The ocean is blue because water absorbs colors in the red part of the light spectrum. Like a filter, this leaves behind colors in the blue part of the light spectrum for us to see. Hardly any light penetrates deeper than 200 meters (656 feet), and no light penetrates deeper than 1,000 meters (3,280 feet).
More than 100 North American bird species supplement their natural diets with birdseed, suet, fruit, and nectar obtained from feeders. Feeding birds can benefit them and also provides great birdwatching opportunities in your own backyard. (Learn how to make your backyard bird friendly.) Often, people think of feeding birds in the winter when their natural
Found in birds such as pigeons and herons, powder down feathers are never molted. Instead, they grow continuously but disintegrate at the tips into something like a fine talcum powder. The powder permeates the other feathers, presumably to provide waterproofing, although the exact function is not well understood. This immature black crowned night heron is
