Competition and specialization in an African forest carnivore community

Abstract

Globally, human activities have led to the impoverishment of species assemblages and the disruption of ecosystem function. Determining whether this poses a threat to future ecosystem stability necessitates a thorough understanding of mechanisms underpinning community assembly and niche selection. Here, we tested for niche segregation within an African small carnivore community in Kibale National Park, Uganda. We used occupancy modeling based on systematic camera trap surveys and fine‐scale habitat measures, to identify opposing preferences between closely related species (cats, genets, and mongooses). We modeled diel activity patterns using kernel density functions and calculated the overlap of activity periods between related species. We also used co‐occupancy modeling and activity overlap analyses to test whether African golden cats Caracal aurata influenced the smaller carnivores along the spatial and/or temporal axes. There was some evidence that related species segregated habitat and activity patterns. Specialization was particularly strong among forest species. The cats and genets partitioned habitat, while the mongooses partitioned both habitat and activity period. We found little evidence for interference competition between African golden cats and other small carnivores, although weak interference competition was suggested by lower detection probabilities of some species at stations where African golden cats were present. This suggests that community assembly and coexistence in this ecosystem are primarily driven by more complex processes. The studied carnivore community contains several forest specialists, which are typically more prone to localized extinction. Preserving the observed community assemblage will therefore require the maintenance of a large variety of habitats, with a particular focus on those required by the more specialized carnivores.

Mesocarnivore community structuring in the presence of Africa's apex predator

“…The apparent dichotomy between the positive and negative effects of lions on species richness and occupancy, respectively, suggest that net suppressive effects by lions may not impact mesocarnivore species to the point of local extinction. The lack of a common negative response in species richness in the presence of lions can also result from synergisms and feedbacks between regulatory processes owing to the smaller carnivore's strong predisposition to intraguild competition [20,31]. Cascading effects of restricted speciesspecific occupancy may reduce lateral competition among mesocarnivores, thus facilitating coexistence and promoting mesocarnivore persistence by controlling dominant species with the potential to outcompete others [60].…”

“…Both processes manifest at the population level by the abundance and distribution of a species at the landscape (or reserve) scale. Multiple species responses to apex predators, lion-focused management or associated changes within community dynamics [31], shape higherlevel community patterns and can drive spatial variation in composition and diversity of mesocarnivore assemblages. In concert, these patterns are difficult to evaluate as it requires spatially replicated sampling of mesocarnivore communities over large geographical extents which include variation in apex predator populations and environmental contexts [22,32,33].…”

African golden cat and serval in forest–savannah transitions in Cameroon

“…Most notable was the records of these two felids in MDNP. This is a rare case of recorded serval/golden cat co‐occurrence with only few sites of co‐occurrence known, such as at Odzala‐Kokoua National Park (hereafter, OKNP) in the northern Republic of Congo (Henschel et al, 2014), the Chinko/Mbari drainage basin of eastern Central African Republic (Hickisch & Aebischer, 2013), the Batéké Plateau National Park in Gabon (Bout, 2006 as cited in Pearson et al, 2007) and the Kibale National Park in south‐western Uganda (Mills et al, 2019). Each of these localities supports forest–savannah mosaics, a likely habitat type for co‐occurrence of these two habitat specialist species.…”

“…Detection rate of the golden cat and serval by protected area and habitat type African Republic (Hickisch & Aebischer, 2013), the Batéké Plateau National Park in Gabon (Bout, 2006 as cited in Pearson et al, 2007) and the Kibale National Park in south-western Uganda (Mills et al, 2019). Each of these localities supports forest-savannah mosaics, a likely habitat type for co-occurrence of these two habitat specialist species.…”

“…Golden cats and servals are closely related felids (Johnson et al, 2006), deriving from a common ancestor approximately 5.4 million years ago (O’Brien & Johnson, 2007). They are known to be sympatric only within a small portion of their collective geographic range, including in the Central African Republic (Hickisch & Aebischer, 2013), in the FSM of the western Congo Basin (Henschel et al, 2014) and in Uganda (Mills et al, 2019).…”