None. They are complemented and enhanced. For example, their bonus to hit extends to all reptilian humanoids (rather than only kobolds) and orcs. And their speak with burrowing mammal spell-like ability is replaced by an extraordinary capacity to speak with all forest animals continually (they know their language). They also get a lot of automatic languages (gnome and common, but also elven and sylvan, plus that animal tongue). They have a constant Pass Without Trace ability like a druid. They have a racial hide that complement their size Hide bonus. And, according to the dragon issue with ECLs for all MM creature (even the Tarrasque, ECL +80), they are ECL +0 like any core race ! Woot ! They should rather get ECL +1, I think.