Population Ecology of American Crocodile (Crocodylus acutus) in Coiba National Park, Panama

2015 ◽  
Vol 49 (3) ◽  
pp. 349-357 ◽  
Author(s):  
Miryam Venegas-Anaya ◽  
Armando H. Escobedo-Galván ◽  
Sergio A. Balaguera-Reina ◽  
Faith Lowrance ◽  
Oris I. Sanjur ◽  
...  
Keyword(s):  
Population Ecology ◽  
National Park ◽  
Crocodylus Acutus ◽  
American Crocodile

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

2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Iván Sandoval Hernández ◽  
Juan José Sánchez Ramírez ◽  
Juan Rafael Bolaños Montero ◽  
Juan Salvador Monrós González
Keyword(s):  
National Park ◽  
Colorado River ◽  
Costa Rican ◽  
Population Status ◽  
North Central ◽  
Caiman Crocodilus ◽  
The North ◽  
Crocodylus Acutus ◽  
American Crocodile ◽  
Significant Difference

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.

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

Oryx ◽  
2021 ◽  
pp. 1-9
Author(s):  
Giovany Arturo González-Desales ◽  
Luis Sigler ◽  
Jesús García-Grajales ◽  
Pierre Charruau ◽  
Martha Mariela Zarco-González ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Biosphere Reserve ◽  
Rigorous Evaluation ◽  
Caiman Crocodilus ◽  
Crocodylus Acutus ◽  
American Crocodile ◽  
Nesting Sites ◽  
The Relationship ◽  
Nesting Season ◽  
Negative Interactions

Abstract 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.

scholarly journals Some aspects of the history and population ecology of the tsessebe damaliscus lunatus lunatus in the Kruger National Park

Koedoe ◽  
1977 ◽  
Vol 20 (1) ◽  
Author(s):  
S.C.J. Joubert ◽  
P.J.L. Bronkhorst
Keyword(s):  
Sex Ratio ◽  
Population Ecology ◽  
Age Structure ◽  
National Park ◽  
Kruger National Park ◽  
Population Trends ◽  
Social Organisation ◽  
Developmental History ◽  
The Social ◽  
History Of

The population trends and distribution of the tsessebe population of the Kruger National Park are evaluated in terms of the available data derived from records compiled in the developmental history of the Kruger National Park (KNP). The recent numerical status of the population is also given. A description of the habitats favoured by tsessebe in the KNP is presented as well as an analysis of the age structure and sex-ratio of the population. Aspects of the social organisation of tsessebe affecting the interpretation of the age structure and sex-ratio phenomena of the population, are also discussed.

scholarly journals Differences in distress: Variance and production of American Crocodile ( Crocodylus acutus ) distress calls in Belize

2020 ◽  
Vol 10 (18) ◽  
pp. 9624-9634
Author(s):  
Miriam Boucher ◽  
Marisa Tellez ◽  
James T. Anderson
Keyword(s):  
Crocodylus Acutus ◽  
American Crocodile ◽  
Distress Calls

Status and conservation of the American crocodile, Crocodylus acutus, in Belize

2000 ◽  
Vol 96 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Steven G. Platt ◽  
John B. Thorbjarnarson
Keyword(s):  
Crocodylus Acutus ◽  
American Crocodile

Scalation of the American Crocodile,Crocodylus acutus(Crocodylidae, Crocodilia), from the Coastal Zone of Northern Belize

2010 ◽  
Vol 46 (2-3) ◽  
pp. 332-338 ◽  
Author(s):  
Steven G. Platt ◽  
John B. Thorbjarnarson ◽  
Thomas R. Rainwater
Keyword(s):  
Coastal Zone ◽  
Crocodylus Acutus ◽  
American Crocodile

The Nest Environment of the American Crocodile (Crocodylus acutus)

Copeia ◽  
1984 ◽  
Vol 1984 (1) ◽  
pp. 153 ◽  
Author(s):  
Peter L. Lutz ◽  
Ann Dunbar-Cooper
Keyword(s):  
Crocodylus Acutus ◽  
American Crocodile

Relative abundance of the central rock-rat, the desert mouse and the fat-tailed pseudantechinus at Ormiston Gorge in the West MacDonnell Ranges National Park, Northern Territory

2013 ◽  
Vol 35 (2) ◽  
pp. 144 ◽  
Author(s):  
G. P. Edwards
Keyword(s):  
Population Ecology ◽  
Relative Abundance ◽  
National Park ◽  
Northern Territory ◽  
Mammal Species ◽  
The West

This study examines the relative abundance of two species of sympatric rodent, the desert mouse (Pseudomys desertor) and the central rock-rat (Zyzomys pedunculatus), and a sympatric dasyurid (Pseudantechinus macdonnellensis) in relation to rainfall in the West Macdonnell Ranges National Park, Northern Territory, over a 6-year period. Seventeen trapping sessions were conducted between July 2000 and September 2006. All three species showed spikes in abundance during 2001 and 2002, which were very wet years, and then declined as rainfall diminished. Z. pedunculatus was not trapped at the sites beyond June 2002 while P. desertor was not trapped beyond September 2002. P. macdonnellensis was trapped in low numbers between September 2002 and February 2005 but was not trapped subsequently. Rainfall and the abundance of all three mammal species were clearly correlated. However, the patterns of abundance were subtly different. Z. pedunculatus exhibited three distinct peaks in abundance during the study (July 2000, April 2001 and March 2002), P. desertor exhibited two distinct peaks (July 2001 and June 2002) while. P. macdonnellensis exhibited only one peak in abundance (March 2002). The results of this study provide more evidence that populations of both arid Australian rodents and some dasyurids are influenced by rainfall. The study also provides some insights into the population ecology of the poorly known and threatened central rock-rat.

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