Accounting for detection unveils the intricacy of wild boar and rabbit co-occurrence patterns in a Mediterranean landscape

Abstract

the patterns of species co-occurrence have long served as a primary approach to explore concepts of interspecific interaction. However, the interpretation of such patterns is difficult as they can result from several complex ecological processes, in a scale-dependent manner. Here, we aim to investigate the co-occurrence pattern between european rabbit and wild boar in an estate in central portugal, using two-species occupancy modelling. With this framework, we tested species interaction for occupancy and detection, but also the interdependencies between both parameters. According to our results, the wild boar and European rabbit occurred independently in the study area. However, model averaging of the detection parameters revealed a potential positive effect of wild boar's presence on rabbit's detection probability. Upon further analysis of the parameter interdependencies, our results suggested that failing to account for a positive effect on rabbit's detection could lead to potentially biased interpretations of the co-occurrence pattern. Our study, in spite of preliminary, highlights the need to understand these different pathways of species interaction to avoid erroneous inferences.Understanding the patterns of species co-occurrence is of fundamental interest for many fields of ecological research. Such knowledge underpins much of our understanding of concepts like community assembly 1 , competitive exclusion 2 , niche partitioning 3 and predator-prey dynamics 4 . In particular, interspecific dependencies in species co-occurrence have served for long as a primary approach to explore concepts related to interspecific interactions 2,5,6 . The way in which a species occurrence probability is conditioned by the presence or absence of a potential competitor, can serve as a non-mechanistic proxy 7 for interference competition or facilitation. However, the interpretation of co-occurrence patterns is inherently difficult. Such patterns can result from complex ecological processes acting in tandem, in a scale-dependent manner 8,9 , or from shared/distinct habitat requirements. For instance, similar habitat preferences could lead to overlapping distributions at a broader scale but, at a patch level, risk/avoidance behaviour of the subordinate species 9 can be interpreted as spatial displacement. Therefore, at a fine scale, effects of interspecific interaction tend to be more subtle and difficult to demonstrate, as they can manifest in complex ways 2 (e.g. activity patterns, space use, species abundance). Given the ecological and conservation relevance 4,6,10 of understanding species co-occurrence patterns, it is important that the complexity underlying these interactions is acknowledged and dully accounted for.Observational studies to discuss hypotheses on interspecific interactions can be useful when controlled experiments are logistically unfeasible 11 . Two-species occupancy modelling 12 has emerged as a tool to investigate hierarchical interactions between co-occurring species 13,14 . Importantly, this method allows ...

Spatial co-occurrence patterns of sympatric large carnivores in a multi-use African system

“…Our findings also further highlight the importance of considering biological scale in habitat use investigations [89,90], as the true extent of the impact of lion occurrence on wild dog would not have been evident from analyses restricted to a single spatial scale. Finally, our study emphasizes the importance of also accounting for interspecific effects on detection when investigating co-occurrence, as recently highlighted by others [91].…”

Camera trap reveals the co‐occurrence patterns of two sympatric muntjac species in southern Anhui Province, China: No spatial segregation

“…Therefore, further studies should focus on the relationship between the coexistence patterns and population density/relative abundance of the two species. Additionally, though occupancy models are increasingly applied to data from wildlife camera‐trap surveys to estimate distribution, habitat use, and patterns of species co‐occurrence of unmarked animals (Burton et al, 2015 ; Estevo et al, 2017 ), the interpretation of co‐occurrence patterns is inherently difficult (Barros et al, 2020 ). Several studies have demonstrated that detection frequency and estimates of detection probability and occupancy were sensitive to movement speed (or the magnitude of animal movement) (Neilson et al, 2018 ; Stewart et al, 2018 ), especially for animal occupied large‐ and medium‐sized home ranges with low population density (Neilson et al, 2018 ), whereas occupancy estimates for scenarios with small home ranges closely matched the simulated asymptotic PAO (proportion of area occupied) (Neilson et al, 2018 ).…”

Sett Use, Density and Breeding Phenology of Badgers in Mediterranean Agro-Sylvo-Pastoral Systems

“…Variables associated to vegetation composition and structure were assessed, in situ, within the minimum convex polygon that encompassed all the sett entrances, plus a buffer of 2 m. The Simpson diversity index [ 38 ] was estimated based on the herbaceous, shrub and bare soil cover in each polygon. Later, we built a Geographic Information System (GIS; QGIS ® version 2.8.3—Wien, Beaverton, OR, USA [ 39 ]), that encompassed remote sensing information regarding the: type of soil (data provided by the Companhia das Lezíria, S.A, Samora Correia, Portugal); land use [ 38 ]; location of setts, game feeding stations and watering pivots, paved and unpaved roads and water points (to allow the estimation of the distance of each sett from these landmarks; data provided by the Companhia das Lezíria, S.A.); grazing pressure per plot (data provided by the Companhia das Lezíria, S.A.); and wild boar occurrence determined in a previous study [ 40 ].…”