Night crawlers   Lee E. Frelich   Jan 26, 2007 06:08 PST  Paul et al.: Since Woodcocks eat nightcrawlers (Lumbricus terrestris), people often ask me what they ate before nightcrawlers were introduced to this continent. The answer is Lumbriculus variegatus (note that the genus is spelled slightly different), which is an aquatic worm native to most of North America and common in riparian areas. Lumbriculus accumulates toxic metal pollution that is present in many aquatic sediments these days, which is why there are so many studies of metals in woodcocks, which still eat Lumbriculus in addition to Lumbricus. Lumbricus terrestris is probably the best suited of the exotic earthworms to invade riparian areas where Lumbiuculus lives, as long as they are alkaline, because it uses Ca to scrub CO2 from their blood under microaerophilic conditions (<5% oxygen). Nightcrawlers eat leaves with high Ca content (ash, basswood, maple), and extract the Ca, and combine the Ca with CO2 to form Calcium Carbonate, which they excrete. Nightcrawlers can survive in microaerophilic conditions such as an aquarium with an oxygenator, for at least two weeks (one of my graduate students did the experiment). A nightcrawlers is bigger than a Lumbriculus, so its a real treat for a woodcock--a lot to eat for relatively little work. Lee PS--there will be an earthworm physiology quiz at the next ENTS meeting   Home