Published June 6, 2022. Updated November 23, 2023. Open access. Peer-reviewed.

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Cochran’s Stream-Lizard (Gelanesaurus cochranae)

Reptiles of Ecuador | Sauria | Gymnophthalmidae | Gelanesaurus cochranae

English common name: Cochran’s Stream-Lizard.

Spanish common names: Lagartija ribereña de Cochran, lagartija payaso de Cochran.

Recognition: ♂♂ 16.8 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.9 cm. ♀♀ 21.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=9.1 cm..13 Species of the genus Gelanesaurus are easily distinguishable from other leaf-litter lizards in their area of distribution by their stream-dwelling habits, heterogeneous dorsal scales, short and slightly compressed tail, and black ring around the nostril.2,4 The Cochran’s Stream-Lizard (G. cochranae) can be distinguished from its only known Ecuadorian congener (G. flavogularis) by having irregular heterogeneous dorsal longitudinal rows of tubercles not approaching the posterior part of head (homogeneous, forming clear lines, and approaching the posterior part of head in G. flavogularis).1 Gelanesaurus cochranae is further differentiated from its congener by the absence of a well-defined white throat patch and by the presence of dorsolateral cream spots and a vertical subocular line (Fig. 1).3 Adult males of G. cochranae differ from females by having femoral pores, a broader head, and a more contrasting dorsal coloration.2

Figure showing variation among individuals of Gelanesaurus cochranae

Figure 1: Individuals of Gelanesaurus cochranae from Narupa Reserve, Napo province, Ecuador. j=juvenile.

Natural history: Gelanesaurus cochranae is a diurnal stream-dwelling lizard that occurs in high densities in riparian habitats within well-preserved evergreen foothill forests, but may as well be found in secondary forests and agricultural fields nearby forest border.36 During the day, Cochran’s Stream-Lizards are active on leaf-litter, rocks, and small understory vegetation, usually along streams or on flooded areas of the forest.36 At night, they roost on leaves, twigs, and branches 6–170 cm above the ground along streams and rivers.3,7 Stream lizards in general are capable of biting as well as shedding the tail as methods of defense and escape.3 One gravid female found in the foothills of Sumaco Volcano contained two eggs,3 but the real clutch size and nesting sites are not known.

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..6 Gelanesaurus cochranae is listed in this category because the species is widely distributed, present in large protected areas, and occurs in areas that retain the majority of their forest cover. Based on the most recent maps of vegetation cover of the Amazon basin,8 the majority (~78%) of the species’ forest habitat in Ecuador and Colombia is still standing. The most important threat to the long-term survival of the species is habitat destruction mostly due the expansion of the agricultural frontier.

Distribution: Gelanesaurus cochranae is distributed over an area of approximately 8,390 km2 along the Amazonian foothills of the Andes of northeastern Ecuador (Fig. 2) and southern Colombia. Along the southern slopes of Sumaco Volcano, this species is known to co-occur with G. flavogularis.

Distribution of Gelanesaurus cochranae in Ecuador

Figure 2: Distribution of Gelanesaurus cochranae in Ecuador. The star corresponds to the type locality: San José Viejo de Sumaco, Orellana province. See Appendix 1 for a complete list of the presence localities included in the map.

Etymology: The generic name Gelanesaurus, which is derived from the Greek words gelanes (=laughing) and saurus (=lizard), refers to the joker-looking head color pattern of the included species.4 The specific epithet cochranae honors Doris Mable Cochran (1898–1968), American herpetologist and curator of the Smithsonian Institution,1,9 in recognition of her contributions to increasing the knowledge about the herpetofauna of the West Indies and South America.

See it in the wild: Cochran’s Stream-Lizards can be found with almost complete certainty along forest streams in well preserved habitats throughout the species’ area of distribution in Ecuador. Although these lizards are diurnal, they are much more easy to locate at night, as they sleep on the upper surface of bright green leaves where their brownish camouflage is not as effective. In Ecuador, lizards of this species are particularly common in Wild Sumaco Wildlife Sanctuary, Narupa Reserve, and Río Bigal Biological Reserve.

Acknowledgments: Special thanks to Fundación Jocotoco for providing access to Narupa Reserve, where some of the individuals of Gelanesaurus cochranae photographed in this account where located.

Author: Alejandro ArteagaaAffiliation: Khamai Foundation, Quito, Ecuador.

Academic reviewer: Jeffrey D CamperbAffiliation: Department of Biology, Francis Marion University, Florence, USA.

Photographer: Jose VieiracAffiliation: Tropical Herping (TH), Quito, Ecuador.,dAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2023) Cochran’s Stream-Lizard (Gelanesaurus cochranae). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/UUMR3098

Literature cited:

  1. Burt CE, Burt MD (1931) South American lizards in the collection of the American Museum of Natural History. Bulletin of American Museum of Natural History 61: 227–395.
  2. Altamirano-Benavides M, Zaher H, Lobo L, Grazziotin FG, Sales Nunes PM, Rodrigues MT (2013) A new species of lizard genus Potamites from Ecuador (Squamata, Gymnophthalmidae). Zootaxa 3717: 345–358. DOI: 10.11646/zootaxa.3717.3.4
  3. Field notes, Reptiles of Ecuador book project.
  4. Torres-Carvajal O, Lobos SE, Venegas PJ, Chávez G, Aguirre-Peñafiel V, Zurita D, Echevarría LY (2016) Phylogeny and biogeography of the most diverse clade of South American gymnophthalmid lizards (Squamata, Gymnophthalmidae, Cercosaurinae). Molecular Phylogenetics and Evolution 99: 63–75. DOI: 10.1016/j.ympev.2016.03.006
  5. Camper JD, Torres-Carvajal O, Ron SR, Nilsson J, Arteaga A, Knowles TW, Arbogast BS (2021) Amphibians and reptiles of Wildsumaco Wildlife Sanctuary, Napo Province, Ecuador. Check List 17: 729–751.
  6. Cisneros-Heredia DF, Arredondo JC, Velasco J (2016) Gelanesaurus cochranae. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2016-1.RLTS.T177901A44952792.en
  7. Torres-Carvajal O, Pazmiño-Otamendi G, Salazar-Valenzuela D (2019) Reptiles of Ecuador: a resource-rich online portal, with dynamic checklists and photographic guides. Amphibian & Reptile Conservation 13: 209–229.
  8. MapBiomas Amazonía (2022) Mapeo anual de cobertura y uso del suelo de la Amazonía. Available from:
  9. Guayasamin JM, Cisneros-Heredia DF, McDiarmid RW, Peña P, Hutter CR (2020) Glassfrogs of Ecuador: diversity, evolution, and conservation. Diversity 12: 222–285. DOI: 10.3390/d12060222

Appendix 1: Locality data used to create the distribution map of Gelanesaurus cochranae in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used. Asterisk (*) indicates type locality.

ColombiaPutumayoEl Pepino, 10 km W ofKU 169925; VertNet
ColombiaPutumayoMocoaiNaturalist; photo examined
ColombiaPutumayoReserva La Isla EscondidaiNaturalist; photo examined
EcuadorNapoBosque Protector la CascadaFang et al. 2020
EcuadorNapoBuena EsperanzaFang et al. 2020
EcuadorNapoCascada de San RafaelPhoto by Peter Janzen
EcuadorNapoCascadas del Río HollínZurita 2015
EcuadorNapoCentro Comunal ChalliayacuAltamirano et al. 2014
EcuadorNapoCocodrilosFang et al. 2020
EcuadorNapoCordillera del DuéKU 122189
EcuadorNapoEl ChacoiNaturalist; photo examined
EcuadorNapoEstandíAltamirano et al. 2014
EcuadorNapoGuagua SumacoAltamirano et al. 2014
EcuadorNapoHuamaníAltamirano et al. 2014
EcuadorNapoNarupa ReserveAltamirano et al. 2014
EcuadorNapoSaladoiNaturalist; photo examined
EcuadorNapoWild Sumaco Wildlife SanctuaryCamper et al. 2021
EcuadorOrellanaReserva Río BigalFSM 20
EcuadorOrellanaSan Jose Viejo de Sumaco*Burt & Burt 1931
EcuadorSucumbíosLa BarquillaFang et al. 2020
EcuadorSucumbíosProyecto Coca CodoMECN & ENTRIX 2009–2013
EcuadorSucumbíosRosa FloridaZurita 2015