DOI: 10.5061/dryad.1ns1rn91s
title: Data from: Seeking temporal refugia to heat stress: Increasing nocturnal activity despite predation risk

description: Flexibility in activity timing may enable organisms to quickly adapt to
 environmental changes. Under global warming, diurnally adapted endotherms
 may achieve a better energy balance by shifting their activity towards
 cooler nocturnal hours. However, this shift may expose animals to new or
 increased environmental challenges (e.g., increased predation risk,
 reduced foraging efficiency). We analysed a large dataset of activity data
 from 47 ibex (Capra ibex) in two protected areas, characterized by varying
 levels of predation risk (presence vs absence of the wolf – Canis lupus).
 We found that ibex increased nocturnal activity following warmer days and
 during brighter nights. Despite the considerable sexual dimorphism typical
 of this species and the consequent different predation-risk perception,
 males and females demonstrated consistent responses to heat in both
 predator-present and predator-absent areas. This supports the hypothesis
 that shifting activity towards nighttime may be a common strategy adopted
 by diurnal endotherms in response to global warming. As nowadays different
 pressures are pushing mammals towards nocturnality, our findings emphasize
 the urgent need to integrate knowledge of temporal behavioural
 modifications into management and conservation planning.
description: <em>Activity data logging: </em>The activity data of
 individual ibex (18 males and 9 females in PNGP, 12 males and 8 females in
 SNP, more details in the Supporting Information Table S1 and Table S2)
 were recorded by means of a dual-axis motion sensor (i.e., accelerometer)
 fitted on the collars. The accelerometer simultaneously measures along two
 orthogonal directions the changes in acceleration associated with the
 actual motion experienced by the collar. On the X-axis, the accelerometer
 was sensitive to acceleration events with forward/backward direction/axes,
 while on the Y-axis, it recorded acceleration events with a sideways and
 rotary direction. The accelerometer had a dynamic range of ±2g and
 measured activity as the change of static acceleration (gravity) and
 dynamic acceleration (collar) with a frequency of 4 Hz. The motion data
 from accelerometers, i.e., activity values, were calculated as the
 difference between consecutive measurements, averaged over a time interval
 of 4 or 5 minutes and given within a relative range between 0 (no
 difference between consecutive data) and 255 (difference of -2 g/+2 g),
 with the associated date and time. The activity data recorded were
 downloaded by means of a handheld terminal (Vectronic Aerospace GmbH,
 Berlin) and Yagi antenna. <em>Weather and
 Astronomical Data: </em>Weather data such as hourly air temperature
 (°C) and hourly precipitation (i.e., the amount of rain expressed in
 millimetres of water) were provided by Meteorological Service of Regione
 Autonoma Valle d’Aosta (weather station of Pont, 45° 31′ N, 7° 12′ E; 1951
 m a.s.l.) and by the Federal Office for Meteorology and Climatology
 (weather station of Samedan, 46° 31′ N; 9° 52′ E; 1710 m a.s.l.), for the
 GPNP and SNP study areas, respectively. We a priori chose to use
 temperature rather than radiation (which are highly correlated) because
 previous research suggested that air temperature was the main driver
 affecting ibex spatial choices (Brivio et al. 2019). Moon illumination was
 calculated using the <em>suncalc</em> package in R (Thieurmel
 and Elmarhraoui 2019) and was expressed as the illuminated fraction of the
 moon, which ranged from 0.0 (new moon) to 1.0 (full moon). Cloud cover
 estimates were downloaded from the NCEP/NCAR data set (Kalnay et al. 1996)
 by using the interpolation method “Inverse Distance Weighting” (Shepard
 1968) by means of the NCEP.interp function in the RNCEP package in R (Kemp
 et al. 2012). Cloud cover data was expressed as the percentage of sky
 covered by clouds and had a spatial and temporal gridded resolution of
 2.5° and 6 hours, respectively. In our analyses, only cloud cover data
 recorded at 00.00 AM were used.
description: # README\_for\_data\_Brivio\_etal\_2023 ## Description: This README file
 describes the data package accompanying the publication: Brivio F.,
 Apollonio M., Anderwald P., Filli F., Bassano B., Bertolucci C., Grignolio
 S. Seeking temporal refugia to avoid heat stress: increasing nocturnal
 activity despite predation risk. Proc. R. Soc. B DOI:
 10.1098/rspb.2023.1587 ## File list: *
 “dataset_ibex.nocturnal.activity.csv” *
 “dataset_ibex.nocturnal.activity_FEMALES-KID.csv” * “ibex nocturnal
 activity analysis.R” ## File description:
 “dataset_ibex.nocturnal.activity.csv”: contains the data about the
 nocturnal activity of Alpine ibex monitored from 2006 to 2019 the critical
 period for ibex when they experience the highest environmental
 temperatures and must acquire energy prior to the rigours of winter,
 (i.e., from 1 May to 31 October) in the Gran Paradiso National Park (Italy
 and in the Swiss National Park (Switzerland). The dataset includes
 information on individual characteristics and weather conditions. The
 variables included in the dataset are the followings: * animal.id: ibex
 identity code * sex: sex of the monitored ibex (f=female, m=male) *
 cohort: year of birth of the monitored ibex * site: site where ibex was
 monitored (gpnp= Gran Paridiso National Park, snp= Swiss National Park) *
 year: year of data collection * j.date: day of data collection expressed
 as Julian date * PNAT: proportion of nocturnal active time * PDAT:
 proportion of active time during the previous diurnal hours *
 night.brightness: night brightness (see the text for details) *
 temp_PDH_min: minimum temperature of the previous diurnal hours (expressed
 in °C) * temp_PDH_mean: mean temperature of the previous diurnal hours
 (expressed in °C) * temp_PDH_max: maximum temperature of the previous
 diurnal hours (expressed in °C) * temp_NH_min: minimum temperature of the
 nocturnal hours (expressed in °C) * temp_NH_mean: mean temperature of the
 nocturnal hours (expressed in °C) * temp_NH_max: maximum temperature of
 the nocturnal hours (expressed in °C) * temp_FDH_min: minimum temperature
 of the following diurnal hours (expressed in °C) * temp_FDH_mean: mean
 temperature of the following diurnal hours (expressed in °C) *
 temp_FDH_max: maximum temperature of the following diurnal hours
 (expressed in °C) * LN_prec_NH: mean of precipitation (i.e., the amount of
 rain expressed in millimeters of water) recorded during the nocturnal
 hours (log-transformed) * LN_prec_PDH: mean of precipitation (i.e.,
 the amount of rain expressed in millimeters of water) recorded during the
 previous diurnal hours (log-transformed)
 “dataset_ibex.nocturnal.activity_FEMALES-KID.csv”: a subset of our data
 corresponding to the periods during which we had information about female
 productivity (i.e., we knew if females were with or without their kid).
 The dataset includes information on individual characteristics and weather
 conditions. The variables included in the dataset are the following: *
 animal.id: ibex identity code * sex: sex of the monitored ibex (f=female)
 * repr.status: reproductive status of the monitored female ibex (2=
 without kid, 3= with kid) * cohort: year of birth of the monitored ibex *
 site: site where ibex was monitored (gpnp= Gran Paridiso National Park,
 snp= Swiss National Park) * year: year of data collection * j.date: day of
 data collection expressed as Julian date * PNAT: proportion of nocturnal
 active time * PDAT: proportion of active time during the previous diurnal
 hours * night.brightness: night brightness (see the text for details) *
 temp_PDH_min: minimum temperature of the previous diurnal hours (expressed
 in °C) * temp_PDH_mean: mean temperature of the previous diurnal hours
 (expressed in °C) * temp_PDH_max: maximum temperature of the previous
 diurnal hours (expressed in °C) * temp_NH_min: minimum temperature of the
 nocturnal hours (expressed in °C) * temp_NH_mean: mean temperature of the
 nocturnal hours (expressed in °C) * temp_NH_max: maximum temperature of
 the nocturnal hours (expressed in °C) * temp_FDH_min: minimum temperature
 of the following diurnal hours (expressed in °C) * temp_FDH_mean: mean
 temperature of the following diurnal hours (expressed in °C) *
 temp_FDH_max: maximum temperature of the following diurnal hours
 (expressed in °C) * LN_prec_NH: mean of precipitation (i.e., the amount of
 rain expressed in millimeters of water) recorded during the nocturnal
 hours (log-transformed) * LN_prec_PDH: mean of precipitation (i.e.,
 the amount of rain expressed in millimeters of water) recorded during the
 previous diurnal hours (log-transformed) “ibex nocturnal activity
 analysis.R”: This R script file reproduces the analyses of the paper cited
 above.