Caiman crocodilus

Studies on the biology of Caiman crocodilus have drawn attention to its biology with emphasis on systematic, taxonomy and ecology. However, anatomical aspects, such as skull characteristics, have not been studied in detail throughout its geographic range. In this study the skull characteristics
for C. crocodilus subspecies, C. c. fuscus, C. c. chiapasius, C. c. crocodilus, and C. c. apaporiensis
were analyzed using geometric morphometrics and descriptive morphology, including
geographic and ontogenetic variation. Variation in skull morphology was found between the
subspecies analyzed. Trans-Andean subspecies, C. c. fuscus and C. c. chiapasius, exhibit brevirostrine
skulls but they are different in the contact between frontal and nasal bones and the size of the
palatine process of the maxilla; therefore, populations in Colombia correspond to C. c. fuscus and,
C. c. chiapasus is not distributed in Colombia. Although cis-Andean subspecies, C. c. apaporiensis
and C. c. crocodilus, have longirostrine skulls, both subspecies differ in the shape of the skull and
in osteological characters; then, adults of C. c. apaporiensis present frontal and nasal in contact
and, V-shape maxillary-premaxillary suture; while C. c. crocodilus specimens exhibit a high
geographic and ontogenetic variation, supporting the hypotheses that there at least two clades of
such subspecies for Colombia. These morphological differences should be considered in future
systematics studies and policies on global conservation of the different C. crocodilus subspecies

Se analizaron los cambios en el tiempo, la frecuencia por tipo de publicación, la ubicación espacial, los temas y especies estudiadas para los Crocodilia de Venezuela. Se localizaron 568 referencias, una cifra 8,8 veces mayor que la primera recopilación efectuada en 1986 y 3,3 veces mayor que la efectuada en 1993. Los artículos en revistas (arbitradas o no) fueron los más frecuentes (148), seguidos de publicaciones en memorias de congresos y resúmenes de congresos y simposios, con 100 y 98, respectivamente. Se han publicado 51 tesis de grado: cinco doctorales, 16 de maestría y 30 de pregrado. El tema mayormente tratado es el de la evaluación del estado poblacional de las especies (74 publicaciones), seguido por aspectos relacionados con la conservación y manejo(71 referencias). La genética, los patrones de movimiento y dispersión, junto a la dilucidación de aspectos taxonómicos han recibido muy poca atención. Las investigaciones se han centrado principalmente en el caimán del Orinoco (Crocodilus intermedius) y en la baba (Caiman crocodilus), con el caimán de la costa (Crocodylus acutus) en un distante tercer lugar. Los Paleosuchus han recibido muy poca atención por parte de los investigadores. El esfuerzo de investigación se ha focalizado principalmente en los estados Apure, Cojedes y Guárico, mientras que en otros estados la investigación ha sido escasa o nula. Todavía hay un amplio campo para el desarrollo de nuevas investigaciones, en especial con las especies más amenazadas y en los estados donde la investigación ha sido insuficiente.

Socioeconomic implausibility of breeding Caiman croc-odilus in Caño Negro, Costa Rica. In the last decade the importance of social participation in the development of conservation projects in Latin America has become obvious. In Costa Rica, Caiman crocodilus is an important species in the Caño Negro Wildlife Refuge. To make an analysis of the social and economic standing of the community, in August 2013 I organized two workshops with 15 people interested in breeding the species. Even if there is a market interested in the skin, breeding would not be profitable and would have to be subsidized in the first six years. Additionally, the project is not feasible because of ignorance about the species, lack of resources, poor integration of social actors, low management capacity and weak linkages with government institutions and NGOs.

Entre finales de marzo y finales de abril de 1982, se visitaron 16 hatos en los estados Apure, Barinas y Portuguesa, Venezuela, los cuales cubren una superficie total de 233.769 ha, con el objeto de establecer la situación de las poblaciones de babas (Caiman crocodilus). La estimación del número de babas de más de un año se hizo en base a conteos nocturnos y/o nocturnos. Los conteos diurnos (13.385 individuos) permitieron discriminar a los animales de acuerdo a su longitud cabeza-cloaca (LCC): Clase II (20 cm ≤  LCC <60 cm) con 17.6% de los individuos, Clase III (60 cm ≤  LCC < 90 cm) con 65% y Clase IV (LCC ≥ 90 cm) con 17.4%. El número de babas contadas de noche fue 3.29 veces mayor que el contado de día para aquellos cuerpos de agua con ambos procedimientos. La población mínima estimada para todas las fincas fue de 55,072 individuos. La relación entre el número de individuos estimados y la superficie total fue de 0.24 ind/ha. Esta relación, al considerar la superficie efectiva total o superficie de los cuerpos de agua, fue de 205 ind/ha. Estas cifras son comparadas con las obtenidas por otros investigadores en otros lugares de Venezuela.

Crocodilians are significant components of many tropical wetland habitats. The international traffic in crocodilian hides has reduced populations of most species to the point of ecological extinction. This situation results in reduced ecosystem stability, loss of biodiversity, and decreased economic potential of the wetlands. Some current conservation programs attempt to reverse this trend via sustainable yield utilization. Conservation of certain species can be promoted by potential economic benefits. This thesis examines the potential for a caiman conservation program in Bolivia based on these concepts.
      The successful caiman conservation and management program conducted in Venezuela is used as a model. In Venezuela, government wildlife officials supervise annual population surveys on large ranches in order to set harvest quotas. Annual counts provide data on natural population fluctuations permitting managers to adjust quotas as needed. Caiman are viewed as part of the ranch livestock inventory. Consequently the wild caiman, along with the cattle, are protected from poachers thereby increasing economic returns to ranch owners. The similarities of Bolivian and Venezuelan land tenure, habitats and caiman biology make the Venezuelan program a suitable model for the proposed Bolivian plan.
      First, I collected extensive printed material regarding the lowlands, caiman biology, and the Venezuelan harvest. Interviews were then conducted with ranch owners and Indigenous Territories representatives in Bolivia who are responsible for the caiman and habitat if used in a similar program. Wildlife authorities were included to ensure government support. Additional interviews were conducted with numerous persons regarding the proposed project.
      I conclude that the proposed conservation and management program incorporating a sustained yield harvest component appears very favorable for Bolivia. Conclusion are based on the current state of recovering caiman populations, positive responses from wildlife officials, a depressed ranching industry and recent gains among Indigenous groups for resource rights. A small-scale pilot program is recommended for initiation of the plan, followed by slow and careful expansion integrating strict controls against fraud.

Introduction: The common or spectacled caiman is a species complex whose taxonomy is in a confused state. Primarily for management and conservation considerations, rather than for nomenclatorial justification, we follow in this chapter the terminology of the Red Data Book (IUCN 1982), using the binomial Caiman crocodilus with four nominal subspecies (C. c. apaporiensis, C. c. crocodilus, C.c.fuscus, and C. c. yacare (King and Brazaitis 1971; Brazaitis 1973)). Medem (1981) discussed the validity of this usage and argued that Caiman sclerops should be applied to this taxon. Likewise he recognized C.c. fuscus as two distinct subspecies (fuscus and chiapasius), and gave full species status to C. c. yacare (Medem 1983). Two additional subspecies C. c. mattogrossiensis and C. c. paraguayensis have been included in another checklist (Wermuth and Mertens 1977). However, the original descriptions were based on commercial hides (Fuchs 1974) and the use of those names should be suppressed (Frair and Behler 1983).
Numerous works on C. crocodilus have been 'published' in Latin America as internal manuscripts of government organizations and as theses of universities. Due to the difficulty in obtaining such material we have been selective and have cited only those that we consider contain data or concepts of particular worth. Given Medem's (1981, 1983) extensive treatment of South American crocodilians and their literature, we have restricted our review in general to publications of the last two decades.

Testosterone is a steroid hormone involved in the expression of many morphological, physiological, and behavioral traits that arguably affect reproductive success. The evidence for that link is, however, incomplete or absent in the research on crocodylian species. Testosterone levels are also known to change throughout the breeding season, often on an hourly basis, which may further complicate studying their relationship with breeding success. We tested here whether baseline testosterone levels, measured out of the breeding season, are correlated with morphometry and reproductive success in Caiman crocodilus (LINNAEUS, 1758). Paternity tests, based on the amplification and genotyping of eight fluorochrome labeled microsatellites, failed to support a continuous relationship between these variables. Although adult males of all sizes contribute to reproduction, paternity was overrepresented in a few males with high values of maleness index (bigger males), supporting a despotic or pyram...

El programa de aprovechamiento de las poblaciones de babas en Venezuela estuvo, hasta el año 1987 estrictamente dirigido al aprovechamiento de las poblaciones naturales de esta especie. A partir de 1987 se empiezan a establecer en algunos hatos llaneros "zoocriaderos abiertos" que consisten en que los individuos levantados en cautividad provienen -ya sea desde la etapa de huevos o de neonatos- del medio natural. El objetivo inicial de estos zoocriaderos era el de probar la factibilidad económica de este tipo de actividad, con miras al aprovechamiento comercial en el futuro, y el de producir individuos para repoblar los mismos hatos donde se realizaba una cosecha comercial de adultos de las poblaciones  naturales. En 1990 se dicta la resolución oficial que establece las normas para el funcionamiento de zoocriaderos de babas con fines comerciales. Para 1991 ya habían 16 zoocriaderos de babas registrados en el país con un stock mínimo de 73.020 individuos. Ese mismo año se permitió el beneficio de 21.795 individuos. El MARNR señala que en el futuro debe tenderse al establecimiento de 'zoocriaderos cerrados", es decir, aquellos donde todo el ciclo vital de las babas se cumple en condiciones de cautiverio. Esta recomendación oficial luce inconveniente al no estimular la conservación de la especie en su medio natural. En este trabajo se dan algunas recomendaciones técnicas para el manejo de zoocriaderos de babas en los llanos de Venezuela

Numerous localities along the northern coast of Venezuela were visited between january and august, 1984. Counts of Caiman crocodilus greater than one year old were related to the distance travelled during the censusings. The maximum number observed was 196.6 individuals/km in a small sector of the Sarare river. In the other localities the values varied from 0.2 to 26.6 individuals/km. Where this species coexists with Crocodylus acutus the observed population densities of Caiman crocodilus were low. It iss considered that the population levels of the spectacled caimans in this region are satisfactory, nd may eeven have been favoured on the one hand by the drastic reduction in numbers of Crocodylus acutus, and on the other hand by construction of dams and other artificial habitats.

O jacaretinga (Caiman crocodilus; Alligatoridae) ocorre na América Central e América do Sul. Na Amazônia brasileira a subespécie encontrada é a Caiman crocodilus crocodilus. Apesar de se alimentar basicamente de peixes e invertebrados, aves e outros animais fazem parte da dieta desta espécie. O registro de consumo de aves por C. crocodilus é pouco relatado na literatura. Em estudos de dieta de C. crocodilus na Amazônia, as aves aparecem quase sempre em pequena porcentagem e os indivíduos predados possuem massa corpórea reduzida se comparada aos demais grupos de animais predados. Neste estudo descrevemos um evento de predação do socó-boi (Tigrisoma lineatum; Pelecaniformes: Ardeidae) por C. crocodilus (Figura 1) em um açude do Parque Zoobotânico (PZ) da Universidade Federal do Acre (UFAC), Rio Branco.

Testosterone is a steroid hormone involved in the expression of many morphological, physiological, and behavioral traits that arguably affect reproductive success. The evidence for that link is, however, incomplete or absent in the research on crocodilian species. Testosterone levels are also known to change throughout the breeding season, often on an hourly basis, which may further complicate studying their relationship with breeding success. We tested here whether baseline testosterone levels, measured out of the breeding season, are correlated with morphometry and reproductive success in Spectacled Caiman (Caiman crocodilus (Linnaeus, 1758)). Paternity tests, based on the amplification and genotyping of eight fluorochrome labeled microsatellites, failed to support a continuous relationship between these variables. Although adult males of all sizes contribute to reproduction, paternity was overrepresented in a few males with high values of maleness index (bigger males), supporting a despotic or pyramidal hierarchy among males. Maternity assignments supported the existence of multiple paternity, a phenomenon previously attributed in this species to the lack of large males caused by human hunting. The idea of larger males having more offspring is widespread in crocodilians, but to our knowledge, this is the first investigation that prove this dogma.

Ecological aspects of nesting in Caiman crocodilus chiapasius (Bocourt 1876) in the Encrucijada Biosphere Reserve, Mexico.— Studies on caiman, Caiman crocodilus chiapasius, in Mexico are scarce. The present study was conducted to evaluate the key characteristics regarding the reproductive ecology of caiman in Mexico. We conducted nest searches from April to September 2014. We observed that nests were built in June and that hatching occurred in September and October. The phase of the moon had an effect on nesting events. The height of the nest, the distance to the nearest tree, and the distance from the top of the nest to the first egg were related to hatching success and incubation temperature. Resumen Aspectos ecológicos de la anidación de Caiman crocodilus chiapasius (Bocourt, 1876) en la reserva de la biosfera La Encrucijada, México.— Existen pocos estudios sobre el caimán de anteojos, Caiman crocodilus chiapasius, realizados en México. En el presente estudio evaluamos las características clave de la ecología reproductiva del caimán en México. Se realizó una búsqueda de nidos entre abril y septiembre de 2014, y se observó que la construcción de los mismos tiene lugar en junio y las eclosiones, en septiembre y octubre. La fase lunar influye en la anidación. Asimismo, la altura del nido, la distancia al árbol más cercano y la distancia desde el borde superior del nido al primer huevo están relacionadas con el éxito de eclosión y la temperatura de incubación.