The world of birds and worms

During the Christmas/New Year holiday season, I took it upon myself to listen in on the electronic Christmas Bird Count (CBC) that's carried on the Internet's Oregon Birds On Line (OBOL). I got onto it to become more aware of what birds have been spotted in Oregon, where and by whom.

Birds like the rare Siberian red-flanked bluetail - a distant relative of our American robin - that turned up in Lewiston, Idaho. Birders from all over the U.S. are converged on Hell's Gate State Park to add this little charmer to their Life List.

Yes, it was, and is, birds like the bluetail that got me onto the OBOL site, but there have also been grand discussions about climate change, birds expanding their range, hybrids, and irregulars sighted while birders were doing the annual Christmas Bird Count (CBC) - and of all things, worms - that made listening in even more fun.

What started the worm discussion was birder/author Harry Fuller conducting the CBC in Yamhill (that's over in The Swamp) who observed a red-tailed hawk dining on earthworms which began an interesting exchange of comments.

Someone remarked "There were none of these earthworms in North America before European contact. Imagine the positive impact it has had on birds. I've learned that gulls will commute at least 40 miles for a good field of worms."

Then another person picked it up with: "Yes, THESE worms are European, but do not assume that North America was wormless before their introduction. North America apparently had a diverse annelid fauna that has been pretty marginalized. The European species seem to tolerate agricultural practices better than the natives."

Then the original observer of the red-tail came back with: "There are numerous native earthworm species but they are being crowded out of our forests by introduced species, to the detriment of the forest. There is one exotic that eats all the forest litter and opens the soil to erosion and desiccation... I learned this as I researched a book I'm writing on what man has done to the environment in the 49 square miles of San Francisco."

Carole Hallet, a fellow raptor-bander - who for the safety of birds and airplanes traps, bands and transports her captive raptors miles from the airport - got into the discussion with: "Out at PDX, its not uncommon to see red-tails taking worms from the grass or picking them up off the pavement after heavy rains.  I don't think it's a preferred food but its easy and seasonally abundant. The first time I saw this behavior I did a good bit of digging around in the literature before I came up with anything that specifically mentioned earthworms. Thanks for posting your very interesting observations."

Which prompts me to comment on worms, American robins, and European starlings. I watched about 15 robins hopping about in one of Dorro Sokol's fields at the south end of Pine Street awhile back, tipping their heads this-way-and-that, gobbling up earthworms like there was no tomorrow, while about 10 feet away a small group of starlings watched them intently.

It only took about 20 minutes for the starlings to catch on; they flew out to the robins, chased them away in their usual belligerent fashion, and began feeding on the earthworms exactly the way the robins had been doing - to the point of even tipping their heads as robins do to make an accurate strike with their bills and hitting the worm(s) dead-center.

Sisters rehabber Elise Wolf, also on the OBOL site, took the subject of worms one step further to include tips on mealworms, which are not "worms" as such, but the larvae of darkling beetles. Because a great many Sisters Country residents use mealworms as food for lizards, fish and birds - and by fishermen (like night crawlers) as bait - her comments are worthwhile in this wormy discussion:

"Mealworms MUST be gut-loaded," she began, "before feeding - meaning they must be fed or you are just feeding mainly exoskeleton, which takes up a birds' energy for little gain, and in the snow this can kill a bird to eat empty calories." For more specifics on raising mealworms you can contact Elise at [email protected]

So much for mealworms, aka beetle larvae. The original subject of this discussion - the earthworm - is in the zoological group as: "tube-shaped, segmented soft-bodied worm in the phylum Annelida commonly found living in soil, feeding on live and dead organic matter."

"Earthworm" is the common name for the largest members of the many species of Oligochaeta (pronounced, o-lig-o-kaa-tee - which is either a biological class or a subclass depending on the author). Folk names for the earthworm include "dew-worm," "rainworm," "night crawler," and "angleworm" (the latter due to its use as fish bait).

Bottom line is they are an acceptable source of protein for a raptor when other food is scarce. And if after a rain they are exposed on the surface of the ground, why waste energy trying to catch a rodent when "spaghetti' is already being served?