my @SList = qw(Name Latitude Longitude);
my $FileA = "Mammal.txt";
open my $Mammals, "<", $FileA or die "Cannot open file'$FileA'.";
while (my $line = <$Mammals>) {
    my %data;
    @data{@SList} = split /\t/, $line, scalar @SList;
    foreach my $species (@SList) {
        printf "%-10.10s : %s\n", $species, $data{$species};
    }
}
close $Mammals;


##</code><code>##

sub CalculateDistance($$$$)
{
 my ($Lat1, $Lon1, $Lat2, $Lon2) = @_;
 my ($nDLat, $nDLon);
 my ($nA, $nC, $nD);
 
 $nDLat = ($Lat1 - $Lat2) * 0.017453293;
 $nDLon = ($Lon1 - $Lon2) * 0.017453293;
 
 $Lat1 = ($Lat1) * 0.017453293;
 $Lat2 = ($Lat2) * 0.017453293;
 
 $nA = (sin($nDLat/2) ** 2) + cos($Lat1) * cos($Lat2) * ( sin($nDLon/2) ** 2 );
 $nC = 2 * atan2( sqrt($nA), sqrt( 1 - $nA )); 
 $nD = 6372.797 * $nC;
 
 return $nD;
}

##</code><code>##

    CalculateDistance (54.988056, -1.619444, $Lat2, $Lon2);

##</code><code>##

Myotis daubentonii	52.12909504	-0.882318328
Myotis nattereri	53.90074722	-1.771685946
Myotis nattereri	54.08052026	-1.770700447
Myotis nattereri	53.54023273	-1.471802022
Eptesicus serotinus	51.40241395	0.250171498
Eptesicus serotinus	51.35533502	0.242835438
Eptesicus serotinus	51.0001581	0.351815969