A biologist friend sent me this link about birds getting scorched at a new concentrated solar plant in the desert along the CA/NV border.

While the numbers of birds killed is probably much lower than the number that are killed by domestic cats and windows, ecologists look at what species are being killed in the context of their overall populations. If your cat kills 10 starlings or English sparrows this has much less ecological impact that if a wind farm kills 10 golden eagles.