The probability of stray babies and children [living] to adulthood is ridiculously low. For young yukkuris, the outside world is an encircling net of death, and to make it through, all they can do is trust to luck.
The parents who scream and cry when their children die are also killed without mercy as punishment for being noisy.
Even so, the stray [population] does not decrease. The reason is that, whether they're abandoned or born [to stray life], there are just so many of them.