About Leucophaeus fuliginosus (Gould, 1841)
Taxonomic Identity
The lava gull, scientifically named Leucophaeus fuliginosus (Gould, 1841), is a distinct gull species.
Adult Size
Adults measure 51 to 55 cm (20–22 in) in length and weigh an average of 380 g (13 oz).
Adult Head Plumage
Adult plumage features a sooty brown to black head that does not change with the season, unlike the heads of other dark-hooded gull species.
Wing Characteristics
The wings are dark gray with a contrasting white line along the leading edge, which is thought to function in courtship or territorial displays and camouflage.
Body Plumage
The lava gull's dark gray body contrasts with its paler gray belly.
Tail Coloration
The uppertail is white, while the lower portion of the tail is gray.
Soft Part Features
Both the bill and legs are black, and the inside of the mouth is bright scarlet.
Facial Markings
The species has white upper and lower eyebrows, with red eyelids.
Immature Plumage
Immature lava gulls are generally uniformly dark brown.
Global Distribution
The entire global population of lava gulls is restricted to the Galapagos Islands, where individuals are found predominantly on the islands of Santa Cruz, Isabela, San Cristobal, and Genovesa.
Population Estimates
Previously, the total population was estimated at 300–400 breeding pairs; this estimate was revised downward to 300–600 total individuals in 2015.
Conservation Status
The lava gull is currently considered the rarest gull species in the world.
