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Caribou, water, and ice - fine-scale movements of a migratory arctic ungulate in the context of climate change.

Leblond M, St-Laurent MH, Côté SD - Mov Ecol (2016)

Bottom Line: Although ice phenology did not change significantly during our study, climate projections indicated that ice availability could decrease considerably before the end of the century, generating a ~28 % increase in distance travelled by caribou during the early spring and fall migrations.We demonstrated that ice availability influenced the movements of a migratory arctic ungulate.The long-term conservation of wide-ranging species will ultimately depend on our ability to identify the fine-scale behavioural reactions of individuals to broad-scale changes in climate and land use.

View Article: PubMed Central - PubMed

Affiliation: Caribou Ungava, Département de biologie, and Center for Northern Studies, Université Laval, 1045 avenue de la Médecine, Québec, QC G1V 0A6 Canada.

ABSTRACT

Background: Freshwater lakes and rivers of the Northern Hemisphere have been freezing increasingly later and thawing increasingly earlier during the last century. With reduced temporal periods during which ice conditions are favourable for locomotion, freshwater bodies could become impediments to the inter-patch movements, dispersion, or migration of terrestrial animals that use ice-covered lakes and rivers to move across their range. Studying the fine-scale responses of individuals to broad-scale changes in ice availability and phenology would help to understand how animals react to ongoing climate change, and contribute to the conservation and management of endangered species living in northern environments. Between 2007 and 2014, we equipped 96 migratory caribou Rangifer tarandus caribou from the Rivière-aux-Feuilles herd in northern Québec (Canada) with GPS telemetry collars and studied their space use. We measured contemporary (digital MODIS maps updated every 8 days, 2000-2014) and historical (annual observations, 1947-1985) variations in freshwater-ice availability and evaluated the concurrent responses of caribou to these changes.

Results: Ice had a positive influence on caribou movement rates and directionality, and caribou selected ice and avoided water when moving across or in the vicinity of large water bodies. When ice was unavailable, caribou rarely swam across (6 % of crossings) and frequently circumvented water bodies for several km. Although ice phenology did not change significantly during our study, climate projections indicated that ice availability could decrease considerably before the end of the century, generating a ~28 % increase in distance travelled by caribou during the early spring and fall migrations.

Conclusions: We demonstrated that ice availability influenced the movements of a migratory arctic ungulate. Warmer air temperatures in the Arctic will undoubtedly modify the phenology of ice forming on freshwater lakes and rivers. If migratory caribou are unable to adjust the timing of their migrations, they could be forced to circumvent unfrozen water bodies more frequently and over broader areas, which may increase the distance, time, and energy they use to reach wintering areas. The long-term conservation of wide-ranging species will ultimately depend on our ability to identify the fine-scale behavioural reactions of individuals to broad-scale changes in climate and land use.

No MeSH data available.


Related in: MedlinePlus

Examples of commonly observed caribou movements in the vicinity of large water bodies. Prolonged “pauses” on water body shores before or after crossings and detours are illustrated using red diamonds. Fast and directional movements on ice are illustrated using green arrows. Unsuccessful attempts at crossing open water lakes are illustrated using grey arrows. These movements were made by two migratory caribou from the Rivière-aux-Feuilles herd in the vicinity of Clearwater Lake between November 2010 and April 2014. Similar movements were observed on other water bodies at different dates by different individuals
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Fig4: Examples of commonly observed caribou movements in the vicinity of large water bodies. Prolonged “pauses” on water body shores before or after crossings and detours are illustrated using red diamonds. Fast and directional movements on ice are illustrated using green arrows. Unsuccessful attempts at crossing open water lakes are illustrated using grey arrows. These movements were made by two migratory caribou from the Rivière-aux-Feuilles herd in the vicinity of Clearwater Lake between November 2010 and April 2014. Similar movements were observed on other water bodies at different dates by different individuals

Mentions: Of the 181 individual-years monitored, 95 (52 individuals) used the vicinity (i.e., surfaces and 5-km buffer zones) of the largest water bodies in the study area. These individuals performed 179 ice crossings, 11 water crossings, and 129 detours. The longest crossing was recorded on reservoir Robert-Bourassa, when a caribou walked on ice for ~30 h over a >60 km distance. The caribou with the longest swimming distance swam across Lake Bienville over a >25 km distance. Based on MODIS maps, ice was completely unavailable during this crossing, which occurred on October 19th ˗ 21st, 2013. All water crossings occurred during the fall migration (i.e., between 16 September and 29 November), and most of them occurred on the northernmost lakes (i.e., Clearwater and Bienville). The frequency of water crossings did not change with time (F = 1.98, df = 5, P = 0.22) or between years with early (2007–2008, and 2013) and late freezing (2009–2012; t = −0.95, df = 3.59, P = 0.40). During 5 of the 11 water crossings, caribou began crossing in water but eventually got out and went around instead (Fig. 4). Many individuals made long “pauses” before or after crossing or circumventing water bodies (Fig. 4). No collared caribou died on or in the vicinity of water bodies during our study.Fig. 4


Caribou, water, and ice - fine-scale movements of a migratory arctic ungulate in the context of climate change.

Leblond M, St-Laurent MH, Côté SD - Mov Ecol (2016)

Examples of commonly observed caribou movements in the vicinity of large water bodies. Prolonged “pauses” on water body shores before or after crossings and detours are illustrated using red diamonds. Fast and directional movements on ice are illustrated using green arrows. Unsuccessful attempts at crossing open water lakes are illustrated using grey arrows. These movements were made by two migratory caribou from the Rivière-aux-Feuilles herd in the vicinity of Clearwater Lake between November 2010 and April 2014. Similar movements were observed on other water bodies at different dates by different individuals
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4837602&req=5

Fig4: Examples of commonly observed caribou movements in the vicinity of large water bodies. Prolonged “pauses” on water body shores before or after crossings and detours are illustrated using red diamonds. Fast and directional movements on ice are illustrated using green arrows. Unsuccessful attempts at crossing open water lakes are illustrated using grey arrows. These movements were made by two migratory caribou from the Rivière-aux-Feuilles herd in the vicinity of Clearwater Lake between November 2010 and April 2014. Similar movements were observed on other water bodies at different dates by different individuals
Mentions: Of the 181 individual-years monitored, 95 (52 individuals) used the vicinity (i.e., surfaces and 5-km buffer zones) of the largest water bodies in the study area. These individuals performed 179 ice crossings, 11 water crossings, and 129 detours. The longest crossing was recorded on reservoir Robert-Bourassa, when a caribou walked on ice for ~30 h over a >60 km distance. The caribou with the longest swimming distance swam across Lake Bienville over a >25 km distance. Based on MODIS maps, ice was completely unavailable during this crossing, which occurred on October 19th ˗ 21st, 2013. All water crossings occurred during the fall migration (i.e., between 16 September and 29 November), and most of them occurred on the northernmost lakes (i.e., Clearwater and Bienville). The frequency of water crossings did not change with time (F = 1.98, df = 5, P = 0.22) or between years with early (2007–2008, and 2013) and late freezing (2009–2012; t = −0.95, df = 3.59, P = 0.40). During 5 of the 11 water crossings, caribou began crossing in water but eventually got out and went around instead (Fig. 4). Many individuals made long “pauses” before or after crossing or circumventing water bodies (Fig. 4). No collared caribou died on or in the vicinity of water bodies during our study.Fig. 4

Bottom Line: Although ice phenology did not change significantly during our study, climate projections indicated that ice availability could decrease considerably before the end of the century, generating a ~28 % increase in distance travelled by caribou during the early spring and fall migrations.We demonstrated that ice availability influenced the movements of a migratory arctic ungulate.The long-term conservation of wide-ranging species will ultimately depend on our ability to identify the fine-scale behavioural reactions of individuals to broad-scale changes in climate and land use.

View Article: PubMed Central - PubMed

Affiliation: Caribou Ungava, Département de biologie, and Center for Northern Studies, Université Laval, 1045 avenue de la Médecine, Québec, QC G1V 0A6 Canada.

ABSTRACT

Background: Freshwater lakes and rivers of the Northern Hemisphere have been freezing increasingly later and thawing increasingly earlier during the last century. With reduced temporal periods during which ice conditions are favourable for locomotion, freshwater bodies could become impediments to the inter-patch movements, dispersion, or migration of terrestrial animals that use ice-covered lakes and rivers to move across their range. Studying the fine-scale responses of individuals to broad-scale changes in ice availability and phenology would help to understand how animals react to ongoing climate change, and contribute to the conservation and management of endangered species living in northern environments. Between 2007 and 2014, we equipped 96 migratory caribou Rangifer tarandus caribou from the Rivière-aux-Feuilles herd in northern Québec (Canada) with GPS telemetry collars and studied their space use. We measured contemporary (digital MODIS maps updated every 8 days, 2000-2014) and historical (annual observations, 1947-1985) variations in freshwater-ice availability and evaluated the concurrent responses of caribou to these changes.

Results: Ice had a positive influence on caribou movement rates and directionality, and caribou selected ice and avoided water when moving across or in the vicinity of large water bodies. When ice was unavailable, caribou rarely swam across (6 % of crossings) and frequently circumvented water bodies for several km. Although ice phenology did not change significantly during our study, climate projections indicated that ice availability could decrease considerably before the end of the century, generating a ~28 % increase in distance travelled by caribou during the early spring and fall migrations.

Conclusions: We demonstrated that ice availability influenced the movements of a migratory arctic ungulate. Warmer air temperatures in the Arctic will undoubtedly modify the phenology of ice forming on freshwater lakes and rivers. If migratory caribou are unable to adjust the timing of their migrations, they could be forced to circumvent unfrozen water bodies more frequently and over broader areas, which may increase the distance, time, and energy they use to reach wintering areas. The long-term conservation of wide-ranging species will ultimately depend on our ability to identify the fine-scale behavioural reactions of individuals to broad-scale changes in climate and land use.

No MeSH data available.


Related in: MedlinePlus