DOI: 10.5061/dryad.h9w0vt4jk
title: Airflow modelling predicts seabird breeding habitat across islands

description: Wind is fundamentally related to shelter and flight performance: two
 factors that are critical for birds at their nest sites. Despite this,
 airflows have never been fully integrated into models of breeding habitat
 selection, even for well-studied seabirds. Here we use computational fluid
 dynamics to provide the first assessment of whether flow characteristics
 (including wind speed and turbulence) predict the distribution of seabird
 colonies, taking common guillemots (Uria aalge) breeding on Skomer island
 as our study system. This demonstrates that occupancy is driven by the
 need to shelter from both wind and rain/ wave action, rather than airflow
 characteristics alone. Models of airflows and cliff orientation both
 performed well in predicting high quality habitat in our study site,
 identifying 80% of colonies and 93% of avoided sites, as well as 73% of
 the largest colonies on a neighbouring island. This suggests generality in
 the mechanisms driving breeding distributions, and provides an approach
 for identifying habitat for seabird reintroductions considering current
 and projected wind speeds and directions.
description: Methods detailed in
 manuscript: https://doi.org/10.1111/ecog.05733.
description: <strong>Variable list for files:</strong>
 SW wind - Section table on Skomer (Standardised).csv / NW wind -
 Section table on Skomer (Standardised).csv / SE wind - Section table on
 Skomer (Standardised).csv /NE wind - Section table on Skomer
 (Standardised).csv and SW wind - Sections on Skokholm
 (Standardised).csv FID: Row ID (for use in
 ArcGIs) Count: Number of guillemots per
 section Area: Total area of each section () 
    Density: Density of guillemots per section (number
 of birds/ Area)     X_Centre: X coordinate of the
 central point of each section Y_Centre: Y coordinate of
 the central point of each section     Sector: Section
 ID    MeanUMedian; MeanUIQR, MeanUSkewness, MeanUCV:
 Median, interquartile range,skewness and coefficient of variation of mean
 wind speed per section    
 HorizontalMedian;HorizontalIQR,HorizontalSkewness,HorizontalCV: Median, interquartile range,skewness and coefficient of variation of horizontal wind speed per section    PMedian;PIQR,PSkewness,PCV: Median, interquartile range,skewness and coefficient of variation of preessure per section TKEMedian;TKEIQR,TKESkewness,TKECV: Median, interquartile range,skewness and coefficient of variation of turbulent kinetic energy per section     TIMedian;TIIQR,TISkewness,TICV: Median, interquartile range,skewness and coefficient of variation of turbulence intensity per section     U_2Median;lU_2IQR;U_2Skewness;U_2CV: Median, interquartile range,skewness and coefficient of variation of vertical wind speed per section     EpsilonMedian;EpsilonIQR,EpsilonSkewness,EpsilonCV: Median, interquartile range,skewness and coefficient of variation of turbulent dissipation rate per section     NutMedian;NutIQR,NutSkewness,NutCV: Median, interquartile range,skewness and coefficient of variation of kinematic viscosity per section     GustsMedian;GustsIQR,GustsSkewness,GustsCV: Median, interquartile range,skewness and coefficient of variation of instataneous gusts per section     MeanSectorSlope: Mean slope per section     ColPresence: Binomial variable, indicating whether a section has birds or not. This variable varies with classification, based on either the count of birds or the density per section <strong>Variable list for file:</strong>  Section table on Skomer - with Mean cliff orientation and Slope (NOT-Standardised).csv FID: Row ID (for use in ArcGIs) Count: Number of guillemots per section Area: Total area of each section ()     Density: Density of guillemots per section (number of birds/ Area)     X_Centre: X coordinate of the central point of each section Y_Centre: Y coordinate of the central point of each section     Sector: Section ID    MeanSectorSlope: Mean slope per section    MeanSectorAspectCircular: Mean cliff orientation per section ApsectClass: Factor indicating whether the mean cliff orientation is lee- or windward to the SW wind ColPresence:  Binomial variable, indicating whether a section has birds or not. This variable varies with classification, based on either the count of birds or the density per section <strong>Variable list for file:</strong>  SW wind - Sections on Skokholm to predict colonies using cliff orientation and slope model from Skomer (NON - Standardised).csv FID: Row ID (for use in ArcGIs) Count: Number of guillemots per section Area: Total area of each section ()     Density: Density of guillemots per section (number of birds/ Area)     Sector: Section ID    MeanSectorSlope: Mean slope per section    MeanSectorAspectCircular: Mean cliff orientation per section