Does life-history variability in salmonids affect habitat use by juveniles? A comparison among streams open and closed to anadromy (original) (raw)

2006, Journal of Animal Ecology

Early juvenile bioenergetic differences between anadromous and resident brook trout ( Salvelinus fontinalis )

Canadian Journal of Fisheries and Aquatic Sciences, 2003

Many salmonids, including brook trout (Salvelinus fontinalis), contain both anadromous (migrant) and nonanadromous (resident) forms within a population (partial migration). Although partial migration is commonly observed, the mechanisms governing the adoption of migration or residency are poorly understood. We used field estimates of fish growth coupled with in situ estimates of food consumption rates to demonstrate that a trade-off exists between the ability to efficiently exploit local environments (resident approach) and the capacity to capitalize from large-scale environmental heterogeneity (migrant approach). We demonstrate that in the year before migration, migrant brook trout have consumption rates 1.4 times higher than those of resident brook trout. However, migrants have lower growth efficiencies (ratio of growth to consumption) than residents, indicating that migrants have higher metabolic costs. Residents and migrants also differed in their stable carbon isotope signature...

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