Data from: Taxonomic scale and community organization impact observed latitudinal gradients of parasite diversity

Aim: While most free-living taxa follow the latitudinal diversity gradient
(LDG), or the trend of higher diversity at lower latitudes, we know little
about how the diversity of parasitic taxa is distributed across latitudes.
To better understand the macroecological patterns of parasite diversity,
we sought to determine if: 1) helminths follow the traditional LDG; 2)
taxonomic resolution impacts observed patterns; 3) latitudinal patterns
are consistent across levels of community organization; and 4) helminth
diversity is correlated with climate- and host- associated variables.
Location: San Juan de Peñas Blancas, Costa Rica; Calnali, Hidalgo, Mexico;
College Station, Texas, USA; Brownsville, Nebraska, USA; Winnipeg,
Manitoba, Canada; Churchill, Manitoba, Canada Taxa: Rodentia: Cricetidae;
Nematoda; Platyhelminthes Methods: We sampled parasites from hosts at
field sites set approximately every 10 degrees in latitude. We evaluated
the relationships between parasite species richness (of all helminths as
well as nematodes, cestodes, and trematodes separately) and latitude,
climate, and host mass at two levels of parasite community organization,
the infracommunity and the component community, using generalized additive
models. Results: Total helminth richness was significantly correlated with
latitude, but the relationship was non-linear. Nematode, cestode, and
trematode diversity were also significantly correlated with latitude, but
the relationship differed between the levels of community organization and
among the taxonomic groups. Climate and host-associated variables were
significantly correlated with different parasite taxa, although the
strength and size of the correlations varied among the groups. Main
conclusions: There are complex associations between parasite richness and
latitude, climate, and host traits, and community organization and
taxonomic grouping affected the observed relationships. Climate has been
implicated as an important factor in shaping LDG patterns and may
similarly influence helminth diversity patterns. Overall, this work
provides further support and exceptions to the LDG and stresses the
importance of considering scale in ecological investigations.