Figure Captions
Figure 1. Fine-scale niche differentiation between island foxes
and island spotted skunks may influence their host-associated
microbiomes. Although they exhibit shared evolutionary history (both
mesocarnivore species are within Order Carnivora) and inhabit the same
two Channel Islands (SCZ = Santa Cruz Island; SRI = Santa Rosa Island),
island foxes and island spotted skunks appear to coexist through niche
partitioning. Island foxes tend to be more generalist in their habitat
use, diet, and temporal activity, whereas island spotted skunks tend to
be more specialist in these areas. Commensal microbial communities may
reflect these differences, as depicted in this schematic created with
BioRender.com.
Figure 2. Alpha diversity differs by species, but not island.(A) Bacterial species richness (as measured by observed features) and
(B) Shannon diversity significantly differed by species, with foxes
exhibiting higher diversity than skunks, but not by island. (C)
Bacterial evenness differed by neither species nor island.
Figure 3. Beta diversity differs by species, island, and
sequencing plate. We observed significant differences between species
when comparing (A) bacterial abundance (as measured using Bray-Curtis
Dissimilarity) and (B) bacterial presence (as measured using the Jaccard
Index). Differences between island populations (SCZ = Santa Cruz Island;
SRI = Santa Rosa Island) were greater within island spotted skunks (C,D)
compared to island foxes (E,F), with additional clustering evident by
sequencing plate. Fox and skunk silhouettes were created with
BioRender.com.
Figure 4. Island foxes and island spotted skunks exhibited the
core mammalian microbiome, with differences in relative abundance
observed between species and island populations. Each bar represents
the combined samples collected from each island population studied,
where SCZ indicates Santa Cruz Island and SRI indicates Santa Rosa
Island. Each color denotes a distinct bacterial class, with all
additional classes summed together and termed “Other”. Taxonomic
groups annotated with an asterisk significantly differed between groups
of interest during differential abundance testing with ANCOM.