Tuesday, March 20, 2012

Happy World Sparrow Day!

March 20 has been designated World Sparrow Day, in recognition of one of the most common, most familiar, and most ubiquitous of all known maniraptors, Passer domesticus, the house sparrow. It is a true sparrow, a passerid, as opposed to American "sparrows", which are actually buntings.

Male Passer domesticus photographed by Fir0002, licensed.

Female Passer domesticus photographed by Diliff, licensed.

It is the most widespread of all wild birds. Its native range covers much of Eurasia, and it has been introduced to all other continents besides Antarctica. It thrives in urban regions, but it's far from being bound to cities and can survive in any environment save for tundra and dense forests.

The house sparrow is frequently maligned, particularly as an introduced species, as it is an aggressive species that takes over the nesting cavities and feeding stations of native birds, and will even kill off the young (and sometimes the adults) of its competitors.

While often considered pests, endeavors to eradicate sparrows (in this case the Eurasian tree sparrow, not the house sparrow, though closely related and very similar) in China ironically led to massive destruction of crops. Although adult tree and house sparrows feed mainly on seeds, the young are fed a diet of insects (as is often the case for many birds), and grasshoppers, major devourers of crops, are their most abundant prey.

Female Passer domesticus feeding young with a caterpillar photographed by Alan Vernon, licensed.

Perhaps surprisingly, for all its adaptability and ubiquity the house sparrow is declining in many parts of the world, especially within its native range. In fact, in the Netherlands it is an endangered species! In North America the house sparrow may be an invasive pest, but as the attempted eradication of Eurasian tree sparrows in China shows, in its native environments the species is as much a key part of the local ecosystems and as deserving of conservation as any other native bird.

I'm sure Dinky here agrees, don't you?

... Dinky?