1
|
Reproductive Dynamics of an Isolated Population of American Crocodiles (Crocodylus acutus) Based on Long-term Monitoring Data. J HERPETOL 2022. [DOI: 10.1670/21-019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
2
|
Mazzotti FJ, Balaguera-Reina SA, Brandt LA, Briggs-González V, Cherkiss M, Farris S, Godahewa A. Natural and Anthropogenic Factors Influencing Nesting Ecology of the American Crocodile in Florida, United States. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.904576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Nesting ecology of American crocodiles (Crocodylus acutus) in Florida has been both positively and negatively influenced by anthropogenic and natural factors since the species was placed on the federally endangered species list in 1975. This includes a shift in nesting sites and an expansion of nesting to anthropogenic habitat. Using a 50-year record of monitoring data (1970-2020), we assessed factors influencing nesting ecology (number of nests, nest morphology, success rate, and habitat use) from a total of 3,013 nests recorded across South Florida. We detected a change in nesting success rate, increasing from 61% in the 1970’s to near 90% since 2010. Our hot spot analysis illustrates that nesting sites in northeastern Florida Bay and Flamingo/Cape Sable (Everglades National Park) were important for American crocodiles. Anthropogenic habitats, such as canals provided vital habitat nesting in areas such as Flamingo/Cape Sable (Everglades National Park), Turkey Point Power Plant, and Crocodile Lake National Wildlife Refuge for the current Florida population. Environmental parameters suspected to affect nesting success have shown an increasing trend over the past 50 years and minimum temperature and rainfall, during the summer season, are correlated with increased nesting success and temporal variation across South Florida. The adaptive capacity that American crocodiles exhibited in Florida gave the species advantages to face changes in climate and landscape over the last 50 years, however, it does not imply that the adaptive capacity of the species to face these changes (evolutionary potential) cannot reach a limit if changes continue. Here, we document C. acutus nesting ecology population responses to ecosystem restoration efforts in Florida; and further demonstrate the value of protecting and restoring habitat to support recovery of listed species.
Collapse
|
3
|
Platt SG, Rainwater TR, McMurry ST. Fauna associated with the nests of Crocodylus moreletii and Crocodylus moreletii × acutus in Belize. J NAT HIST 2021. [DOI: 10.1080/00222933.2021.1895350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Steven G. Platt
- Wildlife Conservation Society - Myanmar Program, Yangon, Myanmar
| | - Thomas R. Rainwater
- Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC, USA
| | - Scott T. McMurry
- Department of Integrative Biology, 521 Life Sciences West, Oklahoma State University, Stillwater, OK, USA
| |
Collapse
|
4
|
Briggs-Gonzalez VS, Basille M, Cherkiss MS, Mazzotti FJ. American crocodiles (Crocodylus acutus) as restoration bioindicators in the Florida Everglades. PLoS One 2021; 16:e0250510. [PMID: 34010342 PMCID: PMC8133456 DOI: 10.1371/journal.pone.0250510] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 04/07/2021] [Indexed: 11/18/2022] Open
Abstract
The federally threatened American crocodile (Crocodylus acutus) is a flagship species and ecological indicator of hydrologic restoration in the Florida Everglades. We conducted a long-term capture-recapture study on the South Florida population of American crocodiles from 1978 to 2015 to evaluate the effects of restoration efforts to more historic hydrologic conditions. The study produced 10,040 crocodile capture events of 9,865 individuals and more than 90% of captures were of hatchlings. Body condition and growth rates of crocodiles were highly age-structured with younger crocodiles presenting with the poorest body condition and highest growth rates. Mean crocodile body condition in this study was 2.14±0.35 SD across the South Florida population. Crocodiles exposed to hypersaline conditions (> 40 psu) during the dry season maintained lower body condition scores and reduced growth rate by 13% after one year, by 24% after five years, and by 29% after ten years. Estimated hatchling survival for the South Florida population was 25% increasing with ontogeny and reaching near 90% survival at year six. Hatchling survival was 34% in NE Florida Bay relative to a 69% hatchling survival at Crocodile Lake National Wildlife Refuge and 53% in Flamingo area of Everglades National Park. Hypersaline conditions negatively affected survival, growth and body condition and was most pronounced in NE Florida Bay, where the hydrologic conditions have been most disturbed. The American crocodile, a long-lived animal, with relatively slow growth rate provides an excellent model system to measure the effects of altered hydropatterns in the Everglades landscape. These results illustrate the need for continued long-term monitoring to assess system-wide restoration outcomes and inform resource managers.
Collapse
Affiliation(s)
- Venetia S. Briggs-Gonzalez
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, Florida, United States of America
- * E-mail:
| | - Mathieu Basille
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, Florida, United States of America
| | - Michael S. Cherkiss
- U.S. Geological Survey, Wetland and Aquatic Research Center, Fort Lauderdale, Florida, United States of America
| | - Frank J. Mazzotti
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Fort Lauderdale, Florida, United States of America
| |
Collapse
|
5
|
Khadka B, Bashyal A, Luitel KP, Kandel RC. Nesting Ecology of Gharials (Gavialis gangeticus): Implications from In Situ and Ex Situ Conservation Programs in Chitwan National Park, Nepal. HERPETOLOGICA 2020. [DOI: 10.1655/herpetologica-d-19-00038.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Bed Khadka
- Gharial Conservation Breeding Center, Chitwan National Park, Chitwan, Nepal
| | | | - Kishor P. Luitel
- Middle Tennessee State University, School of Agriculture, Murfreesboro, TN 37132, USA
| | - Ram C. Kandel
- Department of National Parks and Wildlife Conservation, Kathmandu, Nepal
| |
Collapse
|
6
|
Balaguera-Reina SA, Venegas-Anaya MD, Rivera-Rivera B, Morales Ramírez DA, Densmore LD. How to estimate population size in crocodylians? Population ecology of American crocodiles in Coiba Island as study case. Ecosphere 2018. [DOI: 10.1002/ecs2.2474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Sergio A. Balaguera-Reina
- Department of Biological Sciences; Texas Tech University; Lubbock Texas 79409 USA
- Programa de Biología Ambiental; Facultad de Ciencias Naturales y Matemáticas; Universidad de Ibagué; Carrera 22 Calle 67 Ibagué 730001 Colombia
| | | | | | | | | |
Collapse
|
7
|
Food habits and ontogenetic dietary partitioning of American crocodiles in a tropical Pacific Island in Central America. Ecosphere 2018. [DOI: 10.1002/ecs2.2393] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
8
|
Briggs-Gonzalez V, Bonenfant C, Basille M, Cherkiss M, Beauchamp J, Mazzotti F. Life histories and conservation of long-lived reptiles, an illustration with the American crocodile (Crocodylus acutus). J Anim Ecol 2017; 86:1102-1113. [DOI: 10.1111/1365-2656.12723] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 06/05/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Venetia Briggs-Gonzalez
- Department of Wildlife Ecology and Conservation; Fort Lauderdale Research and Education Center; University of Florida; Fort Lauderdale FL USA
| | - Christophe Bonenfant
- Laboratoire de Biométrie et Biologie Évolutive; Université de Lyon; CNRS; UMR 5558; Villeurbanne France
| | - Mathieu Basille
- Department of Wildlife Ecology and Conservation; Fort Lauderdale Research and Education Center; University of Florida; Fort Lauderdale FL USA
| | - Michael Cherkiss
- U.S. Geological Survey; Wetland and Aquatic Research Center; Center for Collaborative Research; Fort Lauderdale FL USA
| | - Jeff Beauchamp
- Department of Wildlife Ecology and Conservation; Fort Lauderdale Research and Education Center; University of Florida; Fort Lauderdale FL USA
| | - Frank Mazzotti
- Department of Wildlife Ecology and Conservation; Fort Lauderdale Research and Education Center; University of Florida; Fort Lauderdale FL USA
| |
Collapse
|
9
|
Rivas JA, Molina CR, Corey SJ, Burghardt GM. Natural History of Neonatal Green Anacondas (Eunectes murinus): A Chip Off the Old Block. COPEIA 2016. [DOI: 10.1643/ce-15-238] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
10
|
Balaguera-Reina SA, Venegas-Anaya M, Sánchez A, Arbelaez I, Lessios HA, Densmore LD. Spatial Ecology of the American Crocodile in a Tropical Pacific Island in Central America. PLoS One 2016; 11:e0157152. [PMID: 27280554 PMCID: PMC4900666 DOI: 10.1371/journal.pone.0157152] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/25/2016] [Indexed: 12/05/2022] Open
Abstract
Conservation of large predators has long been a challenge for biologists due to the limited information we have about their ecology, generally low numbers in the wild, large home ranges and the continuous expansion of human settlements. The American crocodile (Crocodylus acutus) is a typical apex predator, that has suffered from all of these characteristic problems, especially the latter one. Humans have had a major impact on the recovery of this species throughout its range, even though most of the countries it inhabits have banned hunting. The last decade has made it clear that in order to implement sound conservation and management programs, we must increase our understanding of crocodile spatial ecology. However, in only two countries where American crocodiles have telemetry studies even been published. Herein we have characterized the spatial ecology of C. acutus on Coiba Island, Panama, by radio-tracking (VHF transmitters) 24 individuals between 2010 and 2013, to determine movement patterns, home range, and habitat use. We have then compared our findings with those of previous studies to develop the most comprehensive assessment of American crocodile spatial ecology to date. Females showed a higher average movement distance (AMD) than males; similarly, adults showed a higher AMD than sub-adults and juveniles. However, males exhibited larger home ranges than females, and concomitantly sub-adults had larger home ranges than juveniles, hatchlings, and adults. There was an obvious relationship between seasonal precipitation and AMD, with increased AMD in the dry and “low-wet” seasons, and reduced AMD during the “true” wet season. We found disaggregate distributions according to age groups throughout the 9 habitat types in the study area; adults and hatchlings inhabited fewer habitat types than juveniles and sub-adults. These sex- and age-group discrepancies in movement and habitat choice are likely due to the influences of reproductive biology and Coiba’s precipitation cycle. Juveniles also showed distinct movement patterns and home ranges; however, with sexual maturation and development, these behaviors became more characteristic of adults and sub-adults. Ours is one of a very small number of studies that will allow future management and conservation planning to be based on the comprehensive integration of the spatial ecology of a Neotropical crocodylian apex predator.
Collapse
Affiliation(s)
- Sergio A. Balaguera-Reina
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409–3131, United States of America
- * E-mail: ;
| | - Miryam Venegas-Anaya
- Smithsonian Tropical Research Institute, Apartado Postal 0843–03092, Balboa, Ancón, Republic of Panama
| | - Andrés Sánchez
- Facultad de Biología, Universidad del Quindío, Armenia, Colombia
| | - Italo Arbelaez
- Facultad de Biología Marina, Universidad de Bogotá Jorge Tadeo Lozano, Bogotá, Colombia
| | - Harilaos A. Lessios
- Smithsonian Tropical Research Institute, Apartado Postal 0843–03092, Balboa, Ancón, Republic of Panama
| | - Llewellyn D. Densmore
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409–3131, United States of America
| |
Collapse
|
11
|
González-Desales GA, Monroy-Vilchis O, Zarco-González M, Charruau P. Nesting ecology of the American crocodile in La Encrucijada Biosphere Reserve, Mexico. AMPHIBIA-REPTILIA 2016. [DOI: 10.1163/15685381-00003051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Nesting of the American crocodile (Crocodylus acutus) is affected by natural and anthropogenic processes. In Mexico, few studies exist on reproductive traits of wild populations. We assessed the key reproductive characteristics ofC. acutusin the La Encrucijada biosphere reserve and the environmental and anthropogenic factors that influence them. From February to June 2014, we searched for nests in the reserve. Clutch incubation temperature was recorded by data loggers and climatic variables were obtained from La Encrucijada meteorological station. Additionally, outside the study area, net primary productivity was obtained for different sites in Mexico to relate it to clutch characteristics. We found 34 nests in nine nesting areas. Egg laying occurred in March, and hatching took place from mid-May to early June. Mean clutch and eggs characteristics are among the higher reported forC. acutus. Some egg attributes had a relationship with the net primary productivity. There was no relation between hatching success and external and internal characteristics of the nest. A high percentage of nests was poached (50%) mainly for egg consumption and fear of crocodiles, and the nests closer to the river, trees or human settlements are more likely to be poached.
Collapse
Affiliation(s)
| | - Octavio Monroy-Vilchis
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, México
| | - Martha M. Zarco-González
- Centro de Investigación en Ciencias Biológicas Aplicadas, Universidad Autónoma del Estado de México, México
| | - Pierre Charruau
- Centro del Cambio Global y la Sustentabilidad en el Sureste A.C., Tabasco, México
| |
Collapse
|
12
|
Piña CI, Merchant ME, Verdade LM. Introduction: Reproduction in Crocodilians. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2015. [DOI: 10.2994/sajh-d-15-00006.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|