Thanks to their widespread prevalence and environmental sensitivities, fluctuations in bird population and activity can measure the health of entire biomes. This article [validly] ends with an anxiety provoking lament over lost federal funding for e-sci research, but I also find poignancy with how the article presents the richness of data that birds can provide about the world if we listen and learn from them in general.
By listening to these birds for decades, scientists track signs of a changing forest
Scientists tracking the birds in an experimental forest in New Hampshire have also tracked changes in the forest ecosystem over decades.
npr.org