Data from: Resting metabolic rate in migratory and non-migratory geese following range expansion; go south, go low

While many species suffer from human activities, some like geese benefit
and may show range expansions. In some cases geese (partially) gave up
migration and started breeding at wintering and stopover grounds. Range
expansion may be facilitated and accompanied by physiological changes,
especially when associated with changes in migratory behaviour.
Interspecific comparisons found that migratory tendency is associated with
a higher basal or resting metabolic rate (RMR). We compared RMR of
individuals belonging to a migratory and a sedentary colony of barnacle
geese (Branta leucopsis). The migratory colony is situated in the
traditional arctic breeding grounds (Russia), whereas the sedentary colony
has recently been established in the now shared wintering area (the
Netherlands). We measured RMR by oxygen consumption (V̇O2) during two
ontogenetic phases (juvenile growth and adult wing moult). We also
investigated juvenile growth rates and adult body mass dynamics.
Mass-independent V̇O2 was 13.6% lower in goslings from the sedentary
colony than in goslings from the migratory colony. Similarly, in adult
geese, mass-independent V̇O2 was 15.5% lower in sedentary than in
migratory conspecifics. Goslings in the Netherlands grew 36.2% slower than
goslings in Russia, while we found no differences in body dimensions in
adults. Adult geese from both colonies commenced wing moult with similar
body stores, but whereas Russian barnacle geese maintained this level
throughout moult, body stores in geese from the Netherlands fell, being
8.5% lower half-way through the moult. We propose that the colony
differences in resting metabolic rate, growth rate and body mass dynamics
during moult can be explained by environmental and behavioural
differences. The less stringent time constraints combined with poorer
foraging opportunities allow for a smaller ‘metabolic machinery’ in
non-migratory geese. Our analysis suggests that range expansion may be
associated with changes in physiology, especially when paired with changes
in migratory tendency.