Long-tailed Shrike (Dark morph) info (1 Viewer)

While visiting Hong Kong earlier in the year I was pleased to see these two Long-tailed Shrikes together at Long Valley.
As one of the birds is of the 'Dark Morph' variety I was just curious to know what ratio or percentage this type makes up within the population.
It is obviously a well known form of the Long-tailed Shrike but to date I cannot see much info as to what the ratio might be so any feedback much appreciated.

Many Thanks

Hi from a wet Hong Kong...

"The Avifauna of Hong Kong" (2001) refers to these dusky shrikes….

"…no systematic review of the distribution and frequency of the dark morph has been undertaken; At Mai Po, where 52 birds were trapped during 1985 -1996, only two (3.8%) were of the dark morph, but anecdotal evidence suggests that dark morph birds are more frequent at some other locations."

I reckon about 15% of the LT Shrikes I see are Duskies or intergrades.

Cheers
Mike

The LTS dark morphs are very rare in Shanghai (I don't ever remember seeing one here) but we saw two during a 4 days trip to Poyang Lake, Jiangxi and another on a long weekend to 1,000 Island Lake, Zhejiang. My 'hit rate' for dark morphs must be around 0.01% considering all the LTS I've seen in Shanghai (frequently 100+ per day) and in Zhejiang !