News and Research

Birds: General, including behaviour



We've given you two headlines, the first (in blue) being the original, and the second (in red) aims to be a more informative headline, so you can gain an idea of what the article is about more quickly. The source is also given in case you want to track down the original article.

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Environmental Enrichments for a Group of Captive Macaws: Low Interaction Does Not Mean Low Behavioral Changes.

Macaws benefit from environmental enrichment, even if they spend little time with new toys

Source: Reimer J, Maia C.M., Santos E.F.
Journal Applied Animal Welfare Science. 2016 October-December;19(4):385-95. doi: 10.1080/10888705.2016.1175944. Epub 2016 May 2.

It is well-known that environmental enrichment can improve the lives of captive animals, though it is not always easy to assess what sort of enrichment (such as a toy or a food tree) works best. One way to measure the effect of an enrichment is how much time the captive animals spend using it, and another is to see whether there is any change in the animal’s behaviour after the enrichment was provided. The two can be linked to see if spending a lot of time on an enrichment brought a proportionate improvement in behaviour.

This study looked at 16 macaws which were given six environmental enrichments, one after the other. The way the group of macaws behaved was recorded both before they were given the enrichments, and during the time they had them. Every enrichment has an impact on how the macaws allocated their time to different activitities, such as foraging. The birds spent more time with some objects, like a food tree, and less time with others, like swings. However, the time spent on an object was not related to the effect on the macaws’ overall behavior. There were as many changes in behaviour from the swings, and other objects that the macaws didn’t use much as with objects they used a lot. This means that enrichments can affect behaviours in more complicated ways than was initially apparent. 


Delayed gratification: A grey parrot (Psittacus erithacus) will wait for a better reward 

African Grey parrots can show self-control and wait to obtain a better reward

Source: Koepke A.E, Gray S.L., Pepperberg I.M.
Journal of Comparative Psychology, Vol 129(4), Nov 2015, 339-346.

Delayed gratification means being able to wait to obtain a superior reward, rather than immediately taking an inferior reward. It’s seen as showing that an individual can think ahead, and use self-control, and it has been studied in humans, especially children, as well as non-human animals.

An experiment has shown that an African Grey parrot is capable of waiting to obtain a better reward for up to a quarter of an hour, in other words, the parrot had the capacity for delayed gratification. The bird was first taught how to use English, and then told to ‘wait’. The parrot was able to wait for rewards that it could see, as well as those hidden by the researchers. 


Do hens have friends?

Chickens do not appear to make friends even if kept in small groups

Source: S.M. Abeyesinghe, J.A. Drewe, L. Asher, C.M. Wathes, L.M. Collins. (2013) Do hens have friends?
Applied Animal Behaviour Science, Volume 143, Issue 1, Pages 61–66 January 15, 2013

People are interested in the extent to which ‘friendships’ can improve the welfare of farm animals , so this experiment looked at small groups of chickens to see if they were choosy about which individual chicken they spent time with. Eight pens with 15 pullets in each were observed for eight weeks. The hens were all 15-weeks-old at the start of the experiment, Hyline-brown domesticated layers, and had been reared in a floor system in a house containing 20,000 chickens. The focus was on what the pullets did during daytime activities, and how they roosted in the evening. Their behaviour was recorded by CCTV cameras, and analysed to see whether the hens spent more time together than would be likely by chance .

The pullets showed little aggression with one another, which may be because they were able to set up stable social groups as they acclimatized. They did not appear to be choosy about their companions, either in terms of where they went, or which chicken they were close to, nor were they particularly choosy about where they roosted. Most couple combinations never perched together at night. Some couples did apparently often perch together, and there was possible evidence of preferences for two couples in daytime location in one of the eight pens, though this may not be important given the low numbers. In general , it appears that hens are not choosy about their companions, either when they are active, or when they are resting, even when they are in a group that is small enough for them to get to know one another.

The behaviour of these pullets may have been affected by their having been raised in a large flock, since it may make sense to be socially tolerant of all other chickens in a large group, rather than focusing on individual companions. Chickens also learn social rules from their mothers. It is worth studying chickens raised by their mothers in small groups to see whether they behave differently, and to study the behaviour of the ancestor of chickens, the Red Junglefowl, to see whether the unimportance of friendship is a trait found in chickens’ ancestors.

Finches' tweets knock humans off their perch

Bengal finch songs may use grammatical rules

source: New Scientist vol 211 no 2819, July 2 2011 p16

Bengal finch songs may have grammatical rules, according to Kentaro Abe from Kyoto University, japan. Wild finches respond to unfamiliar songs by singing themselves. Abe collaborated with Dai Watanabe to develop jumbled finch song remixes, and play them to captive finches. They first played unfamiliar songs until the captive finches were used to them. They then developed four jumbled versions. The birds only responded to one jumbled version. This may mean that it failed to respect the syntax of finch song.

Drunk birds on a collision course

Cedar waxwings got drunk on fermented berries

source: New Scientist vol 214 no 2867, June 2nd 2012 p17

Cedar waxwings flew into Los Angeles buildings a number of times from 2005 to 2007. Haim Kinde and team from San Bernardino's California Animal Health and Food Safety Lab have discovered that the birds had eaten large amounts of Brazilian pepper tree berries. The waxwings use a distendible oesophagus to store food, rather than a crop. The berries had fermented, and the waxwings' livers were unable to process the alcohol, so the birds flew when they were dangerously drunk.

Bird brains rooted in baby dinosaur skulls

Bird skulls resemble those of juvenile dinosaurs

source: Michael Marshall
New Scientist vol 214 no 2867, June 2nd 2012 p12

The skulls of adult birds resemble those of juvenile dinosaurs, and birds evolved from feathered relatives of velociraptor-type dinosaurs. Bhart-Anjan Bhullar and team from Harvard University, studied bird, dinosaur and crocodile skulls, and discovered that adult birds have brain cases accounting for more of the total volume of the skull, like juvenile dinosaurs. Birds that retained a juvenile skull shape could have bigger brains. Large brains allow them to see better when they fly. Evolutionary changes often result from changes in development, for example, Adult humans resemble juvenile chimps.

Biological GPS located in pigeons

GPS neurons found in brains of homing pigeons

source: New Scientist vol 214 no 2863, May 5th 2012 p15

Two researchers from Baylor College, Houston, Texas, have recorded a biological GPS in the brainstem of seven homing pigeons. Le-Qing Wu and David Dickman used electrodes to record brain activity in the pigeons. They found that neurons in a part of the brainstem were especially active when the pigeons were in part of a magnetic field. The neurons are likely to be linked to an internal map in the brain, so operate as a sort of biological GPS.

Male bowerbirds grow a garden to attract a mate

Australian bowerbirds influence berry plant distribution

source: New Scientist vol 214 no 2862, April 28th 2012 p15

Australian bowerbirds use Solanum ellipticum berries to decorate their bowers, and the more berries they use, the better their chances of mating. Joan Madden and team from Exeter University, UK, have discovered that the number of S. ellipticum plants near the bowers increases in the year after a bower is built. The bowerbirds are not intentionally cultivating the plant, but they are unintentionally creating 'gardens' round their bowers.

Budgies find yawns irresistible too

Contagious yawning affects budgies

source: New Scientist vol 213 no 2847, January 14 2012 p14

Budgies are affected by contagious yawning, according to Andrew Gallup from Binghampton University, New York. He observed 21 budgies for 15 days, recording their yawns. Previously, contagious yawning had only been observed in primates. Budgies are more likely to copy neighbours yawning following a sudden loud noise, so yawning may help a group deal with a threat by enhancing coordination and group awareness.


Ravens use sticks to attract attention

Ravens initiate relationships with referential gestures

source: Linda Geddes

New Scientist vol 212 no 2841, December 3 2011 p16

Ravens initiate relationships with referential gestures, a trait also found in humans. Children, for example, may point to show another human where to look. This may be the foundation of language, and involves attributing mental states to another animal. Apes also communicate with humans through referential gestures. Simone Piha from Seewiesen's Max Planck Institute for Ornithology, Germany, with Thomas Bugnyar from Vienna University, Austria, observed seven wild raven pairs offering objects like twigs to one another, using their beaks. This involved non-food items, offered to opposite-sex ravens that were looking at them. Ravens are monogamous and raise offspring together, and couples can develop their own vocalisations. They are highly co-operative, and co-operation may have helped with language evolution. Further research is needed into the significance of this raven behaviour.


Of course I was listening, darling

Male birds listen to female partners

source: New Scientist vol 212, no 2838, November 12 2011 p20

Male plain-tailed wrens from Ecuador appear to listen to female partners in a duet more than the females listen to them. The wrens were studied by Eric Fortune from John Hopkins University, Baltimore, Maryland. He studied six captured birds, three of each sex, previously recorded in duets. He anaesthetised the birds, and placed a wire in their high vocal centres (HVCs), involved in birdsong and learning. The males' HVCs were more active while listening to female partners singing, while the females' HVCs were more active while listening to their own songs.

Crow mob rules

Crows can learn from one another

source: New Scientist vol 211 no 2819, July 2 2011 p5

Crows may copy the behaviour of parents and neighbours. They have been observed harassing a human because that human was harassed by other crows.

Parrots join apes and Aristotle in the club of reason

African grey parrots are capable of logical reasoning

source: New Scientist vol 210 no 2818, June 25 2011 p16

African grey parrots are capable of logical reasoning to calculate where they might find food. Sandra Mikolasch and team from the Konrad Lorenz Research Station, Vienna University, Austria, studied seven African greys. They liked both walnuts and seeds. The researchers hid a walnut under one cup, and seeds under another, while the parrots were watching. They then hid the cups and removed a treat, and showed the treat to the parrots. One parrot achieved a 75% success rate in guessing which treat must remain, and where it was, inferring through excluding. The other parrots fared better when they could always see the treats.

Genes explain why some female zebra finches cheat

Promiscuous male zebra finches tend to sire promiscuous females

source: New Scientist vol 210 no 2817, June 18 2011 p21

Zebra finches are monogamous, and may have extra-marital affairs. Males with this tendency tend to sire promiscuous females, according to research by Wolfgang Forstmeier from Seewiesen's Max Planck Institute for Ornithology, Germany. He studied over 1,500 females over five generations. Promiscuous males were found to have more offspring. Their daughters inherited their promiscuous traits, despite this bringing no discernible advantages for females.

Angry birds kiss and make up after a brawl

Captive ravens use touch for reconciliation after squabbles

source: New Scientist vol 210 no 2807, April 9 2011 p18

Captive ravens often squabble, chasing and kicking one another. Afterwards they use touch for reconciliation, when they have fought with an ally. Orliath Fraser from Vienna University, Austria, studied seven captive ravens, and found they were more likely to touch one another with their beaks, or preen one another if they had just fought. Reconciliation is found in mammals, but this is the first recorded observation in birds.

Great tits choose food over sex

Great tits delay morning song when given bird feeders

source: New Scientist vol 209 no 2794, January 8 2011 p15

Great tits delay morning song when provided with feeders. Valentin Amrhein from Basel University, Switzerland, studied great tits in a forest near Oslo, Norway. He taped birds singing the dawn chorus after two weeks with a feeder, comparing this with the singing of birds not provided with feeders. Birds with feeders started singing on average twenty minutes later. Male birdsong is believed to attract and defend a mate. Males with feeders may be too busy defending food to sing for females. Amrhein favours removing bird feeders during the spring. Females choose males on the basis of their songs, so changes in singing behaviour triggered by feeders could adversely affect great tits.

Urge to migrate found in bird genes

Genetic basis for black cap migration

source: Janelle Weaver New Scientist vol 209 no 2800, February 19 2011 p9

Bird migration appears to have a genetic basis, according to Jakob Mueller from the Max Planck Institute for Ornithology at Starnberg, Germany. He and his team studied European black caps (Sylvia atricapilla) recording restlessness at night in captive birds. They are generally only nocturnal when migrating. One gene was linked to this restlessness, and to melatonin secretion, feeding and energy metabolism.

Warm climates boost bird beak size

Birds have smaller beaks in colder climates

source: New Scientist vol 206 no 2767, 3 July 2010 p17

Beak size can be affected by diet, and size may help a bird attract a mate. It is also affected by climate, according to researchers from Ontario, Canada, and Melbourne, Australia. Glen Tattershall and Matthew Symonds have investigated 214 species of birds, relating female beak size to minimum annual temperatures. They calculate that 16% of variations in beak size can be accounted for by temperature, with colder climates associated with smaller bills that reduce heat loss.

Klepto keas crack locks, no problem

Kea parrots plan problem solving

source: New Scientist vol 207 no 2773, 14 August 2010 p18

Hiromitsu Miyata, from Japan's Kyoto University, has found that Kea parrots can solve problems better if they study beforehand. He offered the Keas three boxes containing food. The parrots had to unlock bolts to obtain the food, and managed this even when the bolt systems were very complex. However, they opened the containers faster if they could look at the problem and assess it beforehand. This means that they can probably plan problem solving, rather then attempting haphazard solutions.

Babble to tweet

Babbling helps zebra finches learn to sing

New Scientist vol 198 no 2655,
May 10 2008 p17

Babbling helps zebra finches learn to sing, and helps young finches to try out acoustic ranges. The part of the brain involved in babbling is different from the part that controls mouth muscles used by birds when they sing. Massachussets Institute of Technology's Michale Fee led a team which has discovered that birds lacking the part in their brains controlling mouth muscles do not sing, but babble.

A rousing chorus gets zebra finches in the mood

Hearing songs encourages zebra finches to breed

source: New Scientist vol 185 no 2488
February 26 2005 p20

A team led by Joseph Waas, now at Waikato University, New Zealand, has discovered that male zebra finches are encouraged to sing by hearing recorded songs of other zebra finches, and females' clutches of eggs were larger than if they were not played songs. Females also laid clutches earlier if they heard recordings of unfamiliar males. This may be because the females are seeking to catch up with breeding as they would in a zebra finch colony. Breeding in a large group can give protection against predators. This finding could help with encouraging breeding of some rarer species of birds, which may also be encouraged by recorded songs.

Survival of the fattest

Feeding garden birds

source: Mike Clark
Country Smallholding January 2004 p39

Garden birds can be helped to survive by feeding them during winter months, starting in November, as food elsewhere becomes scarce. The birds can come to depend on food you put out, so they need feeding until April, and can benefit from food put out all year.

Birds' needs increase during very harsh weather, so it helps to put food out twice a day, in the morning and early in the afternoon. The quantity needed depends on what the birds eat, and they are being fed too much if excess food accumulates. Some foods, like bread, fat, and peanuts, can harm baby birds, so it's best to avoid them in spring and summer. It is better to feed good quality bird food than scraps, though some home-prepared food is well-received, like unsalted, cooked rice, pastry, cut up fresh and dried fruits, and also fat outside the breeding season.

Some birds like to feed on the ground, while others cling to feeders, and both types of bird will use bird tables, which offer some safety from cats. The table is best placed on open ground, since birds prefer an open site, but near cover for them to escape in case of danger.

Mesh nut feeders are essential containers for peanuts, since many bird species can be killed if they eat whole peanuts. Mesh bags can be dangerous since birds' feet and legs can get caught in them. The feeders should be cleaned regularly, and the food kept fresh, to reduce risks of spreading disease. Birds also benefit from a dish of water that is changed regularly, or access to an unfrozen pond.

Feather-plucking in psittacine birds: part1, Presentation and medical investigation

Investigating cases of feather plucking in the parrot family

source: John Chitty
In Practice vol 25 no 8, September 2003
starts p484, 10 pages long

Feather plucking is a common syndrome common among many birds from the parrot family, especially grey parrots and Hahn's macaws, though very rare among budgerigars. There may be more than one cause, so it is important to identify as many causes as possible. Investigation can be time-consuming, and should include time spent viewing the bird, and examining droppings. History forms asking for information on the bird's diet, environment, daily regime, and other factors, are useful. A physical examination follows a thorough history, and includes assessing whether the bird is extroverted, how it interacts with the owner, as well as a dermatological examination. The article discusses diagnosis in further detail.

Feather-plucking in psittacine birds: part 2, Social, environmental and behavioural considerations

Social and behavioural factors linked to feather plucking in the parrot family

source: John Chitty
In Practice vol 25 no 9, October 2003
starts p550, 6 pages long

Most cases of feather plucking in birds from the parrot family have more than one cause, so using one therapy alone may not bring about a cure. It is usually important to assess the whole of the bird's lifestyle to work out whether there are non-medical factors involved. It helps to look at how parrots live in the wild to understand the needs of pet birds. Wild parrots live in flocks, and bond in pairs and family groups within those flocks. They may defend specific locations, such as nest sites, though they are not generally territorial. They are prey species that forage during the day, then roost. They seem to have to learn how to preen, though the need for preening seems to be innate.

Feather plucking may have social causes, such as poor socialisation in hand-reared birds, which may leave them anxious and lacking curiosity, and lacking the skills to preen. Birds that pluck because they have not learnt to preen can learn from other birds. Pet birds may also be overtired, especially if kept in a family living room, and may benefit from peace and quiet in a spare room in the evening. Birds also need to be bathed or sprayed, using warm water with nothing added, and they can be taught to enjoy it if they initially appear to dislike it. The cage should not be exposed or near irritants like cooking fumes. Poor wing clipping can also trigger plucking, and it is better not to clip birds' wings except when absolutely necessary.

Behavioural causes include attention seeking, so owners should walk away, and pay attention to the bird when the plucking stops. Separation anxiety has also been linked to plucking, if it happens when birds are left alone. Birds benefit from exercise before being left, and from being able to listen to a radio while the owner is out. They may feel anxious with an owner in the house, but not in the same room, so moving the bird to be in the same room as the owner can help. A parrot sitter may also help, if the bird is left alone for a long time. Encouraging independent play also has beneficial effects. Rehoming may be necessary if no other solution can be found, since flock birds may not be happy if kept alone, and buying a companion bird as a solution is not usually successful.

Drug therapy may help, but finding the right drug at the correct dosage is not easy, and drug therapy alone is unlikely to effect a cure. The article examines causes of feather plucking related to lifestyle in further detail.

Birds that sing complex songs give clue to origins of human syntax

Brain and language studied in song birds

source: Independent February 17 2003 p9

Researchers from Duke University, North Carolina, have discovered key locations in the brains of songbirds, humming birds and parrots, which allow them to develop and remember songs and other complex sound sequences. Only a few types of birds and mammals are able to learn sounds in this way. Cetaceans, bats and humans are the mammals with these skills, and understanding the link between brain and behaviour in birds may help in understanding how syntax, or rules of human language, came about. Glutamate receptors in the cerebrum of birds help transmit nerve impulses, and help to develop new neural connections in birds learning new songs. Hummingbirds can remember very complex songs, though their brains are very small. They defend territory and use songs in courtship, with more complex songs proving more attractive. Surgeons operating on humans could usefully improve their knowledge if similar areas can be located in humans.

Bird brains offer clues to origins of speech

Research on songbirds could help in understanding origins of human speech

source: Tim Radford
Guardian February 17 2003 p16

Erich Jarvis, a neurobiologist from Duke University, North Carolina, has studied the brain structure of songbirds. Songbirds, hummingbirds, and some parrots can continue to learn new sounds, and arrange them using syntax. These birds share brain patterns with receptors for glutamate, a neurotransmitter, in seven locations. This research could help in understanding why human victims of stroke may suffer language deficiencies, and it may help in discovering human brain systems for learning language. Birds attract mates and defend territories through song. Complex songs prove more attractive to the opposite sex, yet predators may also be attracted, so captive birds may be able to develop more complex songs than wild birds.

Any colour you like

Pigmentation in wild and captive birds

source: Tim Birkhead
Independent Review February 10 2003 p12

Humans have long sought to change the colour of birds, from when they were initially domesticated. Pigeons and geese were the first to be domesticated, some 5,000 years ago, followed by chickens. Birds might appear that lacked pigments. Colours might be changed through mutations, or through long-term gradual change. Yellow canaries were gradually developed, and full yellows were recorded by 1700. There are some 30 colours variations for budgies, which are green in the wild. Zebra finches have also been bred with different colour variations.

Dyeing birds was once common, whether by dyeing feathers externally, or by feeding birds such as canaries red peppers when the birds were moulting. Carotenoids can affect the plumage of wild birds, and are found in shrimps and other foods. Captive birds deprived of carotenoids they would eat in the wild can lose their bright colour. A bright red colour may signal good health in some species, especially in a male bird, and females of these species prefer redder males.

In the genes

Study finds that boldness in great tits is inherited

source: New Scientist no 2372, December 7 2002 p27

Dutch researchers have found that boldness in great tits is inherited. The researchers, from the Netherlands Institute of Ecology, Heteren, Holland, rated birds according to how bold they were in investigating novel objects. They used a scale of 1 to 20 in rating the birds. They then matched the boldest birds together, and the shyest birds, and used foster parents to raise the offspring. The bolder birds' descendents were rated nine points higher than the descendents of thes shyer birds, after four generations had been bred.

Look, no hands

New Caledonian crows can use and make tools

source: Stephanie Pain
New Scientist August 17 2002
starts p44, 4 pages long

A species of crow, called Corvus moneduloides, from New Caledonia in the South Pacific, is able to use and make tools to obtain food in ways that show greater understanding of function and form than chimps. This speciesof crow needs to use tools to obtain food. They use sticks to flush out prey, and may make probes themselves from large leaves, bamboo stems, and other materials. They may also use sticks to fish for grubs - the grubs grab the end of the stick. Crows also make and use hooks, from different materials. The hooks are made with the same design. The birds may learn from each other how to make these hooks. One crow, called Betty, was able to fasjion hooks from novel materials.

One characteristic of these crows is laterality, thought to help the brain work more efficiently. Humans are strongly right-handed, and New Caledonian crows also have this characteristic. Humans and crows are also both social animals, and opportunists as well as generalists when it comes to food. Crows and humans may also have had to make behavioural changes to offset physical shortcomings.

They can run but they can't hide, and that's bad news for growing chicks

Chicks raised in featureless cages may fail to develop key skills

source: Betsy Mason
New Scientist no 2354, August 3 2002 p18

Wire cages for battery hens are to be banned in the European Union (EU), but replacing them with featureless pens could hamper the development of chicks. The new EU directive sets out a maximum per square metre of nine birds. Ralph Freire, a researcher from Purdue University, Indiana, has found that chicks raised in featureless pens tend to crowd, and can even suffocate, as well as become aggressive and suffer malnutrition. Chicks normally starts to leave their mothers at the age of 11-days-old, and being separated from their mothers, with mother and chicks unable to see each other, seems to help chicks to understand space. Freire imprinted chicks using a tennis ball, and tested whether they could find the ball when it was hidden behind a screen. Birds that had grown up in pens with barriers tried searching behind a screen. Chicks raised in featureless pens did not attempt to locate the ball. Meanwhile, ethologist, Linda Keeling, working in Sweden, has also found that chicks need to learn to perch while they are young, or it is very difficult for them to learn later.

Flight of the ring-necked parakeets

Ring-necked parakeets colonise suburban parks

source: Sharon Amos
Independent on Sunday Review February 23 2003 p27

The London Bird Project is run by the British Trust for Ornithology, and monitors birds in London's public spaces. Howard Vaughan, from the project, has counted 1,750 ring-necked parakeets in a cemetery in South London. The birds roost in poplars at the cemetery, but appear to nest in another location. They use holes to nest in, and prefer old holes that woodpeckers have left. They can be seen in Windsor Great Park, and Virginia Water during the daytime, and at feeders in gardens. There are many parrots in Richmond, as well as colonies in Surrey and Kent. Ring-necked parakeets can be bought as pets for some 100 pounds sterling. The feral parakeets have been seen since the 1960s, and there are an estimated 4,300 in the UK, according to the RSPB. Other feral parrots have been noted in the UK, but ring-necked parakeets are the most common.

Good food boosts finches' sex appeal

Male zebra finches prefer well-nourished females

source: Michael Brooke
New Scientist no 2049 September 28 1996 p21

Researchers from Glasgow University have discovered that male zebra finches prefer females that have been fed a protein supplement, to those that have not. The researchers took a captive group of female zebra finches, and split them into two groups, feeding one group on just millet, while the other group received hen's egg supplement as well as millet. The males tended to choose the females which had eaten the supplement. Previous work at the university showed that females given the protein supplement tend to lay larger egg clutches, which are also more viable. It is not known how the males could distinguish between the two groups of females.

Aggressive birds

Tackling aggressive feather pecking in chickens

source: Katie Thear
Country Smallholding December 2003 p11

One poultry keeper has had problems of aggressive pecking in a small mixed flock, with Silkies, Leghorns, and Rhode Island Reds. The victims are Silkies and a Leghorn. Aggressive pecking can cause death, and lead to cannibalism, so should be controlled. Hens can also copy each other, so early intervention is important. Keepers should watch their birds to work out which are aggressors, and isolate them in a location where the other birds can still see them. If the aggressors are kept out of sight, the others may attack them when they are put back in the flock. Temporary isolation may work on its own, but other factors may also have to be assessed.

Smaller birds in mixed flocks are more likely to be targets, especially if they are of different ages and colours, with different sorts of feathers. Keeping birds together from when they are very young can help, if keepers really want a mixed flock. Birds also need space to wander around, eat and drink, since overcrowding at drinkers, feeders, nest boxes, and in their free space, is linked to aggression. Birds that suffer dietary deficiencies may also be more prone to pecking, as can birds exposed to excess light. Making a chicken house a little darker may help, though if it is too dark, this could hit egg production. Ventilation and access to clean, cold water are important, since birds that suffer from too much heat may peck. Birds may also peck themselves if they have parasites, such as lice, and this could encourage other birds to peck them. Birds in moult may also become targets. There are also some breeds that are a little wilder than others, though this is less true for many modern breeds, bred especially for docility.

Pecking order

Contribution of early bird breeders to ornithology

source: Tim Radford Guardian
August 23 2002 p9

Tim Birkhead, an animal behaviour professor from Sheffield University, England, has been awarded a three-year grant by the Leverhulme Trust to study the contribution of early European bird breeders to ornithology. This topic has tended to be neglected in the UK, since attitudes to keeping birds tend to be negative, yet contributions from amateur breeders have been very important for conservation and breeding programmes to help endangered species such as many parrots. Goldfinches were especially valued during the Middle Ages, and chaffinches were popular cage birds. Birds were caught in the Middle Ages because they looked good, sang well, or were good to eat, Birkhead notes.

How much water for ducks?

Different types of ducks have different needs for water

source: Katie Thear
Country Smallholding July 2002 p15

Ducks vary in terms of how they use water, and this affects how much water they need. All ducks need some access to water. Some are perchers, others are divers, and then there are dabblers.

Perchers include those from the Cairini family, which like to perch in trees, and they include Muscovy ducks, Mandarins, and Carolinas. They need water depths of between 2.5 ft and 3 ft, or 75cm to 90 cm, and like to nest some way above ground, for example in nest boxes which use long ramps.

The Aythyini family of ducks are the divers, and they seek their food on the bottom. They usually have shorter bodies, and legs further back, a body design that helps them dive. Tufted ducks and Pochards come from this family. They like a minimum of 3ft of water (90 cm).

Dabblers include Mallards and others from the Anas family, and they dabble to find their food on the water surface. They should have at least a foot of water, so as to be able to immerse themselves and tip themselves up-ended.

Argentinian parrots invade Madrid

Freed parrots become a public hazard in Madrid

source: Elizabeth Nash
Independent June 18 2002 p10

Pet parrots freed by owners in Madrid, Spain are becoming a public hazard. The parrots are from the species Myiopsitta monachus, and have strong bills, long tail feathers, and are grey and green. They come from Argentina, where they are seen as pests. There are colonies of the parrots in Canillejas, close to the airport, and in a park west of Madrid called the Casa del Campo. There is concern that native wild birds are being displaced.

No dodo

New Zealand programme to save endangered kakapo parrots

source: Stephanie Pain
New Scientist June 1 2002
starts p 32, 6 pages long

New Zealand's National Kakapo Team is encouraged by the hatching of 26 kakapo chicks in 2002. Kakapos are large parrots, and there were fears that they could become extinct when their numbers dropped to 50 in 1995. These parrots are nocturnal and cannot fly, though they excel at climbing. The sounds they make are varied and include booms and growls. They are the largest parrots known, with some males weighing over 2.5 kg, and they may live to over 100-years-old.

Humans, and animals such as cats and dogs introduced by humans, led to a sharp drop in the population of Kakapos, which were thought to be extinct by the end of the 1960s. Then the birds were discovered in some remote locations, and moved to Maud and Codfish islands where they would be safer, with watches ket over their nests. Extra food was provided, but the birds on Codfish island waited until rimu trees had masted before breeding. This signal to breed led to matings, with 20 females laying eggs in 2002, including some very old females. Eggs were swapped from fertile birds and put into the nests of birds with infertile eggs, to encourage birds with fertile eggs to produce more.

The trigger from the rimu tree is not well understood, and it is possible that a chemical is involved which could be isolated to encourage more breeding. There are also plans to extend the programme to a third island.

Sing out sister

Oestrogen can affect reproduction in zebra finches and other birds

source: Anil Ananthaswarmy
New Scientist March 30 2002 p8

Researchers from the University of California in Davis have found that female hatchling zebra finches given oestradiol, an oestrogen, at doses found in the wild sang more than control female birds, and the region in their brains that specializes in singing was larger. They also laid fewer eggs, and the eggs they laid had more brittle shells. Oestradiol is used in some HRT preparations. US waterways are contaminated with oestrogen pollutants from HRT, birth control tablets, and some pesticides can form oestrogens, when they break down. These findings have led to concerns about the impact of oestrogen pollutants on wild birds, especially song birds.

Your cheating heart

Female faithfulness linked to male singing ability in chickadees

source: New Scientist May 11 2002 p27

A researcher from Queen’s University, Ontario, has found that female chickadees, which are usually monogamous, appear more likely to be promiscuous if their mates lose song contests. The researcher played song recordings to chickadees, so it appeared that another male was competing with the resident male. If the recording was played in an aggressive way, with the timing and pitch matching those of the resident male, the resident was less likely to be the father of chicks born to his partner.

The hole story

How to turn gravel pits into havens for birds

source: Adrian Thomas
Bird watching April 2002
starts p6, 6 pages long

There are some 1,000 gravel pits in production in the UK, and some provide attractive locations for birds, while others are empty. A number of features can help turn pits into attractive habitats. Wavy shorelines with shallow water at the edge help attract birds, and islands can provide nesting sites. Wildfowl like cover, so topsoil on the islands helps to provide this. Plovers and terns like bare ground for nesting, and gravel placed on plastic sheeting helps to attract them. Trees can also be planted to provide shelter-belts. Gravel pits also need care over the long term to continue to attract all types of birds, and this involves cutting reeds, controlling willows, and managing fish stocks.

Gravel pits are increasingly important as bird habitats, and some birds, like Smew, have developed strong links with pits. They have helped sustain numbers of Great Crested Grebes, Tufted Ducks, Pochards, Yellow Wagtails and Lapwings, and many other species. There is great potential for this habitat, as is shown by developments at the Cotswold Water Park, where there are over 110 pits.

Now birds brag by mimicking mobiles

Birds imitate mobile phone sounds

source: Chris Gray
Independent May 18 2001 p5

Some wild birds in Britain have started to imitate the sound of mobile phones ringing. This has been most often observed in starlings, which are related to mynah birds, and song thrushes, with some observations of marsh warblers and blackbirds mimicking ring tones.

The penchant of some birds for imitating whistles, car brakes, and other man-made sounds has been noted by Royal Society for the Protection of Birds’ Mike Everett. He notes that mimickry accounts for some 10% of the song of a starling. Male birds can defend territory better, and more easily find mates if their songs are varied, according to Everett. He sees this development as possibly beneficial for birds, since it could help to encourage breeding. Starlings have suffered a population drop of some 50%.

Talk the squawk

History of human fascination with the parrot family’s ability to talk

source: David Alderton
Guardian, Weekend April 6 2002 p107

Humans have long been fascinated by the parrot family’s ability to talk. There were mentions of this ability by ancient Persians, over 2,500 years ago, and parrots were later taken to Greece from India by the armies of Alexander the Great, in 4th C BC. Romans used precious materials like tortoiseshell and silver in making parrots’ cages, and instructed slaves to teach the parrots to talk. Henry VIII and Queen Victoria both kept African Greys, while George V was the Budgerigar Society’s first patron, and Elizabeth II has a budgie aviary.
African Greys and budgies are especially popular due to their ability to talk, though teachers’ abilities are important as well as those of the birds. Sparkie Williams was a famous budgie who learnt 583 words, and won a BBC talking bird competition in 1958. Prudie was an African Grey who won the National Exhibition of Cage and Aviary Birds award for Top Talking Bird, for 13 consecutive years until 1977.

It is unclear how far talking birds understand what they say, though research on an African Grey called Alex, in the US, carried out by Professor Pepperberg, suggests that he can take decisions and rationalize, using language. Alex can request objects, and will turn down those objects presented to him that he has not requested.

Fly by the stars

Songbirds use the stars to navigate

source: Hazel Muir
New Scientist February 9 2002 p16

Researchers from Odense University in Denmark have found that songbirds use the stars to navigate. They used 20 blackcaps and 34 pied flycatchers, and took them to a planetarium in Aarhus. Migratory songbirds which travel during the night have a habit of jumping in their cages towards the direction that they usually migrate in. The birds were first placed under a simulation of the sky they would see in Aarhus, using the Pole star’s true direction as a pivot for the rotation of the stars, and the birds jumped in the direction of their normal route, which was south-south westerly. The stars were then turned around towards the south, and the birds responded by changing their jumping direction to north east, so they do find north from the stars. The birds jumped south if no rotation was shown, however, so they may locate the Pole star from patterns that are formed by the stars, not by the rotation of the stars. The birds did not appear to be able to use the stars to judge longitude.

Ruffled feathers

Harris hawks brought in to protect schoolchildren from seagulls

source: Independent on Sunday April 21 2002 p12

Two Harris hawks have been brought in by a school in Ayreshire, Scotland, to protect children who were being attacked by seagulls taking the children’s food away from them in the playground.

What really makes the caged bird sing?

History of the study of songbirds’ abilities, and their origins

source: Tim Birkhead
Independent, Review November 30 2001 p8

Bird keeping reached a peak of popularity in the 19th century, and has since declined, though it is interesting to a zoologist. Birds were initially caught for food, or for their song. Nightingales were the most popular songbirds, but then canaries appeared during the late 1400s in continental Europe. Canaries came to be more popular than nightingales, because canaries are easier to keep, and sing throughout the year, while nightingales only sing a few weeks annually.

German breeders pioneered new breeds, such as rolling canaries, with superb singing abilities and rolling songs. There are now some 70 canary breeds. Baron von Pernau was a German scientist who lived from 1660 to 1731, and he realised that canary song was learnt, rather than hard-wired. An eighteenth century English scientist, Daines Barrington, ranked songbirds for their song quality, placing nightingales first, and linnets second. Canaries were not classified in this study but were later placed second. Barrington also had a surgeon dissect birds, and found that well-developed larynxes tended to be associated with the best songs. He found that nightingales had strong larynxes, and males had some muscles that were stronger than those of hens.

Birds’ larynxes are now called srinxes, and modern research has found that males have a larger area in the brain which is linked to song. This area is called the higher vocal centre (HVC). Birds with more complex songs also tend to have larger HVCs. Research on the brains of songbirds carried out in New York, by Rockefeller University’s Fernando Nottebohm has changed ideas about how the brain works. Female canaries given testosterone grow new neurones, and sing as though they were males. He also discovered that the HVC grows and degenerates following seasonal patterns which are linked to seasonal changes in birdsong. This finding runs counter to accepted wisdom that the brain cannot regenerate neurones, and is significant for medical research for humans with brain diseases.

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Domestication effects on foraging strategy, social behaviour and different fear responses: a comparison between the red junglefowl (Gallus gallus) and a modern layer strain

Leghorns conserve their energy for feeding

source: Karin E. Schutz, Bjorn Forkman and Per Jensen
Applied Animal Behaviour Science vol 74 no 1, 2001
starts p 1, 14 pages long

Animals can change in appearance and behaviour as a result of domestication, because their lives are easier, and humans may select for certain traits. Selecting for a particular trait may also affect other traits. Resource allocation theory argues that animals geared for high production (putting on weight, or producing offspring) will spend less time on non-feeding activities. Red junglefowl are found in the wild, and domestic fowl appear to have descended from them, so they can be used as an example of ‘wild’ fowl in research on domestication. Junglefowl from a Swedish zoo were compared with White Leghorn layers in this study. The Leghorns have been bred as layers and to convert food efficiently. The birds were reared under the same conditions, and tested as pairs, since they were calmer than when tested alone.

The White Leghorns were found to conserve energy in different tests. They preferred familiar food, while the junglefowl preferred novel food, though that meant taking longer to eat the same amount. The Leghorns were generally less active, and responded less to frightening stimuli. Some animals, including domestic fowls, have been found to prefer looking for food rather than eating food that is easily available. This may be because looking for food can give animals information about where food can be found. Broilers tend to forage less and be generally less active than layers, according to some studies, and it has also been found that high efficiency of food conversion is linked to lower levels of aggression and activity.

Aggressive behaviour and social activity may be less necessary for domestic animals, since they do not need to compete for food as much as wild animals. However, high ranking domestic chickens can still gain advantages like better roosts. Male Leghorns in this study crowed more when seeking food, displayed more to females, and were more aggressive with humans, when being handled, compared with junglefowl. This male Leghorn aggression could be linked to layers being selected in terms of reproductive success. Junglefowl, however, were generally more vocal in the study, which could mean that their social motivation was higher than that of the Leghorns.

The Leghorns reacted less to a model of a hawk above them, than did the junglefowls. This lower level of reactivity to predators has been found in other domestic species compared with wild counterparts, such as ducks and trout.

Parrot with a well ordered approach

Parrot learns to order objects

source: Tim Radford
Guardian February 15 2002 p12

An African Grey parrot called Griffin has learnt to order objects, according to Massachussetts Institute of Technology researcher, Irene Pepperberg. He understands that some tasks have to be carried out in a particular order, and his behaviour can thus be called ‘rule governed’. Griffin has learnt to combine objects using particular orders. Only monkeys and apes were thought to be able to exhibit physical and vocal combinatorial behaviour, before this discovery, and Pepperberg argues that similar abilities many have gone unnoticed in other vertebrates. Social animals are seen as more likely to be able to reason, researchers argue, in order to deal with one another.

Darling, you look positively fluorescent today

Budgies fluoresce to appear more sexually attractive

source: New Scientist January 12 2002 p22

A team from the University of Queensland, Australia, has carried out research on budgies which shows that fluorescent pigments can be used as a way of signalling sexual attractiveness. The budgies’ yellow cheek and crown feathers were smeared with UV-block to dampen fluorescence, without altering colour. Control birds just had petroleum jelly smeared on them, and this is not a UV light blocker. Female and male budgies were found to prefer mates with a fluorescent glow. This research was reported in Science, vol 295, p92.

Go for the glow

Birds prefer fruit that reflects UV light

source: Anil Anathaswamy
New Scientist October 20 2001 p20

Researchers from Purdue University, Indiana, US, have found that birds prefer fruit that reflects UV light. The team studied 57 types of fruit found on an island in Panama. Unripe fruit doesn’t reflect UV light. The researchers used UV-absorbing filters above a plant, and found that birds tended to avoid fruit that did not have UV light reaching it, focusing on fruit receiving UV light. Birds may perceive colours with more dimensions than humans do. This research was reported in Evolutionary Ecology Research, vol 3 p767.

Sick as a parrot

Illegal poaching threatens some parrot species with extinction

source: Scott Norris
New Scientist June 9 2001 p7

Around a third of parrot species from neotropical regions are in danger of extinction, and poaching could be as serious as habitat loss in causing bird populations to decline. Biologists from the Universities of Maryland and California have analysed data from 23 parrot nesting studies carried out over two decades. Poachers destroyed 30% of nests overall, rising to over 70% for four species, such as the Yellow-crowned Amazon. Larger and more valuable parrot species are more at risk from poachers.

A report is also due to come out in 2002 on legal international trade in parrots, which Convention on International Trade in Endangered Species regulates. There were 1.2 million parrots legally exported between 1991 and 1996, mostly coming from South and Central America. The US Wild Bird Conservation Act prohibits imports of birds which are listed by CITES, but Asia and Europe do no have such laws, and have grown to be the largest markets for these birds. The legal trade may foster illegal imports.

World Parrot Trust director, Mike Reynolds, from the UK, sees the new research as useful in a campaign to tighten European restrictions on endangered parrot imports. American Federation of Aviculture president, Benny Gallaway, however, sees sustainable harvests as preferable, and he argues that the threat from poaching has been exaggerated. This research has been reported in Conservation Biology, vol 15, p1.

Flutter stutter

Research on zebra finches reveals that they can stutter

source: Matt Walker
New Scientist October 23 1999 p23

Zebra finches may repeat syllables of song a number of times before continuing with their songs, in a bird equivalent of stuttering. David Rosenfield, neurologist from Baylor College of Medicine, Houston, Texas, and his colleagues have recorded zebra finch songs and analyzed them digitally. Zebra finches may change their songs by altering syllables, deleting them, or inserting new syllables. There were some 7 per cent of the birds which stuttered regularly, and none had stuttering parents. This finding could help in understanding and treating stuttering in humans.

The call of the wild

Research on ability of zebra finches to detect pitch

source: New Scientist December 4 1999 p41

Zebra finches were studied by Ron Weisman from Canada's Queen's University, Ontario, and their ability to detect pitch was tested against that of human musicians. The birds were rewarded with food, and the humans were rewarded with prize money, when they got the answer right. The birds' score was 85% correct answers, compared to the human musicians' score of around a half. Zebra finches can recognise each other by song pitch range, and are able to identify their mates' songs at 100 yards. Humans with absolute pitch, and birds are both often able to change to relative pitch. Birds are trained in pitch while they are youngsters, listening to neighbours and family.

Listening to Alex

Vocalisation abilities of parrots

source: Gail Vines
based on interview with Irene Pepperberg, researcher from University of Arizona
New Scientist January 15 2000
starts p40, 4 pages long

Parrots are able to vocalise and recognise objects by shape and colour. They are unable to learn from videos. They can imitate inanimate objects, like microwaves, in captivity, though they do not do this in the wild. Microwaves may seem significant for captive birds, since they are related to food.

Alex, a grey parrot, tells his owner he wants to be on her shoulder if he is put elsewhere, so he is aware of the meaning of the language he uses. Alex does not appear to use words creatively, though he has said 'banerry' for apple, which may mean a fruit like a banana and a cherry. He may expect trainers to provide new words for new objects he is provided with. Parrots can live to be 60-years-old, and Alex is 23-years-old.

Give that bird a mouse

Biologist tries to develop web browser for parrots

source: Graham Lawton
New Scientist July 8 2000
starts p28, 2 pages long

Irene Pepperberg is a biologist from the University of Arizona who owns an African Grey parrot called Arthur. She is a visiting professor at MIT, where she is seeking to develop a Web browser that Arthur can use, with the help of Ben Resner, who supervises Arthur. Pepperberg also owns Alex, an African Grey which can recognise some 50 objects, five shapes, seven colours, count as far as six, and use concepts like 'smaller', and 'different'. She sees African Greys as having as much intelligence as dolphins or chimps. Parrots need stimulation due to their intelligence, or they become lonely and bored, with behavioural problems like feather plucking. Arthur has to stay in the lab at night, and needs a diversion. His browser is a box with two levers, and he uses a liquid crystal screen, because parrots' eyes see cathode ray tubes as though they were strobe lights. Arthur is not especially impressed by his new toy, but there is hope that the software and hardware can be improved enough to change this. Parrots could eventually contact each other through the internet, and have their own pages.

Healthy serenades

Female songbirds like males with wide range of songs

source: New Scientist February 6 2000 p25

Female songbirds tend to prefer males which have wide repertoires. The mortality rate for reed warbler chicks is lower for those with fathers with extensive repertoires. Anders Moller heads a team from the Pierre and Marie Curie University, Paris, France, which has examined 38 songbird species. They have found that songbirds' spleen sizes are linked to the sizes of their repertoires. Spleen sizes are also an indication of the condition of immune systems.

Mother's darlings

Testosterone in zebra finch eggs related to the attractiveness of the male

source: Matt Walker
New Scientist October 9 1999 p18

Researchers at the University of Paris, France, and St Andrews University, Britain, have found that female zebra finches deposit more testosterone in eggs from liasons with males they favour. This extra testosterone makes chicks more likely to hatch earlier, grow faster, and beg for food in a more insistent way. The favoured males had red bands attached to their legs, and female zebra finches find these bands attractive. The females may have been more aroused by the red-banded males, which may have boosted their hormone levels, so the levels in their eggs. This finding means that it is difficult to separate the impact of paternal genes from the mother's contribution.

Wise finches opt for the unisex look

Male finches may try to appear unisex to avoid conflict

source: New Scientist April 3 1999 p27

Long-tailed finches have been studied in an aviary, by University of Bristol's Andy Bennett, and Cambridge University's Naomi Langmore. Both sexes of these birds look similar, and they only reveal their sex through the way they behave. Male finches were found to hide their sex if they were in the presence of dominant males, or a group of birds that they did not know. This could be one way for flocks of birds to reduce their levels of conflict.