San Cristóbal Lava-Lizard

Reptiles of Ecuador | Sauria | Tropiduridae | Microlophus | Microlophus bivittatus

Spanish common name: Lagartija de lava de San Cristóbal.

Recognition: ♂♂ 26.8 cm ♀♀ 23.8 cm. Microlophus bivittatus is the only lava lizard occurring on San Cristóbal Island and Lobos Islet. Males and females of this species differ from each other in size, shape, and coloration. Adult males are larger and easily recognized by their raised middorsal crest. They also have a black mark just above the shoulder. Adult females may be recognized by their bright orange coloration on the throat and lower flanks of the body.

Natural history: Extremely common. Microlophus bivittatus is a diurnal lizard that inhabits volcanic rock areas, dry shrublands, dry grasslands, deciduous forests, and urban areas.1 San Cristóbal Lava-Lizards bask and move over 85–813 m2 areas mostly (up to ~95% of the time) on rocks, but also on soil, leaf litter, grass, shrubs, cacti, and trees up to 4.1 m above the ground.1,2 They move into the shade in order to avoid the hottest hours of the day, sitting on surfaces that have not been heated by the sun.3 During this time, the lizards move among rock crevices and within vegetation, thus remaining active.2 At night, individuals of M. bivittatus sleep in rock crevices, under leaf litter or shrubs, in grass clumps, or on tree branches.2

Microlophus bivittatus is a generalist forager that feeds mostly on ants, but also on moths, crickets, roaches, dragonflies, crabs, centipedes, spiders, worms, and plant material such as fruits and seeds.4–6 When threatened, San Cristóbal Lava-Lizard flee into crevices. If captured, they may shed the tail and bite.1 Individuals of M. bivittatus are preyed upon by egrets,7 cats,8 and Eastern Galápagos Racers (Pseudalsophis biserialis).9 Their breeding season takes place between February and March.2 Males routinely perform pushup displays and fight with one another, but are generally unable to keep their territories free from other males.2 Females lay 1–4 eggs per clutch.3

Conservation: Near Threatened.10 Microlophus bivittatus is listed in this category because the species is facing the threat of predation by housecats,8 although it has not been conclusively shown to have undergone population declines due to this threat. It is clear, however, that cats represent a major conservation problem for native animals in San Cristóbal.8,11 A major eradication program should be put in place for feral cats, combined with much stronger control and mandatory sterilization of domestic cats.

Distribution: Microlophus bivittatus is endemic to an estimated 447 km2 area in San Cristóbal Island and Lobos Islet. Galápagos, Ecuador.

Distribution of Microlophus bivittatus Distribution of Microlophus bivittatus in and around San Cristóbal Island

Etymology: The generic name Microlophus, which comes from the Greek words mikros (meaning “small”) and lophos (meaning “crest”), refers to the reduced dorsal crest in another lava lizard species (M. peruvianus).12 The specific epithet bivittatus, which comes from the Latin words bi (meaning “two”) and vitta (meaning “band”), refers to the dorsal longitudinal bands present in some San Cristóbal Lava-Lizards.13

See it in the wild: San Cristóbal Lava-Lizards can be seen year-round with ~100% certainty at most tourism sites on San Cristóbal Island. The best time to look for the lizards is during the first hours after sunrise or right before sunset, when they are active and approachable.

Authors: Alejandro Arteaga,aAffiliation: Tropical Herping (TH), Quito, Ecuador. Gabriela Aguiar, and Juan M GuayasaminbAffiliation: Laboratorio de Biología Evolutiva, Universidad San Francisco de Quito (USFQ), Quito, Ecuador.,cAffiliation: Galapagos Science Center, Galápagos, Ecuador.,dAffiliation: Centro de Investigación de la Biodiversidad y Cambio Climático, Universidad Tecnológica Indoamérica, Quito, Ecuador.

Academic reviewers: Edgar Benavides, John Rowe, and Cruz Márquez.

Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,eAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagaaAffiliation: Tropical Herping (TH), Quito, Ecuador.

How to cite? Arteaga A, Aguiar G, Guayasamin JM (2020) Microlophus bivittatus. In: Arteaga A, Bustamante L, Vieira J, Guayasamin JM (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com

Literature cited:

  1. Field notes, Reptiles of Ecuador book project.
  2. Rowe JW, Martin CE, Clarck DL (2019) Habitat use and spatial ecology of three Microlophus lizard species from Santa Cruz and San Cristóbal islands, Galápagos, and the coastal dry forest of Machalilla, Ecuador. Herpetological Review 50: 43–51.
  3. Koenig MN (2017) The relationship between sex and territorial behavior in the San Cristóbal lava lizard (Microlophus bivittatus). Thesis, St. Joseph, United States, College of Saint Benedict and Saint John's University.
  4. Van Denburgh J, Slevin JR (1913) Expedition of the California Academy of Sciences to the Galápagos Islands, 1905-1906. IX. The Galapagoan lizards of the genus Tropidurus with notes on iguanas of the genera Conolophus and Amblyrhynchus. Proceedings of the California Academy of Sciences 2: 132–202.
  5. Moore JA, Rowe JW, Wessels D, Plivelich MT, Valle CA (2017) Microlophus bivittatus (San Cristóbal Lava Lizard) diet. Herpetological Review 48: 851.
  6. Hervías-Parejo S, Heleno R, Rumeu B, Guzmán B, Vargas P, Olesen JM, Traveset A, Vera C, Benavides E, Nogales M (2018) Small size does not restrain frugivory and seed dispersal across the evolutionary radiation of Galápagos lava lizards. Current Zoology 65: 353–361.
  7. Burke RL, Figueras M, Calle PP (2015) Microlophus bivittatus (lava lizard) predation. Herpetological Review 46: 632.
  8. Carrión PL (2012) Depredación de gatos domésticos y ferales sobre las lagartijas de lava de San Cristóbal (Microlophus bivittatus), Galápagos. Thesis, Quito, Ecuador, Universidad San Francisco de Quito.
  9. Washington Tapia, unpublished data.
  10. Márquez C, Cisneros-Heredia DF (2016) Microlophus bivittatus. The IUCN red list of threatened species. Available from: www.iucnredlist.org
  11. Marra PP, Santella C (2016) Cat Wars: the devastating consequences of a cuddly killer. Princeton University Press, Princeton, 212 pp.
  12. Frost DR (1992) Phylogenetic analysis and taxonomy of the Tropidurus group of lizards (Iguania: Tropidurudae). American Museum Novitates 3033: 1–68.
  13. Peters WCH (1871) Über einige Arten der herpetologischen Sammlung des Berliner zoologischen Museums. Monatsberichte der Königlichen Preussische Akademie des Wissenschaften zu Berlin 1871: 644–652.