Winter survivorship of hatchling broad-snouted caimans (Caiman latirostris) in Argentina

Evangelina V Viotto; Melina Soledad Simoncini; Luciano M Verdade; Joaquin L Navarro; Carlos Piña

doi:10.15451/ec2022-07-11.18-1-13

Authors

Evangelina V Viotto Centro de Investigación Científica y de Transferencia Tecnológica a la Producción - Consejo Nacional de Investigaciones Científicas y Técnicas - Provincia de Entre Ríos-Universidad Autónoma de Entre Ríos. Dr. Materi y España. CP 3105. Diamante, Entre Ríos, Argentina https://orcid.org/0000-0003-2431-4146
Melina Soledad Simoncini Centro de Investigación Científica y de Transferencia Tecnológica a la Producción - Consejo Nacional de Investigaciones Científicas y Técnicas - Provincia de Entre Ríos-Universidad Autónoma de Entre Ríos. Dr. Materi y España. CP 3105. Diamante, Entre Ríos, Argentina https://orcid.org/0000-0002-1010-5231
Luciano M Verdade Universidade de São Paulo, CENA / LE²Ave, Caixa Postal 09 Piracicaba, SP 13416-000 Brazil https://orcid.org/0000-0002-1326-0886
Joaquin L Navarro Instituto de Diversidad y Ecología Animal-Consejo Nacional de Investigaciones Científicas y Técnicas y Universidad Nacional de Córdoba - Rondeau 798, CP 5000, Córdoba, Argentina. https://orcid.org/0000-0002-8717-8797
Carlos Piña CONICET

DOI:

https://doi.org/10.15451/ec2022-07-11.18-1-13

Keywords:

Crocodylia, Kaplan-Meier, Radio telemetry, Wildlife management

Abstract

The first life stage of crocodilians is considered the most critical in terms of survival, particularly in regions that have well-defined cold seasons. To estimate this parameter for hatchling broad-snouted caimans, Class I (CI = snout-vent length < 25 cm), we released 36 caimans (18 in 2018, and 18 in 2019) born in captivity that were equipped with VHF radio-transmitters, and we monitored them during each first winter season. We actively searched for the animals during field trips and registered their status as alive, dead, lost transmitter (LT), or radio signal ceased (SC). Due to the occurrence of LT and SC, we proposed eight possible survival scenarios, assuming different combinations of "alive" and "dead" caimans. We analyzed each scenario and compared it between years. In 2018 we found 55.5% dead and 44.5% LT, resulting in survival estimates from 0 to 0.38 according to the scenario. In 2019 we found 50% alive, 33% LT, and 17% SC, with survival varying from 0.5 to 1. Survival in 2019 was higher than in 2018 in all scenarios. Assuming predation was the most plausible cause of LT, with the most likely scenarios estimated 0% survival in 2018 (although the minimum detectable by this methodology is 5%) and 67% in 2019. This information can be helpful for ranching with release programs, as it allows for a better adjustment of the reintroduction rate and opens up the possibility of earlier releases when resources to keep animals in enclosures are scarce.

Downloads

Download data is not yet available.

References

Bayliss P, Webb GJW, Whitehead PJ, Dempsey K, Smith A (1986) Estimating the abundance of saltwater crocodiles, Crocodylus porosus Schneider, in tidal wetlands of the Northern Territory: A mark-recapture experiment to correct spotlight counts to absolute numbers, and the calibration of helicopter and spotlight count. Wildlife Research 13:309–320. DOI: https://doi.org/10.1071/WR9860309

Brandt LA, Mazzotti FJ (1990) The Behavior of Juvenile Al ligator mississippiensis and Caiman crocodilus Exposed to Low Temper- ature. Copeia 3:867–871. DOI: https://doi.org/10.2307/1446456

Campos Z, Sanaiotti T, Muniz F, Farias I, Magnusson WE (2012) Parental care in the dwarf caiman, Paleosuchus palpebrosus Cuvier, 1807 (Rep- tilia: Crocodilia: Alligatoridae). Journal of Nat- ural History 46:2979–2984. DOI: https://doi.org/10.1080/00222933.2012.724723

Capelle KD (2017) Evaluating survival of re- leased ranched American alligator in coastal Louisiana. Louisiana State University and Agricultural and Mechanical College Follow.

Caughley G (1994) Directions in Conservation Biology. The Journal of Animal Ecology 63:215. DOI: https://doi.org/10.2307/5542

Chapman JL, Reiss MJ (1998) Ecology: principles and Aapplications. Segunda ed. Cambridge. DOI: https://doi.org/10.1017/CBO9781107340893

De la Peña P (1994) Catálogo de nombres comunes de la flora Argentina. Santa Fe.

Diefenbach COC (1988) Thermal and feeding relations of Caiman latirostris (Crocodylia: Reptilia). Comparative Biochemistry and Physiology – Part A: Physiology 89:149–155. DOI: https://doi.org/10.1016/0300-9629(88)91072-9

Fujisaki I, Mazzotti FJ, Dorazio RM, Rice KG, Cherkiss M, Jeffery B (2011) Estimating trends in alligator populations from nightlight survey data. Wetlands 31:147–155. DOI: https://doi.org/10.1007/s13157-010-0120-0

Huntington JL, Hegewisch KC, Daudert B, Morton CG, Abatzoglou JT, McEvoy DJ, Erickson T (2017) Climate Engine: cloud computing of climate and remote sensing data for advanced natural resource monitoring and process understanding. Bulletin of the American Meteorological Society 98:2397–2410. DOI: https://doi.org/10.1175/BAMS-D-15-00324.1

Hussain SA (1999) Reproductive success, hatch- ling survival and rate of increase of gharial Gavialis gangeticus in National Cham- bal Sanctuary, India. Biological Conservation 87:261–268. DOI: https://doi.org/10.1016/S0006-3207(98)00065-2

Hutton JM, Webb GJW (2002) Legal trade snaps back: using the experience of crocodilians to draw lessons on regulation of the wildlife trade. In: IUCN CSG (ed) Crocodiles. Proceedings of the 16st Working Meeting of the IUCN-SSC Crocodile Specialist Group. Gland, pp. 1–10.

Knapp CR, Abarca JG (2009) Effects of radio transmitter burdening on locomotor ability and survival of iguana hatchlings. Herpetologica 65:363–372. DOI: https://doi.org/10.1655/09-003.1

Lang JW (1987) Crocodilian behavior: implica- tions for management. In: Weeb GJW, Manolis C, Whitehead PJ (eds) Wildlife Management: Crocodile and Alligators. pp. 273–294.

Larriera A (1995) Áreas de nidificación y mo- mento óptimo de cosecha de huevos de Caiman latirostris en Santa Fe, Argentina. In: Larriera A, Verdade LM (eds) La Conservación y el Manejo de Caimanes y Cocodrilos de América Latina. Santo Tomé, pp. 221–232.

Larriera A (2011) Ranching the broad-snouted cayman (Caiman latirostris) in Argentina: An economic incentive for wetland conservation by local inhabitants. In: Abensperg-Traun M, Roe D, O’Criodain C (eds) Proceedings of an international symposium on “The relevance of CBNRM to the con- servation and sustainable use of CITES-listed species in exporting countries.” Gland, Switzerland: IUCN and London, UK, pp. 86–92.

Larriera A, Imhof A (2006) Proyecto Yacaré. Cosecha de huevos para cría en granjas del género Caiman en la Argentina. Manejo de Fauna Silvestre en la Argentina Programas de uso Sustentable. Santa Fe, pp. 51–64.

Larriera A, Piña CI (2000) Caiman latirostris (Broad-snouted caiman) nest predation: does low rainfall facilitate predator access? Herpeto- logical Natural History 7:73–77.

Larriera A, Piña CI, Siroski P, Verdade LM (2004) Allometry of reproduction in wild Broad-snouted caimans (Caiman latirostris ). Journal of Her- petology 38:301–304. DOI: https://doi.org/10.1670/145-03A

Larriera A, Siroski P, Piña CI, Imhof A (2006) Sexual maturity of farm-released Caiman latirostris (crocodylia: Alligatoridae) in the wild. Herpetological Review 37:26–28.

Larriera A, Imhof A, Siroski P (2008) Estado actual de los programas de conservación y manejo del género Caiman en Argentina. Contribución al conocomiento de los caimanes del genero Caiman de Sudamerica. Santa Fe, Argentina, pp. 143–179.

Leiva PML, Simoncini MS, Portelinha TCG, Larriera A (2018) Size of nesting female Broad-snouted Caimans (Caiman latirostris Daudin 1802). Brazilian Journal of Biology 79:1–5. DOI: https://doi.org/10.1590/1519-6984.180892

Lorenzon R, Leiva L (2019) Plan de manejo de la Reserva Natural Manejada “El Fisco”, Santa Fe, Argentina. Período 2019-2024. Santa Fe.

Magnusson WE (1984) The peculiarities of crocodilian population dynamics and their pos-

sible importance for management strategies. In: IUCN C (ed) Proceedings of the 7th working meet- ing of the Crocodile Specialist Group, Switzerland. Gland, pp. 434–442.

Mazzotti FJ, Best GR, Brandt LA, Cherkiss MS, Jeffery BM, Rice KG (2009) Alligators and crocodiles as indicators for restoration of Everglades ecosystems. Ecological Indicators 9:137–149. DOI: https://doi.org/10.1016/j.ecolind.2008.06.008

Mazzotti FJ, Cherkiss MS, Parry M, Beauchamp J, Rochford M, Smith B, Hart K, Brandt LA (2016) Large reptiles and cold temperatures: Do ex- treme cold spells set distributional limits for tropical reptiles in Florida? Ecosphere 7:1–9. DOI: https://doi.org/10.1002/ecs2.1439

Montini JP, Piña CI, Larriera A, Siroski P, Ver- dade LM (2006) The relationship between nesting habitat and hatching success in Caiman latirostris Crocodylia, Alligatoridae. Phyllomedusa 5:91–96. DOI: https://doi.org/10.11606/issn.2316-9079.v5i2p91-96

Nichols JD (1987) Population models and crocodile management. In: Webb GJW, Mano- lis SC, Whitehead PJ (eds) Wildlife Management: Crocodiles and Alligators. Chipping Norton, pp. 177–187.

O ́Mara MTO, Wikelski M, Dechmann DKN (2014) 50 years of bat tracking: device attachment and future directions. Methods in Ecology and Evolution 2014 5:311–319. DOI: https://doi.org/10.1111/2041-210X.12172

Piña CI, Siroski P, Príncipe G, Simoncini MS (2010) Populations status of Caiman yacare and Caiman latirostris in North Argentina. Crocodilia 1:1–5.

Portelinha TCG, Verdade LM, Piña CI (2022) Detectability of Caiman latirostris (Crocodylia: Alligatoridae) in night count surveys. South American Journal of Herpetology 23:25–31. DOI: https://doi.org/10.2994/SAJH-D-19-00092.1

R Core Team (2019) R: A Language and envi- ronment for statistical computing. R Founda- tion for Statistical Computing. [ https://www.r- project.org].

Reyes S, Moleón MS, Parachú Marcó, M. Virginia Pietrobon EO, Jahn GA, Siroski PA (2018) Exper- imental consequences of low temperatures on Caiman latirostris inmune and endocrine sys- tems. In: IUCN CSG (ed) Proceedings of the 25th Working Meeting of the IUCN-SSC Crocodile Special- ist Group. IUCN: Gland, p. 183.

Simoncini MS, Leiva PML, Piña CI, Cruz FB (2019)

Influence of temperature variation on incuba- tion period, hatching success, sex ratio, and phenotypes in Caiman latirostris. Journal of Experimental Zoology Part A: Ecological and Integrative Physiology 331:299–307. DOI: https://doi.org/10.1002/jez.2265

Simoncini MS, Piña CI, Siroski PA (2009) Clutch size of Caiman latirostris (Crocodylia: Alligatoridae) varies on a latitudinal gradient. North- Western Journal of Zoology 5:191–196.

Smith AMA, Webb GJW (1985) Crocodylus John- stoni in the McKinlay river area, N.T. VII. A population simulation model. Wildlife Research 12:541–554. DOI: https://doi.org/10.1071/WR9850541

Somaweera R, Brien M, Shine R (2013) The role of Predation in shaping crocodilian natural history. Herpetological Monographs 27:23. DOI: https://doi.org/10.1655/HERPMONOGRAPHS-D-11-00001

Temsiripong Y, Woodward AR, Ross JP, Kubilis PS, Percival HF (2006) Survival and growth of American alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation. Journal of Herpetology 40:415–423. DOI: https://doi.org/10.1670/0022-1511(2006)40[415:SAGOAA]2.0.CO;2

Therneau T (2019) A package for survival analysis in R.

Verdade LM, Zucoloto RB, Coutinho LL (2002) Microgeographic variation in Caiman latirostris . Journal of Experimental Zoology 294:387–396. DOI: https://doi.org/10.1002/jez.10200

Viotto E V., Navarro JL, Piña CI (2020) Growth curves of wild and reintroduced Broad-Snouted Caimans (Caiman latirostris ) and their management implications. South American Journal of Herpetology 16:34–41. DOI: https://doi.org/10.2994/SAJH-D-18-00077.1

White GC, Garrott RA (1990) Analysis of wildlife Radio-Tracking data. San Diego.

Wood JP, Patton TM, Page RB (2017) Movement and overwinter survival of released captive-raised juvenile American Alligators (Alligator mississippiensis) in Southeastern Oklahoma, USA. Herpetological Review 48:293–299.