**The fundamental psychology of the Predators is still unknown to Humans. As such, we are not clear on their selection process for trophies. All of our information is based on anecdotal evidence.** 

 - It could very well be at the end of their hunts, they only take the BEST trophy or trophies, honoring the prey that proved most worthy while the others are discarded or destroyed. (As apex predators, they probably only want to honor the BEST with a place on their trophy wall.)

 - With their advanced technology, it is possible they are able to prepare their kills for transport and once prepared the trophy will remain viable, stashed away in a hidey-hole for a day or two while they finish conducting their business.

 - We have seen Predators with skulls on their belts, so it is possible they just carry them around until they finish hunting. The process they use for preparation must remove all trace of scent, lest it reveal them to other prey/hunters with strong olfactory senses.

 - I imagine like Earth sportsman, they kill far more than they keep and would only mount on their walls the kills with the best stories; or in the case of the Predators the prey that almost killed them or nearly got away before being brought down by their superior hunting ability. I'm sure that's how they tell it.

[![wall of trophies collected by Gaston in "Beauty and the Beast" (Disney animated version)][1]][1]


  [1]: https://i.sstatic.net/O13gI.jpg