What indicates completed growth in eyases?

The completion of growth in eyases, which are young birds of prey, is indicated by both characteristics of being hard penned and full summed.

When an eyas is described as hard penned, it means that the feathers have reached a certain level of firmness and strength, which is crucial for the bird's development and ability to fly effectively. This is an essential stage in the growth of a raptor, as it signifies that the bird has developed the necessary feather structure to support its body during flight.

Similarly, being full summed refers to the condition of the bird's body in terms of weight and overall development. It indicates that the eyas has achieved a healthy weight and has adequately developed muscle mass, which is vital for its survival in the wild and for its eventual training in falconry.

Both criteria together represent a holistic view of the bird's readiness for its next stages of life, whether that be further training or more independent living. Thus, the completion of growth in eyases is best captured by noting that they possess both hard penned feathers and a full sum status.