Gobsmacked
Crossbill bills can be either left or right handed, and (in Common Crossbill) there is a pretty even split between both types. The upper mandible is fixed to the skull and is centrally placed but it is the lower mandible that can swing either way. The ones like this where the lower mandible so obviously swings to the left (its left) are known as sinistrals and when the lower mandible points right they are known as dextrals. Sinister and Dexter are Latin terms for left and right and derived words are still in use today. Left-handedness was once associated with a shifty personality and the word sinister comes from that. Dexterous, meaning adept or nimble-fingered comes for the word for right-handedness. Back to Crossbills, as well as having an asymmetrical beak, they also have more developed musculature on one side of the lower cheek, and left and right handed birds approach cones from different directions. The Scientific name is Loxia curvirostra. Loxia means oblique or crosswise, and curvirostra means curved beak. The name Crossbill was seemingly first used by John Ray in 1678, when he called it the "Shell-apple or Cross-bill". Although Walter Charleston ten years earlier (1668) called it Cross-beak. And Christopher Merrett, who published a nature book eleven years before Ray in 1667 only used the name Shell-apple, apparently from its habit of occasionally turning up during irruptions from Scandinavia and smashing up apples to get at the pips. I have never heard of Crossbills doing this but it is worth remembering there would be scarcely any conifers away from north Scotland during the seventeenth century. So irruptive birds were probably starving, having already left Scandinavia because of a failed cone crop. And finally, many years ago (in 1985) I once saw a rare migrant Nutcracker in Suffolk which was smashing up apples to reach the pips, ignoring all the juicy bits. Nutcracker is another pine seed feeder that only visits Britain when the cone crop fails (in Siberia). Here's a Nutcracker I took in China www.flickr.com/photos/timmelling/45587118575/in/photolist
I thought this was quite a dramatic shot as the female Crossbill perched really close then opened her beak while looking straight at me. This really shows the leftwards swing of the lower mandible. It was taken not far from where I live in West Yorkshire.
Gobsmacked
Crossbill bills can be either left or right handed, and (in Common Crossbill) there is a pretty even split between both types. The upper mandible is fixed to the skull and is centrally placed but it is the lower mandible that can swing either way. The ones like this where the lower mandible so obviously swings to the left (its left) are known as sinistrals and when the lower mandible points right they are known as dextrals. Sinister and Dexter are Latin terms for left and right and derived words are still in use today. Left-handedness was once associated with a shifty personality and the word sinister comes from that. Dexterous, meaning adept or nimble-fingered comes for the word for right-handedness. Back to Crossbills, as well as having an asymmetrical beak, they also have more developed musculature on one side of the lower cheek, and left and right handed birds approach cones from different directions. The Scientific name is Loxia curvirostra. Loxia means oblique or crosswise, and curvirostra means curved beak. The name Crossbill was seemingly first used by John Ray in 1678, when he called it the "Shell-apple or Cross-bill". Although Walter Charleston ten years earlier (1668) called it Cross-beak. And Christopher Merrett, who published a nature book eleven years before Ray in 1667 only used the name Shell-apple, apparently from its habit of occasionally turning up during irruptions from Scandinavia and smashing up apples to get at the pips. I have never heard of Crossbills doing this but it is worth remembering there would be scarcely any conifers away from north Scotland during the seventeenth century. So irruptive birds were probably starving, having already left Scandinavia because of a failed cone crop. And finally, many years ago (in 1985) I once saw a rare migrant Nutcracker in Suffolk which was smashing up apples to reach the pips, ignoring all the juicy bits. Nutcracker is another pine seed feeder that only visits Britain when the cone crop fails (in Siberia). Here's a Nutcracker I took in China www.flickr.com/photos/timmelling/45587118575/in/photolist
I thought this was quite a dramatic shot as the female Crossbill perched really close then opened her beak while looking straight at me. This really shows the leftwards swing of the lower mandible. It was taken not far from where I live in West Yorkshire.