Cuadernos de Investigación UNED
versão impressa ISSN 1659-4266
Resumo
Why sloths defecate on the ground: rejection of the mutualistic model. Cuadernos de Investigación UNED [online]. 2021, vol.13, n.1, e3438. ISSN 1659-4266. http://dx.doi.org/10.22458/urj.v13i1.3438.
Introduction:
Sloths are arboreal mammals that defecate on the ground, increasing the risk of predation. There are several hypotheses that try to explain why they undergo this risk.
Objective:
To critically review all the hypotheses and to propose a new hypothesis that is compatible with all known data.
Methods:
I verified the assumptions and implications of five hypotheses against the literature available February, 2021.
Results:
Previous hypotheses either lack reliable supporting data, or are contradicted by published data. Here I propose that defecation on the ground is an ancestral behavior that persists in all sloth species because there has not been enough natural selection against it.
Conclusions:
Current knowledge of sloth biology is compatible with the hypothesis that there has not been enough selective pressure for sloths to abandon defecation on the ground.
Palavras-chave : Evolution of sloth behavior; natural selection and defecation; algae; mutualism; moths; arboreal mammal evolution.