0:00:02 > 0:00:06In the south of England lies the New Forest.
0:00:06 > 0:00:08A glorious swathe of ancient woodland.
0:00:08 > 0:00:12In autumn, these magical woodlands
0:00:12 > 0:00:17echo with sounds that evoke a prehistoric atmosphere.
0:00:17 > 0:00:19CREATURES CALL
0:00:19 > 0:00:22This is the time of the red deer rut.
0:00:25 > 0:00:27STAG ROARS
0:00:29 > 0:00:31STAG ROARS
0:00:41 > 0:00:44It's September in the New Forest.
0:00:44 > 0:00:46Autumn hasn't really arrived yet
0:00:46 > 0:00:51but already, groups of female red deer, or hinds, are on the move.
0:00:52 > 0:00:55There are about 120 red deer in the forest
0:00:55 > 0:00:58with roughly 15 or 16 mature stags.
0:01:02 > 0:01:06For most of the year, they roam the forest in separate herds.
0:01:06 > 0:01:09But every autumn, for a few short weeks,
0:01:09 > 0:01:13the rut brings the stags and hinds together.
0:01:15 > 0:01:18Young calves, which would have been born back in June,
0:01:18 > 0:01:20can be seen amongst the herd.
0:01:20 > 0:01:24They're clingy youngsters, suckling for up to seven months.
0:01:24 > 0:01:28This helps to get them through their first winter.
0:01:32 > 0:01:37With the arrival of October, the first stags appear on the scene,
0:01:37 > 0:01:40joining the hinds prior to the rut.
0:01:40 > 0:01:44By this time of year, the levels of male hormones in their bodies
0:01:44 > 0:01:46start to go through the roof.
0:01:46 > 0:01:48This has an effect on their appearance.
0:01:50 > 0:01:54They have become more bulky around the neck with increased musculature
0:01:54 > 0:01:57to support their antlers during the rut.
0:01:57 > 0:02:02The eldest stags have developed a kind of shaggy mane,
0:02:02 > 0:02:05not dissimilar to a male lion.
0:02:08 > 0:02:10STAG ROARS
0:02:10 > 0:02:12And just like a lion,
0:02:12 > 0:02:16these males want everyone to know who's king of the forest.
0:02:28 > 0:02:29Nearly 1,000 years ago,
0:02:29 > 0:02:33William the Conqueror wanted to keep the pleasure of hunting deer
0:02:33 > 0:02:36to himself so he created the New Forest.
0:02:36 > 0:02:42Before then, the whole area was just a rough, barren heath land.
0:02:44 > 0:02:46So if it wasn't for a past king's love of deer,
0:02:46 > 0:02:49there wouldn't be a forest here at all.
0:03:04 > 0:03:07By mid October, the weather is still unseasonably warm.
0:03:07 > 0:03:10Usually the rut would be well and truly under way by now
0:03:10 > 0:03:12but the stags don't seem to be bothered.
0:03:12 > 0:03:16They're almost lethargic - just sitting around in the heat.
0:03:19 > 0:03:21They're staying close to the hinds,
0:03:21 > 0:03:23waiting for them to come into season.
0:03:23 > 0:03:27But until the weather becomes cooler, this will not happen.
0:03:34 > 0:03:37At times, the males seem frustrated,
0:03:37 > 0:03:41taking it out on trees or raking the ground with their antlers.
0:03:50 > 0:03:52It's November in the forest
0:03:52 > 0:03:56and the first frosty mornings mean autumn has finally arrived.
0:03:56 > 0:04:00The cooler weather has sparked the deer into action.
0:04:02 > 0:04:07Dominant stags have taken control of their hareem of up to 20 hinds.
0:04:09 > 0:04:11STAG ROARS
0:04:18 > 0:04:20STAG ROARS LOUDLY
0:04:20 > 0:04:24Scent marking is a way of enforcing dominance
0:04:24 > 0:04:29and roaring wards off the younger, inexperienced competitors.
0:04:29 > 0:04:31SHORT ROAR
0:04:38 > 0:04:43But if the stags are more equally matched, roaring is not enough.
0:04:53 > 0:04:57Each stag weighs around 400lbs.
0:04:57 > 0:05:01The sheer force of such a clash of heavyweights is immense.
0:05:01 > 0:05:04There is NO holding back.
0:05:09 > 0:05:14The rut shows off Britain's largest land dwelling mammal
0:05:14 > 0:05:15at its most impressive.
0:05:20 > 0:05:22ANTLERS CRASH
0:05:33 > 0:05:36Depending on the size of the two stags involved,
0:05:36 > 0:05:38these battles can be epic.
0:05:38 > 0:05:42Basically, the bigger the stag, the bigger the fight.
0:05:54 > 0:05:56The challenge ends
0:05:56 > 0:06:01when one stag is pushed backwards over a long distance.
0:06:01 > 0:06:05At this point he seem to know the wrestling match is lost
0:06:05 > 0:06:08and turns to run away from the victor.
0:06:24 > 0:06:28Herding the hinds to keep them safely under control,
0:06:28 > 0:06:31a dominant male is kept so busy that he hardly eats.
0:06:31 > 0:06:34In fact, throughout the rut,
0:06:34 > 0:06:37stags can lose up to 20% of their body weight.
0:06:37 > 0:06:39This can take a real toll on them
0:06:39 > 0:06:43if they are not in the peak of condition from the start.
0:06:44 > 0:06:46STAG ROARS
0:06:50 > 0:06:54As the hinds come into season, the stags claim their prize.
0:06:54 > 0:06:58The strongest males pass on their genes
0:06:58 > 0:07:04ensuring that the forest's red deer population remains strong and fit.
0:07:07 > 0:07:12But there is a twist in this tale of the red stag rut.
0:07:12 > 0:07:17In some parts of the New Forest, Japanese sika deer can be found.
0:07:17 > 0:07:19They escaped from captivity
0:07:19 > 0:07:24and established themselves in the wild over the last century or so.
0:07:26 > 0:07:30Although these deer are much smaller than the reds,
0:07:30 > 0:07:34sika stags are large enough to mate with red deer hinds.
0:07:34 > 0:07:38In a few regions of the UK, this has caused problems
0:07:38 > 0:07:41as the hybrids produced look just like red deer
0:07:41 > 0:07:44and are also able to breed.
0:07:46 > 0:07:50The purity of red deer in some areas is already questionable.
0:07:50 > 0:07:54But, thankfully, the sika of the New Forest
0:07:54 > 0:07:56seem to keep themselves to themselves.
0:07:56 > 0:08:02So, for now, the red deer that roam these woodlands remain purebred.
0:08:08 > 0:08:10With the end of the rut,
0:08:10 > 0:08:13most hinds will now be carrying next year's calves.
0:08:13 > 0:08:16The stags and hinds once again separate
0:08:16 > 0:08:20and will remain apart until next year's rut.
0:08:22 > 0:08:26The red stags are without doubt the most majestic animals
0:08:26 > 0:08:28we have in this country.
0:08:29 > 0:08:33They have survived an ice age and man's constant hunting.
0:08:33 > 0:08:36Hopefully, they will continue to thrive
0:08:36 > 0:08:40and the remarkable sights and sounds of the red deer rut
0:08:40 > 0:08:45will echo through these ancient woods for centuries to come.
0:08:53 > 0:08:56Subtitles by Christina Clark Red Bee Media Ltd 2005
0:08:56 > 0:08:58Email subtitling@bbc.co.uk