Philip Lotter from Knysna asks:
Morning Dave,
My son-in-law and I were standing early one morning about 6 years ago fishing next to Marina Beach’s stand when we saw it.
A swallow had been flying around about ten meters from us, sat down quickly and flew up again and flew around again. Suddenly the swallow sat down again and a crab grabbed him and immediately pulled him into a hole.
We stared at each other and asked each other if we both saw it. We ran to the hole and started digging but the crab and swallow were gone.
My question is will a crab eat a bird. The crab must have been watching the swallow. If only we could take a video.

Ghost crab, Natal north coast. Photo: Dave Pepler

Mangrove Crab, Natal north coast. Photo: Dave Pepler
Dave answers:
Your observation is most interesting. Crabs are found in practically all the oceans and rivers of the world, and about 850 species are known.
The crab you are referring to is most likely one of the Ghost Crabs that live mainly in the intertidal zone, where they dig deep burrows. This is a good choice for a savaging animal, because high tide brings dead animal and plant material to its doorstep.
It is well known that they are aggressive scavengers that will even take live baby sea turtles as they make their way to the shore after hatching.
They are fast, running sideways as all crabs do, and will boldly grab a turtle by the flipper and drag them underground.
So your observation does not surprise me at all, given the crab’s aggressive behavior and speed.
They have excellent vision, with eyes usually on “stalks” and an acute sense of smell. No wonder they are such successful creatures.

The ghost crab is known to catch small prey. Photo: WikiMedia Commons