Ramirez Oscar, Vaughan Christopher, Herrera Geovanny, Guries Raymond
School of Biological Sciences, Universidad Nacional, Heredia, Costa Rica.
Rev Biol Trop. 2011 Dec;59(4):1743-55.
The information on ecological behavior of wild sloths is very scarce. In this study we determined the home ranges and resources used by three adult female three-toed sloths (Bradypus variegatus) and their four young in an agricultural matrix of cacao (Theobroma cacao), pasture, riparian forests and living fencerows in Costa Rica. Births occurred during November-December and the young became independent at five to seven months of age. Initially, mothers remained fixed in one or a few trees, but expanded their use of resources as young sloths became independent from them. Mothers initially guided the young to preferred food and cover resources, but they gradually left their young in small nucleus areas and colonized new areas for themselves. Home range sizes for young sloths (up to seven months of age) varied between 0.04-0.6 hectares, while home range sizes for mothers varied from 0.04-25.0 hectares. During the maternal care period, 22 tree species were used, with the most common being Cecropia obtusifolia (30.9%), Coussapoa villosa (25.6%), Nectandra salicifolia (12.1%), Pterocarpus officinalis (5.8%) and Samanea saman (5.4%). However, young sloths used only 20 tree species, with the most common being C. villosa (18.4%), S. saman (18.5%) and N. salicifolia (16.7%). The cacao agroforest was used only by mother sloths and never by their young following separation. However, in the riparian forest, both mother sloths and young used the tree species. A total of 28 tree species were used by the mother sloth; including the food species: C. obtusifolia, C. villosa, N. salicifolia and P. officinalis. However, the young used 18 trees species in this habitat with N. salicifolia and S. saman most commonly used, although they rested and fed during the day in C. obtusifolia, C. villosa and O. sinnuata. The cacao agroforest with adjacent riparian forests and fencerows provides an important habitat type that links the smaller secondary forests and other patches.
关于野生树懒生态行为的信息非常稀少。在本研究中,我们确定了三只成年雌性三趾树懒(褐喉三趾树懒)及其四只幼崽在哥斯达黎加由可可(可可树)、牧场、河岸森林和现存树篱组成的农业基质中的活动范围和所利用的资源。幼崽出生于11月至12月,在5至7个月大时开始独立生活。最初,母树懒固定在一棵或几棵树上,但随着幼崽逐渐独立,它们对资源的利用范围有所扩大。母树懒最初会引导幼崽前往偏好的食物和遮蔽资源处,但它们会逐渐将幼崽留在小的核心区域,自己去开拓新的区域。幼树懒(7个月龄以下)的活动范围在0.04 - 0.6公顷之间,而母树懒的活动范围则在0.04 - 25.0公顷之间。在母性照料期内,它们利用了22种树木,最常见的是钝叶塞克罗皮亚树(30.9%)、绒毛库萨波阿树(25.6%)、柳叶楠(12.1%)、药用紫檀(5.8%)和雨树(5.4%)。然而,幼树懒仅利用了20种树木,最常见的是绒毛库萨波阿树(18.4%)、雨树(18.5%)和柳叶楠(16.7%)。可可农林仅被母树懒利用,幼崽在与母树懒分开后从未使用过。然而,在河岸森林中,母树懒和幼崽都会利用其中的树种。母树懒总共利用了28种树木;包括作为食物的树种:钝叶塞克罗皮亚树、绒毛库萨波阿树、柳叶楠和药用紫檀。然而,幼崽在这个栖息地利用了18种树木,最常使用的是柳叶楠和雨树,不过它们白天在钝叶塞克罗皮亚树、绒毛库萨波阿树和辛努阿奥氏树中休息和进食。带有相邻河岸森林和树篱的可可农林提供了一种重要的栖息地类型,它连接了较小的次生林和其他斑块。