Variadic function to check equal lengths of STL containers

I am writing my first variadic function template. I am getting the error error: parameter packs not expanded with ‘...’:. Probably I cannot understand some easy concept here. I would like to store all passed in iterators in a vector. What is the right way to do this?

template<typename... Iterator>
bool IsEqualLength(Iterator&... its)
{
    std::vector<Iterator> vec_its {its...};
    int head = vec_its.front().size();

    bool is_diff_size = std::any_of(vec_its.begin(), vec_its.end(), 
        [&head](Iterator& cur){return cur.size() != head;});

    if(is_diff_size)
    {
        return false;
    } else {
        return true;
    }
}

This fails to compile with (under gcc 4.8.4 on Ubuntu):

../proc.h: In function ‘bool IsEqualLength(Iterator& ...)’:
../proc.h:32:24: error: parameter packs not expanded with ‘...’:
  std::vector<Iterator> vec_its {its...};
                        ^
../proc.h:32:24: note:         ‘Iterator’
../proc.h:35:87: error: parameter packs not expanded with ‘...’: