Published October 14, 2021. Updated January 28, 2024. Open access. | Purchase book ❯ |
Iridescent Whorltail-Iguana (Stenocercus iridescens)
Reptiles of Ecuador | Sauria | Tropiduridae | Stenocercus iridescens
English common name: Iridescent Whorltail-Iguana.
Spanish common name: Guagsa iridiscente.
Recognition: ♂♂ 29.4 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=9.9 cm. ♀♀ 21.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=8.3 cm.. The Iridescent Whorltail-Iguana (Stenocercus iridescens) differs from most other medium-sized diurnal and terrestrial lizards in its area of distribution (particularly species in the family Teiidae) by having keeled dorsal scales with pointed ends instead of granular scales.1 Stenocercus iridescens occurs nearby, and is often confused with, S. puyango, S. limitaris, and Microlophus occipitalis. From S. puyango, it differs by lacking a post-femoral mite pocket and posterior circumorbital scales (both characters are present in S. puyango).2,3 From S. limitaris, it differs by having smooth, instead of keeled, head and ventral scales.2 From M. occipitalis, it differs by having 2–5, instead of 7–8, supraocular scales.2,4 Males of S. iridescens differ from females by having a colorful ventral coloration consisting of a pink belly, yellow chest, black neck, and reddish throat (belly cream or pale brown in females and juveniles; Fig. 1).2
Figure 1: Individuals of Stenocercus iridescens from Ecuador: Reserva Biológica Cerro Seco, Manabí province (); Cerro de Hayas, Guayas province (); Vinces, Los Ríos province (); Las Balsas Reserve, Santa Elena province (). j=juvenile.
Natural history: Stenocercus iridescens is a diurnal and terrestrial lizard that occurs in high densities in a variety of natural habitats ranging from dry lowland shrublands and deciduous lowland forests to evergreen montane forests.5 It is a dominant species in semi-open dry forests, but is also adapted to human-modified environments such as pastures, crops, reforested areas, and infrastructures.6–10 Females are most often found on the ground between sticks while males occupy more prominent places such as tree trunks and shrubs.11 Individuals are most active during sunny days and may be seen basking on large rocks.10 At night, they sleep on the leaf-litter, on the ground, or on trunks, twigs, wood poles, shrubs, or Agave plants up to 130 cm above the ground.10,12 The diet is insectivorous, but the specific prey items are not known.11 Iridescent Whorltail-Iguanas escape predators by running or by remaining still and relying on their camouflage.11 If captured, they may shed the tail and bite as a method of defense and escape.10 There are records of birds (Caracara cheriway,13 Falco sparverius,14 and Athene cunicularia15) and snakes (Rhinobothryum bovallii16) preying upon individuals of this species. Stenocercus iridescens is a territorial lizard with an average home range of 21 m2.17 Gravid females containing two eggs have been found in Ecuador,10 but the real clutch size is not known.
Conservation: Least Concern Believed to be safe from extinction given current circumstances..18–20 Stenocercus iridescens is listed in this category because the species is widely distributed, abundant throughout its range, and considered to be facing no major immediate extinction threats.18 It is also found in at least 16 protected areas (Appendix 1). Although the species is widely distributed and tolerates moderate habitat degradation, its populations are fragmented and occur over an area where most (~66%) of the forest cover has been transformed into plantations and human settlements.21 Therefore, S. iridescens may qualify for a threatened category in the near future if its habitat continues to be destroyed.
Distribution: Stenocercus iridescens is native to an area of approximately 58,468 km2 on the Tumbesian lowlands and adjacent foothills of the Andes in Ecuador and southwestern Colombia (Fig. 2).
Figure 2: Distribution of Stenocercus iridescens in Ecuador. The star corresponds to the type locality: Pallatanga, Chimborazo province. See Appendix 1 for a complete list of the presence localities included in the map.
Etymology: The generic name Stenocercus, which comes from the Greek words stenos (=narrow) and kerkos (=tail), refers to the laterally-compressed tail in some members of this genus, which contrasts with the dorsally flattened tail of other Tropiduridae.22 The specific epithet iridescens comes from the Greek word iridos (=rainbow)23 and refers to the colorful belly of the males.
See it in the wild: Iridescent Whorltail-Iguanas can be seen with almost complete certainty during strongly sunny days in protected areas such like Machalilla National Park, Cerro Blanco Protected Forest, and Manglares Churute Ecological Reserve. The easiest way to observe lizards of this species is in open areas near vegetation cover.
Author: Amanda QuezadaaAffiliation: Tropical Herping (TH), Quito, Ecuador.,bAffiliation: Laboratorio de Herpetología, Universidad del Azuay, Cuenca, Ecuador.
Editor: Alejandro ArteagacAffiliation: Khamai Foundation, Quito, Ecuador.
Photographers: Jose Vieira,aAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador. Alejandro Arteaga,cAffiliation: Tropical Herping (TH), Quito, Ecuador. and Sebastián Di DoménicoeAffiliation: Keeping Nature, Bogotá, Colombia.
How to cite? Quezada A (2024) Iridescent Whorltail-Iguana (Stenocercus iridescens). 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/SDWL4438
Literature cited:
- 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.
- Torres-Carvajal O (2007) A taxonomic revision of South American Stenocercus (Squamata: iguania) lizards. Herpetological Monographs 21: 76–178. DOI: 10.1655/06-001.1
- Torres-Carvajal O (2005) A new species of iguanian lizard (Stenocercus) from the western lowlands of southern Ecuador and northern Peru. Herpetologica 61: 78–85. DOI: 10.1655/04-32.2
- Boulenger GA (1885) Catalogue of the lizards in the British Museum. Taylor & Francis, London, 497 pp.
- Torres-Carvajal O (2000) Ecuadorian lizards of the genus Stenocercus (Squamata: Tropiduridae). Scientific Papers Natural History Museum, The University of Kansas 15: 1–38. DOI: 10.5962/bhl.title.16286
- Steihnke J (2016) A comparative study of herpetofauna in a primary forest and reforested area in coastal Ecuador. Journal of Young Investigators 30: 14–19.
- Cruz García FK (2017) Diversidad y preferencia de microhábitats de la herpetofauna del Bosque Protector Pedro Franco Dávila (Jauneche) y del Área Provincial Natural de Recreación Cerro de Hayas (Naranjal). BSc thesis, Universidad de Guayaquil, 94 pp.
- Dávila M, Cisneros-Heredia DF (2017) Use of human-made buildings by Stenocercus lizards (Iguania, Tropiduridae). Herpetology Notes 10: 517–519.
- Yánez-Muñoz MH, Bejarano-Muñoz P, Sánchez-Nivicela JC (2019) Anfibios y reptiles del páramo al manglar. Capítulo II. In: Garzón-Santomaro C, Sánchez-Nivicela JC, Mena-Valenzuela P, González-Romero D, Mena-Jaén JL (Eds) Anfibios, reptiles y aves de la provincia de El Oro. GADPEO–INABIO, Quito, 45–86.
- Field notes, Reptiles of Ecuador book project.
- Brennan R (2010) Un estudio ecológico de las lagartijas del valle seco de Buenavista y de los valles húmedos de La Josefina y Salango. Independent Study Project (ISP) Collection, Vermont, 828 pp.
- Valencia JA, Garzón K (2011) Guía de anfibios y reptiles en ambientes cercanos a las estaciones del OCP. Fundación Herpetológica Gustavo Orcés, Quito, 268 pp.
- Ramírez-Jaramillo S, Jácome-Chiriboga N, Alfaro-Ponce N, Cabrera L, Garzón-Santomaro C (2020) Registros de alimentación y reproducción del carancho norteño Caracara cheriway en el noroeste de Sudamérica. Revista Catalana d’Ornitologia 36: 46–55. DOI: 10.2436/20.8100.01.19
- Ramírez-Jaramillo S, Allan-Miranda A, Salazar M, Jácome-Chiriboga N, Robayo J, Marcayata A, Reyes-Puig J, Yánez-Muñoz MH (2018) Revisión de las presas vertebradas consumidas por Falco sparverius en América del sur y nuevos registros para Ecuador. Hornero 33: 51–57.
- Rodríguez-Reyes E (2015) Abundancia relativa y dieta del búho terrestre Athene cunicularia punensis (Chapman, 1914) en las zonas circundantes de la comuna Atahualpa, provincia de Santa Elena, Ecuador. BSc thesis, Universidad de Guayaquil, 94 pp.
- Photo by Ryan Lynch.
- Morales-Ordoñez M, Salas J (2019) Estimación del ámbito de hogar de Stenocercus iridescens (Günther, 1859)(Squamata: Tropiduridae) durante la época lluviosa en el Bosque Protector Cerro Blanco (Guayas, Ecuador). Revista de Ciencias Naturales y Ambientales 10: 89–96.
- Cisneros-Heredia DF, Velasco J, Bolívar W (2016) Stenocercus iridescens. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2016-1.RLTS.T44579917A44579924.en
- Reyes-Puig C (2015) Un método integrativo para evaluar el estado de conservación de las especies y su aplicación a los reptiles del Ecuador. MSc thesis, Pontificia Universidad Católica del Ecuador, 73 pp.
- Carrillo E, Aldás A, Altamirano M, Ayala F, Cisneros-Heredia DF, Endara A, Márquez C, Morales M, Nogales F, Salvador P, Torres ML, Valencia J, Villamarín F, Yánez-Muñoz M, Zárate P (2005) Lista roja de los reptiles del Ecuador. Fundación Novum Millenium, Quito, 46 pp.
- MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
- 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
- Brown RW (1956) Composition of scientific words. Smithsonian Books, Washington D.C., 882 pp.
Appendix 1: Locality data used to create the distribution map of Stenocercus iridescens in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.
| Country | Province | Locality | Source |
| Colombia | Nariño | Boca Grande | Torres-Carvajal 2007 |
| Colombia | Nariño | San Andrés de Tumaco | ICN 4225; Calderón et al. 2023 |
| Ecuador | Azuay | Tamarindo | FHGO 416; examined |
| Ecuador | Cañar | Hidroeléctrica Ocaña | ELECAUSTRO 2019 |
| Ecuador | Cañar | Huatacón | Reptiles of Ecuador book database |
| Ecuador | Chimborazo | Hostería SantVal | Reptiles of Ecuador book database |
| Ecuador | Chimborazo | Huigra | MZUTI 5395; examined |
| Ecuador | Chimborazo | Pallatanga* | Günther 1859 |
| Ecuador | Chimborazo | Puente sobre el Río Chimbo | Torres-Carvajal 2007 |
| Ecuador | Chimborazo | Recinto Sacramento | Torres-Carvajal 2007 |
| Ecuador | Chimborazo | Sacramento | Photo by David Salazar |
| Ecuador | Chimborazo | Vía Huigra–El Triunfo | MZUTI 5397; examined |
| Ecuador | Cotopaxi | El Jardín de los Sueños | Photo by Christophe Pellet |
| Ecuador | Cotopaxi | La Maná | Torres-Carvajal 2007 |
| Ecuador | El Oro | Buena Vista | Cadle 1991 |
| Ecuador | El Oro | Buena Vista, 7 km SE of | Torres-Carvajal 2005 |
| Ecuador | El Oro | Buenaventura Biological Reserve | Yánez-Muñóz et al. 2019 |
| Ecuador | El Oro | Casacay | iNaturalist; photo examined |
| Ecuador | El Oro | Cascadas de Manuel | Yánez-Muñóz et al. 2019 |
| Ecuador | El Oro | Lote Tituana | Reptiles of Ecuador book database |
| Ecuador | El Oro | Machala | USNM 200957; VertNet |
| Ecuador | El Oro | Machala, 7 km SSE of | Torres-Carvajal 2005 |
| Ecuador | El Oro | Pasaje | Torres-Carvajal 2007 |
| Ecuador | El Oro | Pasaje, 15 km E of | Torres-Carvajal 2007 |
| Ecuador | El Oro | Pasaje, 2 km S of | Torres-Carvajal 2007 |
| Ecuador | El Oro | Piñas | Torres-Carvajal 2007 |
| Ecuador | El Oro | Remolinos | Yánez-Muñóz et al. 2019 |
| Ecuador | El Oro | Río Jubones | AMNH 21944; VertNet |
| Ecuador | El Oro | Road Santa Rosa-Chonta | AMNH 22121; VertNet |
| Ecuador | El Oro | San Jacinto de Chimborazo | iNaturalist; photo examined |
| Ecuador | El Oro | Santa Ana | iNaturalist; photo examined |
| Ecuador | El Oro | Santa Rosa | Torres-Carvajal 2007 |
| Ecuador | El Oro | Satayán, 2 km E of | iNaturalist; photo examined |
| Ecuador | El Oro | Tahuín | Yánez-Muñóz et al. 2019 |
| Ecuador | Esmeraldas | Aguacate | Vásquez et al. 2005 |
| Ecuador | Esmeraldas | Atacames | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Caimito | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Esmeraldas, 13 km S and 8 km W | KU 142697; VertNet |
| Ecuador | Esmeraldas | Esmeraldas, 5 km E of | Cadle 1991 |
| Ecuador | Esmeraldas | Galera, 3 km SW of | iNaturalist; photo examined |
| Ecuador | Esmeraldas | La Unión de Atacames | Torres-Carvajal 2007 |
| Ecuador | Esmeraldas | Montalvo | MHNG 2438.006 |
| Ecuador | Esmeraldas | Playa Escondida | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Quingüe | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Río Esmeraldas | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Río Tiaone | EPN 5906; examined |
| Ecuador | Esmeraldas | Same | Torres-Carvajal 2007 |
| Ecuador | Esmeraldas | Tonchigüe | Torres-Carvajal et al. 2006 |
| Ecuador | Esmeraldas | Tonsupa, 6 km E of | Torres-Carvajal 2000 |
| Ecuador | Guayas | Balzar | Torres-Carvajal 2000 |
| Ecuador | Guayas | Bastión Popular | iNaturalist; photo examined |
| Ecuador | Guayas | Bosque Protector La Prosperina | iNaturalist; photo examined |
| Ecuador | Guayas | Casas Viejas | Salvatierra et al. 2010 |
| Ecuador | Guayas | Cerrito de los Morreños | Nacipucha Quintero 2014 |
| Ecuador | Guayas | Cerro Blanco Protected Forest | iNaturalist; photo examined |
| Ecuador | Guayas | Cerro de Hayas | This work, Fig. 1 |
| Ecuador | Guayas | Cerro Paraíso | iNaturalist; photo examined |
| Ecuador | Guayas | El Empalme | USNM 200996; VertNet |
| Ecuador | Guayas | El Empalme, 21 km SW of | Torres-Carvajal 2007 |
| Ecuador | Guayas | El Morro | Saeteros Gallardo 2014 |
| Ecuador | Guayas | El Triunfo | Photo by Juan Carlos Sánchez |
| Ecuador | Guayas | El Triunfo, 7 km E of | KU 164170; VertNet |
| Ecuador | Guayas | Estación Experimental Cuatro Hermanitos | Torres-Carvajal 2005 |
| Ecuador | Guayas | Estero de Soledad | Torres-Carvajal 2005 |
| Ecuador | Guayas | Fuerte Huancavilca | iNaturalist; photo examined |
| Ecuador | Guayas | Guayaquil | Torres-Carvajal 2007 |
| Ecuador | Guayas | Hacienda San Miguel | USNM 200985; VertNet |
| Ecuador | Guayas | Isla Puná, Subida Alta | Navarrete 2011 |
| Ecuador | Guayas | Isla Santay | Photo by Eduardo Zabala |
| Ecuador | Guayas | La Resistencia, 6 km SE of | iNaturalist; photo examined |
| Ecuador | Guayas | Lago PARCON | iNaturalist; photo examined |
| Ecuador | Guayas | Las Piedras | iNaturalist; photo examined |
| Ecuador | Guayas | Manglares Churute Ecological Reserve | Amanda Quezada, personal observation |
| Ecuador | Guayas | Milagro | Torres-Carvajal 2007 |
| Ecuador | Guayas | Milagro, 5 km E of | Torres-Carvajal 2007 |
| Ecuador | Guayas | Naranjal | iNaturalist; photo examined |
| Ecuador | Guayas | Papagayo Protected Forest | García Aguilera 2017 |
| Ecuador | Guayas | Peñón del Río | Ramírez-Jaramillo et al. 2020 |
| Ecuador | Guayas | Quinta Sandoval | iNaturalist; photo examined |
| Ecuador | Guayas | Río Daule | MHNG 2438.062; collection database |
| Ecuador | Guayas | Río Taura | iNaturalist; photo examined |
| Ecuador | Guayas | Villa Nueva | GBIF |
| Ecuador | Imbabura | Apuela | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Apuela, 1 km E of | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Apuela, 2 km W of | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Intag | Photo by Peter Joost |
| Ecuador | Imbabura | Peñaherrera, 1 km SW of | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Peñaherrera, 10 km S of | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Peñaherrera, 3 km SW of | Torres-Carvajal 2007 |
| Ecuador | Imbabura | Río Apuela, 2 km NE of | Torres-Carvajal 2005 |
| Ecuador | Los Rios | Hostería El Senor de los Caballos | Reptiles of Ecuador book database |
| Ecuador | Los Ríos | Bosque Protector Pedro Franco Dávila | Cruz & Sánchez 2016 |
| Ecuador | Los Ríos | Centro Científico Río Palenque | Torres-Carvajal 2000 |
| Ecuador | Los Ríos | Hacienda El Triunfo, ca. 30 km N Vinces | Torres-Carvajal 2005 |
| Ecuador | Los Ríos | Hacienda La Clementina | MHNG 1117.009; collection database |
| Ecuador | Los Ríos | Jauneche | Torres-Carvajal 2007 |
| Ecuador | Los Ríos | Jauneche, 1 km E of | Torres-Carvajal 2007 |
| Ecuador | Los Ríos | Macul | MZUA.RE.0162; examined |
| Ecuador | Los Ríos | Pacalori | MZUA.RE.0162; examined |
| Ecuador | Los Ríos | Patricia Pilar | Torres-Carvajal 2000 |
| Ecuador | Los Ríos | Quevedo | Torres-Carvajal 2007 |
| Ecuador | Los Ríos | Reserva Forestal Cerro Samama | Yánez-Muñoz et al. 2016 |
| Ecuador | Los Ríos | San Francisco | iNaturalist; photo examined |
| Ecuador | Los Ríos | Ventanas | Torres-Carvajal 2007 |
| Ecuador | Los Ríos | Vinces | This work, Fig. 1 |
| Ecuador | Manabí | Agua Blanca, 4 km SE of | iNaturalist; photo examined |
| Ecuador | Manabí | Bosque Seco Lalo Loor | iNaturalist; photo examined |
| Ecuador | Manabí | Cabo Pasado | Torres-Carvajal 2007 |
| Ecuador | Manabí | Cabuyal | Reptiles of Ecuador book database |
| Ecuador | Manabí | Calceta, 2 km SW of | iNaturalist; photo examined |
| Ecuador | Manabí | Calceta, 4 km W of | Torres-Carvajal 2007 |
| Ecuador | Manabí | Cantalapiedra | Salvatierra et al. 2014 |
| Ecuador | Manabí | Cerro San Sebastián | Cisneros-Heredia et al. 2021 |
| Ecuador | Manabí | Chone | MNHG 2438.061; collection database |
| Ecuador | Manabí | El Limón | Maldonado Vásquez 2017 |
| Ecuador | Manabí | Hacienda Siberia | Hamilton et al. 2014 |
| Ecuador | Manabí | Hostería Chirije | iNaturalist; photo examined |
| Ecuador | Manabí | Jama Campay | Reptiles of Ecuador book database |
| Ecuador | Manabí | Jipijapa, 12 km NNE of | Torres-Carvajal 2007 |
| Ecuador | Manabí | Junín | Torres-Carvajal 2007 |
| Ecuador | Manabí | La Crespa | iNaturalist; photo examined |
| Ecuador | Manabí | Los Frailes | Reptiles of Ecuador book database |
| Ecuador | Manabí | Los Senderos de Tachila | Photo by Tina Swan |
| Ecuador | Manabí | Machalilla National Park | Almendáriz & Carr 2011 |
| Ecuador | Manabí | Pacoche Lodge | Reptiles of Ecuador book database |
| Ecuador | Manabí | Piedra Larga, 2 km S of | iNaturalist; photo examined |
| Ecuador | Manabí | Playa Dorada | Reptiles of Ecuador book database |
| Ecuador | Manabí | Playa Dorada | Reptiles of Ecuador book database |
| Ecuador | Manabí | Puerto Rico | Torres-Carvajal 2007 |
| Ecuador | Manabí | Punta Prieta | Hamilton et al. 2014 |
| Ecuador | Manabí | Rancho San Juan | Maldonado Vásquez 2017 |
| Ecuador | Manabí | Reserva Biológica Cerro Seco | This work, Fig. 1 |
| Ecuador | Manabí | Reserva Jama Coaque | Steinke 2016 |
| Ecuador | Manabí | Río Ayampe | Reptiles of Ecuador book database |
| Ecuador | Manabí | Río Chone | iNaturalist; photo examined |
| Ecuador | Manabí | Río Jama | Photo by Lisa Brunetti |
| Ecuador | Manabí | San Clemente, 2 km N of | Torres-Carvajal 2007 |
| Ecuador | Manabí | San Vicente, 27 km N of | Torres-Carvajal 2007 |
| Ecuador | Manabí | San Vicente, 32 km N of | Torres-Carvajal 2007 |
| Ecuador | Manabí | San Vicente, 9 km N of | Torres-Carvajal 2007 |
| Ecuador | Manabí | Three Forests Trail | Photo by Ryan Lynch |
| Ecuador | Manabí | Tito Santos Biological Reserve | Almendariz et al. 2011 |
| Ecuador | Manabí | Vía Pedernales–Cojimíes | Reptiles of Ecuador book database |
| Ecuador | Manabí | Vicinity of Refinería del Pacifíco | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Calacalí, 12 km N of | iNaturalist; photo examined |
| Ecuador | Pichincha | Chavezpamba | iNaturalist; photo examined |
| Ecuador | Pichincha | Sector Infiernillo | Online multimedia |
| Ecuador | Santa Elena | Comuna Atahualpa | Rodríguez Reyes 2015 |
| Ecuador | Santa Elena | Dos Mangas | Salvatierra et al. 2014 |
| Ecuador | Santa Elena | Dos Mangas, 5 km E of | iNaturalist; photo examined |
| Ecuador | Santa Elena | Dos Ríos | iNaturalist; photo examined |
| Ecuador | Santa Elena | Monte Verde | Ramírez-Jaramillo et al. 2018 |
| Ecuador | Santa Elena | Reserva Las Balsas | This work, Fig. 1 |
| Ecuador | Santo Domingo de los Tsáchilas | El Esfuerzo | iNaturalist; photo examined |