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Simple Summary: Congenital defects have been described in almost every vertebrate group. In crocodiles, teratology alterations have been described in captive animals (pets, zoos, farms) such as Crocodylus niloticus and Gavialis gangeticus. The present study aimed to characterize congenital malformations of C. acutus from a farm in Lomas de Matunilla, Ballestas, Bolívar, Colombia. The analyzed eggs presented macroscopic malformations, with 42 different types of anomalies observed. Limb and tail malformations (29%) were the most common changes observed. The American crocodile (Crocodylus acutus, Cuvier, 1807) (Class Reptilia, Family Crocodylidae) is a crocodile species inhabiting the Neotropics. Congenital defects have been described in almost every vertebrate group. In crocodiles, teratology alterations have been described in captive animals (pets, zoos, farms) such as Crocodylus niloticus or Gavialis gangeticus. The present study aimed to characterize congenital malformations of C. acutus from a farm in Lomas de Matunilla, Ballestas, Bolívar, Colombia. A total of 550 unhatched eggs were examined after embryo death. A total of 61 embryos presented malformations, with 42 different types of anomalies observed. Limb and tail malformations (29%) were the most common malformations observed. Several malformations, such as cephalothoracopagus, thoracopagus, sternopagus, xiphopagus twins, campylorrachis scoliosa, and acrania, were documented in crocodiles for the first time. Research in teratology enhances our understanding of crocodile biology. It plays a role in their conservation and management, thus helping to ensure the long-term viability of these species in their natural habitats. [ABSTRACT FROM AUTHOR]

Introduction: Wildlife tourism is important for the conservation of protected areas, endangered species, and to empower local communities. Nevertheless, when guidelines and practices are not clear and correctly executed, tourism may have a negative impact. Methods: We carried out semi-open interviews (n = 34) and several workshops (n = 50) with locals and tour guides in the village of Punta Allen in Sian Ka'an Biosphere Reserve, Mexico. Data were organized in tables in Excel®, and statistical analysis was conducted with IBM® SPSS® Statistics software. A priori, exploratory data analysis was carried out to identify the general pattern of the data, and a priori data normality test (Shapiro-Wilks) and c2 test were carried out to find out if there were differences in the frequency of a response depending on socioeconomic variables. Results: Most respondents (69%) dedicated 2-10 min to crocodile observation, one quarter (25%) spent 11-20 min, and the remainder (6%) 21-30 min. The majority (97%) of respondents mentioned that when they see a crocodile, they approach at a 5-10 m distance and wait for the occupants of the boat to take pictures, and then leave; only one respondent (3%) said that they feed crocodiles to attract them to the boat. Most respondents (89%) said that crocodile observation does not need to be improved, and it is fine the way it is currently carried out; the remaining 11% said that it could be improved. Workshops were received positively and allowed us to share information on crocodile species, their conservation, and good tourism practices. Discussion: It is necessary to enlighten tourismservice providers about the biology and importance of crocodilian species, to promote conservation and provide services with an educational impact/focus for visitors to the reserve. There is a need to develop a communication program that provides accurate information for new service providers and renews and reinforces concepts for established providers. Additionally, we need to continuously monitor and evaluate wildlife observation activities to enhance current practices in our study area, and to determine if they are having a negative impact on crocodile behavior and biology. [ABSTRACT FROM AUTHOR]

IntroductionWildlife tourism is important for the conservation of protected areas, endangered species, and to empower local communities. Nevertheless, when guidelines and practices are not clear and correctly executed, tourism may have a negative impact.MethodsWe carried out semi-open interviews (n = 34) and several workshops (n = 50) with locals and tour guides in the village of Punta Allen in Sian Ka'an Biosphere Reserve, Mexico. Data were organized in tables in Excel®, and statistical analysis was conducted with IBM® SPSS® Statistics software. A priori, exploratory data analysis was carried out to identify the general pattern of the data, and a priori data normality test (Shapiro–Wilks) and χ2 test were carried out to find out if there were differences in the frequency of a response depending on socioeconomic variables.ResultsMost respondents (69%) dedicated 2–10 min to crocodile observation, one quarter (25%) spent 11–20 min, and the remainder (6%) 21–30 min. The majority (97%) of respondents mentioned that when they see a crocodile, they approach at a 5–10 m distance and wait for the occupants of the boat to take pictures, and then leave; only one respondent (3%) said that they feed crocodiles to attract them to the boat. Most respondents (89%) said that crocodile observation does not need to be improved, and it is fine the way it is currently carried out; the remaining 11% said that it could be improved. Workshops were received positively and allowed us to share information on crocodile species, their conservation, and good tourism practices.DiscussionIt is necessary to enlighten tourism service providers about the biology and importance of crocodilian species, to promote conservation and provide services with an educational impact/focus for visitors to the reserve. There is a need to develop a communication program that provides accurate information for new service providers and renews and reinforces concepts for established providers. Additionally, we need to continuously monitor and evaluate wildlife observation activities to enhance current practices in our study area, and to determine if they are having a negative impact on crocodile behavior and biology.

The American crocodile (Crocodylus acutus, Cuvier, 1807) (Class Reptilia, Family Crocodylidae) is a crocodile species inhabiting the Neotropics. Congenital defects have been described in almost every vertebrate group. In crocodiles, teratology alterations have been described in captive animals (pets, zoos, farms) such as Crocodylus niloticus or Gavialis gangeticus. The present study aimed to characterize congenital malformations of C. acutus from a farm in Lomas de Matunilla, Ballestas, Bolívar, Colombia. A total of 550 unhatched eggs were examined after embryo death. A total of 61 embryos presented malformations, with 42 different types of anomalies observed. Limb and tail malformations (29%) were the most common malformations observed. Several malformations, such as cephalothoracopagus, thoracopagus, sternopagus, xiphopagus twins, campylorrachis scoliosa, and acrania, were documented in crocodiles for the first time. Research in teratology enhances our understanding of crocodile biology. It plays a role in their conservation and management, thus helping to ensure the long-term viability of these species in their natural habitats.

We provide the results on the first systematic effort to study cave-dwelling crocodiles in central Belize. For nearly three decades, managers at Runaway Creek Nature Reserve have frequently observed crocodile tracks and trackways in caves, while subterranean observations of crocodiles were less frequent. We surveyed five caves previously identified as crocodile habitat by wading (up to waist deep) and kayaking; we also deployed trail cameras in five of six flooded caves. Crocodiles were directly observed in two caves and trail camera footage was captured of a crocodile exiting a third cave. Given that introgression between Morelet’s Crocodile (Crocodylus moreletii (A.H.A. Duméril & Bibron, 1851)) and the American Crocodile (Crocodylus acutus Cuvier, 1807) is high throughout their sympatric range and none of the crocodiles were captured, all individuals were identified as Crocodylus acutus x C. moreletii?. Additionally, in the five caves previously identified as crocodile habitat, we identified at least 16 potential prey species including two invertebrate, four fish, one turtle, one bird, several bat, and eight non-bat mammal species via direct observation and trail cameras. Capture, examination, and stomach flushes of cave-dwelling crocodiles, as well as continued monitoring of vertebrates via trail cameras, additional prey species surveys, monitoring of cave temperatures, and developing detailed cave maps of crocodile caves are highly recommended to obtain the information to both characterize crocodile cave use and optimally manage cave resources.

Human-wildlife negative interactions are a recurring phenomenon worldwide, originating from the shared habitats and resources between both. In several coastal communities, negative interactions occur due to the presence of the American Crocodile (Crocodylus acutus). We have developed an index to assess the level of vulnerability of communities to this reptile. The construction of this index is based on the Approximate SustainabilityIndex developed by Gutiérrez-Espeleta in 1994. The Index of Vulnerability (IVU) is built upon several indicators across four parameters: social, biological-environmental, institutional, and spatial. These indicators are assessed using a performance scale and interpretation. The IVU assigns values to the vulnerability condition, which are presented in a color scale corresponding to defined intervals. For each indicator, reference categories and rating scales are represented with traffic light colors and numerical ratings. The IVU value obtained for a community can be visualized with a map and a corresponding figure, including a table of values for the assessed parameters.

The American crocodile Crocodylus acutus occurs across the Americas, with its northernmost distribution being in South Florida, USA. This species has undergone severe declines across its range and is categorized globally as Vulnerable on the IUCN Red List and as Threatened on the U.S. Federal Endangered Species List. Long-term monitoring studies in the USA have documented a shift in American crocodile nesting activity and an expansion of its range throughout the southern and eastern coasts of South Florida. However, no successful American crocodile nests have been recorded until now on the west coast of South Florida. Here we document the American crocodile nest monitoring conducted during 1997–2021 at Rookery Bay National Estuarine Research Reserve and the first successful nest from the west coast of South Florida for C. acutus. Marco Airport and McIlvane Marsh are the two main American crocodile nesting areas identified at the Reserve, with 92 nests and 3,586 eggs recorded during 1997–2021. We found most nests at Marco Airport (95.7%) and only four nests (4.3%) at McIlvane Marsh. To date, none of the nests found at Marco Airport have produced successful hatchlings. In contrast, hatchlings have been produced at McIlvane Marsh since nests were first documented there in 2020. We discuss the implications of our findings in terms of the future conservation of the species.

The American crocodile Crocodylus acutus occurs across the Americas, with its northernmost distribution being in South Florida, USA. This species has undergone severe declines across its range and is categorized globally as Vulnerable on the IUCN Red List and as Threatened on the U.S. Federal Endangered Species List. Long-term monitoring studies in the USA have documented a shift in American crocodile nesting activity and an expansion of its range throughout the southern and eastern coasts of South Florida. However, no successful American crocodile nests have been recorded until now on the west coast of South Florida. Here we document the American crocodile nest monitoring conducted during 1997–2021 at Rookery Bay National Estuarine Research Reserve and the first successful nest from the west coast of South Florida for C. acutus. Marco Airport and McIlvane Marsh are the two main American crocodile nesting areas identified at the Reserve, with 92 nests and 3,586 eggs recorded during 1997–2021. We found most nests at Marco Airport (95.7%) and only four nests (4.3%) at McIlvane Marsh. To date, none of the nests found at Marco Airport have produced successful hatchlings. In contrast, hatchlings have been produced at McIlvane Marsh since nests were first documented there in 2020. We discuss the implications of our findings in terms of the future conservation of the species. [ABSTRACT FROM AUTHOR]

Crocodylus moreletii (Morelet’s crocodile) and Crocodylus acutus (American crocodile) are generalist, apex predators of subtropical aquatic habitats in Central America. As top predators, crocodiles may be exposed to high levels of micro pollutants, such as trace elements via bioaccumulation that enter the food web as a consequence of human activities. As such, the status of their population can be considered indicative of that of the entire ecosystem – i.e., crocodiles constitute as genuine indicator species. In this study, we report on the concentrations of trace elements found in the caudal scutes of 178 specimens of C. acutus and C. moreletii from Belize. Our objectives were three-fold: (1) to assess variation in trace element concentration between species, sexes, age classes and body index; (2) to identify areas with elevated exposure to trace elements by comparing concentrations in the scutes of crocodiles at various sites in Belize; and (3) to explore links between crocodile trace element load and local land use. All elements tested (Hg, Pb, Cd, As, Cu, Zn, Co) could be detected in at least some scutes. Many of the readings of As and Co were under or close to the detection limit and were not further analyzed. Relatively high Hg concentrations were observed in adults from Chiquibul Forest (median 3.170 µg/g) and Ambergris Caye (0.834 µg/g). Concentrations of Hg and Pb tended to be higher in adult animals than in juveniles, especially in C. acutus. On the other hand, concentrations of Cd, Cu and Zn were higher in juveniles than in subadult adult animals. Concentrations of Cu were higher in C. acutus than in C. moreletii, but otherwise no species-effects were found for the other trace elements. We found a negative correlation between Hg and Zn concentrations; correlations among Cd, Pb, Cu and Zn concentrations tended to be positive. In both juveniles and adults, animals with high concentrations of Zn had lower body-indices (a proxy for physiological condition). None of the other element concentrations correlated with the body-index. Specimens of C. acutus were more often sampled at coastal sites, while C. moreletii sampling points were typically closer to agricultural or forested areas. A canonical correlation analysis revealed a significant association between trace element load and habitat characteristics. Animals sampled inland, near submontane forests, contained higher levels of Hg, while animals sampled near agricultural, urban or lowland habitats tended to have higher concentrations of Cd, Pb, Cu and Zn. This study identifies the most prevalent trace element concentrations impacting Belizean watersheds while highlighting the exposure risk to non-essential trace elements in less-urbanised areas or protected areas.

Negative interactions between people and crocodilians have increased worldwide, but in Mexico there have been few systematic reports and no rigorous evaluation of this problem. We compiled information on negative interactions between people and the spectacled caiman Caiman crocodilus and American crocodile Crocodylus acutus from the Worldwide Crocodilian Attack Database for 1993–2018, and we investigated interactions in greater depth, through interviews with people in La Encrucijada Biosphere Reserve. We examined the relationship between the occurrence of negative interactions between people and C. acutus and the species' nesting season and abundance, and presence records. In Mexico, the frequency of negative interactions increases when anthropogenic activities occur close to nesting sites (< 30 km) and during the nesting season (February–September). In La Encrucijada, following negative interactions with crocodiles, the local inhabitants killed 30 crocodiles measuring > 2.5 m long in 2011–2012. The frequency of negative human–crocodilian interactions was not correlated with the abundance of crocodilians but was correlated with the number of presence records of crocodiles. Strategies to minimize these interactions include warnings at nesting sites, increased monitoring of anthropogenic activities during the nesting season, and management of nests to prevent them being destroyed by people. [ABSTRACT FROM AUTHOR]

Two species of crocodilians have been described in Costa Rica, American crocodile, Crocodylus acutus (Cuvier, 1807), and caiman, Caiman crocodilus (Linnaeus 1758). In Costa Rica, data has been generated on both species, but populations in the Pacific have received more attention from researchers; presumably due to the fact that the Pacific slope has a greater development, which brings greater social pressure on the attention of the incidents generated by the encounter between humans and crocodiles. This study, performed during 2017, was done in an area of approximately 400 km2, characterized by having a wide and dense network of water courses, which includes the Matina, Pacuare, Reventazón and Parismina rivers. In these rivers, an average of 25 kilometers were traveled from the coastline up stream to the interior of the territory, including the Tortuguero canals, and other water bodies that connect these rivers, as well as in the most important lagoons and secondary channels. Three repetitions were made per segment. A population of 1 084 caimans and 503 crocodiles is estimated; for a sight count of 8.64 and 2.80 ind/Km respectively. Speaking of caimans, up to 12 % of individuals of reproductive age were observed, while for crocodiles that number was only 2 %. The abundance of both species in the different places studied, turned out to be significantly different for crocodiles and for caimans (Kruskal-Wallis, P ≤ 0.001). Likewise, the size distribution is similar for crocodiles reported in all environments (Kruskal-Wallis, p ≤ 0.15), while for caimans it indicates that there is a different distribution for sizes, according to the environment in which they are found (Kruskal -Wallis, P ≤ 0.001), with a bias against of the Pacuare and Matina rivers. It was possible to estimate a sex ratio of 1.25 and 0.83 males to females, in crocodiles and caimans respectively, with 9 and 11 captures in that same order, in recruit and juvenile sizes. [ABSTRACT FROM AUTHOR]

En los últimos años, la incidencia de ataques por cocodrilos en Costa Rica, se han incrementado, lo cual está asociado al desarrollo de las actividades humanas en áreas consideradas como óptimas en lo que determinó como hábitat potencial de la especie. Dado lo anterior, la presente investigación plantea la identificación de zonas de interacción entre el cocodrilo y el ser humano a partir de la integración de variables físico-geográficas por medio de los Sistemas de Información Geográfica (SIG). De esta manera, se realizó una recopilación teórica para la identificación de las variables físico-geográficas que integran el hábitat del cocodrilo (pendiente, red de drenaje, áreas de inundación y coberturas de uso de la tierra), así como las variables socioambientales que influyen en la alteración y la pérdida del hábitat de la especie (cantidad de poblados, densidad de población, densidad de caminos, y coberturas de uso de la tierra). Así mismo, se integraron los registros de casos con cocodrilos atendidos por el cuerpo de bomberos. Se logró evidenciar que la mayoría de incidentes se presentan en zonas con una alta interacción (áreas adonde se realizan una amplia varie- dad de actividades antrópicas), dentro del hábitat potencial de este reptil. Adicionalmente, los resultados obtenidos en la investigación constituyen un insumo importante en la toma de decisiones a nivel de política y ordenamiento territorial en la Región Pacífico Central, ya que en esta zona el turismo es una de las principales actividades económicas que puede llegar a ser amenazada por un ataque de ésta especie.

Four species of true crocodile (genus Crocodylus) have been described from the Americas. Three of these crocodile species exhibit non-overlapping distributions—Crocodylus intermedius in South America, C. moreletii along the Caribbean coast of Mesoamerica, and C. rhombifer confined to Cuba. The fourth, C. acutus, is narrowly sympatric with each of the other three species. In this study, we sampled 113 crocodiles across Crocodylus populations in Cuba, as well as exemplar populations in Belize and Florida (USA), and sequenced three regions of the mitochondrial genome (D-loop, cytochrome b, cytochrome oxidase I; 3,626 base pair long dataset) that overlapped with published data previously collected from Colombia, Jamaica, and the Cayman Islands. Phylogenetic analyses of these data revealed two, paraphyletic lineages of C. acutus. One lineage, found in the continental Americas, is the sister taxon to C. intermedius, while the Greater Antillean lineage is most closely related to C. rhombifer. In addition to the paraphyly of the two C. acutus lineages, we recovered a 5.4% estimate of Tamura-Nei genetic divergence between the Antillean and continental clades. The reconstructed paraphyly, distinct phylogenetic affinities and high genetic divergence between Antillean and continental C. acutus populations are consistent with interspecific differentiation within the genus and suggest that the current taxon recognized as C. acutus is more likely a complex of cryptic species warranting a reassessment of current taxonomy. Moreover, the inclusion, for the first time, of samples from the western population of the American crocodile in Cuba revealed evidence for continental mtDNA haplotypes in the Antilles, suggesting this area may constitute a transition zone between distinct lineages of C. acutus. Further study using nuclear character data is warranted to more fully characterize this cryptic diversity, resolve taxonomic uncertainty, and inform conservation planning in this system.

Understanding communal nesting has provided a deeper insight into reptile social behavior. Conspecific communal nesting has been reported frequently, while interspecific communal nesting has remained somewhat opaque. Here, we report communal egg-laying involving long-lived reptiles (American Crocodile and Ornate Slider Turtle). Our results from both field observations and literature reviewed indicate this is the first known case of communal nesting between these two species, and could suggest that crocodilians provide secondary nest attendance for nesting turtles. In addition, we present a brief review of commensal egg-laying between crocodilians and other reptiles. [ABSTRACT FROM AUTHOR]

In recent years, the incidence of attacks by crocodiles in Costa Rica has increased, which is associated with the development of human activities in areas considered as optimal in what I determine as the species' potential habitat. Given the above, the present investigation proposes the identification of zones of interaction between the crocodile and the human being from the integration of physical-geographic variables through Geographic Information Systems (GIS). In this way, a theoretical compilation was carried out to identify the physical-geographical variables that make up the crocodile's habitat (slope, drainage network, flood areas and land use coverage), as well as the socio-environmental variables that influence the alteration and loss of habitat of the species (number of neighborhoods, population density, density of roads, and coverage of land use). Likewise, case records were integrated with crocodiles assisted by the fire department. It was possible to demonstrate that most of incidents occur in areas with high interaction (areas where a wide variety of anthropic activities are carried out within the potential habitat of this reptile.) In addition, the results obtained in the investigation constitute an important input in the decision-making at the policy and territorial order level in the Central Pacific Region, since tourism is one of the main economic activities that can be threatened by an attack by this species. [ABSTRACT FROM AUTHOR]

Four species of true crocodile (genus Crocodylus) have been described from the Americas. Three of these crocodile species exhibit non-overlapping distributions--Crocodylus intermedius in South America, C. moreletii along the Caribbean coast of Mesoamerica, and C. rhombifer confined to Cuba. The fourth, C. acutus, is narrowly sympatric with each of the other three species. In this study, we sampled 113 crocodiles across Crocodylus populations in Cuba, as well as exemplar populations in Belize and Florida (USA), and sequenced three regions of the mitochondrial genome (D-loop, cytochrome b, cytochrome oxidase I; 3,626 base pair long dataset) that overlapped with published data previously collected from Colombia, Jamaica, and the Cayman Islands. Phylogenetic analyses of these data revealed two, paraphyletic lineages of C. acutus. One lineage, found in the continental Americas, is the sister taxon to C. intermedius, while the Greater Antillean lineage is most closely related to C. rhombifer. In addition to the paraphyly of the two C. acutus lineages, we recovered a 5.4% estimate of Tamura-Nei genetic divergence between the Antillean and continental clades. The reconstructed paraphyly, distinct phylogenetic affinities and high genetic divergence between Antillean and continental C. acutus populations are consistent with interspecific differentiation within the genus and suggest that the current taxon recognized as C. acutus is more likely a complex of cryptic species warranting a reassessment of current taxonomy. Moreover, the inclusion, for the first time, of samples from the western population of the American crocodile in Cuba revealed evidence for continental mtDNA haplotypes in the Antilles, suggesting this area may constitute a transition zone between distinct lineages of C. acutus. Further study using nuclear character data is warranted to more fully characterize this cryptic diversity, resolve taxonomic uncertainty, and inform conservation planning in this system. [ABSTRACT FROM AUTHOR]

Interspecific hybridization can lead to adaptation and speciation, especially in the context of recent radiations. The emblematic Crocodylus (true crocodiles) is the most broadly distributed, ecologically diverse, and species-rich crocodylian genus. Nonetheless, their within-species evolutionary processes are poorly resolved mainly due to their potential for hybridization. Notably, the evolutionary outcomes when hybridization is ancient and involves long-lived species, like crocodiles, remain largely unexplored. Here, we evaluate the genomic admixture between the American (Crocodylus acutus) and the Morelet's (Crocodylus moreletii) species, and demonstrate that this hybridization system challenges the definition of species boundaries and poses a triple conservation conundrum: what has been recognized as C. acutus is actually two distinct species, therefore its taxonomic reassessment is needed; we identified two evolutionary distinct hybrids lineages, which are genetically discernible from the parental species; the remaining C. moreletii populations evidence its likely extinction as a species and/or evolution via hybridization. Hence, the crocodiles' distinct species and hybrids lineages warrant recognition and need urgent conservation efforts.

C. acutus is cataloged in critical danger in Colombia. We studied its population at Bahia Portete, in order to survey the nesting activities and to obtain valuable information for a conservation management program. This study was undertaken with the participation of the Wayuü community using the Agreement Conservation Model, and took place during July 2007, August 2008, June and August 2009, and March to August 2010 and 2011. Sampling surveys were made by the use of transects along the coast, in order to find nests. For each nesting area found, we recorded the nests biometrics, eggs and hatchlings, fertility of the eggs and reproductive events. We explored a total of 55.12 km, and determined four nesting areas. Colonial nesting and the environmental variables were factors that affected the hatchling success. From the total of nests found, 37% were oriented towards North, and 48% were built next to Stenocereus griseus. Juyui island substrate was mostly constituted by sand (71.9%, 71.44%). The average number of eggs by nest was 28.42 ± 6.63, the largest egg diameter was 71.84 ± 3.54 mm, the average nest weight was 81.54 ± 9.99 g, and the hatchlings presented an average length of 25.47 ± 1.16 cm. For this specific site in Colombia, the reproductive period begins in March and ends in August. The few areas of nesting and the 95% fertility suggest the performance of a conservation management program for this species at Bahía Portete. Rev. Biol. Trop. 65 (1): 211-228. Epub 2017 March 01. [ABSTRACT FROM AUTHOR]

Sentinel species such as crocodilians are used to monitor the health of ecosystems. However, few studies have documented the presence of zoonotic diseases in wild populations of these reptiles. Herein we analyzed 48 serum samples from Crocodylus acutus ( n = 34) and C. moreletii ( n = 14) from different sites in the state of Quintana Roo (Mexico) to detect antibodies to Leptospira interrogans by means of a microscopic agglutination test (MAT). Crocodylus acutus and C. moreletii tested positive to 11 and 9 serovars, respectively, with Grippotyphosa being the serovar with the highest prevalence in Cozumel island (100%), Banco Chinchorro Biosphere Reserve (70.6%), and Río Hondo (100%), while in Chichankanab Lake, it was Bratislava (75%). Titers ranged from 1:50 to 1:3200, and the most frequent was 1:50 in all study sites. Leptospira is present in fresh and saltwater individuals due to the resistance of the bacterium in both environments. Cases of infected people involved with crocodile handling and egg collection suggest that these reptiles could play an important role in the transmission of leptospirosis. Preventive medicine programs should consider the monitoring of reptiles, and testing the soil and water, to prevent outbreaks of leptospirosis in facilities containing crocodiles. [ABSTRACT FROM AUTHOR]

En esta nota se describe el estado de conservación del Cocodrilo de Tumbes en Perú, donde la especie encuentra su límite sur de distribución, por lo que es catalogada como especie rara en la zona. Esto ha generado que se lleven a cabo programas de manejo ex situ para apoyar su conservación. Sin embargo el desconocimiento de los beneficios que brinda la especie, junto con la deforestación, el cambio climático y las actividades antropogénicas, han ocasionado que su población disminuya y se encuentre amenazada.

The American crocodile, Crocodylus acutus, is widely distributed in the American neotropics. It is endangered throughout most of its range and is listed as vulnerable by the International Union for the Conservation of Natural Fauna and Flora (IUCN) and on Appendix I of the Convention for the International Trade in Endangered Species of Wild Flora and Fauna (CITES). Despite this listing, there are few published reports on population status throughout most of its range. We investigated the status of the C. acutus, at several locations along the Pacific coast of Costa Rica. We carried out spotlight and nesting surveys from 2007-2009 along the Costa Rican Pacific coast in four distinct areas, coastal areas of Las Baulas (N=40) and Santa Rosa (N=9) National Parks and the Osa Conservation Area (N=13), and upriver in Palo Verde National Park (N=11). We recorded crocodile locations and standard environmental data at each observation. Encounter rates, population structure, distribution within each area and data on successful nesting (presence of hatchlings, nests, etc) were determined. We attempted to capture all crocodiles to record standard morphometrics. A total of 586 crocodiles were observed along 185.8km of survey route. The majority of animals encountered (54.9%) were either hatchlings (El cocodrilo americano, Crocodylus acutus, se encuentra ampliamente distribuido en el neotrópico Americano y hay pocos estudios publicados sobre el estado de sus poblaciones en la mayor parte de su rango de distribución. Investigamos el estado del Cocodylus acutus en varias ubicaciones a lo largo de la costa del Pacífico de Costa Rica. Se realizaron muestreos nocturnos y de anidación a lo largo de la Costa Pacífica de Costa Rica en cuatro áreas en particular desde 2007-2009,’áreas costeras en los Parque Nacionales de Las Baulas (N=40) y Santa Rosa (N=9), y en el Área de Conservación de la Osa (N=13) y en el curso alto del Parque Nacional de Palo Verde (N=11). Se registraron datos de la ubicación de los cocodrilos y datos ambientales estándar en cada observación. Se determinó la tasa de encuentros, estructura de la población, distribución dentro de cada área y evidencia de anidación exitosa (presencia de neonatos, nidos, etc.). Intentamos capturar todos los cocodrilos para registrar información morfométrica estándar. En total, se observaron 586 cocodrilos a lo largo de 185.8km de ruta de muestreo. La mayoría de los animales encontrados (54.9%) fueron neonatos (

Se utilizó la técnica de ADN Polimórfico Amplificado al Azar (RAPD) para analizar muestras de ADN de 70 individuos de C. acutus provenientes de los ríos Jesús María, Tárcoles y Tusubres en el Pacífico Central de Costa Rica para estimar la diversidad genética, la diferenciación entre poblaciones, el flujo genético y la distancia genética. La diversidad genética fue baja en los tres ríos H = 0.2201 en el río Jesús María, 0.2358 en el río Tárcoles y 0.2589 en el río Tusubres. La diversidad genética para el total de los individuos también fue baja, H = 0.2452. Entre las tres poblaciones hay una dinámica metapoblacional (G ST = 0.0367) principalmente en las poblaciones de los ríos Jesús María y Tárcoles. El valor de flujo genético (Nm = 13.1361) y el número de individuos registrado para cada río por Porras (2004) sugieren que la población del río Tárcoles está cumpliendo el papel de fuente y las de Jesús María y Tusubres constituyen los sumideros. Hubo relación directa entre la distancia genética y la distancia geográfica (z = 1.1449, r = 0.9731, p< 0.0010). Estos resultados indican la necesidad de diseñar una estrategia para la conservación de estos cocodrilos que considere la existencia de la metapoblación entre los tres ríos y también es importante realizar un estudio genético en el resto de la costa Pacífica del Costa Rica y en todo el ámbito de distribución de esta especie.The crocodylid Crocodylus acutus is found in the Central Pacific of Costa Rica only in small populations, and the species is protected by law. RAPD was used to analyze 70 DNA samples of Crocodylus acutus from the rivers Jesus Maria, Tarcoles and Tusubres in the Central Pacific of Costa Rica in order to estimate genetic diversity, differentiation among populations, gene flow and genetic distance between them. Genetic diversity was low in the three rivers, H = 0.2201 in the Jesus Maria river, 0.2358 in the Tarcoles river and 0.2589 in the Tusubres river. Among the three populations there is a metapopulational dynamic (GST = 0.0367), mainly between the populations of the Jesus Maria and Tarcoles rivers. The value of gene flow (Nm = 13.1361) and the number of individuals reported for each river in 2004 suggests that the population of the Tarcoles river is the source and those from Jesus Maria and Tusubres are the drains. There was a direct relationship between the genetic distance and the geographical distance (z =1.1449, r =0.9731, p< 0.0010). A conservation strategy for these crocodiles must consider the existence of the metapopulation between the three rivers and the importance of studying the genetics of the American Crocodile in the rest of the Pacific coast of Costa Rica, as well as over the entire distribution range of this species. Rev. Biol. Trop. 56 (3): 1471-1480. Epub 2008 September 30.

Durante los años 2001 y 2002 se realizaron observaciones sobre la reproducción de Crocodylus acutus (Cuvier, 1807) en el Centro de Acuicultura La Tuna Carranza, localizado en Puerto Pizarro, departamento de Tumbes. El tamaño mínimo de una hembra anidando fue de 2,30 m. El porcentaje de viabilidad y natalidad fue de 61,71% y 93,15% respectivamente.

Se evaluó el crecimiento en peso y longitud en 40 individuos del Cocodrilo de Tumbes en el Centro de Acuicultura La Tuna Carranza, localizado en Puerto Pizarro, Departamento de Tumbes. No se observó una diferencia en el incremento en longitud por clases de edad, mientras que en peso si presentaron diferencias siendo mayor en adultos. El crecimiento promedio de longitud y peso fue de 1,44% y 0,18% en crías, 1,30% y 0,10% en reclutas, 1,24 y 0,22% en juveniles, 1,24 y 0,48% en subadultos, y 1,01 y 0,75% en adultos. En general las hembras presentan un mayor crecimiento que los machos.

The American crocodile, Crocodylus acutus, is widely distributed in the American neotropics. It is endangered throughout most of its range and is listed as vulnerable by the International Union for the Conservation of Natural Fauna and Flora (IUCN) and on Appendix I of the Convention for the International Trade in Endangered Species of Wild Flora and Fauna (CITES). Despite this listing, there are few published reports on population status throughout most of its range. We investigated the status of the C. acutus, at several locations along the Pacific coast of Costa Rica. We carried out spotlight and nesting surveys from 2007-2009 along the Costa Rican Pacific coast in four distinct areas, coastal areas of Las Baulas (N=40) and Santa Rosa (N=9) National Parks and the Osa Conservation Area (N=13), and upriver in Palo Verde National Park (N=11). We recorded crocodile locations and standard environmental data at each observation. Encounter rates, population structure, distribution within each area and data on successful nesting (presence of hatchlings, nests, etc) were determined. We attempted to capture all crocodiles to record standard morphometrics. A total of 586 crocodiles were observed along 185.8km of survey route. The majority of animals encountered (54.9%) were either hatchlings (<0.5m) or juveniles (0.5-1.25m). The average non-hatchling encounter rate per survey for the Pacific coast was 3.1 crocodiles/km, with individual encounter rates ranging from 1.2 crocodiles/km to 4.3 crocodiles/ km in Las Baulas National Park and the Osa Conservation Area respectively. Distribution of size classes within the individual locations did not differ with the exception of Santa Rosa and Las Baulas National Parks, where hatchlings were found in water with lower salinities. These were the first systematic surveys in several of the areas studied and additional work is needed to further characterize the American crocodile population in Costa Rica. [ABSTRACT FROM AUTHOR]

In this paper, length and weigth measurements of 20 newborn Crocodylus acutus (Cuvier, 1807) hached in a pilot farm-bred of the aquaculture center La Tuna Carranza, Puerto Pizarro, Tumbes, Peru, in 2001 are presented. The information is compared with similar reports from others places.

The article presents a study which determines the sexual size dimorphism, size population, morphometrics, sex ratio, and biomass of Crocodylus (C.) acutus in the coastal zone of Belize. It mentions that the measurements obtained from the crocodiles captured during 1996-1998, 2002, and 2008-2009 include total length, snout-vent length (SVL), and dorsal cranial length (DCL). It notes that the sexual size dimorphism index (SDI) for C. acutus was 2.10. It adds that the C. acutus in coastal Belize seem to have a smaller body size than those reported populations.

Intensive crocodile monitoring programs conducted during the late 1970s and early 1980s in southern Florida resulted in an optimistic outlook for recovery of the protected species population. However, some areas with suitable crocodile habitat were not investigated, such as Biscayne Bay and the mainland shorelines of Barnes and Card Sounds. The objective of our study was to determine status and habitat use of crocodiles in the aforementioned areas. Spotlight and nesting surveys were conducted from September 1996 to December 2005. The results revealed annual increases in the number of crocodiles. Crocodiles preferred protected habitats such as canals and ponds. Fewer crocodiles were observed in higher salinity water. The distribution and abundance of crocodilians in estuaries is directly dependent on timing, amount, and location of freshwater delivery, providing an opportunity to integrate habitat enhancement with ongoing ecosystem restoration and management activities. [ABSTRACT FROM AUTHOR]

The crocodylid Crocodylus acutus is found in the Central Pacific of Costa Rica only in small populations, and the species is protected by law. RAPD was used to analyze 70 DNA samples of Crocodylus acutus from the rivers Jesus Maria, Tarcoles and Tusubres in the Central Pacific of Costa Rica in order to estimate genetic diversity, differentiation among populations, gene flow and genetic distance between them. Genetic diversity was low in the three rivers, H = 0.2201 in the Jesus Maria river, 0.2358 in the Tarcoles river and 0.2589 in the Tusubres river. Among the three populations there is a metapopulational dynamic (GST = 0.0367), mainly between the populations of the Jesus Maria and Tarcoles rivers. The value of gene flow (Nm = 13.1361) and the number of individuals reported for each river in 2004 suggests that the population of the Tarcoles river is the source and those from Jesus Maria and Tusubres are the drains. There was a direct relationship between the genetic distance and the geographical distance (z =1.1449, r =0.9731, p< 0.0010). A conservation strategy for these crocodiles must consider the existence of the metapopulation between the three rivers and the importance of studying the genetics of the American Crocodile in the rest of the Pacific coast of Costa Rica, as well as over the entire distribution range of this species. [ABSTRACT FROM AUTHOR]