This is still bugging me.
Did the K-T event force sheltering foraging birds to hop and fly?
Many of the ground dwelling birds before the K-T extinction event may have been ground dwelling and foraging. However, after perhaps surviving while taking shelter where forced to hop and flap and eventually fly. Because their dense vegetative cover was burned and the global temperature of the ground would have been radically raised.
Making it too hot to stand in the one spot for too long. We already have evidence that many (or perhaps all,) of the early prehistoric birds manage to survive the K-T extinction event blast by retreating deep into caves and burrows.
Today there are numerous examples of species of bird that make their homes in burrows, crevices, cavities, under waterfalls, gaps and caves such as Puffins, Swallows, Swifts, Kingfishers, Oilbird’s, Burrowing owls, Skuas, Penguins, Rock Doves, Ground Hornbills, Bee-eaters.
All with their very own fall out shelters.
Furthermore, depending on their location and if it was daytime or nighttime when the asteroid hit. Many of these earliest birds may have been roosting instead of roasting.
Leaving the bulk of the larger nesting, walking, or early flying Dinobirds without cover, out in the open, to be incinerated along with the Dinosaurs.
If evidence could be found, as to whether or not the strike took place during the day or the night. Along with what the predicted global seasonal weather patterns where at the time. This may further determine what type of bird or indeed mammal survived the blast. Moreover, whether or not it was already in or out of its safe haven.
For example sleeping or brooding nesting nocturnal or daytime foraging birds.
Then again, perhaps the thought could be similarly applied to some mammal species well into the process of winter hibernation.
The existing solid cover bird types listed above may be the closest living bird relatives to all of their ancestral sanctuary survivors of that K-T catastrophe. The bulk of which today are small and small brained.
In fact, every bird, presently alive might have a genetic link, in one form or another, to these original K-T sheltering nesting survivor groups. If just these shelter seeking, groups alone where first isolated and then genetically tested. This may proffer explanation the origins to all bird biodiversity stemming from these specific shelter groups.
Furthermore, this may in part account for the relatively few really larger species of bird living today compared with the numerous amounts of smaller species.
In addition, this may be why little evidence of their K-T history is revealed. For if, many did survive, then much of the early prehistoric evidence that they may have left behind would have eroded through time. Mainly because of their small stature and their hidden sheltered habitats. Leaving their confined carcases open to predation. Above the level of the K-T boundary.
What is more, it may be possible that many of these shelter nesting bird survivor groups where omnivorous initially and to avoid starvation after the K-T event had to alter their diets because of the sudden lack of plants and fruits. Leaving them without any option to become carnivorous and feed on the abundance of available dead meat.
Many may have only initially altered their fruit eating diet because of the event and later on returned to their vegetarian roots after the earth’s ecology had fully recovered.
After the catastrophe, birds would have no option to seek out food for themselves and their young whether it was on hot ground or not. If they had have been originally ground dwellers they would have had no choice but to hop and flap from an above ground rock to rock or an above ground burnt branch to burnt branch to avoid touching the earth’s surface.
Depending on the time the ground remained hot or dangerous from overhead ejecta as well as predators, these hopping flapping movements would have brought about biological changes in their off spring leading them to evolve and embrace fully-fledged flight.
I still think that it is possible that birds are testing the ground every time they land by hopping just in case it is not suitable or too hot to land on and this drastic environmental change habit factor contributed to their continued survival and bird flight.
“I know nothing.”