A draft genome sequence of the common, or spectacled caiman Caiman crocodilus

The common, or spectacled, caiman Caiman crocodilus is an abundant, widely distributed Neotropical crocodilian exhibiting notable morphological and molecular diversification. The species also accounts by far for the largest share of crocodilian hides on the global market, with the C. crocodilus hide trade alone valued at about US$86.5 million per year. We obtained 239,911,946 paired-end reads comprising approximately 72 G bases using IlluminaTM sequencing of tissue sampled from a single Caiman crocodilus individual. These reads were de-novo assembled and progressively aligned against the genomes of increasingly related crocodilians; liftoff was used to annotate the draft C. crocodilus genome assembly based on an Alligator mississipiensis (a confamilial species) annotation. The draft assembly has been submitted to the National Center for Biotechnology Information and both assembly and annotation are currently available for review at doi.org/10.5281/zenodo.4755063

Population status of the American crocodile, Crocodylus acutus (Reptilia: Crocodylidae) and the spectacled caiman, Caiman crocodilus (Reptilia: Alligatoridae) in the Costa Rican North Caribbean

Along the Costa Rican Caribbean shoreline, it is possible to find two species of crocodilians, the American crocodile (Crocodylus acutus) and the spectacled caiman (Caiman crocodilus). This region can be divided geographically into three subregions: North, Central, and South Caribbean. We conducted this research in the North Caribbean, between October 6, 2018 and August 31, 2019. Specifically, we worked in the area lying between the Jalova Station of the Tortugero National Park (TNP) and Agua Dulce Lake situated in the northern tip of Machuca Island, at the mouth of the Colorado River inside the Barra del Colorado National Wildlife Refuge (BACORE), which includes other connecting wetlands as well (Sierpe River, Samay Lake). Overall, this study area had an approximate extension of 408 km2 characterized by large, wide and deep canals, as well as wetlands, meanders, and adjacent lakes. The sampling was performed along 10 segments that varied in length from 7.5 km up to 29.49 km, located in the nearby zones of TNP and BACORE. In these zones, nightly counts were carried out using dazzling lamps. Individuals of C. acutus and C. crocodilus were classified into eight and six body size classes, respectively (both with 50 cm intervals). A relative abundance of 0.55 crocodiles and 1.37 caimans per linear kilometer was estimated during these spotlight surveys. The capture of 39 caimans let us to estimate a ratio of 30 males to 9 females (3.3:1 M:F). In stark contrast, only 1 male and 1 female crocodile were captured. A total of 85 C. acutus and 205 C. crocodilus were observed. Regarding the number of caiman sightings in the TNP, a statistically significant difference was found (Χ2=5.62, p≤0.05) for the distribution by sizes between the zones of BACORE and TNP, whereas no such difference was found for C. crocodilus sightings (Z=–1.22, p≥0.222). Some segments had a higher probability of caiman occurrence than did others in the surveys performed during the monitoring period (X2=8.36, p≤0.05), especially the Jalova-Sierpe River, Caño Negro-Tortuguero, and Tortuguero-Samay Lake (Tortuguero subarea) segments. Ninety percent of the sightings occurred in the BACORE zone, and this was significantly different (Χ2=7.34, p≤0.026) from the studied subareas. The number of crocodile sightings in the Colorado River segment was significantly different and higher than the other segments (X2=7.28, p≤0.05). There was a significant statistical difference among the sizes in all areas of study (X2=5.529, p≤0.026). The abundance of C. acutus and C. crocodilus in the north Caribbean part is lower than in the central Caribbean part of Costa Rica, where this species could use the resources available in more urbanized areas.

Reptiles y aves del Distrito de Manejo Integrado Cabo Manglares Bajo Mira-Frontera, Pacífico colombiano

Evaluamos la diversidad de reptiles y aves en el Distrito de Manejo Integrado de Cabo Manglares Bajo Mira-Frontera, en el departamento de Nariño, Colombia, mediante muestreos hechos en noviembre de 2018. Para reptiles se realizaron búsquedas libres delimitadas por tiempo; para aves, se realizaron recorridos libres y puntos de observación. Se obtuvieron 25 registros de reptiles pertenecientes a tres órdenes, 17 familias, 23 géneros y 24 especies. De aves se registraron 179 individuos pertenecientes a 16 órdenes, 40 familias, 106 géneros y 119 especies. Para reptiles se destacan los registros de las tortugas Lepidochelys olivacea, categorizada como Vulnerable, y Chelonia mydas, En Peligro, y las especies Caiman crocodilus y Boa constrictor, incluidas en el apéndice II de CITES. Para las aves se destacan los registros de 31 especies migratorias, y tres especies Casi Amenazadas (Ramphastos ambiguus, Campephilus gayaquilensis, Capito squamatus).

Factors influencing the occurrence of negative interactions between people and crocodilians in Mexico

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.

Mortalidad de vertebrados silvestres por atropellamiento en el departamento de Casanare, Colombia

Las carreteras generan impactos negativos sobre la biodiversidad, dentro de los cuales los atropellamientos configuran una de las causas directas más relevantes. El objetivo de este estudio fue establecer la distribución temporal y evaluar los patrones espaciales relacionados con el atropellamiento de vertebrados silvestres en las rutas Yopal-Quebradaseca y Yopal-variante Jagüeyes, en Casanare, Colombia. Entre 2017 y 2018 se realizaron 18 recorridos a 40 km/hora en los que se registraron eventos de atropellamiento. Se determinaron tasas de atropellamiento, puntos calientes, así como variables del paisaje (humedales, vegetación nativa, construcciones) y de la vía (forma y presencia de señales de paso) relacionadas con este tensor. Se registraron 139 eventos de colisión, que incluyeron ocho especies de mamíferos, 13 de reptiles, 20 de aves y una de anfibio. Caiman crocodilus (n = 17), Rhinella marina (n = 13) y Tamandua tetradactyla (n = 13) fueron las especies más atropelladas. Myrmecophaga tridactyla fue la única especie amenazada reportada dentro de este grupo de vertebrados. La mayor tasa de atropellamiento en ambas vías fue encontrada para los reptiles. Para el total de datos, se identificaron 15 puntos calientes de atropellamiento. De forma general, los atropellamientos estuvieron asociados a tramos curvos de la vía, cercanos a humedales cercanos y en zonas sin infraestructura. El 64 % de los individuos atropellados se encontraron una distancia menor a 2 km a una señal de tránsito, lo que indica una baja efectividad de esta medida. Este es el primer reporte de atropellamiento de fauna para la sabana inundable y se espera que sea una herramienta de mitigación de esta amenaza en el departamento

Procedimentos sanitários operacionais aplicados à abatedouro-frigorífico de Jacaré-do-Pantanal (Caiman crocodilus yacare)

The objective of the work was to identify and describe the operational sanitary procedures (OSP) applied in the slaughterhouse of the Pantanal alligator, as well as the possible corrective actions for non-conformities that may be found during the process, in order to reduce or eliminate cross-contamination. Once the alligator slaughter production flowchart was known, it was possible to identify six control points: bleeding, skinning, evisceration, toilet, washing the carcasses and cooling. The OSP refers to a preventive program, as well as the other self-control programs, which must be executed based on preventive measures, thus avoiding possible non-conformities.