Pterodroma phaeopygia 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Procellariiformes Procellariidae

Scientific Name: Pterodroma phaeopygia (Salvin, 1876)
Common Name(s):
English Galapagos Petrel, Dark-rumped Petrel, Galápagos Petrel
Spanish Petrel de Galápagos
Taxonomic Source(s): Brooke, M. de L. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford.
Identification information: 43 cm. Large, long-winged gadfly petrel. Variable amounts of black marking on white forehead. Similar spp. Exceedingly similar to Hawaiian Petrel P. sandwichensis and not certainly distinguishable at sea. On average, has longer wing, tarsus and bill. P. sandwichensis lacks black forehead markings. Voice Four-syllable kee-kee-kee-koo, the last note drawn out.

Assessment Information [top]

Red List Category & Criteria: Critically Endangered A2bce ver 3.1
Year Published: 2017
Date Assessed: 2016-10-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Contributor(s): Allport, G., Brooke, M., Cruz, F., Hennessey, A., Vargas, H. & Wiedenfeld, D.
Facilitator/Compiler(s): Bird, J., Calvert, R., Clay, R., Isherwood, I., Lascelles, B., McClellan, R., Sharpe, C J, Stuart, T., Symes, A., Temple, H., Martin, R & Ashpole, J
This species has undergone extremely rapid declines in the past three generations (60 years) and is therefore classified as Critically Endangered.

Previously published Red List assessments:

Geographic Range [top]

Range Description:Pterodroma phaeopygia is endemic to the Galápagos Islands, Ecuador, breeding on Santa Cruz, Floreana, Santiago, San Cristóbal, Isabela and possibly other islands in the archipelago (Cruz and Cruz 1987, H. Vargas and F. Cruz in litt. 2000). Between 1978 and 1980, populations on the islands were estimated at 9,000 pairs on Santa Cruz (Baker 1980), c. 11,250 on Santiago, and c. 6,750 on Floreana and San Cristóbal (Tomkins 1985). By 1985, the Santa Cruz population had plummeted to 1,000 pairs, that on Santiago to less than 500 pairs (Cruz and Cruz 1987), and numbers on Floreana and presumably San Cristóbal were estimated to have declined to c. 2,000 pairs (Coulter et al. 1981). An extensive survey of Santa Cruz in 2005 located c. 300 previously unknown nests, but the island population totalled just 700 pairs (Valarezo 2006); a further survey in 2010 calculated 1,135 pairs (Valarezo and Heitmann 2011). Estimates for 2008 suggested a total of 4,500-5,000 active nests on all five islands (I. Guzmán in litt. 2008). Birds forage around the islands, but also disperse east and north towards South America and up to 2,000 km south (Spear et al. 1995). It has recently been recorded off the coast of Peru, and records in Baja California could be this species or Pterodroma sandwichensis (Carboneras et al. 2015).

Countries occurrence:
Colombia; Costa Rica; Ecuador (Galápagos); Mexico; Nicaragua; Peru
Panama; Philippines
Present - origin uncertain:
El Salvador; French Southern Territories; Guatemala
Additional data:
Estimated area of occupancy (AOO) - km2:220Continuing decline in area of occupancy (AOO):Yes
Extreme fluctuations in area of occupancy (AOO):NoEstimated extent of occurrence (EOO) - km2:16800000
Continuing decline in extent of occurrence (EOO):UnknownExtreme fluctuations in extent of occurrence (EOO):No
Number of Locations:5Continuing decline in number of locations:No
Extreme fluctuations in the number of locations:NoLower elevation limit (metres):300
Upper elevation limit (metres):900
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:The global population estimate is best placed in the range of 10,000-19,999 individuals, based on an estimate of 4,500-5,000 active nests (representing 9,000-10,000 mature individuals) in 2008 (I. Guzmán in litt. 2008).

Trend Justification:  This species suffered from the impacts of introduced predators and agricultural expansion on its nesting islands, resulting in very rapid declines up until the 1980s (Coulter et al. 1981, Cruz and Cruz 1987). Declines since then appear to have been much slower (Valarezo 2006), although data is relatively sparse; nevertheless, given the species's long generation time (20 years), it has still undergone extremely rapid declines over the past 60 years (three generations).

Current Population Trend:Decreasing
Additional data:
Number of mature individuals:6000-15000Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:No
No. of subpopulations:2-100Continuing decline in subpopulations:No
Extreme fluctuations in subpopulations:NoAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:It breeds in the humid highlands at 300-900 m, in burrows or natural cavities, on slopes, in craters, sinkholes, lava tunnels and gullies usually in close proximity to Miconia plants (Baker 1980, Cruz and Cruz 1987, 1996). It feeds mostly on squid, fish and crustaceans (Castro and Phillips 1996). On San Cristóbal nests were primarily located along ravines in areas of dense Miconia robinsoniana and native fern cover, with the majority of egg-laying taking place between May and October, peaking in August (Cruz-Delgado et al. 2010).

Systems:Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat:Yes
Generation Length (years):19.8
Movement patterns:Full Migrant
Congregatory:Congregatory (and dispersive)

Threats [top]

Major Threat(s): Introduced dogs, cats and pigs take eggs, young and adults, and black and brown rats eat chicks. Predation by rats was found to be the primary cause of nest failure (72%) in a study of colonies on San Cristóbal in 2002-2003 (Cruz-Delgado et al. 2010). Galapagos Hawk Buteo galapagoensis (Cruz and Cruz 1996) and Short-eared Owl Asio flammeus may take adult birds. Nest-site destruction by goats, donkeys, cattle and horses is a major threat (Cruz and Cruz 1987, 1996, Valarezo 2006). Clearance of vegetation for agriculture and intensive grazing has severely restricted the breeding area on Santa Cruz, Floreana and San Cristóbal (Baker 1980, Tomkins 1985, Cruz and Cruz 1987, 1996, Valarezo 2006), and at least half the breeding range is still farmed on Santa Cruz (Baker 1980, Valarezo 2006). Invasive plants such as Rubus and Cinchona are a further threat to breeding habitat (Wiedenfeld and Jiménez-Uzcátegui 2008).

Adult mortality occurs when birds are caught on barbed wire fences on agricultural land (Cruz and Cruz 1987), and collide with power lines, radio towers and guy wires (Cruz-Delgado and Wiedenfeld 2005). Development of a wind power project on Santa Cruz was a potential threat to many of the breeding colonies on that island, but the development plan aims to minimise effects on the species, and following construction an evaluation of collision risk suggested the turbines will be no more detrimental than other existing man-made structures (Cruz-Delgado et al. 2010). Further development of buildings and other structures in the highlands of the islands threaten nesting colonies (Valarezo 2006). Long-line fishing in the eastern Pacific is a threat, but long-lining in the Galápagos Marine Reserve is particularly likely to affect foraging birds (Alava and Haase 2011). El Niño events seem to have a detrimental impact on nesting and productivity. The species is potentially susceptible to climate change, which may affect food supplies (D. Wiedenfeld in litt. 2012, BirdLife International unpubl. data).

Conservation Actions [top]

Conservation Actions: Conservation Actions Underway
CMS Appendix I. In 1982, predator control commenced in the Cerro Pajas colony (c.2,000 pairs), Floreana (Cruz and Cruz 1996). Predator control involving intensive rat baiting around known colonies and petrel monitoring currently continues on Floreana, Santa Cruz, San Cristóbal and Santiago (H. Vargas and F. Cruz in litt. 2000, D. Wiedenfeld in litt. 2012). In early 2009, it was confirmed that goats have been successfully eradicated from Santiago (American Bird Conservancy 2009). A small number of burrows have recently been discovered on Alcedo, Isabela (Cruz-Delgado 2005). The islands are a national park and, in 1979, were declared a World Heritage Site. World Heritage Site designation encourages Ecuador to work carefully to enact suitable conservation laws and implement existing laws to protect the unique fauna and flora of the Galápagos Islands. There were plans to hold a workshop for fundraising for rat eradication on Santiago in April 2007 (G. Allport in litt. 2007). 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). The wind turbine development includes a series of mitigation and enhancement measures that will be instituted during implementation, many focusing on the petrel, and it is intended that these measures will not only act to minimise impacts but may actually help increase the population. A long-term monitoring programme is included as part of the project activity and ongoing operations (Anon. 2008). Exotic vegetation is being controlled with the help of local landowners on Santa Cruz (Valarezo and Heitmann 2011).

Conservation Actions Proposed
Monitor breeding success under various predator control regimes to determine most appropriate management (M. de L. Brooke in litt. 1999). Continue rat control programs on San Cristóbal, Santa Cruz, Floreana, and Santiago islands (D. Wiedenfeld in litt. 2012). On San Cristóbal, remove invasive plants such as blackberry and guava and reforest with native plants, particularly Miconia robinsoniana (Cruz-Delgado et al. 2010, D. Wiedenfeld in litt. 2012); on Floreana continue to control Lantana, and on Santa Cruz control Cinchona pubescens and blackberries (D. Wiedenfeld in litt. 2012). Continue searching for nesting grounds in agricultural areas which are not protected through the park system on Santa Cruz and Isabela (B. Hennessey in litt. 2008). Conduct a full census for the species as the last comprehensive surveys were in the 1980s and late 1990s (not complete). Ensure wind-power plants are situated so that they do not affect nesting areas or sites with Miconia, and that power lines are buried to prevent aerial collisions as the birds return to their colonies at night. Implement a post-construction monitoring program on San Cristóbal to assess long-term effects of the turbines (Cruz-Delgado et al. 2010). Determine potential effects of long-line fishing in the Galápagos Marine Reserve and elsewhere in the eastern Pacific and assess how to avoid them. Working with landowners in areas outside the park, create conservation easements to protect petrel nesting habitat. Create an education programme in the agricultural areas to motivate and educate landowners in habitat conservation (Valarezo 2012, B. Hennessey in litt. 2008). Create a species action plan involving local stakeholders (B. Hennessey in litt. 2008). Conduct rodent control campaigns around colonies on San Cristóbal. Conduct a Galapagos Petrel pride campaign with the Galápagos National Park (B. Hennessey in litt. 2008).

Amended [top]

Amended reason: EOO updated.

Citation: BirdLife International. 2017. Pterodroma phaeopygia (amended version of 2017 assessment). The IUCN Red List of Threatened Species 2017: e.T22698020A118861782. . Downloaded on 18 August 2018.
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