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Mammalian Biology

, Volume 72, Issue 6, pp 321–329 | Cite as

Feeding ecology and postural behaviour of the three-toed sloth (Bradypus variegatus flaccidus) in northern Venezuela

  • Bernardo UrbaniEmail author
  • Carlos Bosque
Original investigation

Abstract

We studied the diet, activity budget, vertical ranging, and postural behaviour in relation to weather of the three-toed sloth (Bradypus variegatus flaccidus) in disturbed montane forest remnants (1150 m asl) in northern Venezuela. Sloths spent most (72.9%) of their time resting and had a nearly exclusive (99.4%) leaf diet. While resting they assumed a sitting - not hanging - posture mostly (90.2% of observations). Species of three families, Clethraceae, Cecropiaceae, and Clusiaceae accounted for 77% of feeding records. Young leaves (67.2%) accounted for most of the leaf diet. Activity and posture were dependent on weather conditions. Sloths fed more often during mid-day hours and tended to rest more at dawn and dusk. In northern Venezuela sloths tended to use more frequently the upper strata of the canopy, while in warmer lowland sites they use intermediate levels more often. They adopted postures that maximized exposure of ventral surfaces to incident solar radiation when sunny, but minimized their surface area by huddling when cloudy, foggy or rainy. We propose that sunning behaviour of sloths may speed up their fermentation rate, and ultimately, might have been an important selective factor in the evolution of derived upside-down posture of sloths.

Key words

Bradypus variegatus sloth behaviour folivory Venezuela 

Narungsökologie und Haltungsverhalten des Dreizehenfaultieres (Bradypus variegatus flaccidus) in Nordvenezuela

Zusammenfassung

Wir studierten die Nahrung, das Activitats Budget, das Haltungsverhalten, und die vertikale Distribuzion in bezug auf das Wetter, des Drei Finger Faultier(Bradypus variegatus flaccidus) in gestorten montane Waldresten (1150 m asl) in Nordvenezuela. Faultiere investierte das meiste ihrer Zeit (72.9%) im stillstehen, und hatten eine fast exklusive Blattdiät (99.4%). Beim stillstehen, nahmen sie mestens einen sitzende - nicht hängende - Lage an (90.2% von den Beobachtungen). Pflanzen von drei Familien, Clethraceae, Cecropiaceae und Clusiaceae waren verantwortlich für 77% der fütterungs Akte. Junge Blätter erklärten das meiste der Blattdiät (67.2%). Aktiviätat und Haltung waren von der Wetterbedingungen abhängig. Faultiere ernährte sich öfter während der Mittagstunden, an der Morgendämmerung, wehrend an der Dämmerung öfter Stillstehend. In Nordvenezuela neigen die Faultiere die oberen Schichten der überdachung häufiger zu benutzen, während in den wärmeren Tiefland, sie das Mittlerhöheniveaus häufiger benutzen. Sie nahmen Haltungen an, die die aussetzung ventraler Oberflächen zu einfallender solarer Strahlung maximierten, wenn sonnig; aber minimierte ihr Oberflächengebiet durch das zusammendrangen wenn wolkig, neblig oder regnerisch. Wir schlagen vor, daß sonnen-verhalten von Faultiere vielleicht ihre Gärungsrate beschleunigt, und schließlich das dieses ein wichtiger Faktor in der Evolution von der Faultierhaltung sein könte.

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Copyright information

© Deutsche Gesellschaft für Säugetierkunde, e. V. DGS 2007

Authors and Affiliations

  1. 1.Department of AnthropologyUniversity of Illinois at Urbana-ChampaignUrbanaUSA
  2. 2.Departamento de Biología de OrganismosUniversidad Simón BolívarCaracasVenezuela

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