Species co‐occurrences in ectoparasite infracommunities: Accounting for confounding factors associated with space, time, and host community composition

Abstract

1. We explored patterns of co‐occurrence of ectoparasite species on individual hosts from Central Europe (Slovakia) and South America (Argentina) within and between higher taxa while controlling for confounding factors associated with variation between host individuals and host species, as well as spatial and temporal variation. We used a recently developed statistical approach, the hierarchical modelling of species communities. 2. Although the probability of pairwise associations of the majority of species in both regions did not differ from random, all significant species associations in Slovakia were positive, whereas the only three significant species associations in Argentina were negative. On average, associations between ectoparasite species belonging to different higher taxa were positive in Slovakia and negative in Argentina. 3. At the host species level, both positive and negative associations between species were detected in all higher taxa. This was also true for ectoparasite co‐occurrences in the same site, habitat, or year; although the number of co‐occurring species pairs with high posterior probability was much greater in Slovakia than in Argentina. 4. We conclude that consideration of species co‐occurrences across the entire multi‐host assemblage and control for confounding spatial and temporal factors provided important insights into parasite community structure.

Linking Behavior, Co-infection Patterns, and Viral Infection Risk With the Whole Gastrointestinal Helminth Community Structure in Mastomys natalensis

“…We used Hierarchical Modeling of Species Communities [HMSC (84,85)] to analyze the effect of the different intrinsic factors (sex, reproductive age, behavior, and MORV infection history by using the presence of MORV-specific antibodies) on infection probability and load of the different helminths (86). Hierarchical Modeling of Species Communities is a joint species distribution model which includes a hierarchical layer which investigates how species respond to environmental covariates depending on different species traits and phylogenetic relationships (87,88).…”

Weighing the predictors: host traits and coinfecting species both explain variation in parasitism of Rock Ptarmigan

“…Similar cautions of co-occurrence not evidencing species-species interactions may also inform recently developed multivariate approaches to joint species distribution modeling, including the hierarchical modeling of species communities (HMSC; Ovaskainen et al 2017). Such approaches can disentangle various host-and environment-related drivers of multiple parasite species' occurrences, while highlighting resilient parasite-parasite associations (Dallas et al 2019, Krasnov et al 2020, Veitch et al 2020). However, the HMSC framework is currently limited to analyzing parasite presence-absence data as it is ill-equipped to handle highly positively skewed response variables such as parasite abundance (Tikhonov et al 2020).…”

Species associations in arthropod ectoparasite infracommunities are spatially and temporally variable and affected by environmental factors

“…Fleas and mites were analysed separately due to vast differences in their life history, body size, and pattern of host exploitation (see Krasnov, 2008 for fleas and Radovsky, 1985 for mites). In addition, co-occurrences between flea and mite species on individual hosts are mostly random (in contrast to species co-occurrences within each taxon) (Krasnov et al, 2010(Krasnov et al, , 2020. For spatial analyses, we selected infracommunities harboured by those host individuals that were represented in a locality by at least three individuals infested by either fleas or mites and comprising at least two flea or mite species (including in the analyses infracommunities composed of a single species would produce spurious negative interspecific associations).…”