Humans fell sick. Worldwide they got afraid. Most stayed home. They wisely de-crowded themselves. The heat and noise and masses abated from past extremes to decent tolerances.
Other animals had always been around. Humans called them wild, since they themselves were obediently jailed in their settlements. Those they deemed feral actually freed themselves to half-return to nature.
Well, natural, feral, wild, they roamed around more, closer to human sickness incarceration.
Then humans got less afraid, but no less infectious. By then, other animals had expanded their spatial ranges back to our doorsteps. Sweeter morning bird songs. Otters eating exorbitant ornamental fish in expensive homes. Hornbills feasting on beautiful songbird babies.Red jungle fowl strutting at neighbourhood food buildings, rooster 🐓 and hens 🐔 .
Now people have returned, heat and noise and pollution and jams and all. And other animals push for another equilibrium, because locals are not so stupid as elsewhere to extinguish the last of nature in their urban over-buildup.
Whilst animals are now too smart not to take the free food provided daily from scraps and leftovers at people's commercial cafeterias islandwide.
The crows and mynahs observe and re-position. The sparrows fly harmless and unnoticed, because small, they really master the life spaces.