Tail feathers - Black-capped Warbling-Finch
30-08-18 © J. Simón Tagtachian
Not too frequently do we have the chance to see the black-capped warbling-finch's tail completely open. Moving restlessly and quickly in the bushes we can hardly discover this detail. But we must pay attention to it.
The tail feahters are known as rectrices. They are used to steer and brake when in flight. Only the central pair is attached to the pygostyle (last ossification of the column formed by several vertebrae fused). The remaining feathers are inserted in a fiber adipose mass.
The tail feahters are known as rectrices. They are used to steer and brake when in flight. Only the central pair is attached to the pygostyle (last ossification of the column formed by several vertebrae fused). The remaining feathers are inserted in a fiber adipose mass.
17-01-18 © J. Simón Tagtachian
The number of rectrices changes with the species and it is paired. Feathers are counted from the center outward. Passeriformes have 12 rectrices.
17-01-18 © J. Simón Tagtachian
When closed and from a dorsal point of view the central pair of rectrices is seen. The remaining feathers are stacked beneath them. As the tail spreads, the rectrices slide in a fan-like way. Half to one side and the other half to the other side. This is when we can see this white triangular design on both sides in the Black-capped Warbling-Finch.
08-07-14 © J. Simón Tagtachian
Ventrally the tail looks white when closed since the outer rectrices which are almost white all along form the other face of the tail.
20-06-15 © J. Simón Tagtachian
When fanning the tail the black rectrices are exposed