README FILE

Dataset associated with the manuscript:

“Haemosporidian infections limit physiological adaptation to elevation in birds: Evidence from haemoglobin and fat reserves”

DATASET DESCRIPTION

This repository contains individual-level physiological and haemosporidian infection data for birds sampled along an elevational gradient in Eswatini. The dataset was used to investigate whether haemosporidian parasite infections influence haemoglobin concentration and fat reserves under varying elevational conditions.

The repository includes:

1. Main dataset file
2. R script used for statistical analyses
3. Metadata descriptions contained in this README file

FILES INCLUDED

1. Avian_malaria_data.csv
Main dataset containing physiological, infection, sampling, and taxonomic information for sampled bird individuals.

2. R.script.R
R script used for data preparation, statistical analyses, model fitting, and figure generation associated with the manuscript.

DATASET VARIABLES

"Taxonomic note: Two taxonomic naming systems were used in this dataset. Scie_name follows the BirdLife taxonomy to allow direct matching with the AVONET dataset for ecological trait extraction. Columns ending with “T” (FamilyT, GenusT, SpeciesT, and Scie_nameT) follow the IOC World Bird List taxonomy, which was used for standardized taxonomic and phylogenetic analyses, including matching species names with BirdTree.org phylogenies."

Date: Sampling date on which the individual bird was captured and sampled. DD-MON-YY

Location: Sampling locality or field site where the bird was captured.

Season: Season during which sampling was conducted (e.g., wet season or dry season).

Classification: Elevation classification assigned to the sampling site or individual record.

Elevation: Elevation of the sampling locality measured in meters above sea level (m.a.s.l.).

Specimen.ID: Unique identification code assigned to each sampled bird individual.

Scie_name: Scientific name of the sampled bird individual following the BirdLife taxonomy system. These names were used to match species records with the AVONET dataset for ecological trait extraction.

FamilyT: Taxonomic family classification following the IOC World Bird List taxonomy.

GenusT: Taxonomic genus classification following the IOC World Bird List taxonomy.

SpeciesT: Species-level taxonomic designation following the IOC World Bird List taxonomy.

Scie_nameT: Standardized scientific name following the IOC World Bird List taxonomy, used to maintain taxonomic consistency across analyses, including phylogenetic analyses based on BirdTree.org taxa.

Fat.score: Ordinal estimate of visible fat reserves used as an indicator of body condition and energy storage. Empty cells indicate birds for which fat scores were not recorded and were left blank to avoid interference with the R analysis script.

Haemoglobin: Haemoglobin concentration (Hb) measured for each sampled individual and used as an indicator of oxygen-carrying capacity.

Infection: Overall haemosporidian infection status of each bird individual.

Leucocytozoon: Presence, absence, or infection intensity associated with parasites belonging to the genus Leucocytozoon.

Plasmodium: Presence, absence, or infection intensity associated with parasites belonging to the genus Plasmodium.

Haemoproteus: Presence, absence, or infection intensity associated with parasites belonging to the genus Haemoproteus.

DATA COLLECTION SUMMARY

Birds were sampled along an elevational gradient in Eswatini using standard field sampling procedures. Physiological measurements and blood samples were collected from each individual. Blood smears were screened microscopically for haemosporidian parasite infections and parasite genera were identified based on morphological characteristics.

ETHICAL CONSIDERATIONS

No sensitive human data are included in this repository.