Rising temperatures may be having a profound physical impact on one of the world’s favourite songbirds. Researchers in Spain found that over a 20-year period, nightingales had evolved smaller wingspans. The scientists say this is linked to a changing climate in the region which has seen the early onset of spring and increased drought. They are concerned that this could affect the bird’s ability to migrate in winter.
Numbers here have declined markedly over the last half century, down 90%, with multiple factors to blame including deer eating their preferred nesting sites, but also because of a changing climate. The nightingale spends the winter in sub-Saharan Africa, with the small, brown creature clocking up huge distances during migration. Wing size is critical to this endeavour. Now, researchers say that ability to migrate may be impeded by climate change.
The researchers believe that birds like the nightingale normally adapt to the demands of migration by having longer wings, having a larger clutch size but a shorter lifespan. However, the changing temperatures are interfering with this and provoking a response from the birds. Faced with a shorter breeding season, the researchers believe the most successful birds are having smaller families with smaller wings. They argue that these adaptations are likely to come at a price.
Source: BBC
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