Forest Type Influences Population Densities of Nocturnal Lemurs in Manompana, Northeastern Madagascar

Abstract

Forest loss, fragmentation and anthropization threaten the survival of forest species all over the world. Shifting agriculture is one of these threatening processes in Madagascar. However, when its cycle is halted and the land is left to regenerate, the resulting growth of secondary forest may provide a viable habitat for folivorous and omnivorous lemur species. We aimed to identify the response of nocturnal lemurs to different successional stages of regenerating secondary forest, degraded mature and mature forest across a mosaic-type landscape. We surveyed four nocturnal lemur species (Avahi laniger, Microcebus cf. simmonsi, Allocebus trichotis and Daubentonia madagascariensis) in four forest types of varying habitat disturbance in northeastern Madagascar. We estimated densities in mature and regenerating secondary forest for the eastern woolly lemur (Avahi laniger) and mouse lemur (Microcebus cf. simmonsi), two sympatric species with folivorous and omnivorous diets respectively. We did not estimate densities of Allocebus trichotis and Daubentonia madagascariensis due to small sample size, however, we observed both species exclusively in mature forest. We found higher population densities of Avahi laniger and Microcebus cf simmonsi in secondary than in mature forest showing the potential of regenerating secondary forest for lemur conservation. Several environmental factors influenced the detectability of the two lemur species. While observer and habitat type influenced detection of the eastern woolly lemur, canopy height and vine density influenced detection of mouse lemurs. Understanding how different species with different diets interact with anthropogenically impacted habitat will aid future management decisions for the conservation of primate species.

Ecology and morphology of mouse lemurs (Microcebusspp.) in a hotspot of microendemism in northeastern Madagascar, with the description of a new species

“…The studied taxa were found in a variety of habitat types, ranging from nearly undisturbed to selectively logged forest, from shrubby secondary regrowth vegetation to areas dominated by perennial plants (i.e., Aframomum spp. ; Miller et al, 2018; Radespiel et al, 2008; Schüßler et al, 2018). However, species differed most substantially in their altitudinal range and the inferred EOO.…”

“…(Figure 1). In particular, animals were captured around the village of Anjiahely (Makira region; where the holotype of M. macarthurii was obtained; Radespiel et al, 2008), in the fragmented forests around the village of Ambavala (Schüßler et al, 2018), within Mananara‐Nord NP (Ivontaka‐Sud section), around Antanambe village in the vicinity of Mananara‐Nord NP, as well as in the Ambodiriana community protected area (Miller et al, 2018). All study sites comprise habitats ranging from undisturbed near‐primary rainforest to heavily degraded secondary shrub‐, grass‐ and fernlands (Miller et al, 2018; Radespiel et al, 2008; Schüßler et al, 2018).…”

“…One example of increased taxonomic recognition is the genus of mouse lemurs ( Microcebus ). These small‐bodied and nocturnal primates can be found in all regions of Madagascar that offer forested habitats, while partially deforested areas appear to offer at least dispersal opportunities (Knoop, Chikhi & Salmona, 2018; Miller et al, 2018; Schüßler, Radespiel, Ratsimbazafy, & Mantilla‐Contreras, 2018).…”

Identification of crucial stepping stone habitats for biodiversity conservation in northeastern Madagascar using remote sensing and comparative predictive modeling

“…These areas are usually characterized by a mosaic of dense stands of the perennial Aframomum spp. intermixed with smaller tree species like Harungana madagascariensis and Psiadia altissima or, when severely degraded, dense and almost impassable fern-and grasslands with Sticherus flagellatis and the exotic Psidium cattleianum as typical species (Styger et al 2007;Burivalova et al 2015;Miller et al 2018;Schüßler et al 2018b). Homogenization of landscapes and the disruption of previously continuous forest tracts have major implications for landscape connectivity (Haddad et al 2015).…”

“…At least two of these IRSs are predicted to have almost no areas of low deforestation probability (fields C7 and D8 as well as field D6 in Fig. 5), but some forests are already protected by the local community (see Miller et al 2018;Schüßler et al 2018b). These forests still harbor a high lemur diversity and undisturbed habitats despite being surrounded by a deforested matrix.…”