DOI10.47051/FXMG7465

Published October 30, 2023. Updated January 25, 2024. Open access.

Gallery ❯

Knobbed Lava-Lizard (Microlophus occipitalis)

Reptiles of Ecuador | Sauria | Tropiduridae | Microlophus occipitalis

English common names: Knobbed Lava-Lizard, Knobbed Pacific Iguana.

Spanish common names: Capón, capón del Pacífico.

Recognition: ♂♂ 19.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=7.5 cm. ♀♀ 16.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.4 cm..1–3 Lava lizards differ from other lizards –including Anolis, Holcosus, Polychrus, and Stenocercus– by having keeled scales on the tail, a skin fold above the shoulder, a raised mid-dorsal crest, and a conspicuously enlarged interparietal scale.1,4,5 Microlophus occipitalis can be easily differentiated from the only other lava lizard in continental Ecuador (M. peruvianus) by having keeled and imbricate dorsal scales, no lateral folds, and no black throat patch.1,6 Males are larger than females and boast a projected orange dorsal crest adorned with triangular black markings (Fig. 1). Females and juveniles have a more subdued brownish gray coloration and a small dorsal crest.1,7

Figure showing variation among individuals of Microlophus occipitalis

Figure 1: Individuals of Microlophus occipitalis from Ecuador: La Ceiba Reserve, Loja province (); Puerto Rico, Manabí province (). j=juvenile.

Natural history: Microlophus occipitalis is a diurnal lizard that occurs in high densities in xeric and coastal areas,1,8 commonly found in thickets and dry forests as well as in human-modified environments such as pastures, crops, buildings, and rural gardens.1,2,9 Knobbed Lava-Lizards are active throughout the day,3 with greater activity during the sunniest hours.10 They maintain activity mainly by moving between sunny and shaded sand areas3,11 and spend extended periods basking or absorbing heat by pressing their bodies against substrates such as logs, leaf-litter, sand, and stones.9–14 They are primarily terrestrial but also exhibit semi-arboreal behavior, climbing tree trunks and bushes up to 3 m above the ground.1,2 When not active, they seek refuge under logs, stones, and trash or bury themselves in the sand.1,2 These lizards feed primarily on ants, but also include at least 13 other prey item categories ranging from beetles and scorpions to flowers and leaves.10,12 In the presence of a disturbance, these fast and agile lizards usually try to flee or take refuge in crevices, under logs, or in the sand.2 If captured, they may readily shed the tail.2 There are documented instances of predation on individuals of this species by raptors15–17 and the viper Porthidium arcosae.18 Both males and females exhibit territorial behavior.19,20 Males patrol territories of approximately 625 m2 and defend them using a series of exhibitions, which include sagittal compression of the trunk, extending the dewlap, and raising the crest.3,20 Female displays include arching the back, extending the dewlap, and flashing of the throat coloration.7 The breeding season spans from December to July, with gravid females still being found as late as November. Females lay clutches of 2–5 eggs up to five times per season.19

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..21 Microlophus occipitalis is listed in this category because the species has a wide distribution along the Pacific coast of South America and current knowledge indicates that there are no widespread threats affecting affecting its long-term survival.21 This species thrives in human-modified habitats and is found in numerous protected areas in Ecuador and Peru.

Distribution: Microlophus occipitalis is native to the Tumbesian coastal lowlands of western Ecuador (Fig. 2) and northwestern Peru. The species also occurs in continental islands of Ecuador, including Puná, La Plata, and Santa Clara.

Distribution of Microlophus occipitalis in Ecuador

Figure 2: Distribution of Microlophus occipitalis in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Microlophus, which comes from the Greek words mikros (=small) and lophos (=crest),22 refers to the reduced dorsal crest in this species.23 The specific epithet occipitalis refers to the extremely large occipital scale.24

See it in the wild: Knobbed Lava-Lizards can be observed with almost complete certainty along the coast of western Ecuador. The localities having the greatest number of observations are La Chocolatera and Parque Nacional Machalilla. The lizards can be easily observed during sunny hours, basking or moving on sandy substrate among thickets of xeric vegetation.

Authors: Amanda QuezadaaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: Laboratorio de Herpetología, Universidad del Azuay, Cuenca, Ecuador. and Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.

Photographers: Jose VieiraaAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador. and Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.

How to cite? Quezada A, Arteaga A (2023) Knobbed Lava-Lizard (Microlophus occipitalis). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: www.reptilesofecuador.com. DOI: 10.47051/FXMG7465

Literature cited:

  1. Dixon JR, Wright JW (1975) A review of the lizards of the iguanid genus Tropidurus in Perú. Natural History Museum of Los Angeles County Contributions in Science 271: 1–39.
  2. Field notes, Reptiles of Ecuador book project.
  3. Rowe JW, Martin CE, Clark DL, Valle C, Vintimilla Palacios CP (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.
  4. Duméril AMC, Bibron G (1837) Erpétologie générale ou Histoire Naturelle complète des Reptiles. Librairie Encyclopédique de Roret, Paris, 571 pp. DOI: 10.5962/bhl.title.45973
  5. Peters JA, Donoso-Barros R (1970) Catalogue of the Neotropical Squamata: part II, lizards and amphisbaenians. Bulletin of the United States National Museum, Washington, D.C., 293 pp.
  6. Boulenger GA (1885) Catalogue of the lizards in the British Museum. Taylor & Francis, London, 497 pp.
  7. Watkins GG (1997) Inter-sexual signalling and the functions of female coloration in the tropidurid lizard Microlophus occipitalis. Animal Behaviour 53: 843–852. DOI: 10.1006/anbe.1996.0350
  8. Venegas P (2005) Herpetofauna del bosque seco ecuatorial de Perú: taxonomía, ecología y biogeografía. Zonas Áridas 9: 9–24. DOI: 10.21704/ZA.V9I1.565
  9. Cuadrado SS, Loor YA, Narváez AE (2020) Herpetofauna of Engabao, Playas Canton, Ecuador, with notes on the occurrence of Ceratoprhys stolzmanni (Steindachner, 1882). Check List 16: 665–674. DOI: 10.15560/16.3.665
  10. Guzmán-Caldas A (2016) Repartición de recursos entre Stenocercus puyango (Torres-Carvajal, 2005) y Microlophus occipitalis (Peters, 1871) (Sauria: Tropiduridae) en el Parque Nacional Cerros de Amotape, Tumbes, Perú. BSc thesis, Universidad Nacional Mayor de San Marcos, 81 pp.
  11. Rowe JW, Martin CE, Clark DL, Goerge TM, Mulligan WP (2021) Thermal ecology of the Pacific knobbed iguana (Microlophus occipitalis Peters, 1871) in a sand dune habitat of western Ecuador. Herpetology Notes 14: 1305–1311.
  12. Chávez-Villavicencio C, Ibáñez-Álvarez Y, Charcape Ravelo JM (2018) Selección de hábitat y composición de la dieta de Microlophus occipitalis (Reptilia: Tropiduridae) en Sechura, Piura-Perú. Revista Peruana de Biología 25: 221–228. DOI: 10.15381/rpb.v25i3.13403
  13. Jordán JC, Pérez J (2012) Thermal ecology of Microlophus occipitalis (Sauria: Tropiduridae) in the plain dry forest of Tumbes, Peru. Revista Peruana de Biología 19: 97–99. DOI: 10.15381/rpb.v19i1.794
  14. Condo Montano AE (2017) Estructura y distribución poblacional de Microlophus occipitalis en el trópico. BSc thesis, Universidad Nacional de Trujillo, 56 pp.
  15. Medina CA, Estraver WZ, Velásquez LP, Rodríguez EH, Quezada AG (2013) Dieta de la Lechuza de los Arenales, Athene cunicularia, en Trujillo y en el Cerro Campana. Revista de Investigación Científica REBIOL 33: 99–106.
  16. Orihuela-Torres A, Brito J, Pérez-García JM (2019) First observations of the diet of the Pearl Kite (Gampsonyx swainsonii magnus) in southwestern Ecuador. Revista Brasileira de Ornitologia 27: 195–198. DOI: 10.1007/BF03544470
  17. Orihuela Torres A, Ordóñez-Delgado L, Brito J (2019) Dieta del Caracara Crestado Norteño Caracara cheriway (Falconiformes: Falconidae) en el Archipiélago de Jambelí, suroeste de Ecuador. Revista Ecuatoriana de Ornitología 5: 19–24. DOI: 10.18272/reo.vi5.963
  18. Valencia JH, Garzón-Tello K, Barragán-Paladines ME (2016) Serpientes venenosas del Ecuador: sistemática, taxonomía, historial natural, conservación, envenenamiento y aspectos antropológicos. Fundación Herpetológica Gustavo Orcés, Quito, 653 pp.
  19. Watkins GG (1996) Proximate causes of sexual size dimorphism in the iguanian lizard Microlophus occipitalis. Ecology 77: 1473–1482. DOI: 10.2307/2265544
  20. Watkins GG (1998) Function of a secondary sexual ornament: the crest in the South American iguanian lizard Microlophus occipitalis (Peters, Tropiduridae). Herpetologica 54: 161–169.
  21. Cisneros-Heredia DF, Venegas P, Yánez-Muñoz M, Perez J (2016) Microlophus occipitalis. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2016-1.RLTS.T48444876A48444914.en
  22. Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
  23. Frost DR (1992) Phylogenetic analysis and taxonomy of the Tropidurus group of lizards (Iguania: Tropidurudae). American Museum Novitates 3033: 1–68.
  24. 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.

Appendix 1: Locality data used to create the distribution map of Microlophus occipitalis in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

CountryProvinceLocalitySource
EcuadorEl OroArenillas Ecological ReserveGarzón-Santomaro et al. 2019
EcuadorEl OroIsla Costa RicaOnline multimedia
EcuadorEl OroIsla de Santa ClaraGarzón et al. 2019
EcuadorEl OroIsla San GregorioiNaturalist; photo examined
EcuadorEl OroIsla Santa ClaraiNaturalist; photo examined
EcuadorEl OroJambelíiNaturalist; photo examined
EcuadorEl OroLa PuntillaGarzón-Santomaro et al. 2019
EcuadorEl OroLas Casitas, JambelíOrihuela-Torres et al. 2019
EcuadorEl OroRío PuyangoGarzón-Santomaro et al. 2019
EcuadorGuayasBuenos AiresMCZ R-83074; VertNet
EcuadorGuayasCerro del MuertoiNaturalist; photo examined
EcuadorGuayasColonche, 1 km SW ofKU 157996; VertNet
EcuadorGuayasData de PosorjaiNaturalist; photo examined
EcuadorGuayasData VillamilUSNM 201334; VertNet
EcuadorGuayasEl PradoMCZ R-83117; VertNet
EcuadorGuayasEstero de AcumbeCuadrado et al. 2020
EcuadorGuayasGuayaquil, Estero SaladoMVZ:Herp:82371
EcuadorGuayasIsla Puná, Subida AltaReptiles of Ecuador book database
EcuadorGuayasManglaraltoUSNM 200823; VertNet
EcuadorGuayasPlaya el PeladoReptiles of Ecuador book database
EcuadorGuayasPlayas VillamilKU 142715; VertNet
EcuadorGuayasPlayas Villamil, 2.2 km N ofKU 152191; VertNet
EcuadorGuayasPosorjaCAS 64114; VertNet
EcuadorGuayasPosorja, 2 km W ofReptiles of Ecuador book database
EcuadorGuayasPuerto de El MorroiNaturalist; photo examined
EcuadorGuayasPunta CarneroUSNM 2008352; VertNet
EcuadorGuayasSan Antonio, 2 km N ofOMNH 33267.0; VertNet
EcuadorGuayasSan EduardoiNaturalist; photo examined
EcuadorGuayasSan Lorenzo, 2.3 km SW ofiNaturalist; photo examined
EcuadorGuayasValdivia, 5 km SW ofUSNM 200832; VertNet
EcuadorLojaCabeza de Toro, 3 km SE ofiNaturalist; photo examined
EcuadorLojaCabo IngaiNaturalist; photo examined
EcuadorLojaCazaderosiNaturalist; photo examined
EcuadorLojaCazaderos, 8 km NE ofiNaturalist; photo examined
EcuadorLojaEl Huásimo, 2.2 km NW ofiNaturalist; photo examined
EcuadorLojaJorupe ReserveReptiles of Ecuador book database
EcuadorLojaLas PampasiNaturalist; photo examined
EcuadorLojaLucarquiUSNM 201325; VertNet
EcuadorLojaMacaráiNaturalist; photo examined
EcuadorLojaMangahurcoPhoto by Fausto Siavichay
EcuadorLojaMangahurco, 5.7 km NE ofiNaturalist; photo examined
EcuadorLojaProgreso, 1.4 km NE ofiNaturalist; photo examined
EcuadorLojaReserva La CeibaReptiles of Ecuador book database
EcuadorLojaRío CasangaKU 142738; VertNet
EcuadorLojaRío MacaráKU 142740; VertNet
EcuadorLojaValley of CatamayoUSNM 201327; VertNet
EcuadorLojaVía Limo-CazaderosiNaturalist; photo examined
EcuadorLojaZapotilloiNaturalist; photo examined
EcuadorLojaZapotillo, 6.9 km N ofOrihuela-Torres et al. 2019
EcuadorManabíAgua BlancaiNaturalist; photo examined
EcuadorManabíAyampeiNaturalist; photo examined
EcuadorManabíBahía de CaraquezUSNM 2840552; VertNet
EcuadorManabíBosque Húmedo La JosefinaBrennan 2010
EcuadorManabíCabo San MateoReptiles of Ecuador book database
EcuadorManabíCanoaiNaturalist; photo examined
EcuadorManabíIsla de la PlataTorres-Carvajal 2004
EcuadorManabíLa Bramadora, 4 km S ofRowe et al. 2019
EcuadorManabíLos FrailesReptiles of Ecuador book database
EcuadorManabíMachalilla National ParkiNaturalist; photo examined
EcuadorManabíMantaPhoto by Sebastián Valverde
EcuadorManabíManta, BarbasquilloiNaturalist; photo examined
EcuadorManabíMirador de SalangoiNaturalist; photo examined
EcuadorManabíPlaya Los BálsamosiNaturalist; photo examined
EcuadorManabíPlaya PrietaiNaturalist; photo examined
EcuadorManabíPlaya TortuguitaiNaturalist; photo examined
EcuadorManabíPuerto CayoiNaturalist; photo examined
EcuadorManabíPuerto LópeziNaturalist; photo examined
EcuadorManabíPuerto RicoReptiles of Ecuador book database
EcuadorManabíPunta BlancaiNaturalist; photo examined
EcuadorManabíReserva Cerro SecoPhoto by Michi Maissen
EcuadorManabíSalangoBrennan 2010
EcuadorManabíSan ClementeiNaturalist; photo examined
EcuadorManabíSan Clemente, 2 km N of USNM 200874; VertNet
EcuadorManabíSan LorenzoReptiles of Ecuador book database
EcuadorManabíSan Vicente, 9 km N ofUSNM 200879; VertNet
EcuadorManabíTosaguaiNaturalist; photo examined
EcuadorSanta ElenaAguadita, 4.6 km E ofiNaturalist; photo examined
EcuadorSanta ElenaAncónLACM 154365; VertNet
EcuadorSanta ElenaAncón, 6.5 km E ofiNaturalist; photo examined
EcuadorSanta ElenaAtahualpa, 2.7 km W ofiNaturalist; photo examined
EcuadorSanta ElenaAyangueiNaturalist; photo examined
EcuadorSanta ElenaBallenitaiNaturalist; photo examined
EcuadorSanta ElenaCadeateiNaturalist; photo examined
EcuadorSanta ElenaCementerio de Santa ElenaiNaturalist; photo examined
EcuadorSanta ElenaCerro Alto, 2 km NE ofWatkins 1996
EcuadorSanta ElenaEl MorroiNaturalist; photo examined
EcuadorSanta ElenaLa ChocolateraiNaturalist; photo examined
EcuadorSanta ElenaLa LibertadiNaturalist; photo examined
EcuadorSanta ElenaLa Libertad, La PenínsulaiNaturalist; photo examined
EcuadorSanta ElenaLa LoberíaiNaturalist; photo examined
EcuadorSanta ElenaMontañitaiNaturalist; photo examined
EcuadorSanta ElenaPalmariNaturalist; photo examined
EcuadorSanta ElenaPerimetral Santa ElenaiNaturalist; photo examined
EcuadorSanta ElenaPunta BravaiNaturalist; photo examined
EcuadorSanta ElenaSan PabloiNaturalist; photo examined
EcuadorSanta ElenaSanta Elena, 42 km SE ofMCZ 147182; VertNet
EcuadorSanta ElenaValdiviaiNaturalist; photo examined