It might not take a whole herd, but in the world of tamarins, it does take a couple of men. Tamarins split the parenting duties a little unevenly, requiring the males in the group to do all of the heavy lifting once the baby is born. Tamarin females have a statistically high rate of twins, and after the hard work of birthing the tykes, both the father and another male will step in to raise them. They team up to carry the kids around and protect them, only requiring the mom to feed them on occasion.
(Flickr/NOAA Ocean Explorer)