Why don’t dads take parental leave?

Lack of pay, concerns about career path, and employer reluctance — when it comes to parental leave, there are many deterrents. But employees who do take it tend to be female. So why don’t dads take parental leave?
A recent UK report showed that only 1% of fathers there have availed of shared leave, since it came into legislation in April 2015. There are no statistics available here, but anecdotally, it is mostly women who take parental leave — often on a day-per-week basis.