It has long been known by humans that female mammals can be attracted with the call of a young in distress. There is a famous documentary film of the Hadza, a foraging group in Tanzania, in which this method is used by young boys to trap Dasssies (rock Hyrax). First you catch a baby Dassie (not hard) then you hid and bit it in the neck so it cries out, then when the momma Dassies come to rescue it you shoot them at short range with an arrow or whack them with a stick. Adult Efe Pygmy hunters sometimes imitate the call of a young Duiker (a forest antelope) in distress in order to draw in females. I’ve spent a fair amount of time hanging around with adult male Efe hunters and never saw this work, but they claim it does and I tend to believe them.
Now, researchers have demonstrated cross-species response to distress calls by young. They recorded distress calls by various mammals such as seals, dogs, cats, and humans. Never mind how they got the distress calls. Anyway, they played these for White Tailed Deer females and got a response. The mother deer moved towards the recordings. These baby mammals all have similar pitched calls. The researchers also recorded bats and lowered the pitch to be within that range, and the deer responded to this as well.
Presumably there is strong selection on responding to distress calls of young, but not strong selection on being selective, probably because the circumstances do not arise that often.
More here.
