ABSTRACT
OBJECTIVES: To describe the strategy employed by exudativorous primates during seasonal shifts in food abundance using the Javan slow loris as a model. Males and females may cope differently as well as exploit fallback foods in different proportions. MATERIALS AND METHODS: Observing 15 free ranging Javan slow lorises over a year, we quantified their seasonal diet and nutrient intake using intake rates. For gum intake rates, we conducted a trial with 10 captive Javan slow lorises measuring the length of time it took for them to ingest 10 g of gum. We monitored phenology in our field site over five plots that were assessed monthly. We weighed our free-ranging animals every six months. We analyzed all food items slow lorises ingested for macronutrients using the nutritional geometry framework. RESULTS: The slow loris diet consisted of eight food categories, with gum and insects being the major food sources in terms of wet weight intake. The captive gum trials resulted in an intake rate of 0.021 g/s. All food items eaten by wild Javan slow lorises were available in the wet season and were restricted in the dry season. Males and females reacted differently to seasonal abundances with females ingesting more protein, gum, fruits and flowers and males ingesting more fiber. CONCLUSIONS: The strategy used by the Javan slow lorises during periods of lower food availability were similar to folivorous primates and included increased dependence on lower quality foods. The reproductive costs of gestation and lactation may place a burden on females that requires them to alter their foraging strategy during the dry season to ensure enough protein and overall energy is ingested. The overall strategy used by these exudativorous primates is one of nutrient maximization as no nutrient was clearly preferred over another.
Subject(s)
Feeding Behavior/physiology , Lorisidae/physiology , Animals , Anthropology, Physical , Ecology , Energy Intake , Female , Fruit , Indonesia , Insecta , Male , SeasonsABSTRACT
Animals have evolved an array of spectacular weapons, including antlers, forceps, proboscises, stingers, tusks and horns [1]. Weapons can be present in males and females of species needing to defend critical limiting resources, including food (rhinoceros beetles, Trypoxylus) and territories (fang blennies, Meiacanthus) [1-3]. Chemicals, including sprays, ointments and injected venoms, are another defence system used by animals. As with morphological weapons, venom can serve multiple purposes, including to facilitate feeding, in predation, and in defence when attacked [4]. Although rare, several taxa use venom for agonistic intraspecific competition (e.g. ghost shrimp, Caprella spp.; sea anemones, Actinia equina; cone snails, Conidae; male platypus, Ornithorhynchus anatinus) [4-6]. Another group of venomous mammals are the nocturnal slow lorises (Nycticebus) [7]. Slow loris bites often result in dramatic diagnostic wounds characterised by necrotic gashes to the head and extremities. Although these bites are the major cause of death of lorises in captivity, the function of this aggressive behaviour has never been studied in the wild [7]. Here, through an 8-year study of wounding patterns, territorial behaviour, and agonistic encounters of a wild population of Javan slow lorises (Nycticebus javanicus), we provide strong evidence that venom is used differentially by both sexes to defend territories and mates. VIDEO ABSTRACT.
Subject(s)
Aggression/physiology , Behavior, Animal/physiology , Lorisidae/physiology , Venoms/metabolism , Animals , Female , MaleABSTRACT
Slow lorises are enigmatic animal that represent the only venomous primate lineage. Their defensive secretions have received little attention. In this study we determined the full length sequence of the protein secreted by their unique brachial glands. The full length sequences displayed homology to the main allergenic protein present in cat dander. We thus compared the molecular features of the slow loris brachial gland protein and the cat dander allergen protein, showing remarkable similarities between them. Thus we postulate that allergenic proteins play a role in the slow loris defensive arsenal. These results shed light on these neglected, novel animals.
Subject(s)
Allergens , Cats , Dander/immunology , Glycoproteins , Lorisidae , Toxins, Biological , Allergens/chemistry , Allergens/genetics , Amino Acid Sequence , Animals , Base Sequence , Glycoproteins/chemistry , Glycoproteins/genetics , Models, Molecular , Sequence Homology, Amino Acid , Toxins, Biological/chemistry , Toxins, Biological/geneticsABSTRACT
Illegal harvesting and trade are major forces behind population declines of wild slow lorises (genus Nycticebus). The impacts of the wildlife trade on individual slow lorises have not been as well described. In this article, we describe quantitatively the consequences of the wildlife trade for 77 greater slow lorises, N. coucang, who were confiscated en masse and brought to Cikananga Wildlife Center in Indonesia. Medical records indicated that in total, 28.6% of the slow lorises died within the first 6 months, mostly due to traumatic injury, and all the infants died. The greatest sources of morbidity were external wounds (33.1% of 166 total medical events) and dental problems (19.3%). Of the surviving individuals, 25.4% displayed abnormal behavior. Behavioral observations indicated that healthy adults (n = 3) spent 48.2% of their active period performing stereotypies. These data illustrate the physical and behavioral impacts of the illegal wildlife trade on the welfare of slow lorises. We suggest that sharing these individual stories may help generate empathy and educate the public about the impacts of the exotic companion-animal (pet) trade on nonhuman animal welfare.