DOI: 10.5061/dryad.6wwpzgmxg
title: Data from: What factors increase the vulnerability of native birds to the impacts of alien birds?

description: 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.
description: Please refer to the published paper associated with this dataset,
 which provides a detailed description of the data collection
 methods.
description: 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
 (km<sup>2</sup>) (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)