The males somehow cue in to the cascade of hormonal changes going on in their pregnant mates.

The weight gain is an adaptive mechanism. These males that are gaining weight are picking up some type of signaling from the female.

We think that's what's happening in males, too.

Males do most of the carrying of infants usually two once they are born.

It could be the weight gain is preparing men for their investment such as the sleepless nights and taking over the extra work.

We're interested in what motivates dads to be good parents because there are so many men who just aren't good fathers. This work could help to tease apart what makes a good dad.