Evolutionary Response to Climate Change in Migratory Pied Flycatchers

Behavioral responses to spring snow conditions contribute to long-term shift in migration phenology in American robins

“…American robins have vast differences in migration distance and timing across their range (Jahn et al 2019), suggesting shifts in the populations passing through Slave Lake could play a role in long term advancement. Alternatively, advanced migration date may result from inter-generational advances, coupled with static individual migratory timing, as in Icelandic black-tailed godwits (Gill et al 2014), selection in response to changing environments (Charmantier and Gienapp 2014), or evolution in migratory timing programs as recently shown in pied flycatchers (Helm et al 2019). However, our results suggest that responses to environmental conditions en route may, at least in part, contribute to shifts in timing.…”

Evolution: Adapting to a Warming World

“…The latter approach has the advantage that no long-term data are needed but does rely on knowledge on which genes are involved in shaping the phenotype, which is often lacking for species that are not genomic model species. A recent study by Barbara Helm and colleagues [13] in Current Biology uses a much rarer but potentially powerful method to infer genetic change.…”

“…Helm and colleagues [13] carefully repeated an experiment in 2002, which was originally carried out in 1981, 21 years earlier, and assessed the change in phenology. This has been done for insects [14,15] but not for vertebrates.…”

“…Helm and colleagues [13] made use of the fact that endogenous circannual timing programs can be studied using captive birds. In captivity, migratory songbirds also go through their normal annual-cycle events, such as fattening, moulting, gonadal activation and even 'migration', which can be recorded from the so-called 'migratory restlessness' of the birds, which, rather than sleeping, remain active at night.…”

“…In captivity, migratory songbirds also go through their normal annual-cycle events, such as fattening, moulting, gonadal activation and even 'migration', which can be recorded from the so-called 'migratory restlessness' of the birds, which, rather than sleeping, remain active at night. Helm and colleagues [13] took in nestlings from a long-term study population, the same population as was used 21 years earlier in the original study [16], which demonstrated that annual cycle in flycatchers was controlled by an endogenous circannual rhythmicity. The nestlings were hand-raised and their annual-cycles studied under natural photoperiods.…”