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Data from: What factors increase the vulnerability of native birds to the impacts of alien birds?

Citation

Evans, Thomas et al. (2021), Data from: What factors increase the vulnerability of native birds to the impacts of alien birds?, Dryad, Dataset, https://doi.org/10.5061/dryad.6wwpzgmxg

Abstract

This dataset accompanies a published paper (Evans et al. 2021) which aims to identify the factors that influence the vulnerability of native bird species to the impacts of alien bird species. In this paper we used mixed-effects models to test 14 variables that we hypothesised to influence vulnerability: this is a dataset of the 14 varaibles. We carried out our analyses using ten sets of these 14 variables: we provide all ten sets of these variables here. Please refer to Evans at al. (2021) for details on the methods used. An abstract to the published paper follows.

Biodiversity impacts caused by alien species can be severe, including those caused by alien birds. In order to protect native birds, we aimed to identify factors that influence their vulnerability to the impacts of alien birds. We first reviewed the literature to identify native bird species sustaining such impacts. We then assigned impact severity scores to each native bird species, depending on the severity of the impacts sustained, and performed two types of analyses. First, we used contingency table tests to examine the distribution of impacts across their severity, type and location, and across native bird orders. Second, we used mixed-effects models to test factors hypothesised to influence the vulnerability of native birds to the impacts of alien birds.

Ground-nesting shorebirds and seabirds were more prone to impacts through predation, while cavity-nesting woodpeckers and parrots were more prone to impacts through competition. Native bird species were more vulnerable when they occupied islands, warm regions, regions with climatic conditions similar to those in the native range of the invading alien species, and when they were physically smaller than the invading alien species. To a lesser extent, they were also vulnerable when they shared habitat preferences with the invading alien species.

By considering the number and type of native bird species affected by alien birds, we demonstrate predation impacts to be more widespread than previously indicated, but also that damaging predation impacts may be underreported. We identify vulnerable orders of native birds, which may require conservation interventions; characteristics of native birds that increase their vulnerability, which may be used to inform risk assessments; and regions where native birds are most vulnerable, which may direct management interventions. The impacts sustained by native birds may be going unnoticed in many regions of the world: there is a clear need to identify and manage them.

Methods

Please refer to the published paper associated with this dataset, which provides a detailed description of the data collection methods.

Usage Notes

Variable

Description

V1: Phylogenetic distance

The similarity of the interacting native and alien species as measured by their phylogenetic distance

V2: Habitat similarity

The proportion of broad habitat types occupied by a native species that are shared with its alien invader

V3: Diet similarity

The proportion of a native bird species’ diet that is shared with its alien invader

V4: Habitat breadth

The number of major habitats occupied by the native species

V5: Diet breadth

The breadth of a native bird species’ diet

V6: Body mass difference

The difference between the adult body mass (g) (log) of the native species and that of the alien species

V7: Native range size

The native species’ breeding range size (km2) (log10)

V8: Native species richness

The number of different native bird species present within the country or region of impact

V9: Eco-evolutionary experience

A measure of the native species’ experience of the alien invader, and the alien species’ experience of the native species

V10: Island / continent

The broad location of impact: either island or continent

 

V11, V12, V13, V14: Max. and min. av. monthly temp., and max. and min. av. monthly rainfall

Climatic conditions at the location of impact

V15: Climatic similarity

A measure of the similarity of climatic conditions in the alien species’ native range and the area of impact (the area in which impacts to a native bird species were recorded) (numbers closer to 0 = a more similar climate)

Funding

Alexander von Humboldt-Stiftung

German Federal Ministry of Education and Research, Award: 01LC1803A

International IGB Fellowship Program in Freshwater Science

International IGB Fellowship Program in Freshwater Science