DOI: 10.5061/dryad.63xsj3v81
title: Evidence of migratory coupling between grey wolves and migratory caribou

description: Large-scale animal migrations influence population and community dynamics
 along with ecosystem functioning. The migratory coupling concept posits
 that movement of migrant prey can lead to large-scale movements of
 predators. In northern ecosystems, spatial patterns and behavioral
 responses of grey wolf to spatio-temporal changes in its primary prey
 distribution, the migratory caribou, remain poorly documented. We used a
 long-term GPS dataset (2011–2021) of 59 wolves and 431 migratory caribou
 from the declining Rivière-aux-Feuilles herd (Québec, Canada) to
 investigate movement patterns and space use of wolves related to caribou
 seasonal distribution. Wolves home ranges overlapped with areas used by
 caribou year-round, especially in May and winter. Wolves exhibited 3
 annual tactics: sedentary (17%), long-distance migration (&gt;700 km)
 between wintering areas and the tundra (36%), and a medium-distance
 migration, stopping their northward movement near the treeline (47%).
 Migratory wolves started spring migration northward earlier than caribou,
 intercepting their prey on their way to calving grounds, but departed
 southward for fall migration later than caribou, tracking them on their
 way back to wintering areas. Wolves near or overlapping areas used by
 caribou exhibited lower monthly movement rates compared to wolves located
 further away. Overlap of home range among wolves was higher during
 migrations and winter but decreased in summer when wolves rear pups and
 caribou are dispersed on summer grounds. We provide evidence of migratory
 coupling between grey wolves and migratory caribou, with most wolves
 adjusting their space use patterns to match their primary prey
 distribution. Although predation pressure may affect the dynamics of
 declining caribou herds, the global decline of that prey may in turn
 impact predators on the long-term, potentially enhancing intraspecific
 competition for new resources. Highlighting this migratory coupling is a
 key step to developing appropriate conservation and management measures
 for both guilds in the context of large-scale migratory prey decline.
description: We collected data on grey wolf movements in northern Québec in
 the annual range of the Rivière-aux-Feuilles migratory caribou herd (RFH).
 In February and March of 2011–2019, we captured 59 adult grey wolves
 within the RFH range from a helicopter and using either a net gun or a
 tranquilizer dart gun with Telazol (10 mg.kg<sup>-1</sup>). We
 equipped grey wolves with GPS collars (Lotek, Vectronic, Telonics)
 programmed to record a location every 1 to 5 hours depending on the collar
 model and year. Individual grey wolves monitoring lasted on average 419 +
 227 days (mean + SD). We defined each wolf-year as 1 April to 31 March of
 the following year. We captured caribou in the RFH range between December
 and March each year as part of the long-term population monitoring
 conducted by the Ministère de l’Environnement, de la Lutte aux changements
 climatiques, de la Faune et des Parcs (MELCCFP) and Caribou Ungava. We
 captured caribou from a helicopter with a net gun and equipped them with
 GPS collars (Vectronic). GPS collars were set to record a location every 1
 to 13 hours. A total of 431 females from the RFH were monitored for 741.5
 days on average. Please, refer to Material and Methods
 for more details about the data cleaning and processing.
description: # Evidence of migratory coupling between grey wolves and migratory caribou
 [https://doi.org/10.5061/dryad.63xsj3v81](https://doi.org/10.5061/dryad.63xsj3v81) This is the final dataset about wolves metrics, containing the final data and values used in the models performed in our study. It corresponds to the Table S2 cited in our manuscript. For each individual wolf tracked, we calculated different variables at the monthly scale. Each row of the datatable thus corresponds to each wolf-month information: | Column | Definition | | ------ | ---------- | | ID\_wolf | ID of the focal wolf | | Sex | Sex of the focal wolf | | Period | Period during which the focal wolf was monitored (initial year to final year: from 1 April of the year to 31 March of the following year) | | Year | Year of the focal wolf-month | | Month | Wolf-month. Each wolf-year was defined as 1 April of the year y to 31 March of the following year y+1. Month from April to December of the year y will be noted as apr., may, june, july, aug., sept., oct., nov., dec., and month from January to March of the year y+1 will be noted as jan.+1, feb.+1, mar.+1. | | Record\_per | Percentage of the wolf-month recorded by GPS track (number of locations recorded divided by the number of locations expected for one location recorded every 4h or 5h depending on the GPS setting and depending on the month) | | Record\_dur | Duration of the GPS monitoring recorded for the focal wolf during the given wolf-month (in hours) | | Nb\_loc | Number of GPS locations recorded for the focal wolf during the given wolf-month | | Dist\_tot\_month | Total distance traveled by the focal wolf during the given wolf-month (in km) | | Dist\_straight\_month | Straight distance between the initial and final location of the focal wolf during the given wolf-month (in km) | | Dist\_day\_mean | Mean daily distance traveled by the focal wolf during the given wolf-month (in km) | | Straight\_month | Monthly straightness traveled by the focal wolf during the given wolf-month | | Wolf\_HR\_area | Monthly home-range (HR) area of the focal wolf during the given wolf-month (in km²) | | Carib\_AU | Monthly area used (AU) by migratory caribou during the given wolf-month (in km²) | | Wolf\_HR\_over\_carib | Monthly home-range (HR) area of the focal wolf in overlap with migratory caribou area used (AU) during the given wolf-month (in km²) | | Wolf\_prop\_over\_carib | Proportion of overlap between the focal wolf monthly home-range (HR) area and the monthly area used (AU) by migratory caribou during the given wolf-month (in %) | | Dist\_carib\_mean\_month | Mean monthly distance of the focal wolf to the area used (AU) by migratory caribou during the given wolf-month (in km) | | Dist\_carib\_end\_month | Distance between the final location of the month of the focal wolf to the nearest border of the area used (AU) by migratory caribou during the given wolf-month (in km) | | Dist\_carib\_ini\_month | Distance between the initial location of the month of the focal wolf to the nearest border of the area used (AU) by migratory caribou during the given wolf-month (in km) | | Delta\_dist\_carib | Difference in the distance between the final and initial locations for the focal wolf to the area used (AU) by migratory caribou during the given wolf-month (in km) | | Nb\_wolf\_month | Total number of wolves monitored during the given wolf-month | | Nb\_wolf\_other | Total number of wolves monitored during the given wolf-month excepted the focal wolf | | Nb\_wolf\_over | Number of wolves with which the focal wolf home-range (HR) overlaps with during the given wolf-month | | Prop\_nb\_wolf\_over | Proportion of the total wolves number with which the focal wolf has its home-range (HR) in overlap during the given wolf-month (in %) | | Wolf\_HR\_over\_wolf | Monthly home-range (HR) area of the focal wolf in overlap with other wolves monitored during the given wolf-month (in km²) | | Wolf\_prop\_over\_wolf | Proportion of overlap between the focal wolf monthly home-range (HR) area and other wolves HR during the given wolf-month (in %) | Please refer to the Material and Method section in the manuscript for further details about the variables calculation.