Activity Budget and Positional Behavior of the Mysore Slender Loris (Loris tardigradus lydekkerianus) : Implications for Slow Climbing Locomotion

Abstract

Both predator defense and feeding ecology models have been proposed to explain the relatively slow climbing locomotion of the Lorisinae. During a study of the socioecology of the Mysore slender loris (Loris tardigradus lydekkerianus) in Tamil Nadu, India, six categories of behavior and eleven different postures were recorded to estimate a general activity budget for the slender loris, and are examined here particularly in relation to slow climbing locomotor strategies. Reactions to potential predators are also described. The main study population was composed of 15 animals. Activity budgets were compiled in three ways: all instantaneous point samples collected over 1,173 h pooled (n = 13,717), the means of individual lorises (n = 15) and behavior at the moment of first contact (n = 357). No significant difference was found between these three data sets. Approximately 45% of the activity budget was spent in inactive behaviors including sitting vigilant, resting and sleeping. Foraging and traveling comprised nearly half the activity budget, with the rest of the time spent grooming. The most common postures assumed by lorises were sitting and quadrupedal walking. Individual lorises were relatively gregarious and spent up to half their activity budget with other animals. Unlike pottos and angwantibos, lorises did not freeze, head butt or drop from branches in reaction to potential predators, but either ignored them, fled or made loud calls. Cryptic and slow climbing locomotion were used before traveling on open ground between discontinuous substrates, thereby supporting hypotheses relating to predator pressure, and also before capturing fast moving insect prey, supporting hypotheses relating to diet. It is proposed that a divergence in foraging strategies between bushbabies and lorisines may be the best adaptive explanation for their behavioral and morphological differences, including predator defense mechanisms.

Medicinal plant exudativory by the Bengal slow loris Nycticebus bengalensis

“…We combined continuous focal animal sampling (during feeding; Altmann 1974) and instantaneous point sampling at 5 min intervals (for general activity) (cf. Nekaris 2001, Nekaris & Rasmussen 2003. All observations of feeding behaviours were recorded ad libitum (Altmann 1974).…”

Mapping potential distribution of slender loris subspecies in peninsular India

“…Slow lorises are known to occur in northeast India and parts of southeast Asia, while slender lorises are restricted to southern India and Sri Lanka (Roonwal & Mohnot 1977, Nekaris & Bearder 2007. Slender lorises are small, often solitary and nocturnal and, consequently, poorly studied until the late 1990s, when research became more common; see, for example, studies of their distribution (Singh et al 1999, 2000, Kumar et al 2002), behavior (Nekaris 2001, Radhakrishna & Singh 2002a,b,c, 2004a and ecology (Nekaris & Rusmussen 2003, Kumara 2005. The slender lorises of India (Loris lydekkerianus lydekkerianus and L. l. malabaricus) are accorded the status of near threatened in the IUCN Red List of threatened species, and at the national level they have been assigned the highest level of protection under Schedule I, Part I of the Indian Wildlife Protection Act, 1972.…”

Observations of Mating, Birthing and Parental Behaviour in Three Subspecies of Slender Loris (Loris tardigradus and Loris lydekkerianus ) in India and Sri Lanka

“…The African lorisines have now been the topic of two in-depth reports [Charles-Dominique, 1977;Pimley, 2003]; the Asian lorisines, however, have only recently become the subjects of long-term field studies [Kar Gupta, 1995;Nekaris, 2001aNekaris, , 2003Radhakrishna, 2001;Wiens, 2002]. Several species of slow loris are now recognised, as are at least 2 species of slender loris [Groves, 2001].…”