breeding population (Awkerman et al. 2006, J. Croxall in litt. 2006, Anderson et al. 2008). Analysis of birds caught as intentional and incidental take in inshore fisheries has revealed that a disproportionate number of males are taken, which will result in further decreases to the effective population size given that this species has obligate bi-parental care (Awkerman et al. 2006). Even if immediate action was taken to curb adult mortality the population will continue to decline for a decade or so until the current cohort of juveniles reach breeding age (J. Croxall in litt. 2006). Breeding sites may be constrained by the extent and location of take-off points, which are in turn limited by dense vegetation (Gibbs and Woltz 2010).|
Native:Chile; Colombia; Ecuador (Galápagos); Ecuador (Galápagos); Peru
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||On Española, the breeding population was estimated at c.12,000 pairs in 1970-1971, 15,600-18,200 pairs in 1994 and at least 34,694 adults in 2001. On Isla de la Plata, there are probably fewer than 10-20 pairs.|
|Habitat and Ecology:||
Behaviour This species breeds annually, arriving at colonies in late March (with males arriving earlier than females, and older birds earlier than younger birds) (Jahncke 2007) and laying from mid-April to late June. Chicks fledge between late December and early January. The are considered annual breeders, even though some pairs defer breeding (Jahncke 2007). Chicks fledge between late December and early January. The age of first breeding is at four-six years of age, but individuals return to colonies, typically late in the season, from two years of age (Hirschfeld 2008, ACAP 2009). Habitat Breeding It nests on sparsely vegetated areas with lava surrounded by boulders (Harris 1973) but also, more recently, in thick scrub vegetation (Anderson et al. 2002). Diet It feeds on squid, fish and crustaceans (Harris 1973), but recent studies have shown that scavenging food items that other species (such as cetaceans and boobies) have disgorged may be an important feeding strategy (Merlen 1996, Anderson and Cruz 1998).
|Major Threat(s):||Recent studies indicate lower adult annual survival during 1995-2005 than estimates from the 1960s as the species is suffering mortality within some inshore fisheries through intentional harvesting for human consumption and incidental bycatch (Awkerman et al. 2006). This is supported by reports which suggest that the level of harvesting by fishers to supply food and feather markets has increased dramatically in recent years (G. Allport in litt. 2007). Around the Galápagos Islands, the transition from traditional to more modern fishing techniques such as longlining may pose a threat, as there is recent evidence of an increasing propensity for the species to follow fishing vessels (Awkerman et al. 2006). Longline fishing operations along the Peruvian and Ecuadorian coasts may therefore also threaten the species (Guillén et al. 2000, H. Vargas and F. Cruz in litt. 2000, Awkerman et al. 2006). Analysis of birds caught as intentional and incidental take in inshore fisheries has revealed a disproportionate number of males are taken, and this appears to be at least partly responsible for a female-biased sex ratio (1.188 females per male) in adults (Awkerman et al. 2007). The tiny population on Isla de la Plata is threatened from nest-predation by rats and cats, as well as illegal collection of eggs and young (Carboneras 1992). Movement of eggs by parents (frequently resulting in death of the egg) and mass desertions of eggs are yet to be fully explained (Anderson and Cruz 1998). An oiled albatross was found on Española during 2001 (Anderson et al. 2003). The species has shown susceptibility to El Niño southern oscillation (ENSO) events, perhaps owing to increased adult mortality or increased negative interactions with fisheries under these conditions (Awkerman et al. 2006). Plastic ingestion appears to be a relatively minor threat in comparison with some other albatrosses (Anderson et al. 2008). Increased abundance of mosquitoes during warm El Niño events has caused mass abandonment of eggs in the past (Jahncke 2007).Two hillside colonies disappeared entirely by 1994 due to dense vegetation, and overall declines in population in other inland areas have also been attributed to habitat loss associated with vegetation regrowth since goats were eradicated in 1978 (Jahncke 2007).|
Conservation Actions Underway
Española is part of the Galápagos National Park and Marine Reserve. Industrial, but not artisanal, longlining is prohibited in the Galápagos Marine Reserve (Anderson et al. 2003). In 1979, the islands were declared a World Heritage Site. Española is well protected and has no alien fauna (goats having been eradicated in 1978 [Anderson and Cruz 1998]), and tourism is well regulated (Carboneras 1992). A tortoise breeding programme has released over 2,000 tortoises on the island in the last 30 years; as the only native herbivore these animals may play a key role in vegetation control and maintaining suitable habitat for breeding albatrosses (Jahncke 2007). Isla de la Plata is part of Machalilla National Park, but is insufficiently protected (Carboneras 1992). The Agreement for the Conservation of Albatrosses and Petrels organised workshops in Peru and Ecuador in 2007 and 2008 to develop an Action Plan for Waved Albatross. There are proposals to protect more marine key biodiversity areas within the Galápagos Marine Reserve by amending the existing marine zoning scheme to reduce the impact from fishing (Edgar et al. 2008). Conservation Actions Proposed
Census the breeding population regularly and establish a baseline to ascertain trends. Further evaluate the threat of incidental and deliberate take in fisheries within the species's range. Adopt appropriate interim techniques to minimise bycatch. Assess the suitability of Isla de la Plata for breeding (Anderson et al. 2002). Improve protection for the Isla de la Plata colony.
|Citation:||BirdLife International 2012. Phoebastria irrorata. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 22 May 2013.|
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