Recently on this blog I posted images of a juvenile Loggerhead Shrike impaling a dragonfly on thorns and said I hoped to get more documentation of the behavior but it would likely have to wait until next years nesting season. I was wrong. I witnessed and photographed this behavior again just three days ago. This time the shrike was also a juvenile but the prey was a large spider.
Juvenile shrike with spider
What happened after the capture was interesting for me. The bird didn’t simply impale the prey and leave it (as a cache or food store) as might be expected of an adult. Instead, it attempted to impale the spider on different thorns multiple times, like it was practicing – learning how to do it (keep in mind, the bird is a juvenile). In fact, at one point the shrike even seemed to be “studying” its work, as you will see (I’m sure that’s anthropomorphic of me). Sometimes they don’t actually impale the prey, instead they wedge it into crevices or between forked branches/twigs. This shrike tried to do both with the spider. After what I believe was four attempts at impaling/wedging the spider on some thorny branches someone had placed in a campground fire pit, the bird had apparently had enough practice and simply ate the prey in several pieces. Some of the images below aren’t of the best quality but I think they do document what I saw. As far as I could tell, the spider was dead through this whole process.
Attempting to impale spider on thorn directly under bird’s bill
Seeking out a different thorn in another area (the one directly to the left of the spider)
Attempting to impale, again
Here the shrike has let go of the spider, apparently to see if it will stay put. Notice that one leg is hooked over the thorn
Because of the one hooked leg, the spider hangs there for a moment…
And then falls to the ground, which the shrike obviously notices
The shrike retrieves the spider and tries again near where it tried the first time
Here it almost appears as if the bird is studying its work, with its bill resting on the branch
And finally the shrike simply eats the spider, in several pieces
I suspect that the impaling behavior is instinctual but must be practiced repeatedly to get it right. Three times now I’ve seen juvenile Loggerhead Shrikes practice impaling behavior multiple times and then eat their prey immediately. It seems logical to me that they were simply trying to learn and become more skilled at doing it.
Ron