Are default constructors called automatically for member variables?

Say I have this class:

//Awesome.h
class Awesome
{
    public:
        Awesome();
    private:
        membertype member;
}

//Awesome.cpp
#include "Awesome.h"

Awesome::Awesome()
:member()
{
}

If I omit the member() in the initialization list of the constructor of Awesome, will the constructor of member be called automatically? And is it only called when I don't include member in the initialization list?