Carrier pigeons were used during the First World War to relay information when other methods of communication were not possible. Pigeons were used on land, sea and even in the air, some travelling up to 100 miles through dangerous conditions to deliver important messages back to headquarters and bases.
Training the pigeons and caring for them were not easy tasks, and the British Expeditionary Force issued official guidelines for the men working in the Carrier Pigeon Service.
Here are some of the top tips from the 'Carrier Pigeons in War' pamphlet issued in March 1918.
1. Consider if a pigeon is needed
'Before deciding to send off a message by pigeon, it is necessary to consider: (a) the importance of the message; (b) the number of birds available; (c) the prospect of replacing the birds so despatched; and (d) whether the message can be sent by any other means.'
2. Write a clear message
'[Messages] should be written in a clear hand, care being taken to fill in all the particulars as required by the form.'
3. Attach messages with metal holders not rubber rings
'The use of metal carriers is much simpler, and is the method in vogue.'
4. When possible, send two copies
A sailor holding two pigeons who had done valuable work by bringing in many messages. On the right is Pigeon CV 409, given to the navy by King George V. On the left is pigeon No. 4510, a long service bird which joined the Naval Pigeon Service early in the war.
5. Pigeons and tanks
'It is recommended that two copies of a message should be sent whenever sufficient birds are available for this procedure.'
6. Releasing pigeons from seaplanes
'The arrival of a pigeon, bearing no message but known to have been sent out on a seaplane, is now recognised as a signal of distress made by that particular plane. For use with aeroplanes and seaplanes, the special box designed for the purpose of carrying the birds should always be used.'
7. Lofting your pigeons

'Experience has proved that pigeons very quickly become accustomed to shell-fire, which does not appear to disturb them at all in their lofts. It thus becomes possible to take pigeons much closer to the firing line. This is usually done by means of the employment of mobile lofts.'
8. Exercise your birds daily

'In fine weather, the birds need exercise at least twice a day. Once outside the loft they should take exercise and not be allowed to sit about when not on the wing, otherwise this will become and acquired habit and will lead to slowness in entering the loft when returning with a message.'
9. Bathe your pigeons once a week

'A bath should be given to the birds at least once a week, during all seasons of the year.'
10. Transport them in the appropriate basket

'There are several different types of baskets used in the pigeon service…All baskets must be supplied with at least one special water trough, either fixed or detachable, for watering the birds.'
11. Start training your pigeons early

'The young pigeons, known as "squeakers", should be ready for service work when three months old. At this age good strong young birds will be ready to accomplish flights of from 10 to 50 miles in the field.'