Published September 30, 2023. Updated January 12, 2024. Open access.

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Monitor Tegu (Callopistes flavipunctatus)

Reptiles of Ecuador | Sauria | Teiidae | Callopistes flavipunctatus

English common names: Monitor Tegu, False Monitor, Yellow-spotted Tegu Monitor.

Spanish common names: Tegú varano, falsa iguana.

Recognition: ♂♂ 107.3 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=32.5 cm. ♀♀ 75.9 cmMaximum distance from the snout to the tip of the tail. Snout–vent length=23.0 cm..1,2 Tegus differ from other diurnal and terrestrial lizards by their large size, small granular dorsal scales, subrectangular ventral scales arranged in transverse rows, and large plate-like scales on the head.1,3 Callopistes flavipunctatus can be differentiated from the co-occurring whiptails Holcosus septemlineatus, Medopheos edracanthus and Dicrodon guttulatum by being much larger, lacking stripes, and having supraocular plates encircled by rows of granules.1,3 Adult males differ from females by being more robust and having black-bordered cream ocelli along the flanks (Fig. 1).

Figure showing variation among individuals of Callopistes flavipunctatus

Figure 1: Individuals of Callopistes flavipunctatus from La Ceiba Reserve, Loja province, Ecuador.

Natural history: Callopistes flavipunctatus is a relatively common diurnal lizard that inhabits seasonally dry forests, dry shrublands, deserts, and human-altered habitats like cacao plantations and rural gardens.2,4 Monitor Tegus primarily forage at ground level but occasionally climb bushes and trees.2,4 They are thermophilic, active only during hot, sunny hours, typically from 9 am to 2 pm when air temperatures can reach up to 43.6°C.3 During foraging, they display frantic behavior, continuously searching for food while staying close to vegetation cover.4 As soon as sunlight wanes, they retreat into their shelters, which are burrows dug into the sides of hills and along creeks and roads,5 or tree holes and crevices.4 Ground burrows may vary from simple to complex with multiple entrances, and these shelters can be used for months to endure unfavorable cold periods.2 Their omnivorous diet includes lizards (Dicrodon guttulatum),2,6 snakes (Dendrophidion brunneum,4 Mastigodryas heathii5 and Oxyrhopus fitzingeri7), rodents, birds,2 large insects,8 flowers,5 fruits,2,8 and even chicken bones and raw eggs when available.2 Monitor Tegus 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 their tails if captured.4

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Conservation: Near Threatened Not currently at risk of extinction, but requires some level of management to maintain healthy populations..9 Callopistes flavipunctatus is listed in this category primarily because the species’ habitat is severely fragmented and under pressure from encroaching human activities such as agriculture, cattle grazing, and wild fires.9 The species is also under pressure from vehicular traffic10 and hunting for meat and fat.11 However, C. flavipunctatus is not included in a threatened category because it is widespread and present in protected areas.9

Distribution: Callopistes flavipunctatus is native to the Tumbesian lowlands of southwestern Ecuador and northwestern Peru (Fig. 2).

Distribution of Callopistes flavipunctatus in Ecuador

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

Etymology: The generic name Callopistes is derived from the Greek word kallos (=beauty) and pistos (=genuine),12 and probably refers to the beautiful coloration of the type species of the genus: C. maculatus. The specific epithet flavipunctatus, which comes from the Latin words flavus (=yellow), punctum (=spot), and the suffix -atus (=provided with),12 refers to the yellow-spotted dorsal color pattern.

See it in the wild: Monitor Tegus are almost guaranteed sightings in the warm, rainy season (February to April) in the equatorial dry forest. However, they can also be spotted sporadically throughout the rest of the year. Prime locations for observing these jittery reptiles include Jorupe Reserve and La Ceiba Reserve. Visitors to the dry forest can readily observe the lizards running on the ground near shrubs during warm, sunny days.

Acknowledgments: Special thanks to Jeff Lemm for providing photographs and information on natural history of Callopistes flavipunctatus.

Special thanks to Eric Lichtwardt for symbolically adopting the Monitor Tegu and helping bring the Reptiles of Ecuador book project to life.

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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) Monitor Tegu (Callopistes flavipunctatus). In: Arteaga A, Bustamante L, Vieira J (Eds) Reptiles of Ecuador: Life in the middle of the world. Available from: DOI: 10.47051/OZIK4819

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. Crespo S, Koch C (2015) Notes on natural history and distribution of Callopistes flavipunctatus (Squamata: Teiidae) in northwestern Peru. Salamandra 51: 57–60.
  3. Koch C, Venegas P, Santa Cruz R, Böhme W (2018) Annotated checklist and key to the species of amphibians and reptiles inhabiting the northern Peruvian dry forest along the Andean valley of the Marañón River and its tributaries. Zootaxa 4385: 001–101. DOI: 10.11646/ZOOTAXA.4385.1.1
  4. Field notes, Reptiles of Ecuador book project.
  5. Lemm J, Cueva E (2016) Callopistes flavipunctatus (Yellow-spotted Tegu Monitor): diet and social behavior. Herpetological Review 47: 133–134.
  6. Brennan R (2010) Un estudio ecológico de las lagartijas del valle seco de Buenavista y de los valles húmedos de La Josefina y Salango. Independent Study Project (ISP) Collection, Vermont, 828 pp.
  7. Photo by Omar Aguilar.
  8. Schlüter U (2004) Bemerkungen über Warantejus, Tejovaranus flavipunctatus (Duméril & Bibron, 1839). Sauria 26: 17–21.
  9. Gutiérrez de la Cruz G, Perez J, Quiroz Rodriguez A, Venegas P, Cisneros-Heredia DF (2020) Callopistes flavipunctatus. The IUCN Red List of threatened species. Available from: DOI: 10.2305/IUCN.UK.2020-3.RLTS.T50008337A50008346.en
  10. Hurtado Ordinola LJ (2021) Especies de fauna silvestre muertas por atropellamiento en la carretera Sullana–Lancones, Piura, Perú. BSc thesis, Piura, Universidad Nacional de Piura, 112 pp.
  11. Arbulú López CA, del Carpio Ramos PA, del Carpio Ramos HA, Cabrera Coronado RG, González Casas N (2016) Zootechnical characterization of alligator Callopistes flavipunctatus of Morrope. Research and Cultural Journal 5: 112–124.
  12. 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 Callopistes flavipunctatus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

EcuadorEl OroArenillasMZUA.Re.0185; examined
EcuadorEl OroCabo LampaiNaturalist; photo examined
EcuadorEl OroReserva Militar ArenillasGarzón-Santomaro et al. 2019
EcuadorEl OroRío ArenillasiNaturalist; photo examined
EcuadorLojaCabeza de Toro, 5 km W ofiNaturalist; photo examined
EcuadorLojaCangonamá Chico, pasture nearbyiNaturalist; photo examined
EcuadorLojaEl ChilcoArmijos & Valarezo 2010
EcuadorLojaFinca de pesca Don BernaiNaturalist; photo examined
EcuadorLojaGarzaguachanaiNaturalist; photo examined
EcuadorLojaJorupe ReserveReptiles of Ecuador book
EcuadorLojaLa Ceiba ReserveThis work; Fig. 1
EcuadorLojaLas PampasLemm et al. 2016
EcuadorLojaMacará–SozorangaReptiles of Ecuador book
EcuadorLojaMangahurcoFausto Siavichay, pers. comm.
EcuadorLojaParque Nacional Cerros de AmotapeiNaturalist; photo examined
EcuadorLojaProgresoLemm et al. 2016
EcuadorLojaSabiangoGuerra-Correa 2020
EcuadorLojaTablonpambaiNaturalist; photo examined
PeruAmazonasEl ReposoiNaturalist; photo examined
PeruCajamarcaBellavistaCrespo & Koch 2015
PeruCajamarcaPericoMCZ 18770; VertNet
PeruLambayequeBosque de PómacPhoto by Eric LoPresti
PeruLambayequeCaserío Pueblo NuevoiNaturalist; photo examined
PeruLambayequeChaparriiNaturalist; photo examined
PeruLambayequeChaparri ReserveCrespo & Koch 2015
PeruLambayequeMórropeArbulú et al. 2017
PeruLambayequeOlmes, 20 km NE ofLACM 122812; VertNet
PeruPiuraBatanesCrespo & Koch 2015
PeruPiuraBellavistaBurt & Burt 1931
PeruPiuraCarretera Panamericana, near LobitosiNaturalist; photo examined
PeruPiuraCarretera Sullana–Lancones, km 18Hurtado Ordinola 2021
PeruPiuraCarretera Sullana–Lancones, km 43Hurtado Ordinola 2021
PeruPiuraCarretera Sullana–Lancones, km 64Hurtado Ordinola 2021
PeruPiuraDon DiegoiNaturalist; photo examined
PeruPiuraLobitosHarvey et al. 2012
PeruPiuraPalo BlancoVásquez Calle 2018
PeruPiuraPampas de CiciliaiNaturalist; photo examined
PeruPiuraParachique, 15 km S ofiNaturalist; photo examined
PeruPiuraPiuraiNaturalist; photo examined
PeruPiuraQuebrada GramadalCrespo & Koch 2015
PeruPiuraSuena El AguaiNaturalist; photo examined
PeruPiuraSullana, 10 km S ofiNaturalist; photo examined
PeruPiuraTalaraHarvey et al. 2012
PeruPiuraTalara, 6 km N ofHarvey et al. 2012
PeruPiuraVerdun AltoHarvey et al. 2012
PeruTumbesBellidoiNaturalist; photo examined
PeruTumbesBocapanKU 163760; VertNet
PeruTumbesCabo EsmeraldaiNaturalist; photo examined
PeruTumbesCaserío La AngosturaiNaturalist; photo examined
PeruTumbesColinas de Punta SaliNaturalist; photo examined
PeruTumbesPampa de los CeibosiNaturalist; photo examined
PeruTumbesPampas del Hospital, 3.5 km SE ofPhoto by Thibaud Aronson
PeruTumbesTumbesPhoto by Zarel Martinez
PeruTumbesZarumillaiNaturalist; photo examined
PeruTumbesZorritosiNaturalist; photo examined
PeruTumbesZorritos, 10 km E ofiNaturalist; photo examined