Definition of "impaling"

In inspecting numerous shrike impalings I find that where abundant impaling situations, such as barbed-wire fences, are at hand, the unfinished meals of shrikes are distributed along such fences at considerable intervals.

1950, Arthur Cleveland Bent, Life Histories of North American Wagtails, Shrikes, Vireos, and their Allies

I had seen many decapitations and skinnings, impalings and crucifixions […]

2003, David T. Pudlevitcz, Blood of the Dragon