Loggerhead Shrike: Converting Thorns into Meat-hooks
Dr. James J. S. Johnson
Yet within three days shall Pharaoh lift up thy head from off thee, and he shall hang thee on a tree; and the birds shall eat thy flesh from off thee. (Genesis 40:19)
Do Loggerhead Shrikes live where you live? Have you ever seen one?
Just because a trustworthy range map indicates that a bird lives where you live, with suitable habitat (e.g., semi-open fields, forests, xeric scrub-brush, etc.), is no guarantee that you will see that bird, even if you are a careful and consistent birdwatcher.
For example, during the entire calendar year of AD1995, as part of a research project that overlapped with my duties as a Certified Water Quality Monitor (then serving the Trinity River Authority of Texas, and what was then called the Texas Natural Resource Conservation Commission), I did regular birdwatching near some ponds next to a part of Furneaux Creek in Carrollton (Denton County), Texas — a mostly open habitat that included lotic (creek) and lentic (pond) freshwater, semi-open fields, mesquite trees, and a nearby oak-dominated forest. That location was a great place for year-round birding!
Yet during that entire year I never saw, there, a Loggerhead Shrike, although I did see one, once (1-30-AD1995), a few blocks south, along the semi-wooded roadside (at the northwest corner of what was then McCoy and Trinity Mills Road), and later saw another Loggerhead Shrike along a roadside in Aransas National Wildlife Refuge (3-11-AD1996).
In today’s cyber-world we sometimes talk about “open source” categories. But with the parapatric shrikes [i.e., shrikes belonging to the same created “kind”, so they are genetically compatible for hybridization, yet usually live in geographically distinct populations] — such as the Loggerhead Shrike, and its look-almost-alike “twin” (the Northern Shrike), as well as other shrikes of Eurasia — one thinks of an “open pantry” lifestyle – because the predatory shrikes are best known for their behavior of impaling their “too-large-to-eat-all-at-once” prey on plant spines (i.e., thorns) and barbed wire, as if using meat hooks, for convenient storage till time for eating. (Get the point?)
Although the Zorro-masked Loggerhead Shrike shares similar grey, white, and black coloration and some of the markings of the Northern Mockingbird (which has no “Zorro mask”), the Loggerhead Shrike uses completely different food-getting and food-storing techniques than the mockingbird. Also, shrike prefer different prey — often prey too large to consume in one meal.
[Like other shrikes, the Loggerhead Shrike] is a patient and skilled hunter that often perches atop shrubs and small trees, using its keen vision to search for prey. Any small vole, mouse, shrew, lizard, snake, frog or large insect [like a grasshopper, or even a small bird] that comes into view is quickly dispatched [by the shrike’s hook-tipped bill, which can break the neck of a small bird] in a swift swoop [like a hawk on the hunt] and added to a cache of food impaled on thorns [or] barbed wire. Shrikes seem to have an uncanny memory for the location of their food caches, and they have been known to find prey stored for up to eight months. [Quoting Wayne R. Petersen & Rogers Burrows, BIRDS OF NEW ENGLAND (Lone Pine Publishing, 2004), page 225.]
Wow! — there you have it – shrikes impale their “too-large-to-eat-all-at-once” prey, returning to it when convenient (unless a thief gets it while the shrike is elsewhere, not an unlikely contingency).
So, the next time that you see what looks like a mockingbird, wearing a black Zorro mask, watch out! Actually, no need to fear — unless you are small enough to be hung upon barbed wire, or upon a rose-bush’s thorn!