Mount the anemometer a little lower, add some cable ties to any perchable area, 2-3 will suffice, you can cut them but be mindful of the doves leg size and include a little extra, also use the thicker (larger) ones, then you can mount an old disused (or use it) anemometer above the original but offset it a bit, the pigeons/doves will perch on the higher of the 2 because 1, its higher, 2, its far easier to take flight in any direction, it will struggle from the one below, 3, nothing in the way (spikes you added)