Behaviour and Ecology of Male Aye-Ayes (Daubentonia madagascariensis) in the Kianjavato Classified Forest, South-Eastern Madagascar

Abstract

Previous studies found that aye-ayes (Daubentonia madagascariensis) consume a variety of non-invertebrate resources, supporting the hypothesis that aye-ayes are too large-bodied to focus feeding efforts on insects. However, these conclusions were based on introduced populations, with little known about aye-aye behaviour and ecology in its natural habitat. This study investigates activity budgets, diet, and home range/territories of 2 male aye-ayes in the Kianjavato Classified Forest, a disturbed forest in south-eastern Madagascar, from October 2013 to October 2014. We used radiotelemetry and focal-animal sampling methods to collect behavioural data. We recorded GPS coordinates of the focal animal every 20 min, calculating the home range size for each individual. Results showed that male aye-ayes spent most of their time feeding and travelling. Their feeding time primarily focussed on larvae and adult insects from various substrates, and to a lesser extent Canarium spp. seeds. Home range sizes of the 2 males varied between individuals, overlapped greatly, and appeared to be related to the location of females. Our findings indicate that aye-aye behaviours are strongly indicative of insect-centric feeding ecology.

Re‐assessing the applicability of the Jarman/Bell model and Kay's threshold to the insectivorous aye‐aye (Daubentonia madagascariensis)

“…Averaging 2.5 kg, aye‐ayes were often described as too large to be insectivorous, with invertebrates instead a supplemental resource (Kay, ; Sterling & McCreless, ). However, here and elsewhere (Randimbiharinirina et al, ), invertebrates were the aye‐ayes' most frequently consumed resource, supporting our prediction. Additionally, animals that survive on small resources should feed less (Bell, ; Jarman, ); yet feeding and traveling are the aye‐aye's most frequent behaviors (see also Randimbiharinirina et al, ).…”

“…Randimbiharinirina et al () found that two male aye‐ayes primarily consumed invertebrates (65–67% of the diet), supplementing with Canarium seeds (25–34%) and Ravenala nectar (1–7%). Although this would indicate that aye‐ayes can sustain themselves on an insectivorous diet, there exists intraspecific differences in lemur diets based on age and sex, especially when females must abate costs of gestation or lactation (Hemingway, ).…”

“…Our goals were to (1) develop a complete dietary profile of an adult female and juvenile aye‐aye and (2) examine their seasonal feeding behavior. Given xylophagous larvae are a high‐energy resource that aye‐ayes are (a) morphologically and behaviorally adapted to excavate and (b) known to consume (Cartmill, ; Owen, ; Randimbiharinirina et al, ; Sterling, ), we hypothesized that the aye‐ayes will exceed the 30–40% consumption rate of invertebrates to be considered insectivores (Kay, ). More specifically, we predicted that invertebrates would be the most frequently consumed resource for both aye‐ayes.…”

“…More specifically, we predicted that invertebrates would be the most frequently consumed resource for both aye‐ayes. Because our small sample size limits our ability to make inferences about the species, we will assess them in conjunction with results from a previous study (Randimbiharinirina et al, ) in order to evaluate if aye‐aye body size constrains the proportion of the diet composed of invertebrates (Kay, ) or if they overcome body mass constraints (Gaulin, ).…”

An environmental DNA sampling method for aye‐ayes from their feeding traces

“…For primates, the application of target capture from lowquality samples has largely been applied to ancient DNA studies, but Perry, Marioni, Melsted, and Gilad (2010) (Chancellor et al, 2011;Oka & Takenaka, 2001;Quéméré, Crouau-Roy, Rabarivola, Louis, & Chikhi, 2010), it is unlikely to be a feasible method of sampling for aye-ayes. Factors such as aye-aye's nocturnal behavior, the height at which they travel in the canopy, and their large nightly travel distances mean that defecation is difficult to observe and locating and collecting fecal material is problematic (Randimbiharinirina et al, 2017); accordingly, at two sites where aye-ayes have been monitored by Madagascar Biodiversity Partnership since 2010, aye-aye fecal samples have only been collected through routine immobilizations. Therefore, to gain information on the genetics of aye-aye populations to meet the IUCN aims (Schwitzer et al, 2013), we explore the possibility of sampling eDNA from aye-ayes.…”