That assumes the land was available for wildlife before the site was constructed. In the UK our solar sites are on farmland, and provide a far superior habitat to intense agriculture. Wildflowers can grow under the solar panels which is fantastic for bees and butterflys. Also, it is common to do surveys to model the risk to birds and avoid important populations and migrating species.

Also, deaths during construction tend to be workers who have signed up to the risk. That isn't OK, but it is a lot less bad than risk to random members of the public who have not consented. And it is a vast improvement on the deaths caused by fossil fuels.