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Olive Forest-Racer (Dendrophidion dendrophis)
Reptiles of Ecuador | Serpentes | Colubridae | Dendrophidion dendrophis
English common names: Olive Forest-Racer, Tawny Forest Racer.
Spanish common name: Corredora selvática olivácea.
Recognition: ♂♂ 114.2 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=66.8 cm. ♀♀ 118.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=69.3 cm..1–5 Dendrophidion dendrophis can be identified from all other snakes in the Ecuadorian Amazon by presenting a combination of keeled dorsal scales arranged in 17 rows at mid-body, dark crossbands with embedded pale ocelli (Fig. 1), and conspicuously large eyes.1–3 The interstitial skin is yellow, evident when the snake inflates the neck.4 This species differs from Drymobius rhombifer by presenting straight, transverse bars instead of ovoid blotches.2 From the juveniles of Chironius fuscus, it differs in having keeled dorsal scales.1–3
Figure 1: Individuals of Dendrophidion dendrophis: Jatun Sacha Biological Reserve, Napo province, Ecuador (); Leticia, Amazonas state, Colombia (). j=juvenile.
Natural history: Dendrophidion dendrophis is a terrestrial snake that inhabits old-growth to heavily disturbed rainforests. The species also tolerates forest-edge situations, but seems to be absent from pastures and other entirely deforested habitats.4 Olive Forest-Racers are diurnal and more likely to be active during sunny days. The majority of their activity occurs at ground level but individuals may occasionally be spotted on low vegetation.4,6 They can also be seen crossing roads and trails or swimming across bodies of water, including major Amazonian rivers.4,6 At night, they roost on low (within 2 m from the ground) understory vegetation.2–5 These snakes are specialized on feeding on frogs,5 which are located visually through a combination of sit-and-wait and active chasing strategies.1,4 The Forest-Racer, when cornered, subtly inflates its neck, opens the mouth aggressively, and strikes.6 Its tail is long, fragile, and breaks off easily when grabbed by a predator, enabling the escape and survival of the snake.5,7 The clutch size in this species consists of 4–6 eggs.2,4,5 Breeding is presumed to occur year-round.5
Conservation: Least Concern Believed to be safe from extinction given current circumstances..8 Dendrophidion dendrophis is listed in this category primarily because the species is widely distributed, occurs in protected areas, and is able to tolerate some degree of habitat disturbance so long as forest remain. Although little is known about threats to this species, deforestation and the decline in the number of anuran prey due to pollution and emerging diseases could have a negative localized impact on some populations.
Distribution: Dendrophidion dendrophis is widespread throughout the Amazon rainforest Brazil, Peru, Ecuador (Fig. 2), Colombia, Suriname, Guyana, French Guyana and Venezuela.
Figure 2: Distribution of Dendrophidion dendrophis in Ecuador. See Appendix 1 for a complete list of the presence localities included in the map.
Etymology: The genus name Dendrophidion comes from the Greek words dendron (=tree) and ophidion (=snake).9 The specific epithet dendrophis has the same etymological origin as the genus name.
See it in the wild: Prime locations for the Olive Forest-Racer include Yasuní Scientific Station and Jatun Sacha Biological Reserve, where the snakes are most easily spotted sleeping on low vegetation along forest trails at night.
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) Olive Forest-Racer (Dendrophidion dendrophis). 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/BKUM8702
Literature cited:
- Lieb CS (1988) Systematic status of the Neotropical snakes Dendrophidion dendrophis and D. nuchalis. Herpetologica 44: 162–175.
- Duellman WE (1978) The biology of an equatorial herpetofauna in Amazonian Ecuador. Publications of the Museum of Natural History, University of Kansas 65: 1–352.
- Dixon JR, Soini P (1986) The reptiles of the upper Amazon Basin, Iquitos region, Peru. Milwaukee Public Museum, Milwaukee, 154 pp.
- Martins M, Oliveira ME (1998) Natural history of snakes in forests of the Manaus region, Central Amazonia, Brazil. Herpetological Natural History 6: 78–150.
- Da Costa Prudente AL, Maschio GF, Yamashina CE, Santos-Costa MC (2007) Morphology, reproductive biology and diet of Dendrophidion dendrophis (Schlegel, 1837) (Serpentes, Colubridae) in Brazilian Amazon. South American Journal of Herpetology 2: 53–58.
- Field notes, Reptiles of Ecuador book project.
- Natera-Mumaw M (2008) Nuevos registros geográficos y notas bioecológicas de Dendrophidion dendrophis (Schlegel, 1837) y Dendrophidion nuchale (Peters, 1863) (Serpentes: Colubridae) en Venezuela, con comentarios sobre la taxonomía de Dendrophidion nuchale. Herpetotropicos 4: 11–16.
- Ines Hladki A, Ramírez Pinilla M, Renjifo J, Urbina N, Nogueira C, Gagliardi G, Cisneros-Heredia DF, Hoogmoed M, Schargel W, Rivas G (2019) Dendrophidion dendrophis. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2019-3.RLTS.T203286A2762992.en
- 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 Dendrophidion dendrophis in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.
| Country | Province | Locality | Source |
| Colombia | Caquetá | Florencia | Cárdenas Hincapié & Lozano Bernal 2023 |
| Colombia | Putumayo | Reserva La Isla Escondida | iNaturalist; photo examined |
| Colombia | Putumayo | Vereda Palestina | iNaturalist; photo examined |
| Ecuador | Morona Santiago | Chiguaza | USNM 237045; VertNet |
| Ecuador | Morona Santiago | Cusuime | Ortega-Andrade 2010 |
| Ecuador | Morona Santiago | Logroño, 1.4 km N of | Nogueira et al. 2019 |
| Ecuador | Morona Santiago | Macas | Lieb 1988 |
| Ecuador | Morona Santiago | Macuma | iNaturalist; photo examined |
| Ecuador | Morona Santiago | San José de Morona | Lieb 1988 |
| Ecuador | Napo | Ikiam, environs of | iNaturalist; photo examined |
| Ecuador | Napo | Itimandi, 5 km E of | iNaturalist; photo examined |
| Ecuador | Napo | Jatun Sacha Biological Station | This work; Fig. 1 |
| Ecuador | Napo | Pitalala, sendero cañones | Reptiles of Ecuador book database |
| Ecuador | Napo | Río Suno | USNM 237047; VertNet |
| Ecuador | Napo | Suchipakari Lodge | Reptiles of Ecuador book database |
| Ecuador | Napo | Yachana Reserve | Beirne et al. 2013 |
| Ecuador | Orellana | Concepción | USNM 237048; VertNet |
| Ecuador | Orellana | El Coca | MHNG 2397.06; collection database |
| Ecuador | Orellana | Pozo Pindo 11 | Cadena & Brito 2017 |
| Ecuador | Orellana | Reserva Río Bigal | García et al. 2021 |
| Ecuador | Orellana | Río Pucuno | USNM 237049; VertNet |
| Ecuador | Orellana | Tambococha | Nogueira et al. 2019 |
| Ecuador | Orellana | Tiputini Biodiversity Station | iNaturalist; photo examined |
| Ecuador | Orellana | Vía Maxus, km 49 | Nogueira et al. 2019 |
| Ecuador | Orellana | Yasuní Scientific Station | iNaturalist; photo examined |
| Ecuador | Pastaza | Arutam | Nogueira et al. 2019 |
| Ecuador | Pastaza | Cabeceras del Bobonaza | USNM 237054; VertNet |
| Ecuador | Pastaza | Centro Ecológico Zanja Arajuno | Nogueira et al. 2019 |
| Ecuador | Pastaza | Chichirota | USNM 237052; VertNet |
| Ecuador | Pastaza | Comunidad Tarangaro | Nogueira et al. 2019 |
| Ecuador | Pastaza | Juyuintza | Nogueira et al. 2019 |
| Ecuador | Pastaza | Montalvo | Nogueira et al. 2019 |
| Ecuador | Pastaza | Pozo Garza 1 | Nogueira et al. 2019 |
| Ecuador | Pastaza | Río Alpayacu | Lieb 1988 |
| Ecuador | Pastaza | Río Arajuno, headwaters of | USNM 237055; VertNet |
| Ecuador | Pastaza | Río Corrientes | USNM 237053; VertNet |
| Ecuador | Pastaza | Río Huiyayacu | USNM 237056; VertNet |
| Ecuador | Pastaza | Río Pastaza | Lieb 1988 |
| Ecuador | Pastaza | Santa Ana | Nogueira et al. 2019 |
| Ecuador | Pastaza | Sumak Kawsay In Situ | iNaturalist; photo examined |
| Ecuador | Sucumbíos | Brisas del Cuyabeno, 1.6 km N of | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | La Selva Lodge | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | Limoncocha Biological Reserve | Lieb 1988 |
| Ecuador | Sucumbíos | Pitsorie-Setsacco | Nogueira et al. 2019 |
| Ecuador | Sucumbíos | Río Aguarico | USNM 237051; VertNet |
| Ecuador | Sucumbíos | San Pablo de Kantesiya | MHNG 2309.061; collection database |
| Ecuador | Sucumbíos | Santa Cecilia | Duellman 1978 |
| Ecuador | Sucumbíos | Territorio Cofán Dureno | Yánez-Muñoz & Chimbo 2007 |
| Ecuador | Zamora Chinchipe | Bombuscaro | Photo by Darwin Núñez |
| Ecuador | Zamora Chinchipe | Reserva Maycu | Reptiles of Ecuador book database |
| Ecuador | Zamora Chinchipe | Subcuenca del Río Tundayme | Betancourt et al. 2018 |
| Peru | Amazonas | Puerto Galilea | Lieb 1988 |
| Peru | Amazonas | Río Cenepa | Lieb 1988 |
| Peru | Loreto | Campo Andoas | Valqui Schult 2015 |
| Peru | Loreto | Mishana | Lieb 1988 |
| Peru | Loreto | Moropon | MPM H 8919; VertNet |