Genetics of Hyper Flex Wings in Skycutters

by Grigoriy Zilberg
August 16, 2010

Introduction  Skycutters exhibit hyper flexibility in the wrist joint which allows them to have a unique flying style.¹  In wild type the angle of this joint when fully opened is nearly a straight line while in Skycutters it extends forwards from a straight line by up to at least 70 degrees in extreme cases.  While moving the almond trait into the breed measurements of flex angles and numbers of white tail feathers were recorded in hopes of learning about the genetics of hyper flexibility and the white tail feather trait.  Both traits proved to be genetically complex.

 
Discussion  Skycutters are a unique breed of pigeon from Ukraine.  They weigh about 12 ounces.  They have hyper flexibility of the wrist joint in the wings, but all other skeletal structure seems to be normal.   They have long feathers, both wing and tail, relative to wild type. They often have 13 to 16 tail feathers and the standard calls for white tail feathers.  Generally birds with the outer tail feathers colored are acceptable.  The tail feathers are broader than wild type, but not as broad as found in Fantails.  The flying style is often close to a hover and so they are blown about by any wind. When they fly they typically have the tail fully flared in the position a normal pigeon assumes only during landing. They are not strong fliers so flying times are generally under 15 minutes unless they find thermals that give them lift for free.  Presumably they are descended from some form of Tumbler as occasional Skycutters will tumble.  They come in all patterns and have a dirty gene included that darkens them a great deal.  This dirty is not the same as found in Homers and so many other breeds.  It darkens the birds considerably more.  On a bar pattern bird the shield is so dark that from a distance they could almost be mistaken for T patterns.  This is shown in picture 1 comparing a dirty blue bar Roller with a bar pattern Skycutter.  It also makes the colored tail feathers and chest nearly black as shown in the picture below.  The Skycutter shown is not smoky as it has a visible, although fairly pigmented, albescent strip.  The breed does include recessive red and kite.  They have not been known to include almond so a major purpose of this project was to incorporate the stipper gene into the breed.