Ok thanks to Tassie I found the theme, I had assumed it was a purchased one, but it's a default one sorry.
To remove the birds (hoping i have the right thing that you want removed) it's just the background. You don't have to change any code for that, just click somewhere on the background area of the theme when you are in the SCD Pro program and it will give you the settings for all the background area.
At the top you'll see the .png that is in that corner, you can either change it to something else (put the new image location in the box) or you can hit the red X to just take it out completely.
I realize you say you are aware you can remove them via the background, but that's what they are so I'm not sure exactly what it is you are trying to do. If you're planning a different background just insert the location as I said above, but if you want no background, just change the color to the color you want instead or leave it white and that's all it is.
If I am not hitting on the right thing let me know so I can go back in the program and find what you are really after, sorry I have a thick head some days (shut up Tom lol) so sometimes it's not fully obvious what it is people are after. Your post makes it sound like you want the birds gone, removing the image does that so let me know if that's not "exactly" what you want
Have fun with it