477
xkcd #2888: US Survey Foot
(imgs.xkcd.com)
Alt text:
Subway refuses to answer my questions about whether it's an International Footlong or a US Survey Footlong. A milligram of sandwich is at stake!
Right : it would be quite easy to spot someone whistling, even with those bushes around him, at about 85 ft (26 m) distance.
Still it is difficult for an author to create funny and yet realistic fiction.
In the comic, he looks to be about 20ft away, maybe. The last two panels are feet apart (same bush, same bank) lol.
In a jungle (that supposed to be a jungle, isn't it? it does look like a movie jungle), it's not easy at all.