Use of cenotes and the cave environment by mammals on the Yucatán Peninsula, Mexico

Mammals are important sources of nutrients to cave ecosystems, and in some circumstances, caves may be an essential resource for mammals. Few studies, however, have focused on the use of caves by terrestrial mammals. The Yucatán Peninsula encompasses an extensive carbonate karst region that includes the world's largest underwater cave system. Forest in the region overlies fractured limestone bedrock, so flooded caves known regionally as cenotes represent the only reliable source of free-standing water for much of the Peninsula's wildlife. We used camera traps at 17 cenotes on the Yucatán Peninsula to determine patterns of use by mammals. Eighteen non-volant mammal taxa were identified using cenotes, the most commonly occurring being lowland paca (Agouti paca), opossums (Didelphis spp.), white-nosed coati (Nasua narica), gray fox (Urocyon cinereoargenteus), tayra (Eira barbara), and gray four-eyed opossum (Philander opossum); collectively these taxa accounted for 76% of all mammal records. We also recorded several felids using cenotes, including jaguar (Panthera onca) and puma (Puma concolor). Activity patterns at cenotes usually matched normal activity schedules, but some species were nocturnal in the forest but diurnal at cenotes. Mammals mostly accessed cenotes to drink, but a range of activities were recorded including foraging, nesting, mating, resting, and bathing. The Yucatán region has experienced continued population growth and economic development over many decades which directly threatens cenotes. Because our work has revealed that cenotes are important to the Yucatán's mammals, we believe protection of cenotes should be a central issue for regional wildlife conservation.