DOI: 10.5061/dryad.1ns1rn95h
title: Urbanisation is related to the prevalence of threatened species on islands across the globe

description: Aim To assess how environmental characteristics and human impacts
 contribute to the global prevalence of threatened bird species on islands
 globally, and to identify which types of anthropogenic land use are most
 strongly associated with extinction risk on islands. Location Global Time
 period Present-day extant species and land-use patterns Major taxa studied
 Terrestrial birds Methods We compiled bird species occurrence and
 conservation status data from BirdLife International and eBird, alongside
 environmental and land-use variables for islands. We grouped nine
 predictor variables into three categories: island characteristics (e.g.,
 area, isolation, climate), human impacts (urban cover, cropland, human
 appropriation of NPP), and wildlands (intact habitat). Using model
 selection and BIC-based model weights, we evaluated the relative support
 for each variable group and assessed which factors best explained the
 prevalence of threatened species (i.e., the proportion of threatened to
 non-threatened species per island). Results Models including both island
 characteristics and human impact variables explained ~40% of the variation
 in the prevalence of currently threatened bird species across islands. The
 strongest predictor overall was island type: oceanic islands exhibited
 significantly higher threatened species prevalence than continental
 islands. Among human impact variables, urban land cover had the most
 substantial effect, with highly urbanized islands showing up to a
 five-fold increase in threatened species prevalence. Main conclusions The
 prevalence of currently threatened species across islands is shaped by the
 interplay between environmental conditions and anthropogenic pressures.
 Our findings highlight urbanization as a particularly potent driver of
 extinction risk, especially on oceanic islands. This study underscores the
 need to update island biogeography frameworks to explicitly account for
 human-driven impacts, as island ecosystems are increasingly reshaped by
 global land-use transformations.
description: Data_binom_unscaled.csv - table with the raw data used for the analysis\ \
 Data_binom.csv - table with the data scaled used for the analysis
 script_GEBsubmission.R - script containing all the analysis of this study
 \ \ ulm_id - unique id number of each island. The ulm_id follows the data
 extracted from Weigelt el al. 2013 all_sp - total number of species
 present in the island Temperature - mean annual temperature registered in
 the island (Celsius) Precip- mean annual precipitation registered in the
 island (milimiters) Arealog - total island area (log transformed) Elevlog
 - mean elevation of the island (log transformed) Distlog - linear distance
 between the island and the continent (log transformed) NPPlog - mean net
 primary productivity in the island (log transformed) GMMCfact and GMMCisl-
 Last Maximum Glacial Connection to mainland, binomial variable (0= not
 connected, 1= connected) n_threat_noNT - number of threatened species
 registered (Red list categories= VU,EN, CR) in the island not_threat -
 number of species in of Least Concern (not threatened) in the island
 HANPP_prop - percentage of the net primary productivity appropriated by
 human activities Land use classes following Ellis et al., 2021
 [https://www.pnas.org/doi/abs/10.1073/pnas.2023483118](https://www.pnas.org/doi/abs/10.1073/pnas.2023483118) Wild -wildlands (log transformed) SemiWild1- proportion of island area covered by wildlands and remote woodlands SemiWild2- proportion of island area covered by wildlands, remote woodlands and cultured woodlands Range- proportion of island area covered by rangelands Crop - proportion of island area covered by croplands Settle- proportion of island area covered by villages and mixed settlements AllImpacts- sum of all human land uses except wildlands and seminatural Urb1- proportion of island area covered by urban areas and dense settlements Urb2 - roportion of island area covered by urban areas only id- observation-level random effect decimal separation (.) - UK format