Nesting of Morelet's crocodile, Crocodylus moreletii , em Los Tuxtlas, Mexico

• Published in: Brazilian journal of biology Vol. 77; no. 4; p. 724
• Main Authors: Villegas, A, Mendoza, G.D, Arcos-Garcia, J.L, Reynoso, V.H
• Format: Journal Article
• Language: English
• Published: Association of the Brazilian Journal of Biology 01.11.2017
• Subjects: Guatemala; México; Belice
• ISSN: 1519-6984; 1678-4375
• DOI: 10.1590/1519-6984.19015

We evaluated the nesting by Crocodylus moreletii in Lago de Catemaco, Veracruz, southeastern, Mexico. During the nesting and hatching seasons, we searched for nests along the northern margins of the lake and small associated streams. We investigated egg mortality by weekly monitoring each of the nests found, recording sign of predation (tracks and holes dug into the nest) and the effect of water level fluctuations. We not found differences to nest between inland or flooded zones. However, we found that egg size varied among nests. In nests built inland, predation was the major cause of egg mortality whereas flooding resulted in more deaths of eggs in the flooding zone. Flooding killed 25% of eggs monitored in this study. We suggest that to increase nest success in the Morelet's crocodile it is necessary to promote conservation of nesting areas around the lake, recently occupied by urban or tourist developments. Keywords: crocodile, egg mortality, flooding, Mexico, predation. Nos avaliamos a nidificagao numa populagao de Crocodylus moreletii no Lago de Catemaco, Veracruz, sudeste, Mexico. Durante as temporadas de nidificagao e eclosao buscamos ninhos ao longo das margens situadas ao norte do lago e pequenos riachos associados. Estabelecemos a mortalidade de ovos por semana monitorando cada ninho achado, registrando qualquer sinal de predagao (rastros e buracos cavados no ninho) e o efeito das flutuagoes no nivel da agua. Nao achamos nenhuma preferencia para aninhar na terra ou em areas inundadas. Por outro lado, achamos que o tamanho de ovo foi significativamente diferente entre os tipos de ninho. Em ninhos constrmdos na terra, a predagao foi a principal causa da mortalidade de ovos enquanto que nas areas inundadas, inundagao foi um fator importante na morte dos ovos. Em comparagao com depredagao, a ruptura acidental e colonizagao fungica, as inundagoes mataram 25% de ovos monitorados. Nos sugerimos que para aumentar o sucesso de aninhamento do crocodilo do Morelet e preciso promover a conservagao das areas de nidificagao ao redor do lago, recentemente ocupadas pelo desenvolvimento urbano ou turistico. Palavras-chave: crocodilo, mortalidade de ovos, inundagao, Mexico, predagao.