Digging back in my memory...I think the same one of my kids who liked the Wild Kratts also liked Zoboomafoo.
My son LOVED Zoboomafoo but I'm not sure it's was any more deep than Magic School Bus. The Krack brother's who were the stars of Zoboomafoo, made some video's in later years that were more animal documentary's. And I do remember my DS enjoying them.
Opps.. it's the Kratt brothers and I suppose the Wild Kratts is the documentaries I was talking about.
Second correction. The wild Kratts is not the documentaries I'm talking about but I don't have the time to track them down right now.