Truly a (Deadly) Songbird like no Other.

• Position: NORTHERN SHRIKE

Late last fall, John Wright of Fairbanks, Alaska, heard a thump against a window above his deck. He pulled on his coat and walked out to investigate. He was surprised to see a lovely pine grosbeak down on the deck. Standing above it was a northern shrike--a predatory songbird with a black eye-mask.

Wright ran inside for his camera. He was back on the deck 20 seconds later. "Both the shrike and grosbeak were gone. We searched in vain to spot the shrike in our yard but never saw it, or the limp grosbeak. A grosbeak would seem to be a large prey for the shrike, but it had apparently carried it away," he told researchers from the University of Alaska's Geophysical Institute.

Wright had witnessed the butcher bird in action. Though northern shrikes are songbirds and sing all year long, they do not eat fruits or seeds. They are carnivores, devouring what they kill. That includes other songbirds, such as redpolls, chickadees, and, as Wright saw, tangerine and red pine grosbeaks, which are about the same size as a shrike. In summer, shrikes capture insects, but they strike and gobble up voles and other small mammals all year long.

Northern shrikes are about the size and color of gray jays, but one look at their beaks tells you what you need to know. While gray jays have straight cone-like beaks, northern shrikes sport an upper beak with a fierce curve.

That hooked upper beak...