Corvus corone & Corvus cornix
Crows again.
Corvus corone is the binomial name for a carrion crow. It’s the “black” bird pictured above - the one that you might know as making a typical “caw” sound. They’re opportunistic feeders (hence the name), the biggest of the songbirds (songbirds are a suborder of the Passerines, or perching birds, named because of the arrangement of their toes that allows them to perch on stuff. The songbirds have a vocal organ that is developed enough to allow a diverse song… often an elaborate one. Crows might not be the most musical of birds, but I’ve certainly heard them make a bunch of noises…) and my personal favourite of the Corvids in Britain.
Corvus cornix is the binomial name for the hooded crow. Like the carrion crow, it was first described by good old Carl Linnaeus, and was long thought of as a subspecies of carrion crow. But they are now considered a distinct species. Even though, genetically, basically the only difference is in the genes that code for their colouring, and the two species do sometimes mate and create fertile hybrids (which in itself is unusual), they prefer… not to.
A study of carrion crows and hooded crows in western Europe suggested that the crows will pick their mates based on colour. The grey crows would rather not mate with the black crows, and vice versa. And when they do, and a hybrid happens, the hybrid struggles to find a mate because its colouring isn’t what the crows expect. And it doesn’t just happen in that one location - we have hooded crows and carrion crows here in Scotland, but the hooded crows basically live exclusively in the north west, whereas here on the east coast, I don’t think I’ve ever seen one. This isn’t true speciation (the creation of a new species from a group or groups of another) quite yet, because the two can still mate and produce fertile offspring, but it’s the beginning of it, and that’s quite interesting.
References are mostly linked, I also used the RSPB and Wildlife Trusts for a it more crow background. Fancy more crows next week too? Or are we in the mood for something else? Let me know…