The numbers reported in any scientific study need to be kept in perspective, even if we ignore the credibility of numbers...Headlines in the popular press often quote the sensational number that "3 BILLION birds have been lost from N Am in the last 50 yrs!!"...That would be sensational news if there were only 3.1 B to start with, but in fact, they estimate 10B as the intial pop count, so a 25% fall is a little less impressive..Almost all of that can be attributed to habitat loss....
John Muir grew up in a marshy part of WI near Portage (wet lands. Good habitat for RWBBs). In his biography, he states that every spring trees would be covered by hundreds of redwinged blackbirds. That was 150 y/a when the total population of people in WI was 500,000..Now it's 6,000,000-- almost all growth in that southern half of the state....RWBBs no longer cover entire trees in the spring...Is it from all those new cats or loss of breeding & feeding grounds?
I'm not a fan of industrial sized Unreliable Energy installations. The large wind turbines kill more birds than the Feds are willing to admit, but right now, they probably only account for a small percentage of "extra" avian mortality...But to go "Net Zero" we'd have to increase the number installations by 1,000,000 (!!)
https://heartland.org/opinion/net-ze...-1--wind-only/ Right now, we have only 71,000 in service....It's gunna get ugly.