>>50583310>>50585049Hoopoe and Bearded Vulture would both be excellent choices. I could also see them going with a sandgrouse that evolves into a bustard, or some other common species like a lark or shrike.
My personal prediction is that they’ll go with an Iberian Magpie. They’d conspicuous and flashy, unique to Spain and Portugal, and they have a counterpart species (Azure-winged Magpie) that is found in Japan. A lot of the regional birds are based on a species common in the inspiration region and represented by a familiar relative in Japan (European and Japanese Robins for Fletchling, Great and Japanese Tits for Rookidee, of course Rock Pigeon for Pidove). It might be a bit too similar to the Corviknight line, though.