Seasonal host community dynamics constrain the risk of parasite transmission between migrant and resident species

Seasonal migration shapes the community dynamics that influence pathogen transmission between migrants and resident species. While theoretical and empirical evidence has accumulated, whether migration increases or decreases the risk of cross-species infection remains inconclusive. We studied how the seasonal arrival and departure of a single avian migrant species change the composition of local communities in breeding areas affecting the haemosporidian infection dynamics. The seasonal reordering of resident species abundances induced by migrants, minimizes the opportunities for contact between highly infected hosts and susceptible species, either migrants or residents, thereby limiting the transmission of parasites to occasional spillover events. The occurrence of spillover dynamics during the seasonal sympatry between migrants and residents provides a plausible explanation that reconciles empirical inconsistencies in the intersection of animal migration and infection risk at the host c..., Between October 2015 and September 2019, we studied local communities of closely related bird species (Order: Passeriformes) and their haemosporidian parasites at five study sites in Southern Chile (Fig. 1A). Each of these sites represents different habitat types, where the long-distance migrant Elaenia albiceps occurs in sympatry with local resident species during the austral spring and summer, between October and March (hereafter, breeding season). The local absence of E. albiceps occurs during the austral fall and winter, between April and September (hereafter, non-breeding season). Llancahue (39°84’ S; 73°14’ W) is an evergreen forest, supporting remnants of old-growth temperate rainforest and secondary forests (Biscarra et al. 2021). Quempillén (41°87’ S; 73°77’ W) is a secondary forest with dense understory vegetation covered by a mixture of native berry trees, native bamboo, fern species, and exotic shrublands (Díaz & Armesto 2007). San José (39°55’ S; 72°98’ W) is an anthrop..., , # Data from: Seasonal host community dynamics constrain the risk of parasite transmission between migrant and resident species

[https://doi.org/10.5061/dryad.j0zpc86nj](https://doi.org/10.5061/dryad.j0zpc86nj)

R script and data used to estimate seasonal host community dynamics and the contribution of each host to the transmission of haemosporidian parasites in resident bird communities seasonally visited by a migrant species within the Neotropical austral bird migration system.

## **File list (files found within Navarrete\_et\_al\_data.zip)**

Navarrete_et_al_analyzes.R

Navarrete_et_al_relative_abundance_change.csv

Navarrete_et_al_NMDS.csv

Navarrete_et_al_NMDS_points.csv

Navarrete_et_al_community_dynamics.csv

Navarrete_et_al_RAC_change.csv

## **File descriptions**

**Note:** .csv files are semi-colon delimited.

Navarrete_et_al_analyzes.R – The only file that you need to open. Has the code to make the figures of the paper and perform the statistical analyzes related to the seas...