INVESTIGADORES
PUJOS FranÇois Roger Francis
congresos y reuniones científicas
Título:
Hearing capacity in extinct grounds sloths: does size limit plasticity
Autor/es:
H. GREGORY, MCDONALD; GERARDO, DE IULIIS; FRANÇOIS, PUJOS; CASTÓR, CARTELLE
Lugar:
Paris, Francia
Reunión:
Congreso; 8th International Congress of Vertebrate Morphology; 2007
Institución organizadora:
Society of Vertebrate Morphology
Resumen:
    Recent work by Blanco and Rinderknecht has demonstrated the application of techniques for calculating the expected lower frequency, best frequency and higher frequencies of hearing in the extinct ground sloths. Calculations of these frequencies are based on the surface area of the tympanic area as defined by the enclosed area of the ectotympanic ring. Based on their initial work we have examined a selection of extinct ground sloths to see if the range of hearing in different taxa is related to their ecology, with taxa living in open habitat having hearing in the lower frequencies, including subsonics while forest taxa utilized higher frequencies for communication. We compared the range of frequencies in all major groups of grounds sloths and focused on closely related taxa with different inferred habitat preferences. The sample included the largest ground sloths, Megatherium which inhabited open country in temperate climates and Eremotherium which is found in tropical to subtropical forest, as well as megalonychids, mylodonts and nothrotheres. Since the extinct ground sloths range in size from a few kilograms to thousand’s of kilograms we can examine whether an animal’s increase in size and the concurrent increase in the area of the tympanic thus limits a taxon’s ability to hear higher frequencies. Our examination of taxa of ground sloths over a large range of body mass indicates that the range of hearing is directly related to size and the range of frequencies that an animal can hear does not reflect its preference for a particular environment.