Lower adaptive immunity in invasive Egyptian geese compared to sympatric native waterfowls

Successful invasive species increase their spreading success by trading off nutritional and metabolic resources allocated to reproduction and range expansion with other costly body functions. One proposed mechanism for reallocating resources is a trade-off between the immune function and the regulation of oxidative status. 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 mute swan) in Germany, we tested the hypothesis that the invasive species would have (i) lower investment in immune function, (ii) lower levels of oxidative damage, and (iii) no higher antioxidant defenses compared to the native species. We found lower levels of adaptive immune markers (lymphocytes and immunoglobulin Y), in the invasive species compared to the two native species. Reactive oxygen metabolites, a marker of oxidative damage, were also lower in Egyptian geese compared to the other..., 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 linear models (LMs) to assess the differences between species in each single marker. Therefore, for each model, we included..., , # Lower adaptive immunity in invasive Egyptian geese 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 = haematocrit (Eryth...