Am I doing something wrong? Where are the gecko skins?

Hey there new player to fallout 2 started last week. An npc mention that Gecko skins go for a high price and I decided to try and hunt Geckos to get more mulla early game, figure it be needed.

However I have killed 75ish Geckos of lesser and golden variety and have gotten no skins. Is there a stat I need to level up that affects loot drops?