|Scientific Name:||Crocodylus intermedius Graves, 1819|
|Red List Category & Criteria:||Critically Endangered A2bcd; C2a(i) ver 3.1|
|Assessor(s):||Balaguera-Reina, S.A., Espinosa-Blanco, A., Antelo, R., Morales-Betancourt, M. & Seijas, A.|
|Contributor(s):||Velasco, A., Babarro, R. & Hernandez, O.|
An inferred reduction in population size of more than 80% over three generations (75 years) due to species over-hunting in the early and mid 1900s meets the criterion A threshold for Critically Endangered. This threat is understood, but it is currently not ongoing due to national and international legislation blocking any trade of this species (CITES Appendix I). However continuing threats by persecution, habitat loss and the limited number of mature individuals occurring in protected areas constitute continuing concerns for this species. Estimations of mature population sizes were not completed across Orinoco Crocodile range before 1980. However, Medem (1981) estimated that between 1920 and 1950 a minimum of 254,000 skins from mature animals were exported. Mature population size estimates done in the 1980s in both Venezuela and Colombia report an overall mature population of ~550 individuals, 273 from Venezuela and 280 from Colombia. Current studies show a general reduction in these numbers in both Venezuela (Seijas et al. 2010) and Colombia (Lugo 1996), indicating that the situation for the species continues to decline. Lugo (1996) estimated an overall mature population size of 123 individuals in the Lipa, Cuiloto, Ele, Cravo Norte, Santo Domingo, Duda, Lozada, Alto Guayabero, Meta, and Vichada rivers. Currently, the population size is estimated at ~250 mature individuals across its range with the largest population harbouring ~40 mature animals in both Colombia (Ele, Lipa, Cravo Norte River System) and Venezuela (Cojedes River System and Capanaparo River). However, population size is not currently possible to be estimated in 17 out of the 34 areas reported with presence of the species (Balaguera-Reina et al. 2017).
|Previously published Red List assessments:|
|Range Description:||The Orinoco Crocodile (Crocodylus intermedius) is distributed in the northern part of South America, occurring in both Colombia and Venezuela (Medem 1983). This species has been described as restricted (endemic) to the Orinoco basin, occurring historically from the Lozada-Duda-Guayabero river system in central Colombia to the Orinoco delta in northeastern Venezuela from 0 to 350 m asl (Medem 1981, 1983; Seijas et al. 2010; Balaguera-Reina et al. 2017). Crocodylus intermedius has never been reported in the Amazon basin, with the Paragua and Jao rivers (Orinoco River tributaries) between San Fernando de Atabapo and La Mision de La Esmeralda being the historically southernmost distribution (Humboldt 1805 in Medem 1981, Gorzula and Mendoza 1993). Geographical barriers, especially mountain systems (such as the eastern Andes, the Merida Cordilleras in the west, the Venezuelan coastal range in the north, and the Guiana shield in the southeast), have also delimited the Orinoco crocodile distribution. Historical data suggests that it has never occurred in the Caroni River Basin (Castro and Gorzula 1986). To date, it is still not clear why the species has never colonized the Atabapo and Casiquiare rivers (likely waterways towards the Amazon basin), remaining an interesting question to be resolved (Medem 1981). However, indigenous communities have reported seeing C. intermedius, including breeding events, in the Casiquiare River (Antelo 2008), raising questions about the presence of the species in this area.|
Currently, the Orinoco Crocodile can be found in a small portion of its historical distribution in large rivers such as Arauca, Bita, Cinaruco, Guaviare, Guayabero, Lozada, Meta, Vichada, Orinoco, Casanare, Cusiana, Ele, Lipa, Cravo Norte, Cravo Sur, Ariporo (Morales-Betancourt et al. 2015, Moreno-Arias et al. 2016, Antelo et al. 2016), Manacacias, Apure, Portuguesa, Tucupido, Cojedes, Manapire, Capanaparo, Ventuari, Caura, Zuata, and some of their tributaries (Gorzula and Mendoza 1993, Arteaga et al. 1996, Antelo 2008, Seijas 2011, Babarro per. comm). Recent studies have identified 34 areas across the Orinoco Crocodile range [16 in Colombia, 16 in Venezuela, and two covering both countries (Meta River - Lower basin and Arauca River), which are the remnants of a much larger distribution (Balaguera-Reina et al. 2017)].
Native:Colombia; Venezuela, Bolivarian Republic of
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Crocodylus intermedius inhabits a wide variety of aquatic-land areas within the Orinoco basin, with the highest population numbers being recorded in seasonal rivers from savanna ecosystems (Medem 1981, Seijas et al. 2010). Orinoco Crocodile population data have been recorded from 34 areas [16 in Venezuela, 16 in Colombia, and two covering both countries (Meta River - Lower basin and Arauca River); Balaguera-Reina et al. 2017].|
Areas in Venezuela are: Guaritico and Macanillal System, Capanaparo River, Cojedes River System (Agua and Amarillo creeks, Cojedes-Sarare and Cojedes rivers), Manapire River System (Larga and Chigüichigüe lakes and Manapire River), Anaro River, Cinaruco River, Aguaro-Guariquito River, Camaguan Estero, Portuguesa River, Zuata River, Tucupido River System, Apure River, Ventuari River, and Orituco River.
Regarding Colombia, studies have been done in Ele, Lipa, Cravo Norte River System, Guayabero River, Tomo River - (Tuparro National Natural Park), Duda River, Lozada River, Tillava, Planas, Guarrojo, and Muco rivers system, Vichada River, Manacacias River, Iteviare and Guaviare rivers, Cinaruco River upper basing, Capanaparo River, Ariporo River, Guanapalo and Meta rivers system (La Hermosa and Picapico creeks), Cravo Sur River, Casanare River, Casanare River, and la Aurora Natural Reserve (Ariporo and Chire rivers).
Only 26 of these 34 areas (14 in Venezuela and 12 in Colombia) have at least two population surveys carried out in different years that allow analysis of current populations trends (Balaguera-Reina et al. 2017). Relative abundance values reported in Venezuela at these 14 localities ranged between 0 ind/km (Anaro River from 1990–1992 and 2000; Garavito 2003) and 10 ind/km (Laguna de Chigüichigüe-segment of the Manapire River, from 2008–2009; Arcila 2009). Some Orinoco Crocodile populations have increased in relative abundance through time with Laguna de Chigüichigüe having the highest population growth. In contrast, localities such as Caño Amarillo-Merecure (creek) have been reduced from 4.9 ind/km between 1991 and 1997 to 1.78 in 2009. Cojedes River has shown an oscillation through the last 20 years with peaks of 5.8 ind/km in 1997 and troughs of 0.2 ind/km in 2006 (Seijas et al. 2010, Espinosa-Blanco 2010). The last study published in 2007 shows a relative abundance value of 4.1 ind/km (Espinosa-Blanco and Seijas 2012). Caño Guaritico (creek) did not have any reported sightings between 1987 and 1988, but did between 1990 and 1994, 1998 and between 2002 and 2007 (Lugo-Rugeles 1998, Chavez 2000, Antelo 2008). Capanaparo River has faced a population decline of 63% between 2001 and 2011 (Moreno 2012).
Population data from Colombia had been collected using a variety of survey methods (i.e., diurnal or nocturnal counts, and/or aerial surveys), of which several did not report the actual distances surveyed (instead they reported number of individuals/sector or zone). Regardless this disparity, “of concern” data (where zero individuals were sighted) were reported from surveys carried out in La Hermosa and Picapico Creeks (1994 and 2010), Ariporo River (1994 and 1995), Cravo Sur River (1995 and 2010), and Tomo River (1995, 1996, and 1997; Lugo-Rugeles 1997, Castro et al. 2012). Other areas such as the Cravo Norte (1994–1995, 2000–2001, 2012), Casanare (1996, 2012), and the Orinoco (1994, 1995) Rivers, as well as the Guanapalo (2010) and Meta (1995, 1996, 1998, 2010, 2011, 2012) River System, have been studied over a 20-year span with relative abundances ranging from 0.0 to 0.81 ind/km (Lugo-Rugeles 1997, Castro et al. 2012, Barahona and Bonilla 1999, Ardila-Robayo et al. 2002, Rios and Trujillo 2004). The Lipa and Ele Rivers consistently had a low relative abundance value over a 15-year span (0.2 and 0.3 ind/km in 1995 and 2012; 0.3 ind/km in 1995 and 2001; 0.2 ind/km in 2012; Lugo-Rugeles 1997, Castro et al. 2012). However, Anzola and Antelo (2015) reported an increase in populations inhabiting the Lipa, Ele, and Cravo Norte River Systems over a 13 years-span based on nest surveys.
Mature population size estimates done in the 1980s in both Venezuela and Colombia report an overall mature population of ~550 individuals, 273 from Venezuela in the Cojedes (76 individuals), Capanaparo (78 individuals), Meta (67 individuals), Cinaruco (19 individuals), Portuguesa (12 individuals), Orinoco (five individuals), San Carlos (four individuals), Riecito (three individuals), and Tinaco and Guanare (two individuals each) Rivers (Godshalk 1978, 1982) and 280 from Colombia mainly in departments such as the Arauca (180 individuals), Casanare (49 individuals), Meta (14 individuals). and Vichada (37 individuals; Medem 1981). Current studies show a general reduction in these numbers in both Venezuela (Seijas et al. 2010, Espinosa-Blanco and Seijas 2012, Moreno 2012) and Colombia (Lugo-Rugeles 1996), indicating that the situation of the species is worse than previous reports. Lugo-Rugeles (1996) estimated an overall mature population size of 123 individuals in the Lipa, Cuiloto, Ele, Cravo Norte, Santo Domingo, Duda, Lozada, Alto Guayabero, Meta, and Vichada rivers. Historic estimations (before 1980) regarding mature population sizes were not completed across Orinoco Crocodile range. However, Medem (1981) estimated that between 1920 and 1950 a minimum of 254,000 skins from mature animals were exported.
Restocking processes have been highly uneven between Venezuela and Colombia. To date, Venezuela has released into the wild 9,812 individuals in consecutive years between 1990 and 2016 in five states (Apure, Guárico, Barinas, Cojedes, and Portuguesa), with a maximum of 763 individuals released during 2009 and a minimum of 40 during 1990 (Chavez 2002, Babarro 2014). In contrast, even though efforts at restocking in Colombia have not been as vigorous as in Venezuela, it is notable that starting in 2015 two institutions (The Palmarito Foundation and the National University of Colombia) have released a total of 57 individuals in three departments (Casanare, Vichada, and Meta; Antelo 2015, Antelo et al. 2016, Moreno-Arias et al. 2016).
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||The Orinoco Crocodile is one of the largest crocodylian species extant in the world (largest individual recorded 669 cm total length; Humboldt 1860 in Medem 1983). This species dwells a variety of habitats including rivers in tropical evergreen forest, piedmont streams in the foothills of the Andes, and seasonal rivers in savannas (Medem 1983). Females become mature at approximately 250 m total length (Antelo 2008), nesting in riverbanks between January and February (dry season) with hatchlings emerging around three months later, generally synchronized with the beginning of the wet season (Seijas et al. 2010). Eggs are laid in holes excavated by the female and clutch size range between 32 and 44 eggs, with a reported maximum of 66 eggs (Jiménez-Oráa et al. 2007; Navarro 2007). Crocodylus intermedius is reported to aestivate in isolated streams or pools in the dry season, digging burrows into the riverbanks (Medem 1981, Antelo 2008).|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Generation Length (years):||25|
|Movement patterns:||Not a Migrant|
|Congregatory:||Congregatory (and dispersive)|
|Use and Trade:||Orinoco Crocodile was heavily hunted in the early and mid 1900s mainly for its skin. Medem (1983) reports a total of at least 254,000 skins from mature animals were extracted from five main areas in Colombia between 1920 and 1950. The species is currently protected by national and international laws that prohibit its use of any kind, with the exception of scientific research an zoo interchanges. However, low scale poaching is still reported in some rivers of Venezuela and Colombia mainly because fear or local consumption (meat and eggs).|
|Major Threat(s):||Prior threat from over exploitation is no longer significant. However, low levels of illegal harvest due to fear of crocodiles and for local consumption are reported. Continuing threats are habitat change, habitat fragmentation, and pollution due to riverside development and human occupancy.|
Conservation programs are ongoing in both Colombia and Venezuela since the 1990s, focused on restocking populations and understanding the ecology of the species to reduce conflict with human populations (Balaguera-Reina et al. 2017). In this regards, Venezuela has released a total of 10,122 individuals in consecutive years between 1990 and 2017 in five states (Apure, Guárico, Barinas, Cojedes, and Portuguesa), with a maximum of 763 individuals released during 2009 and a minimum of 40 during 1990 (Chávez 2002, Babarro 2014, Velasco per. comm). On the other hand, Colombia has released a total of 101 individuals since 2015 in three departments (Casanare, Vichada, and Meta; Antelo 2015, Antelo et al. 2016, Moreno-Arias et al. 2016). However, despite the number of population ecology studies and restocking programs developed during the last two decades in these two countries, reliable information about the status of populations in both Venezuela and Colombia is lacking (Espinosa-Blanco and Seijas 2012, Morales-Betancourt et al. 2015). New efforts to identify relevant areas where research projects are ongoing and populations information allow researchers to define the local status of the species (regional habitat priority/crocodile conservation unit RHP/CCU) as well as areas with low information and no research currently being done (regional research priority RRP) defined a total of 34 critical areas (16 in Colombia, 16 in Venezuela, and two covering both countries), 10 RHP/CCU (six from Venezuela and four from Colombia) and 24 RRP (10 from Venezuela, 12 from Colombia, and two in both countries; Balaguera-Reina et al. 2017). From these, Caño Guaritico (Creek) and the Capanaparo River in Venezuela and the Ele, Lipa, Cravo Norte River System and the Guayabero River in Colombia were defined as areas with the most optimal conditions for long-term preservation and maintenance of Crocodylus intermedius populations.
Crocodylus intermedius was listed in Appendix I of CITES at the convention inception and no international trade, legal or illegal, has been reported since.
|Citation:||Balaguera-Reina, S.A., Espinosa-Blanco, A., Antelo, R., Morales-Betancourt, M. & Seijas, A. 2018. Crocodylus intermedius. The IUCN Red List of Threatened Species 2018: e.T5661A3044743.Downloaded on 26 September 2018.|
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