This page includes an interactive calculator that lets you plug in your own numbers for happiness and suffering for various species to compute an estimate of total welfare that accounts for lifespan and infant mortality.
As far as the painfulness of starvation, I wrote a bit here.
The painfulness of other kinds of deaths and life experiences is something that Sentience Politics wild-animal researchers will write more about in the future, and Animal Ethics also writes about such things.
This page includes an interactive calculator that lets you plug in your own numbers for happiness and suffering for various species to compute an estimate of total welfare that accounts for lifespan and infant mortality.
As far as the painfulness of starvation, I wrote a bit here.
The painfulness of other kinds of deaths and life experiences is something that Sentience Politics wild-animal researchers will write more about in the future, and Animal Ethics also writes about such things.