WC’s world view is skewed a bit towards birds and things avian. Well, perhaps more than a bit. Avifauna are so incredibly diverse, so well-adapted to the world and capable of such incredible behavior that they are endlessly fascinating.
For WC, the impact of climate change is made more real, somehow, by its impact on birds. It’s one thing to read that the ice along the Antarctic Peninsula is melting earlier; it’s another to see starving Adelie Penguin chicks, because the parents can’t get back to them with food in time to feed them. Read Fraser’s Penguins (Amazon link) for the whole story, although the impact of a book is less than the sight of hundreds of starving Adelie chicks.
The University of East Anglia recently documented another instance of climate modification and its impact on birds. A long term study of Black-tailed Godwits, a largish shorebird, has shown they are migrating north earlier and earlier. Interestingly, any individual bird tends to migrate at the same date. Older birds keep their regular migration dates. But younger birds, migrating north to breed, arrive earlier. Presumably, by fledging their chicks earlier they have more opportunity to get the kids well-fed before the migratory flight south, increasing their chances of survival. Of course, that adversely impacts the food supplies of later migrants; as a consequence, birds that migrate later are dramatically declining in populations.
In North America, there is compelling evidence that over 200 bird species have experienced northward range shifts consistent with climate change (e.g. La Sorte and Thompson 2007, Hitch and Leberg 2007, Zuckerberg et al. 2009). Similar findings have been reported in Europe (Thomas and Lennon 1999, Brommer 2004), where the largest climate change induced range shifts have been recorded (Maclean et al. 2008). However, despite this, the magnitude of these responses may still be insufficient to keep pace with climate change. In France, for example, the temperature increase since 1989 is equivalent to a northward shift of 273 km; however, over the same period there has only been a 91 km northward shift in bird community composition (Devictor et al. 2008). Effectively, birds are lagging behind climate warming, and the long-term implications of this discrepancy could be profound.
In this context, “profound” means “high risk of extinction.” We’re already in the midst of the Anthropocene Extinction. Some scientists view the Anthropocene Extinction as merely a continuation, perhaps an acceleration, of the Holocene Extinction, the wave of extinctions of animal species that follows humankind’s migration across Africa and Asia and into the New World. Manmade climate change threatens to further accelerate those extinctions. Highly respected biologist E. O. Wilson predicts that as many as half of species on the planet may go extinct.
There are similar signs in Alaska of climate-driven impacts on bird species. Among the most highly vulnerable are Gyrfalcon and Common Eider. Less vulnerable but still seriously threatened are seven other species, including: Brandt, Steller’s Eider, Pomerine Jaeger, Yellow-billed Loon, Buff-breasted Sandpiper, Red Phalarope and Ruddy Turnstone. All of these species are strongly linked to specific habitats – generally coastal areas – that are expected to suffer the most dramatic changes as the Artic warms.
By contrast, more generalist species, including the Savannah Sparrow, Lapland longspur, White-crowned Sparrow, American Tree-sparrow and Common Redpoll are likely to increase in number, according to the same assessments. It’s a small consolation.
WC will grant that for many folks the loss of bird species may pale in comparison to, say, the complete drowning of the nation of Bangladesh as oceans rise. It may not have the news appeal of a super typhoon possibly caused by increased ocean temperatures.
But for WC, birds and avian diversity are the clearest possible signal that the environment we share is in deep, deep trouble. The loss of an avian species is a tragedy; the implications of the loss of a species are terrifying. The failure to recognize the consequences is criminally stupid.