The Vulnerable fosa Cryptoprocta ferox is the largest native carnivore in Madagascar, fulfilling a unique ecological niche in the island's remaining forests. Negative interactions with humans threaten the long-term viability of most remaining fosa populations across Madagascar. Threats to the fosa include habitat loss and persecution by humans resulting from perceived predation on domestic animals. We used GPS collars to record space use and activity patterns of five fosas in Ankarafantsika National Park, Madagascar, during the dry seasons of 2016 and 2017. The results, with up to 2,110 recorded locations per individual, indicated fosas’ home ranges and movements were not limited to the forest, and all collared individuals used networks of habitat patches and corridors to navigate deforested areas. The fosas studied in Ankarafantsika National Park had significantly larger home ranges than those reported in previous studies in other protected areas. They were rarely found within village boundaries and appeared to avoid areas of human habitation, suggesting that during the study period livestock was not a significant component of the fosas’ diet in this Park. Our results suggest that fosas have some flexibility that enables them to adapt to living near deforested and human-dominated areas by altering their space-use patterns, but they are compensating by increasing their home range size.

Forest carnivores are threatened globally by logging and forest fragmentation yet we know relatively little about how such change affects predator populations. This is especially true in Madagascar, where carnivores have not been extensively studied. To understand better the effects of logging and fragmentation on Malagasy carnivores we evaluated species composition, density of fossa Cryptoprocta ferox and Malagasy civet Fossa fossana, and carnivore occupancy in central-eastern Madagascar. We photographically-sampled carnivores in two contiguous (primary and selectively-logged) and two fragmented rainforests (fragments <2.5 and >15 km from intact forest). Species composition varied, with more native carnivores in the contiguous than fragmented rainforests. F. fossana was absent from fragmented rainforests and at a lower density in selectively-logged than in primary rainforest (mean 1.38±SE 0.22 and 3.19±SE 0.55 individuals km−2, respectively). C. ferox was detected in fragments <2.5 km from forest and had similar densities in primary and selectively-logged forests (0.12±SE 0.05 and 0.09±SE 0.04 adults km−2, respectively) but was absent in fragments >15 km from forest. We identified only two protected areas in Madagascar that may maintain >300 adult C. ferox. Occupancy of broad-striped mongoose Galidictis fasciata was positively related to fragment size whereas occupancy of ring-tailed mongoose Galidia elegans elegans was negatively associated with increasing exotic wild cat (Felis spp.) activity at a camera site. Degraded rainforest fragments are difficult environments for Malagasy carnivores to occupy; there is a need to prioritize the reconnection and maintenance of contiguous forest tracts.

Despite major efforts to understand and conserve Madagascar’s unique biodiversity, relatively little is known about the island’s carnivore populations. We therefore deployed 43 camera-trap stations in Ranomafana National Park, Madagascar during June–August 2007 to evaluate the efficacy of this method for studying Malagasy carnivores and to estimate the relative abundance and density of carnivores in the eastern rainforest. A total of 755 camera-trap nights provided 1,605 photographs of four endemic carnivore species (fossa Cryptoprocta ferox, Malagasy civet Fossa fossana, ring-tailed mongoose Galidia elegans and broad-striped mongoose Galidictus fasciata), the exotic Indian civet Viverricula indica and the domestic dog Canis familiaris. We identified 38 individual F. fossana and 10 individual C. ferox. We estimated density using both capture-recapture analyses, with a buffer of full mean-maximum-distance-moved, and a spatially-explicit maximum-likelihood method (F. fossana: 3.03 and 2.23 km-2, respectively; C. ferox: 0.15 and 0.17 km-2, respectively). Our estimated densities of C. ferox in rainforest are lower than published estimates for conspecifics in the western dry forests. Within Ranomafana National Park species richness of native carnivores did not vary among trail systems located in secondary, selectively-logged and undisturbed forest. These results provide the first assessment of carnivore population parameters using camera-traps in the eastern rainforests of Madagascar.

In the 2003 Durban Vision the Malagasy government committed to tripling the amount of protected areas in Madagascar by 2009. This extensive expansion needs to involve an assessment of the potential impacts on the people who rely on forest resources for subsistence. Wildlife for human consumption (bushmeat) is one such resource that has received great attention on mainland Africa but has largely been ignored in Madagascar until recently. In terms of biomass, hunting in Madagascar appears to be on a lesser scale compared to areas of mainland Africa. However, because of the life-history characteristics associated with hunted primate and carnivore species in Madagascar even small-scale hunting is a major threat to long-term conservation. In this study I used semi-structured interviews to quantify annual rates of bushmeat harvest in 14 villages adjacent to the Makira Forest in north-eastern Madagascar. Interviews revealed that 23 mammal species were hunted for consumption, providing a new insight into the scale and frequency of bushmeat use. Harvest data and life-history information were sufficient to allow quantitative assessments of sustainability for four species of lemur (black and white ruffed lemur Varecia variegata, indri Indri indri, eastern bamboo lemur Hapalemur griseus and white-fronted brown lemur Eulemur albifrons) and a species of the carnivore family Eupleridae (fossa Cryptoprocta ferox). Model results suggest hunting of these species is probably unsustainable. This research presents clear evidence that hunting is a major conservation and livelihoods issue in Madagascar and needs to be considered in the planning stages of protected area development to address better the needs of local people.

The widespread geographical distributions of mammalian carnivores such as the Carnivora and the Dasyuridae have often been erroneously equated with abundance. Their low densities and high demands on habitat area can render mammalian carnivores especially vulnerable to habitat fragmentation and destruction. The fossa Cryptoprocta ferox (Viverridae) is a mammalian carnivore threatened by the rapid loss of Madagascar's forests, to which it is endemic. A 3-year mark-recapture study, comprising four censuses, generated an estimate of fossa population density at 0.18 adults km−2, or 0.26 individuals km−2. This was supported by a similar estimate from home range data. The fossa is thought to be unusually common in the study area, yet the estimated density was lower than that predicted for a typical tropical carnivorous mammal of the body mass of a fossa. Ecologists are frequently under pressure to provide estimates of local and global population numbers of their study species; we discuss the numerous factors that limit our ability to do this on the basis of a single population estimate. Nonetheless, our findings are sufficient to suggest that none of Madagascar's 46 protected areas supports a viable population of fossas, indicating a demand for corridors and enlarged reserves to ensure this species' long-term survival. Loss of the top predator can have a knock-on effect on an ecosystem. The findings indicate that, to maintain intact tropical forest ecosystems, it may be essential to consider the requirements of their often little-known mammalian carnivores. These requirements could be far greater than previously assumed.