Glasgow Zoo Park
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Contented Poultry

Contented chickens let you know instantly by their body language and their " vocalisation "; clucking, how they are feeling.
In the wild the ancestor of the chicken - the Red Jungle Fowl - needs a mixture of open ground and cover, safe roosting and nests, food, water, dust-bathing facilities and no more than one cockerel to six or eight hens.
They don't like vast amounts of bare, open space - or jammed, shoulder to shoulder, in restricted areas.
Hens in particular, find the presence of a cockerel nearby greatly reassuring and come to rely on him as a sort of avian guard dog.
How these requirements can all be met by the commercial keeping of huge numbers of poultry is quite another problem requiring slightly more than a guideline from supermarkets.

Feather Plucking

Recent research on their humble chicken suggests that the cause of the horrific feather plucking that chickens get in crowded surroundings may be associated directly with an inability to dust bathe.
Several universities in different countries are working on this and have found that, deprived of dry earth or anything suitable to dust-bathe in, the birds become so unhappy they peck at the feathers of their companions.
This can lead to serious wounds and eventually even to death.

It is believed dust-bathing removes grease from the feathers of chickens, just like chinchillas.
Chickens kept at semi-liberty or free range rarely feather-pluck. Over several years,in our children's farm, we have never had a single case in a multi-coloured flock of more than 80 hens. All of them dust-bathe on a regular or daily basis.
Chicken welfare is becoming a subject of great concern to amateur and professionals alike. The Scottish connection is provided by Professor Brambell, whose committee laid down the original five guidelines for battery hen cages in the 1960s.
I have long suspected that the size of the cages was not the fundamental reason causing distress to the hens.
I wondered whether the lack of cockerels in presence or in ear-shot, or some other bodily function such as dust-bathing, was of important significance.
If you think back to chinchillas, which have been known to sicken and die when deprived over a lengthy period of the opportunity to dust-bathe, perhaps we shouldn't be surprised that chickens can suffer a similar sort of reaction.
The surgical removal of the tip of the top half of the beak so that the bird can no longer peck in a precise manner is based on the similar principle of the surgical removal of baby pigs tails.
It doesn't stop the fundamental cause of the disorder, causing chickens to peck each other and pigs to chew each other's tails, just their ability to carry this out.

Cockerels as Watchdogs

I have noticed many times how much our hens at Glasgow Zoopark appreciate the " watchdog " role assumed by the cockerels in their flock.
I have also learned the meaning of the different alarm calls of these cockerels, which vary according to the nature of the threat, which can be crow, hawk, cat or seagull.
I was intrigued when a natural history TV programme confirmed all this and showed extensive film of poultry carrying out this warning behaviour.



Scientists at the University of Chicago have recently discovered that birds - songbirds this time - dream and practice their songs in their sleep.
The boffins recorded birds' brain waves which seem to show that they rehearse while asleep.

Poultry Politics at the ZooPark

March 1999 I visited the Scottish Poultry Club Championship Show in Peebles.

I saw several breeds and colour varieties I hadn't encountered before, especially among the magnificent array of Polish birds.

However, I am now immersed in poultry politics - the avian kind, not the human variety.

Three years ago, for our 80-strong poultry flock at the zoo, we arranged a sturdy set of roosting perches running at 35 deg from two and a half metres above ground down to the floor.

As a young cockerel moves "up the pecking order," he promoted himself higher and higher each night up these perches.

Eventually after several months we find him roosting on the top spar and you know he is "top dog";

The reverse also applies - last year's dominant cockerel, a five-year-old Silver Campine, is now so subordinate he has demoted him to the halfway stage.

Amazingly, his beautiful silvery cape, the "mane" of shimmering feathers, has become dulled and greyish in colour.

Each feather appears to have changed colour - where it was pure white before, it now has a black or grey centre.

Not only does this cockerel move our of the way of the more dominant young cockerels - some of whom are his sons - but he poses less of a threat to them.

Incubating Eggs

Each year we hatch and rear a great number of poultry in our Children's Farm at Glasgow Zoo including chickens, ducks, turkeys and pea fowl.

Time after time, I'm surprised at the lack of understanding of the incubation process with many people thinking an egg automatically has to be kept warm.

Provided a newly-laid egg is not incubated, i.e. kept cool, it will remain capable of hatching for up to six weeks if, of course, it is fertile.

Fertility drops off by about 20 per cent after six days, but if the eggs are looked after and turned each day they remain reasonably constant thereafter. Incubation only commences when the mother birds sits in earnest on the eggs - going "broody" we call it.

From the date at which she goes broody, it takes 21 days until the eggs hatch in the case of chickens and 28 days for ducks, with pea fowls and turkeys taking longer.

If the mother is kept off the eggs for any length of time during this period, perhaps by being accidentally shut outside, the eggs will cool and may not hatch.

The broody hen alters in other ways. A bird's feathers are designed to keep her body heat in and act as an insulating layer.

When she starts to incubate her eggs, she moults many of the feathers on her breast thus creating a " brood patch ".

Her bare skin is then in direct contact with the eggs and the incubation temperature soon rises to resemble that of a small oven. This behaviour is completely different from that of birds of prey, owls, parrots and parakeets.

When a hen starts incubating when her clutch is complete at about 10 or 12 eggs, these sorts of birds start incubating on the laying of the second egg. As one egg is laid each day or every second day, it follows then that the eggs also hatch in a staggered manner.

This is nature's way of ensuring that any chicks reared by these species are strong.

If food is short, either because prey is scarce or because of drought conditions, in the case of many parakeets, only the biggest chicks or perhaps just one chick, will survive.

Red Jungle Fowl

Tesco have sponsored state-of-art "happy chicken" chicken houses located near Sherwood Forest , Nottinghamshire.
According to Malcolm Pye, agriculture director for Premier Poultry, they have used research from academics who have travelled to the Far East to study the Red Jungle Fowl, the ancestor of all domestic chickens.

As a result, they report: "We can tell when the birds are happy. They express themselves by their natural behaviour , darting about, dust bathing, foraging, and, in our view, they are happier."

The birds live in large houses with verandahs and can move freely around their terrain - a mixture of woodland, pasture, long grass and cover crops. There is also an area of peaty, jungle-type soil, sun shelters and windows.

Every detail has been included to stimulate a chicken's natural behaviour. Light levels inside the house are raised and lowered to imitate natural dawn and dusk.

Temperature and humidity are also controlled to match a jungle atmosphere, with artificial rain.
Even the walls of the house are painted green to imitate jungle surroundings while blue roofs depict the sky.

Jungle Fowl Compared with Domestic Chicken

We were asked the following queries:

  • Would you be able to tell me how differently the domestic chicken lives, for example, does the Jungle Fowl lay as frequently as the domestic chicken, does the Jungle Fowl fly?
  • Because man has domesticated the Jungle Fowl, how different is the domestic chicken from its ancestor.

It is self-evident that jungle fowl lay nothing like as many eggs as domestiacted chickens, because they have not been 'improved'. Domesticated chickens have been subject to at least 3000 years of domestication (probably much longer). 'Factory' chickens selectively bred to lay are at one extreme, producing over 250 eggs in a 365 day year; jungle fowl at the other, 2 clutches of 12-15 eggs, maximum per year! The jungle fowl flies easily and roosts in bushes and trees (out of the way of ground-dwelling predators) at night.

Even the most domesticated of domestic chickens will, in my experience, 'revert' to normal chicken behaviour quite quickly when given the chance. We have released battery chickens into our Children's Farm. After three weeks, normal behaviour is quite obvious. After 10 weeks all bald patches have disappeared as all the feathers regrow. One such hen has now incubated and reared at least six clutches of chicks. Under normal circumstances, such a computer-bred 'broiler' would have been killed and eaten by the age of 10 weeks or so.

These observations do not apply if they have been bred to appear abnormal, ie. huge feather crests, or long feathers on the legs, or abnormally short legs, eg., Barbu d,uccles breed.

Domestic Chicken Behaviour

Further discussion on domestic chickens was prompted by the following questions:

  • 1. If one took the eggs away from the chicken would she continue to lay until she had a clutch?
  • 2. What is the normal 'laying' life of a chicken?
  • 3. What is the natural life span of a chicken?
  • 4. Is it 'kinder' to remove unfertilised eggs or let a chicken lay a clutch of unfertilised eggs, and if the latter how long would a chicken stay on the eggs before it realised they weren't going to hatch?
  • 5. Finally, you mention that if the chicken has been bred to be 'abnormal' it cannot revert to its natural instincts. In what way has man bred it to be abnormal?

To these points Richard O'Grady responded:

I think Richard Ryder's book on domesticated animals (I cannot remember the exact title) may discuss chickens, or the newsletter of 'Compassion in World Farming'.

However, some of the following may help -

  • 1. Laying eggs itself presents no strain to most birds, be they budgies or eagles. A 'battery' chicken asked to lay over 200 eggs in a year - one a day - will suffer 'physical stress' if deprived of calcium or minerals to a substantial extent (needing these for the egg shells). In other words, if you keep taking the eggs away, most domesticated chickens have been selectively bred to continue laying. If you leave her with 10-20 eggs, then she may - faced with a 'complete' clutch, become 'broody'. Sometimes they will go 'broody' in the absence of significant numbers of eggs, but, kept at semi-liberty as ours are, it usually takes the stimulus of a full clutch to get them going.

  • 2.The normal laying life of a chicken can - from my own practical experience - be up to 12 years, with gaps along the way of up to 3 months at a time whilst the hen moults. However, in the language of commercial egg producers, most hens are culled - sold or otherwise disposed of - when they reach 15 months and start a serious moult because maximum 'productivity' thereafter drops off year by year. They claim margins are so tight they cannot afford to feed them through the moult and if they are not laying at peak productivity.

  • 3. The 'natural' lifespan of a chicken could be over 12 years. However, even in the wild they are predated upon by everything. An 'oldish' chicken looks like that and is likely to be selectively picked out by a predator, plus its reactions will be slowing down. One of our hens here, 'Rambo', is over eight years already and still laying.

  • 4. Removing eggs or not makes little difference to a chicken. Hatched chicks are a different matter altogether, and most hens will defend them vigorously, even to the extent of sacrificing their own lives in the process. Unfertilised eggs should always be removed - and eaten. Otherwise, the hen might go broody. She will diligently sit on the eggs well past the 21 days incubation period, and may only desert after 8 weeks or so when the eggs start 'exploding' with build up of putrifying gases, etc., I feel it is kinder and cleaner, and less stressful on the chicken, to ulitise the eggs in an eco-friendly positive manner, and not 'waste' the hen's effort.

  • 5. When I said 'abnormal' I wasn't referring to its instincts. They will remain intact. However, a glance at any poultry book will show you birds of strange shapes - tiny legs, frizzled feathers, crests shading the eyes, long feathers on the feet and legs. Such birds, try as they might, are unsuited to life in the rough and tumble outside and would be very unhappy, and incapable of coping, when faced with wind and rain and crows and cats, etc.

Predation by peafowl of poultry chicks