Published June 5, 2022. Updated November 23, 2023. Open access. Peer-reviewed.

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Yellow-throated Stream-Lizard (Gelanesaurus flavogularis)

Reptiles of Ecuador | Sauria | Gymnophthalmidae | Gelanesaurus flavogularis

English common name: Yellow-throated Stream-Lizard.

Spanish common names: Lagartija ribereña de garganta amarilla, lagartija payaso de garganta amarilla.

Recognition: ♂♂ 15.4 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=6.5 cm. ♀♀ 17.8 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=7.5 cm..1 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 slightly compressed tail, and black ring around the nostril.1,2 The Yellow-throated Stream-Lizard (G. flavogularis) can be distinguished from its only known Ecuadorian congener (G. cochranae) by having homogeneous dorsal longitudinal rows of tubercles closely approaching the posterior part of head (irregular, heterogeneous, and not so close to posterior part of head in in G. cochranae). Gelanesaurus flavogularis can be further differentiated from its congener based on the presence of a well-defined white throat patch, absence of dorsolateral cream spots, and no vertical subocular line in males (Fig. 1).3 Adult males of G. flavogularis differ from females by having a broader head and a more contrasting coloration consisting of a light brown dorsum and a white or yellow throat outlined by a black border. In most females the dorsum is uniformly dark brown and the throat is dark brown (Fig. 1).1

Figure showing variation among individuals of Gelanesaurus flavogularis

Figure 1: Individuals of Gelanesaurus flavogularis from Ecuador: Pacto Sumaco, Napo province (); Narupa Reserve, Napo province (); Tzarentza, Pastaza province (). j=juvenile.

Natural history: Gelanesaurus flavogularis is a diurnal, stream-dwelling lizard that occurs in high densities in riparian habitats within well-preserved evergreen foothill forests. During the day, Yellow-throated Stream-Lizards are active on leaf-litter, rocks, and small understory vegetation, usually along streams or on flooded areas of the forest.35 At night, they roost on shrubs, ferns, herbs, and twigs 10–160 cm above the ground along streams and small rivers.1,3,6 Stream lizards in general are capable of biting as well as shedding the tail as methods of defense and escape.3

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..5 Gelanesaurus flavogularis is listed in this category because the species is widely distributed, present in large protected areas, and its habitat is still largely intact. Based on the most recent maps of vegetation cover of the Amazon basin,7 the majority (~71%) of the species’ forest habitat in Ecuador is still standing. The most important threat to the long-term survival of the species is habitat destruction mostly due to mining and the expansion of the agricultural frontier.8

Distribution: Gelanesaurus flavogularis is distributed along the Amazonian foothills of the Andes of eastern Ecuador (Fig. 2) and northwestern Peru. Along the southern slopes of Sumaco Volcano, this species is known to co-occur with G. cochranae.

Distribution of Gelanesaurus flavogularis in Ecuador

Figure 2: Distribution of Gelanesaurus flavogularis in Ecuador. The star corresponds to the type locality: Narupa Biological Reserve, Napo 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.2 The specific epithet flavogularis comes from the Latin words flavus (=yellowish) and gularis (=throat).1

See it in the wild: Yellow-throated 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 Narupa Reserve, Río Anzu Reserve, and Río Zuñac Reserve.

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

Special thanks to Cheryl Vogt for symbolically adopting the Yellow-throated Stream-Lizard and helping bring the Reptiles of Ecuador book project to life.

Click here to adopt a species.

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) Yellow-throated Stream-Lizard (Gelanesaurus flavogularis). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/BLIO7320

Literature cited:

  1. 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
  2. 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
  3. Field notes, Reptiles of Ecuador book project.
  4. 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.
  5. Yánez-Muñoz MH (2021) Gelanesaurus flavogularis. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2021-3.RLTS.T89929298A89929301.en
  6. 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.
  7. MapBiomas Amazonía (2022) Mapeo anual de cobertura y uso del suelo de la Amazonía. Available from:
  8. Chicaiza G (2010) El enclave minero de la Cordillera del Cóndor. Acción Ecológica, Quito, 39 pp.

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

EcuadorAzuaySopladoraMZUA.RE.0032; examined
EcuadorMorona SantiagoÁrea Protegida Río Negro SopladoraFrenkel & Rodas 2017
EcuadorMorona SantiagoBosque Protector AbanicoLozano & Medranda 2008
EcuadorMorona SantiagoCerro Pan de AzúcarFang et al. 2020
EcuadorMorona SantiagoChiguazaAltamirano et al. 2014
EcuadorMorona SantiagoComunidad Shuar Kunkuk, 3 km SE ofFang et al. 2020
EcuadorMorona SantiagoEl GuabiMZUA.RE.0176; examined
EcuadorMorona SantiagoEl RosarioFang et al. 2020
EcuadorMorona SantiagoMera, 5 km S ofiNaturalist; photo examined
EcuadorMorona SantiagoParque Nacional SangayBrito & Almendariz 2013
EcuadorMorona SantiagoPuchimiFang et al. 2020
EcuadorMorona SantiagoSan Juan BoscoMZUA.RE.0221; examined
EcuadorMorona SantiagoSardinayacuFang et al. 2020
EcuadorMorona SantiagoSiete Iglesias ReserveJungle Dave's Tours
EcuadorMorona SantiagoYukutaisFang et al. 2020
EcuadorNapoEstación de Bombeo SarayacuFang et al. 2020
EcuadorNapoNarupa Reserve*Altamirano et al. 2014
EcuadorNapoPacto SumacoThis work; Fig. 1
EcuadorNapoReserva Colonso ChalupasMármol–Guijarro 2020
EcuadorNapoReserva WayraiNaturalist; photo examined
EcuadorNapoRío PucunoPhoto by Andy Proaño
EcuadorNapoSendero abajo CocodrilosReptiles of Ecuador book database
EcuadorNapoWild Sumaco Wildlife SanctuaryCamper et al. 2021
EcuadorPastazaAlpayacuUzzell 1966
EcuadorPastazaCascada Las LajasiNaturalist; photo examined
EcuadorPastazaMeraBurt & Burt 1931
EcuadorPastazaOglán AltoUSNM 196113; VertNet
EcuadorPastazaReserva TamandúaReptiles of Ecuador book database
EcuadorPastazaRío Challuwa YakuZurita 2015
EcuadorPastazaRío ShilcayacuUSNM 196112; VertNet
EcuadorPastazaRío VillanoUSNM 196119; VertNet
EcuadorPastazaSumak Kawsay In SituBentley et al. 2021
EcuadorPastazaTzarentzaThis work; Fig. 1
EcuadorTungurahuaAbitaguaUzzell 1966
EcuadorTungurahuaRío MachayTorres-Carvajal et al. 2016
EcuadorTungurahuaRío NegroAltamirano et al. 2014
EcuadorTungurahuaRío VerdeZurita 2015
EcuadorTungurahuaRio ZuñacAltamirano et al. 2014
EcuadorTungurahuaTrail to Finca El EncantoiNaturalist; photo examined
EcuadorZamora ChinchipeCampamento Fruta del NorteAlmendáriz et al. 2014
EcuadorZamora ChinchipeLa HerraduraAlmendáriz et al. 2014
EcuadorZamora ChinchipeMiazi AltoAlmendáriz et al. 2014
EcuadorZamora ChinchipeQuebrada de MiaziZurita 2015
EcuadorZamora ChinchipeReserva Natural MaycuFang et al. 2020
EcuadorZamora ChinchipeValle del QuimiBetancourt et al. 2018
PeruAmazonasCoangos, RAP7Almendáriz et al. 2014
PeruLoretoCerro de KampankisCatenazzi & Venegas 2016