A Hypothesis to Account for Birds Surviving Chicxulub While Dinosaurs Perished. 2021-08-31 Jorma Jyrkkanen

A Hypothesis to Account for Birds Surviving Chicxulub While Dinosaurs Perished 2021-08-31 Jorma Jyrkkanen

While watching White crowned sparrows at my feeder on Knox Mtn we were struck by a hailstorm. The sparrows all headed instantly under a dense young spruce tree and were completely protected from aerial missiles about one to two centemetres in diameter. This action was instinctive because they all did it and immediately came out to the feeder when the hail stopped. I wondered if birds brains had greater intellect than dinosaurs or if thick hides of dinosaurs protected them from abrasive or contusive impacts. This seemed logical. Dinosaurs may simply not have evolved evasive tactics to deal with aerial missiles.

This observation made me ponder if this behaviour set them apart from dinosaurs and perhaps it did and perhaps was the reason they survived bombardment from fiery missiles generated by the Chicxulub asteroid 66 million years ago. Birds being smaller than most dinosaurs would have been in greater peril from missiles created by volcanic blasts as well as hail storms and would have had greater evolutionary pressure to learn avoidance behaviors than tough skinned dinosaurs. This might have been a factor in avian brain evolution differences as well enabling them to think of consequences better than dinosaurs. Birds as a group generally frighten very easiy and this fright to flight behaviour may have been a saving grace when complimented by the wisdom to go to cover when frightened. Fright flights would have been evolved to deal also with attacks from the sky by predators such as the Pterodactyls. Being able to fly certainly augmented their ability to get to good cover more quickly than land bound animals.

Dinos. Just not smart enough to carry on except as their brighter relatives, Aves. A good question.