It's getting easier to find the definition of 'parasitic' online - washingtonpost.com

Ostensibly, this is the story of dictionary Web sites and their impending demise. But really, this is the story of the oxpecker. I ask your patience while I get ornithological.

Meet the oxpecker, a plucky, selfless little bird. Its life amounts -- as for so many of us -- to little more than consumption for the sake of others. The oxpecker is a helpful friend to the bigger game of the sub-Saharan grasslands. Giraffes, wildebeests and cattle all welcome oxpeckers onto their hides. The oxpeckers, meanwhile, feed off of the parasites, insects and ticks they're picking off their gracious hosts. It's a symbiotic relationship, one of those quirks of nature that keeps an ecosystem churning. You scratch my back, I'll fatten yours...