Home Range Size and Seasonal Variation in Habitat Use of Aye-Ayes (Daubentonia madagascariensis) in Torotorofotsy, Madagascar

Abstract

Madagascar’s dramatic climatic fluctuations mean most lemurs adjust behaviors seasonally as resource availability fluctuates. Many lemurs will adopt one of two strategies, a resource maximizer or an area minimizer, when adjusting to seasonal shifts in resource availability. However, it is unknown if and how aye-aye (<i>Daubentonia madagascariensis</i>) ranging behavior is influenced by seasonality. We explored whether habitat use changed seasonally. We followed two aye-ayes, an adult male and an adult female, in the undisturbed forest of Torotorofotsy, Madagascar, from April 2012 to December 2017. We used instantaneous focal-animal sampling to collect behavioral data every 5 min and GPS locations every 20 min. We used the minimum convex polygon (MCP) to determine overall home range, and the Brownian bridge movement model (BBMM) to estimate overall and seasonal home range of the female aye-aye from November 2014 to October 2017. We used Wilcoxon signed-rank tests to determine whether there were significant differences in home range sizes between seasons across years and to examine whether there were seasonal differences in height of invertebrate foraging, generalized linear models to assess seasonal differences in travel rates and nesting locations, and χ<sup>2</sup> tests to determine whether there were differences in forest strata use when foraging on invertebrates. The male’s MCP home range was 2,586 ha, and the female’s MCP home range was 765 ha. The seasonal BBMM for the female varied between 443.6 and 1,010.0 ha, though infant rearing appears to have influenced these values. There were no significant differences in seasonal home range, travel rates, nesting locations, or height of invertebrate feeding. However, canopy level invertebrate foraging occurred more often than understory or ground levels. It appears aye-ayes in this undisturbed forest were not influenced by seasonal shifts and had larger home ranges than any previously reported. These findings may indicate that aye-ayes in an undisturbed forest are resource maximizers, closely linked to invertebrate assemblages.

Initial Reintroduction of the Aye-Aye (<b><i>Daubentonia madagascariensis</i></b>) in Anjajavy Reserve, Northwestern Madagascar

“…However, because these values were determined based solely on sleeping sites, they may not be directly comparable to our results which also included data on the female's ranging behavior. Additionally, recent findings from Torotorofotsy revealed that an adult female aye-aye had a home range of 765 ha and traveled at an average rate of 300 m/h [Sefczek et al, 2020a]. Although the distance traveled per hour by the female aye-aye at Torotorofotsy is remarkably similar to what we have found at Anjajavy, the home DOI: 10.1159/000520332 range of the female aye-aye at Torotorofotsy was much larger.…”

“…For example, like other aye-ayes, the reintroduced female spent the majority of her time feeding, moving/traveling and resting. Her home range of 85 ha is within the known limits for female aye-aye home ranges of 30-765 ha [Sterling and McCreless, 2006;Randimbiharinirina et al, 2018;Sefczek et al, 2020a]. She built, refurbished and reused nests in the upper canopy comprising fresh and dead foliage.…”

“…Most studies on the ecology of D. madagascariensis have been carried out in the eastern rain forests of Madagascar [Petter and Peyrieras, 1970;Iwano and Iwakawa, 1988;Iwano, 1991;Sterling, 1993a, b;Ancrenaz et al, 1994;Erickson, 1995;Farris et al, 2011;Sefczek et al, 2012;Sedera, 2014;Solofondranohatra, 2014;Randimbiharinirina, 2015;Thompson et al, 2016;Sefczek et al, 2017;Randimbiharinirina et al, 2018, Sefczek et al, 2020aRakotondrazandry et al, 2021;Randimbiharinirina et al, 2021]. In these habitats, aye-ayes have been reported to feed on insects and larvae, fruits and seeds [Andriamasimanana, 1994], nectar and flowers [Sterling, 1993;Ancrenaz et al, 1994;Sterling, 1993b], bamboo shoots and outgrowths on trees [Pollock et al, 1985;Sterling and McCreless, 2006].…”

Possible Infanticidal Event of an Aye-Aye (Daubentonia madagascariensis) in Torotorofotsy, Madagascar

“…At this time, it would be inappropriate to attribute this infanticidal event to a single hypothesis. There is at least one other male in this female's territory [Sefczek et al, 2020b], so there is likely male competition for reproductive opportunities, as well as intraspecific competition for resources. Yet, we lack additional information on subsequent siring by the infanticidal male or additional observed infanticidal events that would be necessary to contextualize the adaptive benefit of this behavior.…”

Lemur paparazzi: Arboreal camera trapping and occupancy modeling as conservation tools for monitoring threatened lemur species

“…In the reforestation areas, a majority of the camera trapping sites (N = 22) were located closer to one another (~0.35 km apart) due to the constricted amount of area from fragmentation and the need to have an appropriate number of trapping sites for occupancy modeling. Most lemur home ranges were unlikely to overlap multiple camera sites in fragments, except for the most wide-ranging species such as aye-ayes (Sefczek et al, 2020).…”