Foraging-predator avoidance trade-offs made by migrant and resident elk (Cervus elaphus) on their sympatric winter range

Migratory behaviour of the Ya Ha Tinda (YHT) elk population is diminishing
while the number of residents remaining on the YHT winter range year-round is
increasing. Previous research addressing the fitness consequences of each
migratory strategy assumed there was no advantage to either segment when they
shared the YHT winter range. In testing this assumption, I found no spatial
segregation of migrant and resident home-ranges during winter. Both groups were
exposed to similar forage resources and residents were exposed to higher nighttime,
but not day-time predation risk. Residents were better than migrants at
reducing the foraging costs of vigilance and increased vigilance in areas of high
wolf predation risk, but not near human activity because of habituation. Migrants
were not habituated to humans and exhibited more constant vigilance regardless
of spatial variations in risk. My results do not support the previous assumption.
Instead, I found residents may be at an advantage on the winter range while forage
is abundant and no snow is present.

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