Well women and children doesnt surprise me since they usually pick up things easier when their excited (for whatever reason) and they usually find drama quite exciting
joke aside, yeah I think it is something to the high pitch in female and childrens voices that peaks their interest more, I mean a man (well can't speak for everyone but my voice is quite dark) when I slightly up my pitch to speak to the birds my voicepitch is still quite a bit lower than most females in a normal conversation and when a female ups her pitch to speak to birds/animals its miles in difference between me and them... But a lot of birds seems to catch on while doing something that causes over excitement such as showering...