271:"laying" stage of their lives. Furthermore, if a member of the flock has had its feather pecked, they will stay in this category as the damage to the feathers are a physical indicator to others that that bird is being targeted. One study found that fear could increase feather pecking and primary cannibals can influence secondary cannibals by initiating cannibalism by becoming more aggressive in pecking. Cannibalism within a flock is seen as a chain reaction where if one member of the flock begins, if left unattended, will cause others around it to learn the behaviour and engage in cannibalism. The social order of a flock will also play into the risk of cannibalism. This can be seen if a primary cannibal is a higher ranked bird in the flock, it could influence more secondary cannibals and spread this behaviour more rapidly.
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allows for less feeding space which therefore means that dominant birds will take majority of the food supply leaving less dominant birds susceptible to becoming underweight and easier targets to the dominant birds for cannibalism. An optimal flock size are either large flock of greater than 30 where the group is too large to recognize an established dominant bird and the social hierarchy breaks down, or a small group size where a social order can easily organize itself. Intermediate group sizes cause confusion among the flock and leads to higher aggression of different birds attempting to become the dominant one and therefore leading to increased risk of cannibalism.
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the different farms the flocks grew up in. While the genetics of these flocks were similar, the environmental factors ultimately influences the introduction of cannibalism in the flocks. In some flocks 36.4% of the deaths due to cannibalism was observed. To minimize cannibalism in domesticated poultry, different approaches such as ecology, environmental physiology, epidemiology, molecular genetics and ethology have been taken. But the approach with the most success was the molecular genetic with behavioural research and could lead to the decline of server practices to reduce cannibalism such as beak trimming.
19:
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mainly to cannibalism, can be up to 15% in egg-laying flocks housed in aviaries, straw yards, and free-range systems. Because egg-laying strains of chickens can be kept in smaller group sizes in cage systems, cannibalism is reduced, leading to a lowered trend in mortality as compared to non-cage systems. In a study which examined 'skin damage' (most of which would have been caused by pecking) on hens at the end of their productive lives, damage was lowest in hens from
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86:, although they are mainly herbivorous in adulthood. Feather pecking is often the initial cause of an injury which then attracts the cannibalistic pecking of other birds – perhaps as re-directed foraging or feeding behaviour. In the close confines of modern farming systems, the increased pecking attention is easily observed by multiple birds which join in the attack, and often the escape attempts of the cannibalised bird attract more pecking attention.
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engage in high feather-pecking behaviour had on average had a higher egg production. Therefore, selecting against feather pecking could reduce egg production. Farmers would have to choose between a trade off of either possibly having higher egg production with a high potential of flock death due to cannibalism, versus lower egg production with a lower risk of death due to cannibalism.
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be as high as 0.56. Another study found that brown-egg laying hens are more likely to engage in feather pecking than white-egg laying hens. The genetics of poultry will not guarantee a bird will engage in cannibalism, but the genes a bird possesses play a part in the degree of aggressiveness a bird could engage in feather pecking and increases their risk engaging in cannibalism.
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chronic pain to the bird. The beaks of poultry are highly sensitive to pain, touch, heat and pressure. They use their beaks to forage the ground. Trimming their beaks makes them lose their ability to sense the external world and could cause neuromas, which are bundles of severed nerve endings becoming exposed due to beak trimming.
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acid and needs an external source to obtain its required amount. Oftentimes in flocks it is the first limiting amino acids. Methionine contains sulfur which is used to grow feathers and this may explain the biological purpose for increased pecking. This pecking behavior then escalates into more extreme forms of cannibalism.
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Within a pen, if another bird is injured or dead, the sight of this can encourage other pen members to engage in cannibalistic behaviours. This is due to the social order created by poultry, as well as their attraction to blood. Poultry are attracted to the colour red and the sight of blood can cause
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is targeted. There are several causes that can lead to cannibalism such as: light and overheating, crowd size, nutrition, injury/death, genetics and learned behaviour. Research has been conducted to attempt to understand why poultry engage in this behaviour, as it is not totally understood. There are
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While genetics and learned experience can influence behaviour, ultimately it is an interaction of the two that gives the expressed behaviour. The
Netherlands study found the flocks of the same breed had different outcomes of whether cannibalism developed or not depending on the management control of
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Cannibalism among layer hen flocks is highly variable; when it is not problematic, mortalities among production systems are generally similar. Published data on the prevalence of cannibalism could be misleading due to the inclusion of vent-pecking by some researchers but not others. Mortalities, due
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A particular diet of low protein but high energy is shown to lead to less aggressive behaviours, but despite that, a diet lacking the protein component (amino acid) methionine is shown to cause aggressive behaviours. Methionine is an essential amino acid. This means the body cannot produce the amino
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Pecking and other forms of pecking (feather pecking, vent pecking, aggressive pecking) are normal behaviours that have genetic influences One study in the
Netherlands tested if a specific farming style had an effect on cannibalism. During the study they estimated the heredity of feather pecking to
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Certain genetic technologies such as linkage analysis could identify genes related to feather pecking and could be screened against to select birds that are less likely to engage in pecking. However, one study found a correlation between feather pecking and egg production and found that birds that
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Poultry have a gland called the preen gland that secretes an oily, salty tasting substance. When their diets lack salt, the gland produces the oily substances but without the salty taste. The bird then believes it is not getting its requirement from the gland and will peck at another bird's preen
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Feather eating is another potential cause to cannibalism. Feather eating is a behaviour similar to feather pecking where poultry will peck at other members of the flock to eat their feathers. In a study of F2 cross of hens for aggressive pecking behaviour it was seen that feather eating during a
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Poultry have a social hierarchy and when crowds are too close together, dominant birds will fight more often to obtain or sustain dominance which can increase risk of cannibalism. The increase crowd size also plays into a few more factors. With a larger crowd there is less space in the pen. This
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Pecking and feather pecking are normal behaviours, but cannibalism can be learned. Feather eating is also a normal behaviour that can lead the bird into engaging in feather pecking. As a chick during rearing engages in feather eating, they are more likely to engage in feather pecking during the
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is the most common method of preventing or reducing injuries by cannibalism. In a three-year study of floor-housed laying hens, death by cannibalism was reported as 7% in beak-trimmed birds but was increased to 18% in non-trimmed birds. This method can be considered cruel as it causes acute and
241:. The piercing method is illegal in the UK. It is theorized that — as with placing red filters over windows, or keeping the birds in red light — the coloured lenses prevent the birds from recognising the blood or raw flesh of other hens, thereby diminishing cannibalistic behaviour.
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chicks rearing stage of life meant it had a higher likelihood of feather pecking in the laying stage of its life. One reason they believed why feather eating was prevalent, is that keratin from feathers was not a nutritional source per se, but could enhance the gut microbiome.
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Rodenburg, T.B., Komen, H., Ellen, E.D., Uitdehaag, K.A., and van
Arendonk, J.A.M., (2008). Selection method and early-life history affect behavioural development, feather pecking and cannibalism in laying hens: A review. Applied Animal Behaviour Science, 110:
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Zimmerman, P.H., Lindberg, A.C., Pope, S.J., Glen, E., Bolhuis, J.E. and Nicol, C.J., (2006). The effect of stocking density, flock size and modified management on laying hen behaviour and welfare in a non-cage system. Applied Animal
Behaviour Science, 101:
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Nordquist, R.E., Heerkens, J.L.T., Rodenburg, T.B., Boks, S., Ellen, E.D. and van der Staay, F.J., (2011). Laying hens selected for low mortality: Behaviour in tests of fearfulness, anxiety and cognition. Applied Animal
Behaviour Science, 131:
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Lay Jr., D.C., Fulton, R.M., Hester, P.Y., Karcher, D.M., Kjaer, J.B., Mench, J.A., Mullens, B.A., Newberry, R.C., C.J., O'Sullivan, N.P. and Porter, R.E., (2011). Hen welfare in different housing systems. Poultry
Science, 90: 278-294
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Gunnarsson, S., Keeling, L.J. and
Svedberg, J., (1999). Effects of rearing factors on the prevalence of floor eggs, cloacal cannibalism and feather pecking in commercial flocks of loose housed laying hens. British Poultry Science, 40:
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Flock, D.K., Laughlin K.F. and
Bentley, J., (2005). Minimizing losses in poultry breeding and production: how breeding companies contribute to poultry welfare. World's Poultry Science Journal, 61: 227–237
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Appleby, M.C. and Hughes, B.O., (1991). Welfare of laying hens in cages and alternative systems: Environmental, physical and behavioural aspects. World's
Poultry Science Journal, 47:109-128
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When feeding, it is important to give enough space and to lay the feed to mimic the environmental conditions and spread the feed so poultry spend time pecking at the food and not each other.
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which has caused denuded areas and bleeding on a bird's skin. Cannibalism can cause large mortality rates within the flock and large decreases in production due to the stress it causes.
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Increased group sizes in larger cages or floor systems can elevate the risk of cannibalism and feather pecking, probably due to the spread of the behaviour through social learning.
643:
Gibson, S.W., Dun, P. and Hughes, B.O., (1988). The performance and behaviour of laying fowls in a covered strawyard system. Research and
Development in Agriculture, 5: 153-163
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Keeling, L.J., Hughes, B.O. and Dun, P., (1988). Performance of free range laying hens in a polythene house and their behaviour on range. Farm Building Progress, 94: 21-28
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Sherwin, C.M., Richards, G.J. and Nicol, C.J., (2010). Comparison of the welfare of layer hens in 4 housing systems in the UK. British Poultry Science, 51: 488-499
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While cannibalism of poultry is a learned behaviour, there is a genetic component that can make the bird be more susceptible to engaging or initiating cannibalism.
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High intensity light with prolonged exposure can lead to cannibalism of poultry in captivity due to the increase of stress and overheating that causes discomfort.
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is the act of one individual of a poultry species consuming all or part of another individual of the same species as food. It commonly occurs in flocks of
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Lights are sometimes provided in nest-boxes to attract hens to use the nests, but this practice has been correlated with an increased risk of cannibalism.
57:, sometimes called 'cloacal cannibalism', is considered to be a separate form of cannibalistic pecking as this occurs in well-feathered birds and only the
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A sibling-selection programme has genetically selected a low mortality line which shows decreased mortality from cannibalism compared to a control line.
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known methods of control to reduce cannibalism such as crowd size control, beak trimming, light manipulation, perches, selective genetics and eyewear.
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Rearing chicks with access to perches by four weeks of age has been associated with increased use of perches, and reduced cannibalism, in adulthood.
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Hill, J.A. (1986). Egg production in alternative systems - a review of recent research in the UK. Research and Development in Agriculture, 3: 13-18
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them to be attracted to the injured bird and peck at it more to increase their rank in the pecking order. Sometimes this even leads to their death.
49:. When pressure occurs within the flock, pecking can increase in aggression and escalate to cannibalism. Cannibalism can occur as a consequence of
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431:"Genetic parameters for feather pecking and aggressive behavior in a large F2-cross of laying hens using generalized linear mixed models"
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gland to meet their requirements. When the behaviour of pecking other birds is introduced, it can lead to increased risk of cannibalism.
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Bennewitz, J.; Bögelein, S.; Stratz, P.; Rodehutscord, M.; Piepho, H. P.; Kjaer, J. B.; Bessei, W. (2014-04-01).
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Savory, C.J., (1995). Feather pecking and cannibalism. World's Poultry Science Journal, 51: 215–219
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385:"Feather Pecking and Cannibalism in Small and Backyard Poultry Flocks – Small and backyard poultry"
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Koene, Paul (1997). "Cannibalism in Extensive Poultry Keeping: Interfacing Genetics and Welfare".
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Savory, J., (2010). Nutrition, feeding and drinking behaviour, and welfare. In
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Cannibalism may be reduced by fitting hens with a range of eyewear. Rose-tinted
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Codes of Recommendations for the Welfare of Livestock: Laying Hens
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Department of Environment, Food & Rural Affairs (July 2002).
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species. Poultry create a social order of dominance known as
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599:"10 Provocative Questions About Raising Chickens…Answered!"
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775:"Blinders Make A Spectacle For Chicken-hearted Collectors"
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Traditional Chinese medicines derived from the human body
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reared for egg production, although it can also occur in
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or contact lenses have been used. Opaque spectacles, or
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545:"Frequently asked questions about chickens & eggs"
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The Welfare of Domestic Fowl and Other Captive Birds
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547:. Ferry Landing Farm & Apiary. Archived from
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70:Poultry species which exhibit cannibalism are
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551:on 16 September 2008
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187:Light manipulations
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530:Ethology Group
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441:(4): 810–817.
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1785:Animal rights
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1609:Placentophagy
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1569:Autovampirism
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1399:
1398:Thomas Sebeok
1396:
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1388:Konrad Lorenz
1386:
1384:
1383:Julian Huxley
1381:
1379:
1378:Heini Hediger
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1307:Zoomusicology
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1240:Neuroethology
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1148:Anthrozoology
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987:Chick culling
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911:Pigeon breeds
909:
907:
904:
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901:Turkey breeds
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753:"Mutilations"
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580:. 26 May 2016
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300:Battery cages
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172:Beak-trimming
167:Beak-trimming
159:
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156:battery cages
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118:
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100:
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56:
52:
48:
47:pecking order
44:
40:
36:
32:
31:domestic hens
28:
20:
16:
1749:Vorarephilia
1691:
1656:The Americas
1492:
1485:
1478:
1471:
1464:
1423:E. O. Wilson
1373:Jane Goodall
1333:Donald Broom
1302:Zoosemiotics
1255:Sociobiology
997:Chicken coop
992:Chick sexing
976:
967:Battery cage
906:Goose breeds
863:Muscovy duck
778:
768:
759:
746:
736:
726:
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699:
688:. Retrieved
684:
675:
666:
657:
648:
639:
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607:. Retrieved
605:. 2010-09-11
602:
593:
582:. Retrieved
577:
553:. Retrieved
549:the original
538:
529:
498:
489:
481:
438:
434:
392:. Retrieved
388:
335:Vent pecking
278:
269:
260:
256:
248:
239:nasal septum
220:
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198:
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182:
170:
144:
135:
126:
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119:
115:
106:
98:
69:
55:Vent pecking
26:
25:
15:
1795:Bird health
1555:Cannibalism
1363:Dian Fossey
1328:Marc Bekoff
1316:Ethologists
962:Antibiotics
896:Duck breeds
555:14 November
330:Toe pecking
1769:Categories
1723:Literature
1706:In fiction
1685:In animals
1265:Structures
1260:Stereotypy
1037:Hock burns
1017:Free range
848:Guineafowl
690:2019-10-14
609:2019-10-27
584:2019-10-27
394:2019-11-17
341:References
179:Group size
148:free range
141:Prevalence
103:Crowd size
41:and other
1739:Man-eater
1643:In humans
1494:Behaviour
1437:Societies
1275:Honeycomb
1007:Debeaking
939:Scaly leg
868:Puna ibis
457:0032-5791
112:Nutrition
82:or young
72:omnivores
39:pheasants
1800:Ethology
1513:Category
1458:Journals
1285:Instinct
1235:Learning
1230:Instinct
1205:Ethogram
1188:Grooming
1111:Branches
1104:Ethology
1032:Hatchery
972:Blinders
921:Diseases
578:Engormix
465:24706957
325:Savaging
284:See also
231:circlips
227:blinders
1692:Poultry
1671:Oceania
1604:Oophagy
1599:Medical
1562:By type
1215:Feeding
1062:Yarding
934:Malaria
929:Fowlpox
833:Chicken
826:Species
819:Poultry
741:110-122
721:111–124
503:217-228
305:Chicken
266:Nurture
233:in the
223:glasses
211:Eyewear
195:Perches
80:lizards
76:insects
43:poultry
1697:Spider
1666:Europe
1651:Africa
1633:Sexual
1589:Filial
883:Breeds
873:Turkey
463:
455:
253:Nature
90:Causes
59:cloaca
1614:human
1579:Endo-
1574:Child
1292:Swarm
1220:Hover
1173:Breed
843:Goose
762:: 21.
756:(PDF)
731:12–18
235:nares
1718:Film
1676:List
1661:Asia
1626:list
1621:Self
1584:Exo-
1280:Nest
1270:Hive
838:Duck
557:2011
461:PMID
453:ISSN
84:mice
706:doi
443:doi
1771::
777:.
758:.
683:.
618:^
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576:.
565:^
508:^
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451:.
439:93
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348:^
158:.
37:,
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708::
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612:.
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559:.
532:.
467:.
445::
397:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
