By Alison Stenlake
This week the BBC News website is looking at people who do unusual jobs. In the second of the series we speak to the man who looks after the famous ravens at the Tower of London.
"Morning Thor, hello Munin."
Derrick Coyle's working day starts at the crack of dawn - literally - when he greets each of his ravens by name, letting them out of the cages where they spend the night.
Name: Derrick Coyle
Job title: Yeoman Warder Ravenmaster, HM Tower of London
As he opens each door, the impressive birds half fly, half scurry out, reclaiming their territories on the Tower of London's greens, hours before the first visitors come through the gates.
The next hour or so is spent checking on the ravens, feeding and watering them and cleaning out their cages. And that's all before his own breakfast.
As the Tower of London's Yeoman Warder Ravenmaster, Derrick is responsible for the birds' welfare, and therefore ensuring the royal decree issued by Charles II - that there are always six ravens at the Tower - is obeyed.
Legend has it that if the birds leave the site, its White Tower will crumble and the Kingdom of England will fall.
Weighty stuff, but Derrick's day-to-day duties caring for his six adult ravens and two young "spares", recently found abandoned on Dartmoor, are more down to earth.
Gwylum (male), aged 17
Thor (m), 14
Hugine (f), 10
Munin (f), 10
Branwen (f), 3
Bran (m), 2
Gundulf (m), 5 months
Baldrick (m), 5 months
They include chopping the raw meat he buys from Smithfield Meat Market to feed the birds, filling their water bowls, and generally keeping an eye on them as he performs his other tasks as one of the Tower's 35 Yeoman Warders, or Beefeaters.
It can be a long day. The ravens are out in the grounds from dawn until dusk, when they are locked up to protect them from roaming foxes or feral cats.
In the height of summer, this means his day can end as late as 9.30pm, and he rises as early as 4.30am for a shower and shave before starting all over again.
"Getting up in the morning is the worst part," Derrick, 61, admits. "And I don't have a social life in the summer, as if I go anywhere I always have to get back to put the ravens to bed.
"You can't really have a drink either, as alcohol dulls the senses, and you've got to be alert to what they're doing at all times. One lapse, a bit of over-familiarity, and if a bird goes for you it could have your eye out."
But these are only small hardships to endure for a job he so obviously loves.
"The best thing is looking after the birds, the working relationship I have with them. It's a lot of fun, and gives me a lot of pleasure," he says.
"I wouldn't have it any other way. The ravens are part of the family. They all have their own characters - they're very intelligent and mischievous."
So intelligent, in fact, that one of them - the self-appointed leader, Thor - can even speak.
He started imitating Derrick, who often receives a "good morning" from him - as, apparently, did a delighted Russian President Vladimir Putin when he visited the Tower.
RAVENMASTER'S DAY (SUMMER)
As early as 0500: Let ravens out of cages, feed, fill water bowls. Transfer young ravens to aviary, hand feed them
0630: Home for breakfast and to change into uniform
0830: Go to warders' hall, check daily duties, collect keys and radio
0900: Start first post duty. These continue throughout the day, rotating on hourly basis
0945-1030: Home for tea break
1230-1330 Lunch break. Feed young ravens again around this time
1530-1600: Tea break
1730-1800: Feed all ravens, then home for half an hour
18:30: General check on ravens
19:00: Home for evening meal
As late as 21:00: Whistle ravens to bed, lock them up for night
To be considered as a Yeoman Warder candidates need to have spent at least 22 years in the Armed Forces, with a good conduct record, reaching the rank of warrant officer.
Derrick, originally from County Durham, first donned his Beefeater's uniform at the age of 39, after serving as a regimental sergeant major in the Green Howards.
As an animal lover with a lifelong interest in birds, he became a ravenmaster's assistant just two months later.
Finally, after two ravenmasters retired, he got the top job in 1999, and plans to keep doing it until retiring at 65.
His hard work was recently rewarded in the Queen's Birthday Honours - he was awarded the Royal Victorian Medal.
"It's a great honour, and something else for the ravens really," he says. "I try to keep them high profile."
Adults: 6oz raw meat daily
Young: 9oz raw meat daily
Meat is usually liver, lambs' hearts and beef or pork trimming
A boiled egg, complete with shell for the adult birds, every other day
Bird biscuits soaked in blood every other day
Occasional part of rabbit, complete with fur for roughage
Monthly food bill is about £120
He adds that, according to regular surveys, the birds are "the third most popular reason why people come to the Tower, after the Crown Jewels and us, the Beefeaters".
Like the other Yeoman Warders, Derrick lives in an apartment within the Tower walls - about 6% of his annual salary is deducted as rent.
But on his days off he heads for Wallington, Suffolk, where he and his wife Marnie have their own home with an acre of land.
They used to keep goats, chickens and ducks, but more recently downsized to three dogs, two cats and a former Tower raven, Hardey, who retired there two years ago after going blind at the age of 27.
Derrick's work schedule follows a regular pattern of seven days on followed by two off, with a three-day weekend every third week. He gets seven weeks' holiday a year, including bank holidays.
Monitoring the ravens' health is an important part of Derrick's job, and he is in close contact with vets at London Zoo where he takes them when they fall ill.
Once a week, with the help of one of his three assistants, he gives the birds a thorough check over, and every three weeks trims the lifting feathers on their right wings to prevent them from flying away.
To protect his own health, he gets a regular tetanus jab and wears plastic gloves when feeding the ravens in case they transfer a possible infection picked up from rats or other wild animals.
Although the birds are obviously comfortable around humans, Derrick says he never forgets that they're essentially wild birds, and tries to keep them "stand offish" so they don't become too tame.
He wears a full face mask and gauntlets when examining them, and admits that at other times he does receive the "odd little peck".
"But they're more or less love pecks - they're being affectionate and don't know their own strength."
They also generally do what he says - and come obediently when he whistles for them to go to bed in their cages at the end of the day.
"I'm the king raven here, they look at me as part of them," he says. "I'm the one who does things for them so I'm the boss.
"The fact it's an unusual job does give me a little bit of a fillip. There's no one else who can say 'I'm the only Ravenmaster Yeoman Warder in the world'."