Published September 26, 2023. Updated January 15, 2024. Open access.

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Blue-bellied Whiptail (Holcosus bridgesii)

Reptiles of Ecuador | Sauria | Teiidae | Holcosus bridgesii

English common name: Blue-bellied Whiptail.

Spanish common name: Lagartija ventriazul.

Recognition: ♂♂ 38.2 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=11.8 cm. ♀♀ 37.7 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=11.1 cm..1,2 The Blue-bellied Whiptail (Holcosus bridgesii) stands as the sole medium-sized, striped, diurnal, and terrestrial lizard in the northern region of the Ecuadorian Chocó rainforest. It differs from other co-occurring lizards by having moveable eyelids, small granular dorsal scales, large squarish ventral scales, and large plate-like scales on the head.3 In its juvenile stage, this lizard presents a blackish dorsum adorned with five vibrant yellow longitudinal lines, accompanied by a cyan tail. As it matures, the dorsum gradually assumes a brown hue, the vivid lines fade, and the tail undergoes a transition from cyan to brown (Fig. 1). The lizard most akin to it in terms of size and coloration is H. septemlineatus, a saurian distinguishable by having a set of plate-like scales on the upper arm.3

Figure showing variation among individuals of Holcosus bridgesii

Figure 1: Individuals of Holcosus bridgesii from Esmeraldas province, Ecuador: Canandé Reserve (); FCAT Reserve (). sa=subadult, j=juvenile.

Natural history: Holcosus bridgesii is a locally abundant terrestrial lizard that inhabits semi-open areas in old growth to moderately disturbed rainforests.4 The species prefers clearings, tree fall areas, forest edges, and rural gardens.5 Blue-bellied Whiptails are active only during hot, sunny hours. They forage frantically, essentially never stopping as they search for food at ground level, never too far from vegetation cover.5 As soon as sunlight wanes, they retreat to their shelters, which include ground holes, leaf litter, log crevices, or man-made structures.5 Their diet is primarily insectivorous,6 but the specific prey items consumed have not been reported. Individuals of H. bridgesii are notably skittish, maintaining a vigilant watch for potential predators. Their primary defense mechanisms are alertness and rapid sprinting, though they may resort to biting or readily shedding the tail if captured.5

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Conservation: Least Concern Believed to be safe from extinction given current circumstances..7 Holcosus bridgesii is listed in this category because the species is widely distributed throughout the Chocoan lowlands, particularly in regions that have remained relatively untouched by deforestation, such as the Colombian Pacific coast. Consequently, the species is considered to be facing no major immediate extinction threats. The main threat to the long-term survival of populations of H. bridgesii is the continuing decline in the extent and quality of its habitat, mostly due to encroaching human activities such as agriculture and cattle grazing. In Ecuador, an estimated ~49% of the habitat of the Blue-bellied Whiptail has been destroyed.8 Therefore, the species may qualify for a threatened category in the near future if this threat is not addressed.

Distribution: Holcosus bridgesii is distributed throughout the Chocoan lowlands of western Colombia and northwestern Ecuador (Fig. 2).

Distribution of Holcosus bridgesii in Ecuador

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

Etymology: The generic name Holcosus is probably derived from the Greek word holkos (a kind of grain). It may refer to the many grain-like keeled scales on the head of lizards of this genus. The specific epithet bridgesii honors Robert Bridges, Professor of Chemistry in the Philadelphia College of Pharmacy, and an active member of the Academy of Natural Sciences.9

See it in the wild: Blue-bellied Whiptails are virtually guaranteed sightings within their distribution range in Ecuador, especially forest-edge situation in Canandé Reserve and Bilsa Biological Reserve. These jittery reptiles can be readily observed running on the forest floor along forest borders during warm, sunny days.

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

Photographer: Jose VieirabAffiliation: Tropical Herping (TH), Quito, Ecuador.,cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2024) Blue-bellied Whiptail (Holcosus bridgesii). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/NABK1655

Literature cited:

  1. Harvey MB, Ugueto GN, Gutberlet Jr RL (2012) Review of teiid morphology with a revised taxonomy and phylogeny of the Teiidae (Lepidosauria: Squamata). Zootaxa 3459: 1–156. DOI: 10.11646/zootaxa.3459.1.1
  2. Barbour T, Noble GK (1915) A revision of the lizards of the genus Ameiva. Bulletin of the Museum of Comparative Zoology, Harvard University 59: 417–479.
  3. Peters JA (1964) The lizard genus Ameiva in Ecuador. Bulletin of the Southern California Academy of Sciences 63: 113–127.
  4. Urbina JN, Londoño MC (2003) Distribución de la comunidad de herpetofauna asociada a cuatro áreas con diferente grado de perturbación en la Isla Gorgona, Pacifico colombiano. Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales 102: 105–113.
  5. Field notes, Reptiles of Ecuador book project.
  6. Castro-Herrera F, Valencia-Aguilar A, Villaquirán-Martínez DF (2012) Diversidad de anfibios y reptiles del Parque Nacional Natural Isla Gorgona. Universidad del Valle, Cali, 112 pp.
  7. Cisneros-Heredia D, Brito J, Yánez-Muñoz M (2017) Holcosus bridgesii. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2017-2.RLTS.T44579564A44579573.en
  8. MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
  9. Cope ED (1868) Sixth contribution to the herpetology of tropical America. Proceedings of the American Philosophical Society 20: 305–313.

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

ColombiaNariñoBoca del CurayHarvey et al. 2012
ColombiaNariñoBosque del AcueductoPinto-Erazo et al. 2020
ColombiaNariñoCabo ManglaresHiguera Rojas et al. 2021
ColombiaNariñoDirección General Marítima (DIMAR)Pinto-Erazo et al. 2020
ColombiaNariñoEl DivisoPhoto by Carlos Luna
ColombiaNariñoEl MiraCalderón et al. 2023
ColombiaNariñoEl MorroHarvey et al. 2012
ColombiaNariñoEl PalmichalPinto-Erazo et al. 2020
ColombiaNariñoEstación Mar AgrícolaPinto-Erazo et al. 2020
ColombiaNariñoIsla del GalloPinto-Erazo et al. 2020
ColombiaNariñoLa PrimaveraPinto-Erazo et al. 2020
ColombiaNariñoLlorenteiNaturalist; photo examined
ColombiaNariñoReserva La NutriaiNaturalist; photo examined
ColombiaNariñoReserva Natural El PangániNaturalist; photo examined
ColombiaNariñoRío MatajeHarvey et al. 2012
ColombiaNariñoTangareal del MiraHarvey et al. 2012
ColombiaNariñoTumacoiNaturalist; photo examined
ColombiaNariñoUniversidad Nacional de Colombia, Sede NariñoPinto-Erazo et al. 2020
EcuadorCarchiChinambíiNaturalist; photo examined
EcuadorCarchiDestacamento MilitarYánez-Muñoz 2009
EcuadorEsmeraldasBilsa Biological ReserveOrtega-Andrade et al. 2010
EcuadorEsmeraldasCaimitoReptiles of Ecuador book database
EcuadorEsmeraldasCamaronesDHMECN 451; examined
EcuadorEsmeraldasCanandé Biological ReserveThis work; Fig. 1
EcuadorEsmeraldasCerro ZapalloiNaturalist; photo examined
EcuadorEsmeraldasDurangoAndrango 2019
EcuadorEsmeraldasDurango, 3.5 km W ofAndrango 2019
EcuadorEsmeraldasEl AguacateVázquez et al. 2005
EcuadorEsmeraldasEl PlacerUSNM 152440; VertNet
EcuadorEsmeraldasEstero AnchoDHMECN 448; examined
EcuadorEsmeraldasEstero ChipaVázquez et al. 2005
EcuadorEsmeraldasEstero InésVásquez et al. 2005
EcuadorEsmeraldasGualpíMorales 2004
EcuadorEsmeraldasItapoa ReserveReptiles of Ecuador book database
EcuadorEsmeraldasJeyambiMorales 2004
EcuadorEsmeraldasLa EsperanzaDHMECN 443; examined
EcuadorEsmeraldasLa Lagartera, near mouth of CaoniUIMNH 54309; collection database
EcuadorEsmeraldasLa PierinaiNaturalist; photo examined
EcuadorEsmeraldasLagartoAndrango 2019
EcuadorEsmeraldasLote EscobarYanez-Muñoz 2005
EcuadorEsmeraldasLote QuijanoYanez-Muñoz 2005
EcuadorEsmeraldasLote RoseroReptiles of Ecuador book database
EcuadorEsmeraldasLote SalvadoresThis work; Fig. 1
EcuadorEsmeraldasLote VentanasYánez-Muñoz 2005
EcuadorEsmeraldasPajonalMorales 2004
EcuadorEsmeraldasPlaya de OroiNaturalist; photo examined
EcuadorEsmeraldasPulúnBurt & Burt 1931
EcuadorEsmeraldasQuingueAndrango 2019
EcuadorEsmeraldasQuinindé, 6 km N ofKU 152706; VertNet
EcuadorEsmeraldasRío BalsalitoUSNM 193284; VertNet
EcuadorEsmeraldasRío BogotáUSNM 193253; VertNet
EcuadorEsmeraldasRío CachabiUSNM 193285; VertNet
EcuadorEsmeraldasRío CanandéiNaturalist; photo examined
EcuadorEsmeraldasSan LorenzoHerpmapper record 168885
EcuadorEsmeraldasSan Lorenzo, 20 km S ofMCZ 80965; VertNet
EcuadorEsmeraldasSan MateoHarvey et al. 2012
EcuadorEsmeraldasSan Miguel de CayapasAndrango 2019
EcuadorEsmeraldasTerminal Marítimo OCPValencia & Garzón 2011
EcuadorEsmeraldasTundaloma LodgeReptiles of Ecuador book database
EcuadorEsmeraldasZapallo GrandePeters 1964
EcuadorImbaburaLitaUSNM 201512; VertNet
EcuadorImbaburaPalma RealUSNM 193246; VertNet
EcuadorImbaburaParambaMNHN 1898.296; collection database
EcuadorManabíGuanábanasiNaturalist; photo examined
EcuadorManabíReserva Ecológica Mache-ChinduliNaturalist; photo examined
EcuadorPichinchaCelicaiNaturalist; photo examined
EcuadorPichinchaHostería Selva VirgenThis work
EcuadorPichinchaKapari LodgeReptiles of Ecuador book database
EcuadorPichinchaLower MashpiReptiles of Ecuador book database
EcuadorPichinchaManduriacuPhoto by Ryan Lynch
EcuadorPichinchaMilpe Bird SanctuaryReptiles of Ecuador book database
EcuadorPichinchaMindoiNaturalist; photo examined
EcuadorPichinchaPuerto QuitoDHMECN 452; examined
EcuadorPichinchaPuerto Quito–GolondrinasReptiles of Ecuador book database
EcuadorPichinchaRío CaoniUSNM 193283; Vertnet
EcuadorPichinchaRío Silanche Bird SanctuaryPhoto by Tom Murray
EcuadorSanto Domingo de los TsáchilasRío Blanco, below mouth of Río ToachiPeters 1964