As wartime food shortages began to bite in Britain, posters and newspaper adverts appeared bearing the headline 'Shooting Homing Pigeons'. The posters warned: "Killing, wounding or molesting homing pigeons is punishable under the Defence Of The Realm regulations by six months' imprisonment or a £100 fine.
"The public are reminded that homing pigeons are doing valuable work for the government, and are requested to assist in the suppression of the shooting of these birds."
A £5 reward was on offer for any information leading to a conviction.
Some 100,000 courier pigeons were used by all sides during the war, with a remarkable success rate estimated at 95pc. As a means of communication, pigeons were clearly superior to telegraph lines that could be cut or blown up, and motorised vehicles that were forever breaking down and presented a large target for enemy fire.
The pigeons proved their worth early on at the First Battle Of The Marne in 1914, which prevented the fall of Paris. Pigeon messages enabled the French to move swiftly to cut off the German advance, and even though the advancing French took their 72 lofts with them as they pursued the Germans, the birds managed to find their way back to their nesting boxes that were moving miles every day.
If pigeons were the light brigade of the conflict, horses and mules did the heavy lifting.
The Great War broke out in an age when the cavalry charge was still regarded as the ultimate expression of battlefield glory. When it ended four years later, that age lay dead and buried following a number of suicidal horseback charges into the deadly hail of machinegun fire. The last charge on the Western Front took place in March 1918 by the Canadian Cavalry Brigade. Of 150 horses that started, only four survived.
Throughout the war, horses played a key role in transporting materials to the front. The internal combustion engine was still a work in progress and mechanised transport was prone to breaking down for any number of reasons, while the sea of mud sucked many heavy vehicles under.
Horses, along with mules, were reliable forms of transport and, compared with a lorry, needed little upkeep.
It's estimated that more than eight million horses died in total on either side of no man's land during the conflict.
The most versatile of the animals sent in large numbers to the front line were dogs, with the Germans employing some 30,000 in and around the trenches during the conflict, and almost the same number again used on the other side.
The two breeds that proved of most tactical worth to both sides were the German Shepherd and the Doberman Pinscher. Agile, smart and readily trained, these animals could fill a number of roles, from carrying messages to standing guard to sniffing out enemy scents.
While the Dobermans and Shepherds took the plaudits, it was the little terriers who won the grateful affection of the footsoldiers as, in their capacity as 'ratters', they kept down the huge population of vermin infesting the trenches.
Like their human keepers, the dogs of the front were segregated into ranks. Sentry dogs were crucial to camp security and Dobermans were considered the best sentries.
Scout dogs were selected for their quiet, disciplined nature. Their role was to work with troops on foot, patrolling the terrain ahead of them. These animals could detect enemy scent up to 1,000 metres away.
A special base was set up in Scotland to train messenger dogs, which filled much the same role as courier pigeons, but over shorter distances. A trained dog was faster than a human runner and presented less of a target to a sniper.
Many dogs, whether they were messengers, scouts or sentries, were adopted by the men in the trenches as a source of affection and comfort in terrifying times. Such companions were called mascot dogs, and one distressed corporal that kept his pet dog close was Adolf Hitler.
Most movingly, there were the casualty, or mercy dogs, which were equipped with medical supplies and dispatched to seek out the wounded and dying on the battlefields. Those soldiers who could help themselves to the supplies might survive by tending to their own wounds, while those who knew they were dying would be grateful for the comfort of a mercy dog as their life slipped away.
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