the.com/turtle dove

means A small, soft-voiced wild dove known for pairing with one mate and cooing tenderly, long used as a living symbol of devoted love.

from The 'turtle' here has nothing to do with shells — it comes from the Latin 'turtur,' which is simply an imitation of the bird's soft, purring coo. English borrowed 'turtur' as 'turtle' centuries before the reptile sense became dominant, so for a long stretch 'turtle' meant only the dove. The 'dove' part was added later as a clarifying English gloss, giving us the doubled-up name 'turtle dove' — essentially 'coo-coo bird, the dove kind.' Its reputation for faithful pairing made it a stock emblem in poetry and scripture long before the word took on any shelled-animal confusion.