DOI: 10.5061/dryad.8kprr4xqc
title: Data from: Taxonomic scale and community organization impact observed latitudinal gradients of parasite diversity

description: 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.
description: We collected rodents and their helminths from six field sites set
 approximately every 10 degrees in latitude across North and Central
 America. We report rodent weight and measurements
 (lengths of total body, tail, hind foot, and ear). Parasites were
 collected from each individual and identified using standard
 keys. Parasites were identified down to the lowest level when possible,
 and otherwise were sorted by morphotype. Rodent specimens were prepared
 for museum installation and were archived into multiple natural history
 collections. Following host and parasite collection and
 identification, we assembled data on the abundance of each parasite
 species, host species, host body mass, and latitude and longitude
 of<br> the collection site for each host individual. We used the
 geographic coordinates to obtain climate data from WorldClim at 30 arc
 seconds resolution (~1 km, Hijmans, Cameron, Parra, Jones, &
 Jarvis, 2005); specifically, coordinates were translated onto the WGS84
 geographic coordinate system and used to extract climate data specific to
 each locality. We extracted all BioClim variables. For
 detailed and specific methodologies, please see the published
 manuscript.