Now an underlying cause for the Arkansas event has been found: loud noise from fireworks. It seems likely that the explosions shocked the birds from their roosts and sent them flying, confused (and with natively poor vision), into the night sky, where they collided with houses, trees, and power lines.
Now birds and whales are vastly different species, with different ecologies, but the die-off in Beebe couldn’t help but make me think of the oceans and the growing problem that marine wildlife is facing from disruptive, manmade noise. There certainly are limits to the comparisons you can draw, but the reactions of birds, which are generally far easier to study, can shed some light on marine animals and how they are adjusting or failing to compensate for the urbanization of their world.
One thing we can say about the blackbirds’ behavior in Arkansas is that it was maladaptive. The birds weren’t in any direct physical danger from the fireworks, and by tearing off into the dark sky they put themselves at risk of collision and death.
But the “fight-or-flight” response, which is highly conserved across species, doesn’t always lead to the best results. Take for comparison the melon-headed whales caught in a naval sonar exercise off Hawaii, in 2004. The exercise seems to have herded a large pod – representing a significant part of the melon-head population – towards the main islands and around Kauai, where they wound up stranded for two days in Hanalei Bay and might well have died were it not for a brilliant local rescue.
In the end it would have been better for the whales to have braved the Navy’s high-intensity sonar signals than to have fled, just as it would have been better for the blackbirds to have stayed put as the fireworks boomed around them. Sometimes it is just hard to deny the primal urge to run.