A new blue-and-green-throated hummingbird species has been discovered in a cloud forest in Colombia, and already needs protection from human encroachment, the experts who found the bird said yesterday.

Called the gorgeted puffleg, the new species is easily twice as big as the thumb-sized hummingbirds found in the eastern United States, measuring between 3.5 inches and 4 inches in length, its discoverers said in answer to e-mailed questions.