Initial Reintroduction of the Aye-Aye (Daubentonia madagascariensis) in Anjajavy Reserve, Northwestern Madagascar.

Madagascar's biodiversity is imperiled by habitat loss and degradation. Furthermore, species may be locally extirpated due to targeted hunting or disease. Translocating at-risk individuals to areas devoid of the species may be an effective conservation intervention. The aye-aye, Daubentonia madagascariensis, is uniquely susceptible to hunting pressure due to a cultural superstition. In June 2018, we reintroduced two aye-ayes in the Anjajavy Reserve, a dry deciduous forest in northwestern Madagascar. The translocated individuals, an adult female and juvenile offspring, were rescued from a neighboring forest that was subjected to pressure from fires and logging. We safely secured and transported the aye-ayes to Anjajavy and put them in a quarantine enclosure, where they were subjected to biomedical and behavioral monitoring. After release in the adjacent, protected forest, we conducted postrelease monitoring of the adult female using radio-tracking and scan sampling to determine ranging and activity patterns. We conducted behavioral observations from October 2018 to February 2019 and collected sleeping site data from October 2018 to September 2019. The female aye-aye fed on local resources including Canariumsp. seeds. During the study period, the aye-aye used 31 nests, occupied a home range of approximately 85 ha and traveled, on average, at a pace of 320 m/h. Our findings are comparable with published data on wild aye-ayes in other regions of Madagascar and provide support for future reintroductions of adult aye-ayes, and potentially other endemic species to the natural and protected habitats of Anjajavy.

Gut microbiota of frugo-folivorous sifakas across environments.

BACKGROUND: Captive animals, compared to their wild counterparts, generally harbor imbalanced gut microbiota owing, in part, to their altered diets. This imbalance is particularly striking for folivores that fundamentally rely on gut microbiota for digestion, yet rarely receive sufficient dietary fiber in captivity. We examine the critically endangered Coquerel's sifaka (Propithecus coquereli), an anatomically specialized, rather than facultative, folivore that consumes a seasonal frugo-folivorous diet in the wild, but is provisioned predominantly with seasonal foliage and orchard vegetables in captivity. Using amplicon and metagenomic sequencing applied to fecal samples collected from two wild and one captive population (each comprising multiple groups), we clarify how dietary variation underlies the perturbational effect of captivity on the structure and function of this species' gut microbiota. RESULTS: The gut microbiota of wild sifakas varied by study population, most notably in community evenness and in the abundance of diet-associated microbes from Prevotellaeceae and Lachnospiraceae. Nevertheless, the differences among wild subjects were minor compared to those evident between wild and captive sifakas: Unusually, the consortia of captive sifakas were the most diverse, but lacked representation of endemic Bacteroidetes and metagenomic capacity for essential amino-acid biosynthesis. Instead, they were enriched for complex fiber metabolizers from the Firmicutes phylum, for archaeal methanogens, and for several metabolic pathways putatively linked to plant fiber and secondary compound metabolism. CONCLUSIONS: The relatively minor differences in gut microbial structure and function between wild sifaka populations likely reflect regional and/or temporal environmental variability, whereas the major differences observed in captive conspecifics, including the loss of endemic microbes, but gain in low-abundance taxa, likely reflect imbalanced or unstable consortia. Indeed, community perturbation may not necessarily entail decreased community diversity. Moreover, signatures of greater fiber degradation indicate that captive sifakas consume a more fibrous diet compared to their wild counterparts. These results do not mirror those typically reported for folivores and herbivores, suggesting that the direction and strength of captivity-induced 'dysbiosis' may not be universal across species with similar feeding strategies. We propose that tailored, species-specific dietary interventions in captivity, aimed at better approximating naturally foraged diets, could functionally 'rewild' gut microbiota and facilitate successful management of diverse species.