Affiliate Marketing Secrets

If an individual species in itself were widely diversified and a bunch of those species had this diversity, then it would be harder for the ecosystem to fall because diversity brings a higher chance for survival because natural selection can occur more readily since there are variations among the individuals in the species to select against the ones whose traits are less conducive to survival (being able to reproduce). So, extinction would occur less often in the ecosystem and all of the niches would be filled up.

I’m planning to write a post-apocalyptic story about the adventures of animals living after humanity destroys itself in a nuclear war. I’ve decided to have many of the general groups of invertebrates, amphibians, and reptiles survive in my story, but I’m having more trouble deciding on what types of fish, birds, and mammals would live.
The fish that I decided that I would use so far are the ones like lobe-finned fish, sharks, rays, jawless fish, seahorses, and mummichogs, but I can’t think of much else, because don’t know the exact nature of the impact that an event like this would have on modern marine life. With mammals I’ve got species like rodents, shrews, bats, pigs, wolves, and honey badgers, but again, I’m stuck. Birds are the ones that are giving me the most trouble, crows are actually the only birds that I’ve really decided on so far. So what other kinds of birds are likely to be post-apocalyptic survivors?
Also, what types of animals would likely evolve to replace large land predators if those were to go extinct? It’s just that I once read an old speculative biology book about how animals may evolve 50 million years in the future, and it had rats replace the large predators, but I also read on the Internet that there were more likely candidates to fill in that niche, but I don’t know exactly which.