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DOI10.47051/XBAZ9538 Published March 31, 2023. Open access.

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American Crocodile (Crocodylus acutus)

Reptiles of Ecuador | Crocodylia | Crocodylidae | Crocodylus acutus

English common name: American Crocodile.

Spanish common names: Cocodrilo de la costa, caimán aguja.

Recognition: ♂♂ 6.25 mMaximum distance from the snout to the tip of the tail. 1,100 kg ♀♀ 4.4 mMaximum distance from the snout to the tip of the tail..^1,2 The American Crocodile (Crocodylus acutus) is Ecuador’s largest crocodilian. It can be distinguished from the other crocodilian inhabiting the Ecuadorian coastal region (Caiman fuscus) by having a narrow snout, fourth tooth on the lower jaw visible when the mouth is closed (not visible in C. fuscus), and by lacking a bony inter-orbital ridge (Fig. 1).^3–5

Figure 1: Individuals of Crocodylus acutus from Guayas province, Ecuador. sa=subadult, j=juvenile.

Natural history: Crocodylus acutus is an uncommonUnlikely to be seen more than once every few months. species along Ecuador’s coastline. Only in the gulf of Guayaquil it reaches densities of 0.2–0.9 crocodiles/km.^6,7 American Crocodiles are nocturnal and occur in a variety of primarily brackish to hypersaline⁸ aquatic habitats, including coastal mangroves, lagoons, marshes, and tidal sections of rivers.^4,9 They occur in polluted waters⁶ and also wander inland along rivers or into the open sea.^5,9 Movements of up to 76.3 km and 700 km have been reported for juveniles¹⁰ and adults, respectively.¹¹ Average home range is 0.08–11.7 km² and increases with the size of the animal.¹² Individuals prefer to bask on sand beaches and river banks so long as these are not steep.⁵ Juveniles usually remain in the edges of the water bodies, surrounded by floating vegetation or mangrove roots, where they wait in ambush for prey to pass by.⁵ There is a dietary shift from invertebrate to vertebrate prey over the lifetime of C. acutus.⁵ Their diet as juveniles is primarily composed of insects, arachnids, mollusks, crustaceans, and frogs.^3,8,13 The diet in adults also includes crustaceans,^13,14 but in most populations it is based primarily on fish and to a smaller degree on mammals (including marsupials⁸ and dogs¹⁵), birds, turtles (including Lepidochelys olivacea¹⁶ and Rhinoclemmys nasuta¹⁷), iguanas (Iguana iguana),³ snakes,¹⁸ smaller crocodilians (including Caiman fuscus¹⁹ and conspecifics⁸), echinoderms, and fruits.^4,5,15 There are records of American Crocodiles attacking and even killing humans.²⁰

American Crocodiles reach sexual maturity at 8–18 years old or at a length of about 2.3–2.5 m.^5,21 The nesting season in Ecuador is not known but elsewhere it coincides with the annual dry season.^9,22 Males fight with each other to defend territories, which they also maintain by producing loud sounds.^3,5 Females breed once a year⁵ and build simple nests by excavating in soft sand or gravel or by building low mounds.^4,9 These are located ~9–14 m from the water.^22,23 Clutches consist of 9–80 eggs that measure 6.2–7.3 cm in length, weigh 63–140 g, and take 75–90 days to hatch.^5–9,22,23 Temperature during incubation determines the sex of the hatchlings: low and high temperatures produces females and mid-temperatures result in males.^23,24 Flooding of the nests is the main cause of egg mortality.⁵ Hatchlings measure 24–27 cm in total length at birth.^5,8 They remain in groups and communicate acoustically with their siblings and with the mother.⁵ Females aggressively defend the nests and the hatchlings.^3,5 Wild cats, raccoons, birds of prey, vultures, herons, catfish, and ants are known to prey on eggs and neonates.⁵ Caimans (Caiman fuscus) are also known to prey on the juveniles of C. acutus,⁸ but the adults have no reported natural predators. An individual in Venezuela was estimated to be 65 years old.⁸

Conservation: Vulnerable Considered to be facing a high risk of extinction in the mid-term future..²⁵ Although Crocodylus acutus is widely distributed and occurs in protected areas, the species was the subject of overexploitation for decades, particularly between the 1930s and 1970s.^6,26 Uncontrolled large-scale hide hunting was the main driver of the decline,⁶ but so was direct killing,²⁵ and habitat loss and degradation.²⁵ The mangrove ecosystem that is so critical to the survival of the species continues to be transformed into shrimp farms, human settlements, and agricultural areas.²⁷ Crocodylus acutus is now internationally protected and populations in most of the 18 countries where the species occurs appear to be recovering despite decades of overexploitation.⁶ However, recovery appears to be limited or non-existing in Ecuador, where only two presumably stable but severely depleted populations are known.^7,27

Distribution: Crocodylus acutus is the most widely distributed New World crocodilian. It occurs from the southern tip of Florida, along both the Atlantic and Pacific coasts of southern México and Central America to northern South America.⁹ It also occurs in several Caribbean islands.⁹ In Ecuador, populations persist in the gulf of Guayaquil and along the Río Puyango and its tributaries in extreme southwestern Ecuador. Records of C. acutus elsewhere in Ecuador correspond to vagrant or migrating individuals. The species has been recorded at elevations between 0 and 345 m (Fig. 2).

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

Etymology: The name Crocodylus is apparently classical Latin for crocodile and is derived from the Greek word krokodeilos.²⁸ The specific epithet acutus is a Latin word meaning “pointed.”²⁹ The snout of this species is narrower than that of other crocodilians.

See it in the wild: In Ecuador, American Crocodiles can be seen reliably in two protected areas: Manglares El Salado and Reserva Cazaderos. These shy reptiles are most easily found at night by detecting their bright orange eye-shine.

Acknowledgments: Special thanks to Ernesto Arbeláez (Bioparque Amaru) and Ricardo Chiriboga and María Belén Chiriboga (Zoo el Pantanal) for prodiving photographic access to specimens of Crocodylus acutus under their care.

Author: Alejandro Arteaga^aAffiliation: Khamai Foundation, Quito, Ecuador.

Photographer: Jose Vieira^bAffiliation: Tropical Herping (TH), Quito, Ecuador.^,cAffiliation: ExSitu, Quito, Ecuador.

How to cite? Arteaga A (2023) American Crocodile (Crocodylus acutus). 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/XBAZ9538

Literature cited:

1. Platt SG, Rainwater TR, Thorbjarnarson JB, Martin D (2011) Size estimation, morphometrics, sex ratio, sexual size dimorphism, and biomass of Crocodylus acutus in the coastal zone of Belize. Salamandra 47: 179–192.
2. Domínguez-Laso J (2009) Record size for a female Crocodylus acutus in the Grijalva River, Chiapas, Mexico. Crocodile Specialist Group Newsletter 28: 14–15.
3. Savage JM (2002) The amphibians and reptiles of Costa Rica, a herpetofauna between two continents, between two seas. The University of Chicago Press, Chicago, 934 pp.
4. Brazaitis P (1973) The identification of living crocodilians. Scientific Contributions of the New York Zoological Society 58: 59–101.
5. Morales-Betancourt MA, Lasso CA, De La Ossa V J, Fajardo-Patiño A (2013) Biología y conservación de los Crocodylia de Colombia. Serie Editorial Recursos Hidrobiológicos y Pesqueros Continentales de Colombia, Instituto de Investigación de Recursos Biológicos Alexander von Humboldt (IAvH), Bogotá, 335 pp.
6. Carvajal RI, Saavedra M, Alava JJ (2005) Population ecology, distribution and habitat assessment of Crocodylus acutus (Cuvier 1807) in the “Reserva de producción de fauna manglares El Salado” of the Guayaquil Gulf Estuary, Ecuador. Revista de Biología Marina y Oceanografía 40: 141–150.
7. Fernández Porras LM (2018) Línea base de Eretmochelys imbricata y Crocodylus acutus en el Golfo de Guayaquil y el Archipiélago de Jambelí. Ceiba Foundation for Tropical Conservation, Guayaquil, 40 pp.
8. Seijas AE (2011) Los Crocodylia de Venezuela. Experimental de Los Llanos Ezequiel Zamora, Barinas, 281 pp.
9. Thorbjarnarson JB (2010) American Crocodile, Crocodylus acutus. In: Manolis SC, Stevenson C (Eds) Crocodiles: status survey and conservation action plan. Crocodile Specialist Group, Darwin, 46–53.
10. Crespo R, Beauchamp JS, Mazzotti F, Cherkiss MS (2015) Crocodylus acutus (American Crocodile): long distance juvenile movement. Herpetological Review 46: 623–624.
11. Balaguera-Reina SA, Moncada-Jimenez JF, Prada-Quiroga CF, Hernandez-Gonzalez F, Bolaños-Cubillos NW, Farfán-Ardila N, Garcia-Calderón LM, Densmore III LD (2020) Tracking a voyager: mitochondrial DNA analyses reveal mainland-to-island dispersal of an American crocodile (Crocodylus acutus) across the Caribbean. Biological Journal of the Linnean Society 131: 647–655. DOI: 10.1093/biolinnean/blaa121
12. Balaguera-Reina SA, Venegas-Anaya M, Sánchez A, Arbelaez I, Lessios HA, Densmore LD (2016) Spatial ecology of the American Crocodile in a tropical Pacific island in Central America. PLoS ONE 11: e0157152. DOI: 10.1371/journal.pone.0157152
13. Platt SG, Thorbjarnarson JB, Rainwater TR, Martin DR (2013) Diet of the American Crocodile (Crocodylus acutus) in marine environments of Coastal Belize. Journal of Herpetology 47: 1–10.
14. Cervantes JÁ, Charruau P, Cedeño-Vázquez R, Varela BJ, Larsson HCE (2017) Crocodylus acutus (American Crocodile): diet. Herpetological Review 48: 839–840.
15. Platt SG, Chenot-Rose C, Rose V, Rainwater TR (2014) Crocodylus acutus (American Crocodile): frugivory. Herpetological Review 45: 120–121.
16. Escobar-Lasso S, Gil-Fernández M, Sáenz J, Carrillo-Jiménez E, Wong G, Fonseca LG, Gómez-Hoyos DA (2017) Distribution and hotspots of the feeding areas of jaguars on sea turtles at a national park in Costa Rica. Neotropical Biology and Conservation 12: 2–11. DOI: 10.4013/nbc.2017.121.01
17. Medem F (1962) La distribución geográfica y ecología de los Crocodylia y Testudinata en el Departamento del Chocó. Revista de la Academia Colombiana de Ciencias Exactas, Físicas, y Naturales 11: 279–303.
18. Geluso K, Harner MJ (2013) Nerodia clarkii clarkii (Gulf Saltmarsh Watersnake): predation. Herpetological Review 44: 156–157.
19. Medem F (1981) Los Crocodylia de Sur América. Volumen I. Los Crocodylia de Colombia. Colciencias, Bogotá, 354 pp.
20. Pooley S, Siroski PA, Fernandez L, Sideleau B, Ponce-Campos P (2021) Human–crocodilian interactions in Latin America and the Caribbean region. Conservation Science and Practice 3: e351. DOI: 10.1111/csp2.351
21. Briggs-Gonzalez V, Bonenfant C, Basille M, Cherkiss M, Beauchamp J, Mazzotti F (2017) Life histories and conservation of long-lived reptiles, an illustration with the American crocodile (Crocodylus acutus). The Journal of Animal Ecology 86: 1102–1113. DOI: 10.1111/1365-2656.12723
22. Casas-Andreu G (2003) Ecología de la anidación de Crocodylus acutus (Reptilia: Crocodylidae) en la desembocadura del Río Cuitzmala, Jalisco, México. Acta Zoológica Mexicana 89: 111–128.
23. Barragán Lara R, Grajales JG, Martínez Ramírez E (2021) Nest temperature assessment in an American crocodile (Crocodylus acutus) population on the central coast of Oaxaca, Mexico. Journal of Thermal Biology 99: 103012. DOI: 0.1016/j.jtherbio.2021.103
24. Lang JW, Andrews HV (1994) Temperature-dependent sex determination in Crocodilians. The Journal of Experimental Zoology 270: 28–44.
25. Rainwater TR, Platt SG, Charruau P, Balaguera-Reina SA, Sigler L, Cedeño-Vázquez JR, Thorbjarnarson JB (2020) Crocodylus acutus. The IUCN Red List of threatened species. Available from: www.iucnredlist.org. DOI: 10.2305/IUCN.UK.2022-1.RLTS.T5659A212805700.en
26. Ross JP (1998) Crocodiles: status survey and conservation action plan. IUCN/SSC Crocodile Specialist Group, Gainesville, 97 pp.
27. Alava JJ, Carvajal R, Baquerizo J (2003) Crocodylus acutus in the Gulf of Guayaquil Bioregion: current status and census of captive individuals. Crocodrile Specialist Group Newsletter 22: 15–16.
28. Uetz P, Freed P, Hošek J (2021) The reptile database. Available from: www.reptile-database.org.
29. 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 Crocodylus acutus in Ecuador (Fig. 2). Go to the section on symbols and abbreviations for a list of acronyms used.

Country	Province	Locality	Source
Colombia	Nariño	Barrera	Fig.1; Balaguera-Reina et al. 2015
Colombia	Nariño	La Ensenada	Fig.1; Balaguera-Reina et al. 2015
Colombia	Nariño	Quebrada La Segunda	Fig.1; Balaguera-Reina et al. 2015
Colombia	Nariño	Río Rosario	Fig.1; Balaguera-Reina et al. 2015
Ecuador	El Oro	Humedal La Tembladera	Garzón-Santomaro et al. 2019
Ecuador	El Oro	Jambelí	iNaturalist; photo examined
Ecuador	El Oro	Puerto Balao	Ernesto Arbeláez, pers. comm.
Ecuador	El Oro	Puerto Bolívar	César Zambrano, pers. comm.
Ecuador	El Oro	Puerto Jelí	Fernández Porras 2018
Ecuador	Esmeraldas	Atacames	MAE Esmeraldas 2016
Ecuador	Esmeraldas	Cabo San Francisco	GAD Cabo San Francisco 2017
Ecuador	Esmeraldas	Esmeraldas, Calle Delgadillo	EL UNIVERSO 2021
Ecuador	Esmeraldas	Estero Salima	Diario La Hora 2016
Ecuador	Esmeraldas	Isla Luis Vargas Torres	EL UNIVERSO 2008
Ecuador	Esmeraldas	Majúa	EL UNIVERSO 2021
Ecuador	Esmeraldas	Reserva Ecológica Manglares Cayapas Mataje	MAE Esmeraldas 2008
Ecuador	Esmeraldas	Río Verde	El Telégrafo 2013
Ecuador	Guayas	Cerro de los Morreños	Fernández Porras 2018
Ecuador	Guayas	Estero Bajen	Fiallos et al. 1979
Ecuador	Guayas	Estero Plano Seco	Fernández Porras 2018
Ecuador	Guayas	Estero Puerto Hondo	Alvarado Avilés 2016
Ecuador	Guayas	Guayaquil	MCZ 4041; VertNet
Ecuador	Guayas	Guayaquil, Planta Termoeléctrica	Álava et al. 2003
Ecuador	Guayas	Isla Puná, La Concordia	iNaturalist; photo examined
Ecuador	Guayas	Isla Santay	Photo by Elena Sergeeva
Ecuador	Guayas	Manglares El Morro	iNaturalist; photo examined
Ecuador	Guayas	Manglares El Salado	Carvajal et al. 2005
Ecuador	Guayas	Puerto Naranjal	UPMA 2023
Ecuador	Guayas	Puerto Sabana Grande	Fernández Porras 2018
Ecuador	Guayas	Punta Mandinga	MAE 2016
Ecuador	Guayas	Río Daule	César Zambrano, pers. comm.
Ecuador	Guayas	Río Guayas	AMNH 22109; VertNet
Ecuador	Guayas	Río Guayas, near Punta de Piedra	MCZ 10920; VertNet
Ecuador	Guayas	Río Taura	iNaturalist; photo examined
Ecuador	Guayas	Salitral	iNaturalist; photo examined
Ecuador	Guayas	Salvador	Photo by Ernesto Arbeláez
Ecuador	Guayas	Sector Churute	Online multimedia
Ecuador	Guayas	Urbanización Puerto Azul	Fernández Porras 2018
Ecuador	Guayas	Yaguachi	Proyecto Crocodylus Ecuador 2022
Ecuador	Loja	Bolaspamba	iNaturalist; photo examined
Ecuador	Loja	Bosque Petrificado Puyango	Garzón-Santomaro et al. 2019
Ecuador	Loja	Cazaderos	Photo by Santiago Hualpa
Ecuador	Loja	Mangahurco	Photo by Fausto Siavichay
Ecuador	Loja	Río Puyango	César Zambrano, pers. comm.
Ecuador	Manabí	San Clemente	MAE Manabí 2017
Ecuador	Manabí	San Vicente	MAE Manabí 2017
Perú	Piura	Río Chira	Medem 1983
Perú	Tumbes	Bocana Murciélago	Galván & Vargas 2003
Perú	Tumbes	Cabo Inga	Galván & Vargas 2003
Perú	Tumbes	Caño Ucumares	WCS 1979
Perú	Tumbes	Estero Corrales	Vásquez & Pickens 1995
Perú	Tumbes	Guanábano	Galván & Vargas 2003
Perú	Tumbes	Quebrada Honda	Galván & Vargas 2003
Perú	Tumbes	Río Zarumilla	Medem 1983
Perú	Tumbes	Santuario Natural Los Manglares de Tumbes	Pooley et al. 2021
Perú	Tumbes	Zorritos	YPM 006519; VertNet

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