Oriental Magpie-robin – tail development

posted in: Morphology-Develop. | 1

“Over the past 10-15 years I become more aware of Oriental Magpie-robin (Copsychus saularis musicus) with odd tail development or moults.

Oriental Magpie Robin-1a-Ipoh, Perak, Malaysia-22nd September 2017-1

The above is a juvenile (notice gape and plumage) with what I expect as ‘normal’ development. The tail feathers have grown out, black above and white below.

Oriental Magpie Robin-2a-Ipoh, Perak, Malaysia-22nd September 2017

“The image above is of an odd immature male bird, the kind that has become more common to observe in recent years. The plumage in general is moulting into adult plumage, no juvenile gape, but the tail is short with the white under feathers better developed that the black feather on top. I do not consider this an adult moult but a first year bird.

Oriental Magpie Robin-3a-Ipoh, Perak, Malaysia-22nd September 2017

“Above shows a bird that has adult male plumage but again the tail is odd with white feathers grown out, but the black covering feathers still to develop. Is this the final stage in some juvenile-to-adult-moult or is this an adult-tail-moult?

Oriental Magpie Robin-4a-Ipoh, Perak, Malaysia-22nd September 2017

“The above is the same bird feeding on a caterpillar.”
 
Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
22nd September 2017

Location: Ipoh, Perak, Malaysia
Habitat: Urban environment
 

One Response

  1. Lee Chiu San

    In my opinion, those birds do not appear to be moulting, but have suffered loss of tail feathers for other reasons.
    The fact that all three pictures show male birds makes me suspect that these are birds that escaped from attempts to trap them using bird lime.
    Males will come down to challenge a decoy, and could land on a branch upon which adhesive has been spread.
    The central tail feathers of Magpie Robins, (and Shamas) tend to be the first to get stuck when the bird attempts to escape. Sometimes, the bird breaks free, but leaves the tail feathers behind.
    If you visit shops where wild-caught Magpie Robins and Shamas are offered for sale, you will see many whose plumage has been damaged in the manner shown in the pictures.

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