The survival of any birds at all has puzzled me, as modern birds seem to have very active lifestyles and metabolisms that would not tolerate long-term scarcity (as many Cretaceous birds flew, I am guessing the same applied to them.)
This is also true of small mammals, though many can hibernate. I sometimes wonder if it was winter in one hemisphere, and all the surviving mammals were hibernating.
Some modern birds, such as scrub jays, cache food for the lean season - perhaps that is how their ancestors survived?
Right, the article hints at this at the very end, hypothesizing that those animals that did survive were able to adapt to the conditions of an extended winter better than the larger herbivores and their predators.
Birds for instance can subsist on nuts and insects -- things that might survive a disturbed global climate -- and recover the next year, with some local die-offs.
Large herbivores though have to eat plant matter constantly. They can hardly survive a week without eating, let alone months. Those population die-offs then in turn cause a die-off among any species that depends on hunting those animals.
The article mentions that small animals that could subsist on seeds rather than live plants could have survived. This sounds plausible depending on how long it took for plant life to reestablish.
Don't forget, animals (dinosaurs, but also insects) of this size needed the higher concentrations of oxygen in the atmosphere that was present, pre impact. Even a temporary disturbance in oxygen output of the huge forests and robust plant life (including algaes) would have killed animals of this size much quicker than starvation or temperature change.
That's one thing I haven't read about yet, what happened to those oxygen levels of the distant past? Has anybody tried to estimate oxygen levels over time, especially during the extinction event?
Thanks - I was overlooking that seeds can survive a lot longer than the plants that make them. Also roots and rhizomes can survive the death of their above-ground components. Then there are plants that germinate only in response to fire, plants that undergo mass flowerings, and cyclical insects like cicadas - I imagine any of these things could help small mammals and birds survive.
This is also true of small mammals, though many can hibernate. I sometimes wonder if it was winter in one hemisphere, and all the surviving mammals were hibernating.
Some modern birds, such as scrub jays, cache food for the lean season - perhaps that is how their ancestors survived?