Hotspots of accelerated bird decline linked to agricultural activity

[nitpicked]

1. It could also be related to a decline in "bugs on the windshield"

Less of those bugs may equal less food for birds.

From Wikipedia: https://en.wikipedia.org/wiki/Windshield_phenomenon

The windshield phenomenon (or windscreen phenomenon) is the observation that fewer dead insects accumulate on the windshields and front bumpers of people's cars since the early 2000s. It has been attributed to a global decrease of insect populations caused by human activity, e.g. use of pesticides.

((When I was a kid, my father used to have to keep cleaning his windshield. I don't.))