sub buildList
{
    my ($name,$gender,$father,$mother,$age);
    my %bear_ref=();

    open IN, "<input.txt" or die "can't open file";

    while(<IN>) {
        ($name, $gender, $father, $mother, $age ) = split(/:/);
        $bear_ref{ $name } { 'gender' } = $gender;
        $bear_ref{ $name } { 'mother' } = $father;
        $bear_ref{ $name } { 'father' } = $mother;
        $bear_ref{ $name } { 'age' } = $age;
    }
    close IN;
    return %bear_ref;
}

for my $name (keys %$ref) {
   $father= $ref->{ $name }->{ 'father'}; # works
   $mother= $ref->{ $name }->{ 'mother'}; # works
   getTree($name, $ref);
}

sub getTree
{
    my $bear = shift;
    my $ref = shift;
    my ($father, $mother);
     $father= $ref->{ $name }->{ 'father'}; # doesn't work...have also tried with %$ref->
     $mother= $ref->{ $name }->{ 'mother'}; # doesn't work...have also tried with %$ref->
    print "$father : $mothern";

}

sub getTree
{
    my $bear = shift;
    my $ref = shift;
    my ($father, $mother);
    ## note that I am using $bear instead of $name since $name is not defined
    $father= $ref->{ $bear }->{ 'father'};
    $mother= $ref->{ $bear }->{ 'mother'};
    print "$father : $mothern";
}