Published September 26, 2023. Updated January 15, 2024. Open access. | Gallery ❯ |
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 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
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).
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: www.reptilesofecuador.com. DOI: 10.47051/NABK1655
Literature cited:
- 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
- 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.
- Peters JA (1964) The lizard genus Ameiva in Ecuador. Bulletin of the Southern California Academy of Sciences 63: 113–127.
- 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.
- Field notes, Reptiles of Ecuador book project.
- 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.
- Cisneros-Heredia D, Brito J, Yánez-Muñoz M (2017) Holcosus bridgesii. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2017-2.RLTS.T44579564A44579573.en
- MAE (2012) Línea base de deforestación del Ecuador continental. Ministerio del Ambiente del Ecuador, Quito, 30 pp.
- 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.
| Country | Province | Locality | Source |
| Colombia | Nariño | Boca del Curay | Harvey et al. 2012 |
| Colombia | Nariño | Bosque del Acueducto | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | Cabo Manglares | Higuera Rojas et al. 2021 |
| Colombia | Nariño | Dirección General Marítima (DIMAR) | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | El Diviso | Photo by Carlos Luna |
| Colombia | Nariño | El Mira | Calderón et al. 2023 |
| Colombia | Nariño | El Morro | Harvey et al. 2012 |
| Colombia | Nariño | El Palmichal | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | Estación Mar Agrícola | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | Isla del Gallo | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | La Primavera | Pinto-Erazo et al. 2020 |
| Colombia | Nariño | Llorente | iNaturalist; photo examined |
| Colombia | Nariño | Reserva La Nutria | iNaturalist; photo examined |
| Colombia | Nariño | Reserva Natural El Pangán | iNaturalist; photo examined |
| Colombia | Nariño | Río Mataje | Harvey et al. 2012 |
| Colombia | Nariño | Tangareal del Mira | Harvey et al. 2012 |
| Colombia | Nariño | Tumaco | iNaturalist; photo examined |
| Colombia | Nariño | Universidad Nacional de Colombia, Sede Nariño | Pinto-Erazo et al. 2020 |
| Ecuador | Carchi | Chinambí | iNaturalist; photo examined |
| Ecuador | Carchi | Destacamento Militar | Yánez-Muñoz 2009 |
| Ecuador | Esmeraldas | Bilsa Biological Reserve | Ortega-Andrade et al. 2010 |
| Ecuador | Esmeraldas | Caimito | Reptiles of Ecuador book database |
| Ecuador | Esmeraldas | Camarones | DHMECN 451; examined |
| Ecuador | Esmeraldas | Canandé Biological Reserve | This work; Fig. 1 |
| Ecuador | Esmeraldas | Cerro Zapallo | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Durango | Andrango 2019 |
| Ecuador | Esmeraldas | Durango, 3.5 km W of | Andrango 2019 |
| Ecuador | Esmeraldas | El Aguacate | Vázquez et al. 2005 |
| Ecuador | Esmeraldas | El Placer | USNM 152440; VertNet |
| Ecuador | Esmeraldas | Estero Ancho | DHMECN 448; examined |
| Ecuador | Esmeraldas | Estero Chipa | Vázquez et al. 2005 |
| Ecuador | Esmeraldas | Estero Inés | Vásquez et al. 2005 |
| Ecuador | Esmeraldas | Gualpí | Morales 2004 |
| Ecuador | Esmeraldas | Itapoa Reserve | Reptiles of Ecuador book database |
| Ecuador | Esmeraldas | Jeyambi | Morales 2004 |
| Ecuador | Esmeraldas | La Esperanza | DHMECN 443; examined |
| Ecuador | Esmeraldas | La Lagartera, near mouth of Caoni | UIMNH 54309; collection database |
| Ecuador | Esmeraldas | La Pierina | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Lagarto | Andrango 2019 |
| Ecuador | Esmeraldas | Lote Escobar | Yanez-Muñoz 2005 |
| Ecuador | Esmeraldas | Lote Quijano | Yanez-Muñoz 2005 |
| Ecuador | Esmeraldas | Lote Rosero | Reptiles of Ecuador book database |
| Ecuador | Esmeraldas | Lote Salvadores | This work; Fig. 1 |
| Ecuador | Esmeraldas | Lote Ventanas | Yánez-Muñoz 2005 |
| Ecuador | Esmeraldas | Pajonal | Morales 2004 |
| Ecuador | Esmeraldas | Playa de Oro | iNaturalist; photo examined |
| Ecuador | Esmeraldas | Pulún | Burt & Burt 1931 |
| Ecuador | Esmeraldas | Quingue | Andrango 2019 |
| Ecuador | Esmeraldas | Quinindé, 6 km N of | KU 152706; VertNet |
| Ecuador | Esmeraldas | Río Balsalito | USNM 193284; VertNet |
| Ecuador | Esmeraldas | Río Bogotá | USNM 193253; VertNet |
| Ecuador | Esmeraldas | Río Cachabi | USNM 193285; VertNet |
| Ecuador | Esmeraldas | Río Canandé | iNaturalist; photo examined |
| Ecuador | Esmeraldas | San Lorenzo | Herpmapper record 168885 |
| Ecuador | Esmeraldas | San Lorenzo, 20 km S of | MCZ 80965; VertNet |
| Ecuador | Esmeraldas | San Mateo | Harvey et al. 2012 |
| Ecuador | Esmeraldas | San Miguel de Cayapas | Andrango 2019 |
| Ecuador | Esmeraldas | Terminal Marítimo OCP | Valencia & Garzón 2011 |
| Ecuador | Esmeraldas | Tundaloma Lodge | Reptiles of Ecuador book database |
| Ecuador | Esmeraldas | Zapallo Grande | Peters 1964 |
| Ecuador | Imbabura | Lita | USNM 201512; VertNet |
| Ecuador | Imbabura | Palma Real | USNM 193246; VertNet |
| Ecuador | Imbabura | Paramba | MNHN 1898.296; collection database |
| Ecuador | Manabí | Guanábanas | iNaturalist; photo examined |
| Ecuador | Manabí | Reserva Ecológica Mache-Chindul | iNaturalist; photo examined |
| Ecuador | Pichincha | Celica | iNaturalist; photo examined |
| Ecuador | Pichincha | Hostería Selva Virgen | This work |
| Ecuador | Pichincha | Kapari Lodge | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Lower Mashpi | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Manduriacu | Photo by Ryan Lynch |
| Ecuador | Pichincha | Milpe Bird Sanctuary | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Mindo | iNaturalist; photo examined |
| Ecuador | Pichincha | Puerto Quito | DHMECN 452; examined |
| Ecuador | Pichincha | Puerto Quito–Golondrinas | Reptiles of Ecuador book database |
| Ecuador | Pichincha | Río Caoni | USNM 193283; Vertnet |
| Ecuador | Pichincha | Río Silanche Bird Sanctuary | Photo by Tom Murray |
| Ecuador | Santo Domingo de los Tsáchilas | Río Blanco, below mouth of Río Toachi | Peters 1964 |