I caught a mouse last night and put the body out in the garden. It was in amongst some plants but close to the house door in an area not normally frequented by birds. It didn’t take long for the corpse to be removed by a Magpie. Given the direction from which the Magpie approached, it wouldn’t have been able to see the corpse but it came pretty much directly to it. So, my question: how did the Magpie know the dead mouse was there? Could it smell the mouse? Or … ?
Birds have a very variable sense of smell.
Carrion birds mostly have a stronger sense of smell for obvious reasons.
“Contemporary opinion among ornithologists is that the sense of smell is weak at best in passerines, and particularly so in corvids which lack developed olfactory apparatus.”
But (and more or less coterminous):
“In field experiments designed to examine whether Black-billed
Magpies (Pica pica) use olfaction to locate hidden food, we found that magpies
uncovered significantly more caches of suet and raisins scented with cod liver oil
than control caches.”
And, more recently:
“Today there is overwhelming evidence that certain birds have an incredible sense of smell.”
Many thanks. I’ll take a bit more care with hiding any future victims and see if the Magpies manage to find them.
I must remember to dig a bit deeper here. It looks like fertile ground for a “consolidating” review by someone more competent. As a brilliant chemist I once worked for would occasionally say when an experiment yielded an unexpected result: “I feel a paper coming on…”
nice and interesting links, thanks