Why Are London’s Iconic Sparrows Disappearing?

London’s house sparrow population has declined by an astonishing 71% over just 24 years, and a new study suggests that avian malaria may be the cause.

© by GrrlScientist for Forbes | LinkTr.ee

An adult male house sparrow (Passer domesticus). (Credit: Joe Ravi / CC-BY-SA 3.0)

When I first began bird watching (“birding”) in Washington State, I quickly learned that some birds are more equal than others. Some, like the house sparrow, Passer domesticus, are alien invasive species that were either reviled or overlooked by most serious birders. To be fair, house sparrows are invasive in many places, but people intentionally introduced these birds to these new places and the sparrows simply did the same thing that people did under the same circumstances: they multiplied — dramatically. Their burgeoning numbers were often detrimental to native bird species, which suddenly found themselves homeless and hungry.

Now that I live overseas where house sparrows are native, I’ve come to appreciate them and to admire their astonishing resilience and adaptability. But the extraordinarily common house sparrow — seemingly underfoot in every city and town throughout Europe, filling the air with their tuneless chatter — is markedly declining in many of their former strongholds, particularly in suburban and urban areas. For example, a new study reports that the house sparrow, which was one of the most abundant bird…