Maybe they're sounding an alarm...
4
Nice story, but an oversight was to neglect a link or even a reference to the actual study. It was published in The Condor: Ornithological Applications, http://www.bioone.org/doi/10.1650/CONDOR-17-69.1
7
"Love will find a way" or DNA transmission (survival of the species) demands/forces adaptation.
2
Thank you for this fascinating look at evolution in action.
4
Actually, this is the inherent flexibility that evolution offers. The oil field noises are not selecting for birds with different songs, instead the birds are adapting their songs to the local environment because evolution has selected for birds with this ability.
6
This remarkable adaptive behavior to a significant environmental stressor is noteworthy for its effect on bird songs, but it also reminds us that sound production itself is a significant energy depleting activity for birds and any modifications they are required to make to do it adds to their survival challenges.
8