Goblins in .13 must be bugged to some extent. I embarked on an evil biome and checked to see that goblins were present on the embark area screen. I had 200+ dwarves with a .13 native fort and just had the population cap ignoring problem as a new wave of migrants arrived, boosting my total to 210. I have not had a single goblin arrive.



I abandoned and checked the legends maps - there were only a few goblin settlements present on the map. I tried reclaiming and checked the embark point, and goblins were listed as at war at the location of the abandoned fort.



The siege and ambush numbers must be coming from goblin populations. I would imagine that the goblin populations are just too small to support a full scale siege or ambush and so just never come.