Brown Shrike – adult females vs first year birds

posted in: Morphology-Develop. | 0

“There is much variation to Brown Shrikes (Lanius cristatus) that’s makes sexing, age and sub-species identification a challenge at times, especially for adult females and first year birds. In addition there is suggestion of hybridisation between the various subspecies.

Brown Shrike.

“I was sitting in our garden in the morning after cycling when this Brown Shrike attempted to catch our Tailor-birds; fortunately it failed (our bird are sharp). It then turned its attention to me to see if I was suitable for a meal and came real close, allowing for an opportunity to get close up images. At a glance it looked like a first year bird, and I would like to make some observations.

Brown Shrike.

1. The Bill
The bills of adults are usually black or blackish. First year birds tend to have paler bills as seen in this bird.

2. Ear coverts
The ear coverts are black in most adults. Here they are brown supporting a first year bird, but this can also be seen in some adult females (see: LINK).

Brown Shrike.

3. Lores
Adults usually have dark black, well developed lores. The colour of lores in this bird is not well developed (incomplete) supporting a first year bird. However some females are noted to have pale lores (see: LINK).

4. Supercilium
The supercilium in first year birds is said to run only from the anterior eye level (see Wells 2007). However in this bird it is clearly outlined from the base of the beak to the back of the eye.

5. Underpart Barring
Females have some variable amounts of vermiculations on the underparts. This bird has significant barring of the breast sides and flanks supporting a first year bird. The leg-feathering was not brown but more buff.

Brown Shrike.

“Unfortunately, like any good predator, it did not turn its back to m e, so images of the wings, tail or back. I have many more images of the front if there is any request. Although this bird looks more mature than a first year (juvenile) bird but it has insufficient criteria for an adult female.”

Dato’ Dr Amar-Singh HSS
Ipoh, Perak, Malaysia
27th September 2018

Location: Ipoh, Perak, Malaysia
Habitat: Wild Urban Garden

Reference:
Wells, D.R., 2007. The birds of the Thai-Malay Peninsular. Vol. II, Passerines. Christopher Helm, London. 800 pp.

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