Did you know that some song birds are carnivores and that their prey, including amphibians, reptiles, mammals, and other birds, may be the same size or bigger than them? If you watched the tv show Hannibal or read the book Red Dragon, you may already be familiar with the shrike.
There are over 30 species of shrike around the world, with most occurring in grasslands. They are generally dull-colored with hooked beaks suitable for snapping necks, which makes their family name Laniidae extremely appropriate (Laniidae is Latin for “butcher”). But while they’re active during the day and eat meat, shrikes lack the strong, grasping talons of raptors like hawks, eagles, and falcons. Therefore, shrikes employ an ingenious method to hold onto their prey as they eat.
If you’re traversing a farm field in Colorado, you may have come across a shrike cache. Perhaps it was a moth or the skull of a lizard festooning a fence-line or a sparrow hanging from the branch of a wild plum. After killing, the shrike will impale its prey on a thorn or a piece of barbed wire. This holds the food in place so that the shrike can rip off chunks at its leisure. The shrike can also return to the impaled food item later, like accessing a pantry. Caching food may allow it to survive in times of scarcity.
Colorado is home to 2 shrike species, the Loggerhead Shrike (Lanius ludovicianus) and the Northern Shrike (Lanius borealis). The Loggerhead Shrike can be found year-round in southern Colorado, but along most of the Front Range they’re present only in the spring and summer. They can be distinguished from the Northern Shrike, which is only found in Colorado during the winter, by a broader black mask, less hooked bill, and clean breast lacking the faint barring seen on the Northern Shrike.
Unfortunately, because of the loss of grassland and pasturage in much of the United States, as well as the decline in prey species, particularly insects, the Loggerhead Shrike is imperiled. Less is known about population trends of the Northern Shrike since it breeds far north in the tundra, but likely it too is in decline as it loses wintering habitat. This is in line with the overall decline in numbers of grassland birds across North America.
To protect these bizarre song birds and their neighbors, we must come up with more creative ways to protect their habitat.