#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my $n=5; #Anfangsanzahl an Tieren
my @age;

for my $i ( 0 .. $n ){
    $age[$i] = int(rand(10));

}

print "Beginn: ", Dumper(\@age),"\n";

for my $t ( 0 .. 3 ){ #Zeitraum 10 Jahre
    for my $i ( reverse 0 .. $n ){
        $age[$i]++;
        if ($age[$i] >= 11){
            splice @age, $i, 1;
        }
    }
    print "Nach ", $t+1, " Jahren: ", Dumper(\@age),"\n";
}