Actually the human-scent claim seems to be a myth. Most birds have a quite poor sense of smell.
Blog post quoting a biologist. Snopes.com confirms. However, unless they’re very young indeed it’s still best to leave them alone:
Possibly this widespread caution against handling young birds springs from a desire to protect them from the many well-intentioned souls who, upon discovering fledglings on the ground, immediately think to cart them away to be cared for. Rather than attempting to impress upon these folks the real reason for leaving well enough alone (that a normal part of most fledglings’ lives is a few days on the ground before they fully master their flying skills), a bit of lore such as this one works to keep many people away from young birds by instilling in them a fear that their actions will doom the little ones to slow starvation. Lore is thus called into service to prevent a harmful act that a rational explanation would be much less effective in stopping.
Oh, we were mislead into taking the correct action. Fair enough I suppose. I had wondered why they were so sensitive and also why the advice was “don’t touch” rather than “put on gloves”. Consider me enlightened.
(Mind you the just so story justifying the myth lacks credibility. It seems more likely that the myth exists for the usual reason myths exist and the positive consequences are pure coincidence. Even so I can take their word for it regarding the observable consequences if not the explanation.)
Actually the human-scent claim seems to be a myth. Most birds have a quite poor sense of smell. Blog post quoting a biologist. Snopes.com confirms. However, unless they’re very young indeed it’s still best to leave them alone:
Oh, we were mislead into taking the correct action. Fair enough I suppose. I had wondered why they were so sensitive and also why the advice was “don’t touch” rather than “put on gloves”. Consider me enlightened.
(Mind you the just so story justifying the myth lacks credibility. It seems more likely that the myth exists for the usual reason myths exist and the positive consequences are pure coincidence. Even so I can take their word for it regarding the observable consequences if not the explanation.)