Stable isotope analysis of ectoparasites as a tool for understanding trophic interactions with mammalian hosts

Climate change is expected to expand the geographic ranges of ectoparasites, increasing the transmission of vector-borne diseases and thereby necessitating a better understanding of ectoparasite-host trophic dynamics. Haematophagous ectoparasites can serve as valuable subsamples of their hosts, retaining isotopic values that reflect dietary information in both their blood meals and tissues. However, the differences in the lifestyles and feeding strategies of lice, fleas, and ticks may influence how these isotopic values are preserved. Here, stable isotope values of carbon (δ13C) and nitrogen (δ15N) were used to investigate trophic interactions between ectoparasites and their mammalian hosts in three pairings: lice (Anoplura: Polyplacidae; n = 101) and Eurasian red squirrels Sciurus vulgaris, fleas (Siphonaptera: Ceratophyllidae; n = 92) and fat dormice Glis glis, and ticks (Ixodida: Ixodidae; n = 16) and European hedgehogs Erinaceus europaeus. Our findings indicate ectoparasites reflect..., , # Stable isotope analysis of ectoparasites as a tool for understanding trophic interactions with mammalian hosts

Dataset DOI: [10.5061/dryad.qfttdz0t8](10.5061/dryad.qfttdz0t8)

## Description of the data and file structure

Stable isotope ratios of carbon (*δ*13C) and nitrogen (*δ*15N) were compared between host (fat dormouse, red squirrel, European hedgehog) and ectoparasite (louse, flea, tick) for various tissues. 

### Files and variables

**File included:**

* Mortier_et_al._-_Data_Dryad.xlsx - Excel file with four sheets containing metadata and stable isotope data for host tissues and ectoparasites.

**Sheet descriptions:**

**Table S1:** Metadata for host specimens and associated ectoparasites, including species, collection details, tissue types, ectoparasite counts, and feeding status.

**Table S2:** *δ*15N and *δ*13C values (‰ mean ± SD) of fed and unfed fleas, lice, and ticks, with isotopic differences between feeding groups.

**Table S3:** Isotopic values (‰ mean ± SD) for h...,