My 2 cents:

- Try other type of images for first evaluation. Dont mean that birds don't sell.
- Forget that image. I don't know what lens used, but 1/1000 @ f/7.1 and with -1 stop of compensation ( dunno if on raw ) made it very dark and PP will lead u to:

A) - More light -> More Noise -> More noise reduction -> Less sharp / Less Detail
b) - Less light -> Less Noise, More Sharp -> Too dark

I take birds photos too, with sigma 120-400 (!!) and work always around 1/400 for 400mm, even with OS on ( except on tripod/base ) and ISO 200 on a 450D, which gimme more sharp photos. When birds are on bushes I set partial metering and sometimes set +1/2 stop compensation on camera.

Even SS accept some of my bird work. On istock is on "approval drama"  

My 2 cents:

I've take a photo of a portuguese red cross ambulance, and send it to all agencys ( high,middle and lower's ):

- Some refuse because red cross ( for them I sent new version without red cross )
- One agency refuse because mercedes symbol on wheels ( LOL it is same agency that refuse one photo because a red line on an excavator ), but they don't mentioned nothing about red cross
- Some accepted the phot "as is".

So, dependes a bit of each agency.

For my "safety", and having a second version without "logos", I replace it.

This site is a navigational nightmare. The revenue overview gives no info on which image was sold.

Same here. Sold one image,but "image" column is empty.

In DT, 99% of my few sales were images with few views. They would change "download algorithm" LOL