DOI: 10.5061/dryad.cnp5hqc21
title: When does weather synchronise life history traits? Spatiotemporal patterns in juvenile body mass of two ungulates

description: 1. Theory predicts that animal populations will be synchronised over large
 distances by weather and climatic conditions with high spatial synchrony.
 However, local variation in population responses to weather, and low
 synchrony in key weather variables or in other ecological processes may
 reduce the population synchrony. 2. We investigated to what extent
 temperature and precipitation during different periods of the year
 synchronised juvenile body mass of moose and reindeer in Norway. We
 expected high synchronising effect of weather variables with a high and
 consistent explanatory power on body mass dynamics across populations, and
 a weaker synchronising effect of weather variables whose effect on body
 mass varied among populations. 3. Juvenile body mass in both species was
 related to temperature and precipitation during several periods of the
 year. Temperature had the strongest explanatory power in both species,
 with a similar effect across all populations. 4. There was higher spatial
 synchrony in temperature compared to precipitation, and accordingly
 temperature had the strongest synchronising effect on juvenile body mass.
 Moreover, periods with strong explanatory power had stronger synchronising
 effect on juvenile body mass in both species. However, weather variables
 with large variation in the effects on body mass among populations had
 weak synchronising effect. 5. The results confirm that weather has a large
 impact on the spatial structure of population properties, but also that
 spatial heterogeneity for instance in environmental change or population
 density may affect how and to what extent populations are
 synchronised. 
description: In both species body mass
 was measured as carcass mass, which is body mass minus head, skin,
 metapodials, bleedable blood, and viscera (Sæther et al., 1996). In the
 uploaded data it is reported as the mean body mass of all harvested calves
 in a municipality (moose) or herding district (reindeer) in a given
 year. Moose
 juvenile body mass was based on calves harvested and weighed during the
 hunting season in autumn, from which body mass is collected as part of the
 National monitoring program for wild cervids in Norway (Solberg et al.,
 2017). Hunters also recorded sex, place (municipality) and the date the
 animal was shot and slaughtered. The hunting season lasted from 25th of
 September or 5th of October, to the end of October, but has recently been
 extended to December. Because calf body mass increases during the autumn
 (Herfindal et al., 2006), we only use calves harvested in September and
 October, and adjusted it according to the date of harvest and to sex
 assuming similar weather effects on males and females (see procedure in
 Herfindal et al., 2006). We then calculated the mean body mass per
 municipality and year. Body mass of semi-domestic
 reindeer calves are reported by slaughterhouses. Data are reported as mean
 carcass mass and number of calves slaughtered per reindeer herding
 district and year. Slaughtering normally occurs at the same time each year
 within a district, typically two weeks prior to the rut which starts in
 ultimo September. Data on temperature and
 precipitation were obtained from the Norwegian Meteorological Institute as
 downscaled 1×1 km gridded daily data covering all of Norway (Engen-Skaugen
 et al., 2002). For each municipality or reindeer district we calculated
 monthly mean temperature and sum of precipitation by averaging the value
 of all pixels falling inside the population borders. For moose, we
 restricted the calculation to pixels below the climatic tree line,
 obtained from Moen (1999), to exclude alpine habitat that are rarely used
 by moose. This was not necessary for reindeer, as all areas within
 districts potentially can be used by reindeer during a year.
 References: Engen-Skaugen, T., Hanssen-Bauer,
 I., & Førland, E. J. (2002). Adjustment of dynamically downscaled
 temperature and precipitation data in Norway. Oslo: Norwegian
 Meteorological Institute Report 20/02. Herfindal, I., Solberg, E. J.,
 Sæther, B.‑E., Høgda, K. A., & Andersen, R. (2006). Environmental
 phenology and geographical gradients in moose body mass. Oecologia,
 150(2), 213–224. https://doi.org/10.1007/s00442-006-0519-8 Moen, A. (1999). National atlas of Norway: vegetation. Hønefoss, Norway: Norwegian Mapping Authority. Solberg, E. J., Strand, O., Veiberg, V., Andersen, R., Heim, M., Rolandsen, C. M., . . . Eriksen, R. (2017). Hjortevilt 1991-2016. Oppsummeringsrapport fra Overvåkingsprogrammet for hjortevilt. NINA Rapport, 1388. Sæther, B.‑E., Andersen, R., Hjeljord, O., & Heim, M. (1996). Ecological correlates of regional variation in life history of the moose Alces alces. Ecology, 77(5), 1493–1500. https://doi.org/10.2307/2265546
description: Data is stored as
 tab-separated text-files.  Description of the columns in the
 data table (similar for moose and reindeer data): nr: Identity of the reindeer
 herding district or moose municipality Year: Year of birth and
 slaughter Svekt:
 Annual mean calf carcass mass (i.e. body mass minus head, skin,
 metapodials, bleedable blood, and viscera). Adjusted for sex and kill date
 in moose UTMX:
 Center x-coordinate in district or municipality (UTM, zone 33,
 WGS84) UTMY:
 Center y-coordinate in district or municipality (UTM, zone 33,
 WGS84) NovTAM.1:
 Mean temperature (Celcius-degrees) in November previous year
 DecTAM.1: Mean temperature
 (Celcius-degrees) in December previous year JanTAM: Mean temperature
 (Celcius-degrees) in January birth year FebTAM: Mean temperature
 (Celcius-degrees) in February birth year MarTAM: Mean temperature
 (Celcius-degrees) in March birth year AprTAM: Mean temperature
 (Celcius-degrees) in April birth year MayTAM: Mean temperature
 (Celcius-degrees) in May birth year JunTAM: Mean temperature
 (Celcius-degrees) in June birth year JulTAM: Mean temperature
 (Celcius-degrees) in July birth year AugTAM: Mean temperature
 (Celcius-degrees) in August birth year SepTAM: Mean temperature
 (Celcius-degrees) in September birth year NovRR.1: Precipitation (mm) in
 November previous year DecRR.1: Precipitation (mm) in
 December previous year JanRR: Precipitation (mm) in
 January birth year FebRR: Precipitation (mm) in
 February birth year MarRR: Precipitation (mm) in
 March birth year AprRR: Precipitation (mm) in
 April birth year MayRR: Precipitation (mm) in May
 birth year JunRR:
 Precipitation (mm) in June birth year JulRR: Precipitation (mm) in July
 birth year AugRR:
 Precipitation (mm) in August birth year SepRR: Precipitation (mm) in
 September birth year