Black-breasted thrush female vs. Grey-backed thrush female (1 Viewer)

[Ralph Kong]

Hi everyone, I have been sorting through my bird photo taken in North Vietnam. I came across a few thrush and while trying to id them, I encountered the problem of trying to distinguishing the female black-breasted thrush from the female grey-backed thrush.

I have looked through the internet and guidebooks (Craig Robson's etc...) but most sources provided a very brief description of the differences between the two species of thrushes, namely: 1. Grey-backed has whiter breast than Black-breasted, 2. Grey-backed has brownish bill while Black-breasted has more yellowish bill, 3. Grey-backed has paler and more olive-tinged headsides/upperparts. I felt like these traits are subjected to the environmental conditions and age of the birds and am wondering whether is there any better way of distinguishing these two species of thrushes?

Thank you in advance!

 

[KC Foggin]

Hi again Ralph!

I've move this thread to the Bird Identification section of the Forum and have subscribed you to it so that you will get an email when someone posts an answer to you query

 

[Ralph Kong]

Thank you!

 

[johnallcock]

I don't have a lot of experience of Black-breasted but thought I'd bump this up, in the hope that someone else may be able to add something.

From checking online photos, I think that the breast pattern seems to be quite useful - it seems that the background colour of the breast on Black-breasted is quite dark, so that the spots on the breast contrast less against the background. There also seems to be a contrast between the dark breast and a white throat, so that they appear to have a breast-band.
I think the upperparts also look a shade darker than Grey-backed (as mentioned in your point 3), but as you mention this might be affected by lighting.

Hopefully someone with experience will be able to add more about what is useful in the field.

 

[andyb39]

Ralph, do you have some photos?