Activity patterns of sympatric living exotic and endemic carnivores (the fosa) in Western Madagascar's deciduous forests

Abstract

Western Madagascar's deciduous forest is an important, threatened habitat to little‐known Eupleridae, such as the fosa Cryptoprocta ferox. Using camera‐trap grids established in two important deciduous forests, Ankarafantsika National Park and Andranomena Special Reserve, we explore the activity patterns of endemic and exotic carnivores and evaluate how exotics may be influencing fosa temporal activity across these two protected areas. Three methodologies, kernel density, circular and wave analysis, were used to evaluate the activity pattern overlap between exotic free‐ranging cats Felis sp. and dogs Canis familiaris, exotic small Indian civets Viverricula indica and the endemic fosa. Our results showed fosas to be cathemeral, peaking in activity in the evening and at dawn. Cats were nocturnal, whilst also highly active at dusk. Civets did not display a dominant period of activity, but were relatively more active in the night, and at dusk. In contrast, dogs were diurnal and also active at dawn, in alignment with human activity. Fosa activity significantly overlapped with the nocturnal cat and civet, whilst being distinct from the diurnal dog and humans. Our results suggest that there is potentially a competitive impact of exotic free‐ranging dogs and cats when present across fosas’ dry forest habitat. This highlights the need for further examination into the impact of Madagascar's exotic carnivores, and the experimental trial to investigate the impact of their removal (or reduced abundance), on Madagascar's wildlife.

Ecological Consequences of a Millennium of Introduced Dogs on Madagascar

“…Some dog owners have reported that their dogs harass and kill C. ferox around Ranomafana (Valenta et al, 2016;Kshirsagar et al, 2020). Data from live traps and camera traps suggest that C. ferox avoids dogs in several national parks (Figure 1), which may follow from a combination of aggressive interactions and disease transmission (Dollar et al, 2007;Barcala, 2009;Gerber et al, 2012;Farris et al, 2015;Pomerantz et al, 2016;Rasambainarivo et al, 2017;Merson et al, 2019a). For example, C. ferox is typically cathemeral, yet individuals around Ankarafantsika in the NW and Masoala-Makira in the east tend to be primarily nocturnal, where dogs are active during the dawn and day (Farris et al, 2015;Merson et al, 2019a).…”

Spatiotemporal mechanisms of coexistence in an European mammal community in a protected area of southern Italy

“…Interference occurs through physical interactions and their indirect effects (i.e. fear of predators), whereas resource exploitation involves the consumption of a limiting resource by the superior competitor, which reduces its availability to the inferior one (Tilman, 1982;Merson et al, 2019;Nagy-Reis et al, 2019;Pudyatmoko, 2019). Amongst mammals, interference through interspecific aggression is quite common amongst carnivores, with larger predators being usually dominant over smaller ones and often affecting their behaviour, ecology and/or numbers (Palomares & Caro, 1999;Donadio & Buskirk, 2006), but it is rare in ungulates (Valeix et al, 2007;Ferretti et al, 2011a), for which indirect interactions seem relatively more frequent.…”

“…Space and time are two major components of the ecological niche. Interspecific overlap in spatiotemporal behaviour may imply interspecific competition, for example through direct interference or resource exploitation (Kronfeld‐Schor & Dayan, ; Merson et al , ). Interference occurs through physical interactions and their indirect effects (i.e.…”

Spatial dynamics and activity patterns of the fosa Cryptoprocta ferox in Ankarafantsika National Park, Madagascar: carnivores navigating a human-influenced landscape

“…The preference for crepuscular hours may reduce temporal overlap with humans, making it unnecessary for fosas to restrict their activities to nocturnal hours. A study in the Park that examined fosa and exotic carnivore activity patterns found fosas were active at different times compared to dogs and humans (Merson et al, 2018).…”