i'm just curious about my new BD. he's about a month old, and i've had him for 2 weeks. whenever i take him out for feeding, half of his tail (from the middle down to the tip) gets dark. i've heard of "black beards" and the whole body going dark, but not this. after feeding is over and he's back in the viv, his tail returns to normal after a while. when he's out, i'll let him explore a bit and give him baths. he seems fine and he eats and runs around (though he's finicky about eating) and tolerates his bath. yet during all of this (2 or 3 times a day for 15 - 30 minutes) his tail remains dark.
Tsam blackbeards a lot of the time due to just discovering he's male, and yes - his tail goes dark as well. His shoulderplates go darker and his chest goes black too.