Ecto- and endoparasites of common reedbuck, Redunca arundinum, at 2 localities in KwaZulu-Natal Province, South Africa: community and network structure

Abstract

Parasite community structure is governed by functional traits of hosts and parasites. Notably, parasite populations and communities respond to host social and spatial behaviour. Many studies demonstrating these effects dealt with small-bodied host species, while the influence of host social patterns on parasite communities in large hosts remains understudied. In an earlier study on nyalas (Tragelaphus angasii), host age was more important than sex in structuring helminth communities and networks, but the influence of both was mediated by local environmental conditions, creating different locality patterns. Common reedbuck (Redunca arundinum) differ from nyalas in spatial and social behaviour. Based on helminth and ectoparasite data from 56 reedbuck examined at 2 localities in KwaZulu-Natal Province, we asked which patterns are similar and which differ between the 2 host species. Similar to nyalas, reedbuck age was more important than sex in structuring communities and networks. However, local environmental conditions exerted the strongest influence on transmission patterns, especially in ectoparasites. Complex interactions between reedbuck traits, parasite traits and local environmental conditions modulated the risk of infection differently at the 2 sites, confirming our earlier findings in nyalas that pooling data from different locations may obscure location-specific parasite community patterns. Similarities between patterns in reedbuck and nyalas, despite their behavioural differences, suggest some common patterns in parasite community ecology that, in turn, are determined mostly by parasite traits and population dynamics.

Keywords: helminths; host–parasite interactions; infracommunities; lice; nestedness; ticks.

Graphical abstract

Figure 1.

Median (horizontal line), lower and upper quartiles (boxes) and maximal and minimal numbers (whiskers) of (A) Cooperia yoshidai in female and male reedbuck; (B, C, D) Dictyocaulus viviparus, Haemonchus contortus and Longistrongylus schrenki, respectively, in reedbuck from the Eastern Shores Nature Reserve (ES) and Himeville (HM); and (E) Setaria bicoronata in adult (white boxes) and young (grey boxes) reedbuck from the Eastern Shores Nature Reserve (ES) and Himeville (HM).

Figure 2.

Median (horizontal line), lower and upper quartiles (boxes) and maximal and minimal numbers (whiskers) of (A) Rhipicephalus decoloratus in adult and young reedbuck; (B) Damalinia reduncae in female (white boxes) and male (grey boxes) reedbuck from the Eastern Shores Nature Reserve (ES) and Himeville (HM); and (C) Linognathus fahrenholzi in reedbuck from the Eastern Shores Nature Reserve and Himeville.

Figure 3.

Biplots of non-metric multidimensional scaling of species composition of helminth (A) and ectoparasite (B) infracommunities harboured by adult and young female and male reedbuck in the Eastern Shores Nature Reserve and Himeville.

Figure 4.

Results of DSPCA applied to helminth infracommunities in adult (ad in community label) and young (y in community label) male (M in community label) and female (F in community label) reedbuck from the Eastern Shore Nature Reserve (ES in community label) and Himeville (HM in community label), based on parasite prevalence in sex/age cohorts from the 2 localities either considering helminth species as maximally dissimilar (A, B) or based on similarities in a helminth's life cycle (C, D) or based on similarities among helminths according to preferred site within a host (E, F) (see text for details). Hosts: host scores on principal components PC1 and PC2; helminths: parasites scores on principal components PC1 and PC2. See Supplementary Table S1 for parasite species names.

Figure 5.

Results of DSPCA applied to tick communities in adult (ad in community label) and young (y in community label) male (M in community label) and female (F in community label) reedbuck from the Eastern Shore Nature Reserve (ES in community label) and Himeville (HM in community label), based on parasite prevalence in sex/age cohorts from the 2 localities either considering tick species as maximally dissimilar (A, B) or based on similarities among tick species according to their preferred sites of attachment (C,D) or based on similarities in seasonal patterns of occurrence (E, F) (see text for details). Hosts: host scores on principal components PC1 and PC2; Ticks: parasites scores on principal components PC1 and PC2. See Supplementary Table S2 for parasite species names.

Figure 6.

Nested (i.e. sorted by row/column sums) network matrices of (A) individual reedbuck–helminth and (B) reedbuck–ectoparasite associations in 2 localities based on presence/absence data. M and F, male and female hosts, respectively; A and Y, adult and young hosts, respectively. See Supplementary Tables S1 and S2 for parasite species names.

Figure 7.

Mean (±s.e.) values of (A) individual host specialization (d’) of adult and young reedbuck in reedbuck–helminth networks; (B, C) individual host strength and centrality, respectively, of reedbuck from the Eastern Shores Nature Reserve (ES) and Himeville (HM); (D) centrality of female (F) and male (M) reedbuck in reedbuck–ectoparasite networks.