DOI: 10.5061/dryad.8w9ghx3z5
title: Latitude-specific responses of European birds’ population growth rates to temperature and water availability

description: Climate limits the distribution of species and varies along a latitudinal
 gradient. However, studies relating climate variation to species
 population growth rates in different climatic zones while taking into
 account species’ ecological traits are scarce. We assessed species
 population responses to the main climatic constraints at a continental
 scale by studying how precipitation and temperature at different latitudes
 influence interannual growth rates while considering species’ life-history
 traits. We gathered data on the abundance of 141 European breeding bird
 species from national breeding bird monitoring schemes in the
 Mediterranean (Catalonia, NE Spain), temperate (Czech Republic), and
 boreal (Sweden) climatic zones for the period 2002–2022. We used
 generalized linear models to relate the interannual population growth
 rates of bird species to spring and winter temperature, water availability
 and heavy rainfall in the breeding season. We considered migration
 strategy as a covariate possibly shaping bird responses to climate. We
 found general positive effects of spring and winter temperatures and water
 availability, and negative effects of heavy rainfall. Increased
 temperatures affected residents more positively in southern Boreal than in
 continental and Mediterranean climatic zones. Long-distance migrants
 responded negatively to temperatures in continental and northern Boreal
 zones. Higher water availability supported residents and short-distance
 migrant populations more in lower and higher latitudes than in
 mid-latitudes. Heavy rainfall tended to affect birds, especially
 residents, more negatively towards the north, where we revealed the
 strongest effect among the considered climate variables. Similarly,
 short-distance migrants suffered more from the intensive rains in northern
 Boreal than in other climatic zones. Previously, temperature has been
 shown to be a strong climatic constraint of bird population dynamics. Our
 results suggest that future changes in precipitation regimes during the
 birds’ breeding season should also be considered among the important
 climatic pressures on bird population growth rates in different climatic
 regions.
description: # Code and data for: Latitude-specific responses of European birds'
 population growth rates to temperature and water availability Data and R
 script allowing to reproduce the modelling in the accompanied journal
 article. The models are stored for convenience. All files are available
 in Climate_growth_rate.zip. ## **Description of the data and file
 structure** ### File tree * data * model ### *Data* `dt_growth_r_clim.csv`
 Data set containing the following variables: * `EURING` = bird species
 code * `Spec_name` = bird species name * `Reg` = breeding region, i.e.,
 MED = Mediterranean, CONT = Continental, S_BOR = Southern Boreal, N_BOR =
 Northern Boreal * `Year` = year corresponding to breeding season (2002 to
 2021) * `Growth_r` = interannual population growth rate (ratio of annual
 population indices in year t+1 and t) * `Growth_r_SE` = standard error of
 population growth rate * `Dens` = population density (log-transformed
 annual population index) * `Dens_SE` = standard error of population
 density * `Migr` = migration status, i.e. R = resident, S = short-distance
 migrant, L = long-distance migrant * `Diet` = species' diet (values 1
 to 5, from obligatory herbivores (1) to obligatory insectivores (5)) *
 `Bmass` = species' body mass (g) * `Therm_coord` = thermal coordinate
 (range from 0 to 1, from species occupying relatively cold to relatively
 warm sites of their European breeding range) * `MC1` = MC1 scores
 describing species' habitat preference (a position along a gradient
 from coniferous and deciduous forests (negative values) to wetlands and
 water bodies (positive values)) * `MC2` = MC2 scores describing
 species' habitat preference (a position along a gradient from rocky
 habitats and mountain meadows (negative values), through grasslands
 (around zero), to wetlands and water bodies (positive values)) * `Temp` =
 temperature (breeding season, °C) * `ETr` = water availability (range from
 0 to 1, a ratio of actual evapotranspiration to potential
 evapotranspiration) * `R10` = heavy rainfall (mean number of heavy
 rainfall days, i. e., daily rainfall ≥ 10 mm) * `Twin` = winter
 temperature relevant for residents only (°C) ### *Model* `m1_clim.rds`
 Stored model testing the overall effects of climate variables, can be
 loaded instead of fitting the model.\ `m2_clim.rds` Stored model testing
 the effects of climate variables in regions and in migration strategies,
 can be loaded instead of fitting the model.\ `m3_clim.rds` Stored model
 testing the effects of climate variables in migration strategies within
 regions, can be loaded instead of fitting the model.\ `m4_clim.rds` Stored
 model testing the overall effect of winter temperatures on residents, can
 be loaded instead of fitting the model.\ `m5_clim.rds` Stored model
 testing the effects of winter temperature on residents in particular
 regions, can be loaded instead of fitting the model.\ ## **Code/Software**
 `R-script_bird_growth.R` R script for preparing the data, fitting the
 models, and deriving various statistics for the effects of climate
 variables. R is required to run the code. ## Usage notes R is required to
 run the script `R-script_bird_growth.R`, as well as to load the stored
 models (.rds files). The models can be loaded using the base R function
 readRDS(), but we recommend following the code provided in the R script in
 order to assign names to the models anticipated within the workflow.
 Microsoft Excel or a similar spreadsheet editor can be used to
 open `dt_growth_r_clim.csv` data set.