A lot of the vertical axis windmills are very bird friendly, partly because of their small footprint.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Small footprint means small power output... not that it matters because all IWTs are useless.
By small footprint I mean compact design, rather than long blades spinning at very high speed catching birds off guard. The same power producing area can be incorporated in a verticle spinner that doesn’t extend out like a blade. A spinning cylinder is easier for them to see and avoid.