Creagrus furcatus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Aves Charadriiformes Laridae

Scientific Name: Creagrus furcatus
Species Authority: (Néboux, 1842)
Common Name(s):
English Swallow-tailed Gull
Taxonomic Source(s): del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions BirdLife International.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2015
Date Assessed: 2012-05-01
Assessor(s): BirdLife International
Reviewer(s): Butchart, S. & Symes, A.
Facilitator/Compiler(s): Butchart, S., Calvert, R. & Ekstrom, J.
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Previously published Red List assessments:
2009 Least Concern (LC)
2008 Least Concern (LC)
2004 Least Concern (LC)
2000 Lower Risk/least concern (LR/lc)
1994 Lower Risk/least concern (LR/lc)
1988 Lower Risk/least concern (LR/lc)

Geographic Range [top]

Range Description: The Swallow-tailed Gull breeds mainly on the Galapagos Islands, Ecuador (all major and several minor islands) but also on Malpelo Island, Colombia. When not breeding it can be found along the Pacific coast of South American from Ecuador to northern Chile1.
Countries occurrence:
Chile; Colombia; Costa Rica; Ecuador; Peru
Continuing decline in area of occupancy (AOO): Unknown
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 79300
Continuing decline in extent of occurrence (EOO): Unknown
Extreme fluctuations in extent of occurrence (EOO): No
Continuing decline in number of locations: Unknown
Extreme fluctuations in the number of locations: No
Range Map: Click here to open the map viewer and explore range.

Population [top]

Current Population Trend: Unknown
Additional data:
Continuing decline of mature individuals: Unknown
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: Unknown
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: No

Habitat and Ecology [top]

Habitat and Ecology: This species feeds mostly at night but also by day, heavily exploiting squid at night but also taking clupeid fish. It appears to suffer from periodic food shortages, and is often observed feeding 500 km from the nearest land. It breeds throughout the year and asynchronously across the Galapagos, with individual subcolonials being synchronised by social interactions. It forms loose colonies with large inter-nest distances but can be solitary, nesting on steep slopes or broken cliffs, often on broad clifftop ledges but also just above the wave line, and on gravelly beaches and under vegetation. Adults leave the colony after breeding and become highly pelagic, returning in 4-5 months often to their previous nest site.
Systems: Terrestrial; Marine
Continuing decline in area, extent and/or quality of habitat: Unknown
Generation Length (years): 17.4
Movement patterns: Full Migrant
Congregatory: Congregatory (and dispersive)

Citation: BirdLife International. 2015. Creagrus furcatus. The IUCN Red List of Threatened Species 2015: e.T22694493A85016956. . Downloaded on 01 December 2015.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided