Lower baseline immunity in invasive Egyptian Goose compared to sympatric native waterfowls

Successful invasive species out-compete native species for vital resources. To increase their spreading success, invasive species need to trade off nutritional and metabolic resources allocated to reproduction and range expansion with other costly body functions. One proposed mechanism for the reallocation of resources is a trade-off with the immune function. According to the evolution of the increased competitive ability hypothesis, a reduced investment in immunity would be favoured by parasite loss in colonised habitats. It is also suggested that invaders would reallocate resources among different immune effectors depending on the new pathogens they encounter in the new habitat. Reallocation of resources may also involve the regulation of oxidative status given its fundamental link with the immune system. Relying on a panel of blood-based markers of immune function and oxidative status quantified in an invasive species (Egyptian Goose) and two native competing species (Mallard and Mut..., Adult individuals of the study species were live trapped in June and July 2016 in the Rhine and Mosel area in Western Germany (50.4° N, 7.6° E; Fig. S1). All individuals in this study were locally breeding and mostly in the phase of guiding goslings/ducklings at the time of sampling. Birds were caught using either loops or landing nets. Each bird was individually ringed, and body mass and sex were recorded. A blood sample from each bird was collected, either from the vena metatarsalia plantaris superficialis or the vena ulnaris, using a needle of 0.06 mm diameter. Blood samples were kept cool during field procedures, then centrifuged for 15 minutes to separate plasma from red blood cells which were stored separately in liquid nitrogen within 8 hours from blood collection. At the end of fieldwork, samples were stored at -80 °C until laboratory analyses.
We performed a principal component analysis (PCA) on the correlation matrix between all markers of the immune system and of oxidative st..., , # Lower baseline immunity in invasive Egyptian Goose compared to sympatric native waterfowls

[https://doi.org/10.5061/dryad.kh18932fh](https://doi.org/10.5061/dryad.kh18932fh)

The dataset included 74 actively reproducing individuals of which 28 were Egyptian Geese, 10 Mallards, and 36 Mute Swans. We collected blood samples from both female and male Egyptian Geese (females = 12; males = 16), Mute Swans (females = 21; males = 15), and only female Mallards. Sample sizes varied slightly for different immunological markers due to limited amounts of blood for certain individuals (Table 1).

## Description of the data and file structure

Species

* CYOL Mute Swan
* ANPL Mallard
* ALEG Egyptian Goose

Parameters

* basos_rv = basophils (cells/10000 erythrocytes)
* eos_rv = eosinophils (cells/10000 erythrocytes)
* heteros_rv = heterophils (cells/10000 erythrocytes)
* lymphos_rv = lymphocytes (cells/10000 erythrocytes)
* monos_rv = monocytes (cells/10000 erythrocytes)
* hkt = ...