Backyard and Beyond

The Blue Jay’s “flying zoo” includes “one flea, six species of lice, five types of ticks, and eight species of mites, in addition to being infected by nine kinds of flukes (trematodes), three tapeworms, one acanthocephalan (thorny-headed worm) and sixteen kinds of roundworms.”

Michael Stock’s The Flying Zoo: Birds, Parasites and the World They Share can get a little gross. Nasal leeches, anybody? Your adorable bird may be laden with parasites externally and internally, fighting off feather-chewers, blood-suckers, and gut-robbers.

A birding friend and reader of this blog (thank you, Janet!) thought I would like this book, and how right she was. The details are fascinating.

A few tidbits: Black swans have black lice, white swans with white lice, good camouflage for the lice. Different species of lice can be found on the wings, head, and body (not unlike the three specialized species that enjoy H. sapiens). A species of soft tick can stay dormant for 18 years, particularly helpful in bleak, isolated, seabird colonies. A nest being a great place to get lice, researchers can find out which bird species fostered Brown-headed Cowbird chicks by identifying the lice.

But beyond the details is the co-evolutionary story between parasite and host. “It does seem clear that intense selection pressure involving the immune system by birds against fleas has promoted flea specialization and likely flea speciation as well.” Eastern Screech Owls transport Blind Snakes to their cavity nests, where the snakes live off fly larvae, beetles, and fleas. “Owl nestlings in nests with snakes grew faster and lower mortality rates.” Fleas in the nests of Great Tits make it too humid for blowfly larvae; blowflie can have a worse effect on nestlings, so the fleas “may actually be helpful to their hosts.”

Using the example of a Black-capped Chickadee, Stock notes that a lot isn’t known about even common birds and their parasites.

This is a book that will make you look at birds with very different eyes.