DOI: 10.5061/dryad.h81s5
title: Data from: Correction of location errors for presence-only species distribution models

description: 1. Species distribution models (SDMs) for presence-only data depend on
 accurate and precise measurements of geographic and environmental
 covariates that influence presence and abundance of the species. Some data
 sets, however, may contain both systematic and random errors in the
 recorded location of the species. Environmental covariates at the recorded
 location may differ from those at the true location and result in biased
 parameter estimates and predictions from SDMs. 2. Regression calibration
 is a well-developed statistical method that can be used to correct the
 bias in estimated coefficients and predictions from SDMs when the recorded
 geographic location differ from the true location for some, but not all
 locations. We expand the application of regression calibration methods to
 SDMs and provide illustrative examples using simulated data and
 opportunistic records of whooping cranes (Grus americana). 3. We found we
 were able to successfully correct the bias in our SDM parameters estimated
 from simulated data and opportunistic records of whooping cranes using
 regression calibration. 4. When modeling species distributions with data
 that have geographic location errors, we recommend researchers consider
 the effect of location errors. Correcting for location errors requires
 that at least a portion of the data have locations recorded without error.
 Bias correction can result in an increase in variance; this increase in
 variance should be considered when evaluating the utility of bias
 correction.
description: Exact
 100mThe file ‘Exact
 100m.csv’ includes environmental covariates calculated within a 100 m
 radius buffer around the 32 whooping crane group locations obtained with a
 global positioning system as well as within a 100 m radius buffer around
 the 10,000 Monte Carlo integration points used in the analysis. The column
 ‘presence.location’ indicates if the covariates are associated with a
 location of a whooping crane group (yes) or a Monte Carlo integration
 point (no). Columns ‘aquatic’ and ‘development’ represent the proportion
 of aquatic habitat and development within a 100 m radius buffer around the
 whooping crane group locations and the Monte Carlo integration points.
 Columns ‘aquatic.section’ and ‘development.section’ represent the
 proportion of aquatic habitat and development within a 100 m radius buffer
 around whooping crane group locations that were degraded in accuracy to
 the section level and the Monte Carlo integration points. Columns
 ‘aquatic.small’ and ‘development.small’ represent the proportion of
 aquatic habitat and development within a 100 m radius buffer around
 whooping crane group locations that included a small degradation (σ = 100
 m) in location accuracy and the Monte Carlo integration points. Columns
 ‘aquatic.large’ and ‘development.large’ represent the proportion of
 aquatic habitat and development within a 100 m radius buffer around
 whooping crane group locations that included a large degradation (σ = 1000
 m) in location accuracy and the Monte Carlo integration points. The
 accuracies of the 10,000 Monte Carlo integration points were not degraded
 and thus the proportion of aquatic habitat and development within the 100
 m radius buffers are the same across respective columns. Note: the same
 10,000 Monte Carlo integration points were used in all
 analyses.Exact
 250mThe file ‘Exact
 250m.csv’ includes environmental covariates calculated within a 250 m
 radius buffer around the 32 whooping crane group locations obtained with a
 global positioning system as well as within a 250 m radius buffer around
 the 10,000 Monte Carlo integration points used in the analysis. The column
 ‘presence.location’ indicates if the covariates are associated with a
 location of a whooping crane group (yes) or a Monte Carlo integration
 point (no). Columns ‘aquatic’ and ‘development’ represent the proportion
 of aquatic habitat and development within a 250 m radius buffer around the
 whooping crane group locations and the Monte Carlo integration points.
 Columns ‘aquatic.section’ and ‘development.section’ represent the
 proportion of aquatic habitat and development within a 250 m radius buffer
 around whooping crane group locations that were degraded in accuracy to
 the section level and the Monte Carlo integration points. Columns
 ‘aquatic.small’ and ‘development.small’ represent the proportion of
 aquatic habitat and development within a 250 m radius buffer around
 whooping crane group locations that included a small degradation (σ = 100
 m) in location accuracy and the Monte Carlo integration points. Columns
 ‘aquatic.large’ and ‘development.large’ represent the proportion of
 aquatic habitat and development within a 250 m radius buffer around
 whooping crane group locations that included a large degradation (σ = 1000
 m) in location accuracy and the Monte Carlo integration points. The
 accuracies of the 10,000 Monte Carlo integration points were not degraded
 and thus the proportion of aquatic habitat and development within the 250
 m radius buffers are the same across respective columns. Note: the same
 10,000 Monte Carlo integration points were used in all
 analyses.Exact
 500mThe file ‘Exact
 500m.csv’ includes environmental covariates calculated within a 500 m
 radius buffer around the 32 whooping crane group locations obtained with a
 global positioning system as well as within a 500 m radius buffer around
 the 10,000 Monte Carlo integration points used in the analysis. The column
 ‘presence.location’ indicates if the covariates are associated with a
 location of a whooping crane group (yes) or a Monte Carlo integration
 point (no). Columns ‘aquatic’ and ‘development’ represent the proportion
 of aquatic habitat and development within a 500 m radius buffer around the
 whooping crane group locations and the Monte Carlo integration points.
 Columns ‘aquatic.section’ and ‘development.section’ represent the
 proportion of aquatic habitat and development within a 500 m radius buffer
 around whooping crane group locations that were degraded in accuracy to
 the section level and the Monte Carlo integration points. Columns
 ‘aquatic.small’ and ‘development.small’ represent the proportion of
 aquatic habitat and development within a 500 m radius buffer around
 whooping crane group locations that included a small degradation (σ = 100
 m) in location accuracy and the Monte Carlo integration points. Columns
 ‘aquatic.large’ and ‘development.large’ represent the proportion of
 aquatic habitat and development within a 500 m radius buffer around
 whooping crane group locations that included a large degradation (σ = 1000
 m) in location accuracy and the Monte Carlo integration points. The
 accuracies of the 10,000 Monte Carlo integration points were not degraded
 and thus the proportion of aquatic habitat and development within the 500
 m radius buffers are the same across respective columns. Note: the same
 10,000 Monte Carlo integration points were used in all
 analyses.Full
 100mThe file ‘Full 100m.csv’
 includes environmental covariates calculated within a 100 m radius buffer
 around the 32 whooping crane group locations obtained with a global
 positioning system, the 36 locations that were recorded as the center the
 Public Land Survey System section, and the 10,000 Monte Carlo integration
 points. The column ‘presence.location’ indicates if the covariates are
 associated with a location of a whooping crane group (yes) or a Monte
 Carlo integration point (no). Columns ‘aquatic’ and ‘development’
 represent the proportion of aquatic habitat and development within a 100 m
 radius buffer around whooping crane group locations and Monte Carlo
 integration points. The column ‘accuracy’ indicates if the location was
 recorded as the center of a Public Land Survey System section (section) or
 if the location was recorded with a global positioning system (gps). The
 location of the 10,000 Monte Carlo integration points were recorded
 without error and therefore the ‘accuracy’ is recorded as exact. Note: the
 same 10,000 Monte Carlo integration points were used in all
 analyses.Full
 250mThe file ‘Full 250m.csv’
 includes environmental covariates calculated within a 250 m radius buffer
 around the 32 whooping crane group locations obtained with a global
 positioning system, the 36 locations that were recorded as the center the
 Public Land Survey System section, and the 10,000 Monte Carlo integration
 points. The column ‘presence.location’ indicates if the covariates are
 associated with a location of a whooping crane group (yes) or a Monte
 Carlo integration point (no). Columns ‘aquatic’ and ‘development’
 represent the proportion of aquatic habitat and development within a 250 m
 radius buffer around whooping crane group locations and Monte Carlo
 integration points. The column ‘accuracy’ indicates if the location was
 recorded as the center of a Public Land Survey System section (section) or
 if the location was recorded with a global positioning system (gps). The
 location of the 10,000 Monte Carlo integration points were recorded
 without error and therefore the ‘accuracy’ is recorded as exact. Note: the
 same 10,000 Monte Carlo integration points were used in all
 analyses.Full
 500mThe file ‘Full 500m.csv’
 includes environmental covariates calculated within a 500 m radius buffer
 around the 32 whooping crane group locations obtained with a global
 positioning system, the 36 locations that were recorded as the center the
 Public Land Survey System section, and the 10,000 Monte Carlo integration
 points. The column ‘presence.location’ indicates if the covariates are
 associated with a location of a whooping crane group (yes) or a Monte
 Carlo integration point (no). Columns ‘aquatic’ and ‘development’
 represent the proportion of aquatic habitat and development within a 500 m
 radius buffer around whooping crane group locations and Monte Carlo
 integration points. The column ‘accuracy’ indicates if the location was
 recorded as the center of a Public Land Survey System section (section) or
 if the location was recorded with a global positioning system (gps). The
 location of the 10,000 Monte Carlo integration points were recorded
 without error and therefore the ‘accuracy’ is recorded as exact. Note: the
 same 10,000 Monte Carlo integration points were used in all
 analyses.Whooping crane location
 dataThe file ‘Whooping crane
 location data.csv’ contains 68 whooping crane group locations that were
 obtained opportunistically in Nebraska, USA from 2000‒2012. The file
 contains latitude, longitude, and accuracy of each location. The column
 ‘accuracy’ indicates if the location was recorded as the center of a
 Public Land Survey System section (section) or if the location was
 recorded with a global positioning system (gps).