Owl called "Hanka" on Madagascar stamp issued in 1999

Hanka stamp
Detail of Hanka
Asio madagascariensis
Stamp issued in 1999 showing an owl named "Hanka"
Detail view of the "Hanka"
 Image of a Madagascar Long-eared Owl (Asio madagascariensis) from "Birds of the Indian Ocean Islands" (Sinclair and Langrand 1998)
When I first saw this stamp, I thought it might show the Madagascar Scops Owl (Otus rutilus).  However while checking in "Birds of the Indian Ocean" I noticed the other owl found on the island with ear tufts, the Madagascar Long-eared Owl (Asio madagascariensis) had a call which was described as 'Kahaan-kahaan-Kahaan'.  In "Birds of Prey of Africa and its Islands" (Kemp & Kemp 1998) the call is described as 'han-kan han-kan han-kan' and the same illustration, by Peter Hayman, is used but is much more rufous than the one above.  I suggest that the bird is named locally after its call.

Does anyone have a further comments for the "Hanka"?

Added 6th  September, 1999