How do mag­pies di­vorce?

Adult Aus­tralian mag­pies usu­ally set­tle down to a life­time of cou­ple­dom and par­ent­hood. But, just oc­ca­sion­ally, one or both part­ners de­cide they’ve got hitched to the wrong bird. So they split – with many of the trau­matic reper­cus­sions that af­flict hu­mans

Australian Geographic - - Snapshot -

“I’ve seen such sep­a­ra­tions in mag­pies sev­eral times and it’s ev­ery bit as mean and heart­break­ing as it is for hu­man be­ings,” ex­plains Pro­fes­sor Gisela Ka­plan, a neu­ro­science and an­i­mal be­hav­iour ex­pert at the Univer­sity of New Eng­land, who is in­ter­ested in the so­cial life of birds and has stud­ied wild mag­pies for more than 20 years. Ex­ten­sive f ield re­search has al­lowed her to wit­ness go­ings-on in mag­pie so­ci­ety that other ob­servers may miss. “The nas­ti­est case con­cerned a pair I’d watched for years. One day the male dis­ap­peared for days, leav­ing all the feed­ing of two off­spring to the fe­male. Then he came back with two young fe­males and evicted his part­ner and her young­sters from the ter­ri­tory.”

An­other time, a fe­male evicted her male part­ner, ap­par­ently for not pro­tect­ing their nest and young­sters well. “She didn’t al­low him near the nest. Even­tu­ally an­other male turned up and stayed,” says Gisela, who’s found that when a male takes over an­other’s ter­ri­tory, he plays no part in rais­ing his pre­de­ces­sor’s young. “I ended up sup­port-feed­ing the two off­spring as the fe­male was clearly strug­gling to raise them on her own.”

Gisela has stud­ied about 30 mag­pie groups on the North­ern Table­lands of New South Wales and the ad­ja­cent coast, as well as in Victoria and out­back South Aus­tralia. Given that her cho­sen f ields are cog­ni­tion, com­mu­ni­ca­tion, song-learn­ing and mimicry, par­tic­u­larly among Aus­tralian birds, sta­ble so­cial groups make ideal re­search sub­jects.

Dur­ing the past two decades she has pub­lished 250 re­search ar­ti­cles and 21 books, spo­ken on ra­dio and been a con­sul­tant for tele­vi­sion doc­u­men­taries. In her award-win­ning 2015 book, Bird Minds: Cog­ni­tion and Be­hav­iour of Aus­tralian Na­tive Birds, Gisela draws on her own ex­ten­sive re­search, as well as the work of other sci­en­tists, to show how smart, sen­si­tive and per­cep­tive Aus­tralian birds re­ally are.

Grow­ing ev­i­dence sug­gests many bird groups, in­clud­ing all mod­ern song­birds, evolved in East Gond­wana (now Aus­tralia) and spread around the globe mil­lions of years ago, tak­ing their skills with them and spawn­ing more than half the bird species on Earth today. Aus­tralia, it turns out, was a cra­dle of bird evo­lu­tion af­ter the mass ex­tinc­tion that claimed the di­nosaurs about 66 mil­lion years ago.

What gave Aus­tralian birds their unique tal­ents? Gisela be­lieves one fac­tor was this con­ti­nent’s harsh and ever-chang­ing en­vi­ron­ment. To sur­vive here, birds had to be highly adapt­able, in­no­va­tive and good de­ci­sion-mak­ers. An­other fac­tor was co­op­er­a­tive be­hav­iour. Birds that lived in close-knit so­cial groups and helped each other – rais­ing young, de­fend­ing nests and/or f in­d­ing food – were more likely to pros­per. A sta­ble fam­ily life lies at the core of such co­op­er­a­tion. “There is no other class of an­i­mals that has such a high in­ci­dence of pair-bond­ing and joint par­ent­ing as do birds,” Gisela writes, “and, in Aus­tralia, this is of­ten cou­pled with life-long com­mit­ments.” That’s un­til di­vorce do them part, of course.

Gisela’s book is a trea­sury of ex­am­ples of the as­ton­ish­ingly so­phis­ti­cated be­hav­iour of Aus­tralian na­tive birds. She tells of prob­lem-solv­ing, tool use, em­pa­thy, griev­ing, for­ward plan­ning, co­op­er­a­tive de­fence, fa­cial recog­ni­tion, mimicry, im­i­ta­tion, song-learn­ing, long mem­ory, de­cep­tion, Machi­avel­lian schem­ing, brain plas­tic­ity, com­plex play, count­ing and even point­ing be­hav­iour (the f irst time this had been re­ported in a bird).

To lighten the avian brain for flight, nat­u­ral se­lec­tion has minia­turised it ruth­lessly.

UN­TIL THE 1900S, many peo­ple ridiculed the idea that a crea­ture with a brain as small as a bird’s might be ca­pa­ble of com­plex learn­ing, let alone thought or emo­tions. Although Dar­win sug­gested hu­man men­tal pow­ers dif­fered from those of other an­i­mals only in de­gree, not kind, the con­sen­sus was that birds ran on in­stinct and were men­tally on a par with in­sects and f ish.

Size was deemed to mat­ter: big brains were smarter than small ones. Birds were, well…bird-brained.

As proof, scep­tics pointed out that birds lacked a fore­brain, the pow­er­house of higher mam­mal think­ing, although this no­tion failed to ap­pre­ci­ate evo­lu­tion’s breath­tak­ing in­ge­nu­ity.

To lighten the avian brain for f light, nat­u­ral se­lec­tion has minia­turised it ruth­lessly. In a cock­a­too, for ex­am­ple, it can be wal­nut-sized. But, as well as hav­ing of­ten elab­o­rate so­cial re­la­tion­ships, birds move through a com­plex three-di­men­sional world at great speed, dodg­ing ob­sta­cles, judg­ing dis­tances, gaug­ing wind speed and di­rec­tion, and cal­cu­lat­ing ap­proaches to tight land­ing spots or prey. The tor­rent of in­for­ma­tion en­ter­ing the brain must be pro­cessed in mi­crosec­onds. How does this tiny or­gan do it? The an­swer has be­come clearer in re­cent years.

We now know birds do have the equiv­a­lent of a fore­brain. It’s called the pal­lium and although it dif­fers struc­turally from the mam­malian fore­brain, it sits in a sim­i­lar po­si­tion and per­forms a surprising num­ber of sim­i­lar func­tions.

Just as sig­nif icantly, in 2016, an in­ter­na­tional group of neu­ro­sci­en­tists pub­lished the re­sults of a study that showed that birds pack twice as many neu­rons per unit of mass into their brains as mon­keys and apes do.

“Thus, large-brained par­rots and corvids [crows and ravens] have fore­brain neu­ron counts equal to or greater than pri­mates with much larger brains,” the sci­en­tists con­cluded. “More­over, a short in­terneu­ronal dis­tance, the corol­lary of the ex­tremely high pack­ing den­si­ties of their te­len­cephalic neu­rons, likely re­sults in a high speed of in­for­ma­tion pro­cess­ing, which may fur­ther en­hance cog­ni­tive abil­i­ties of these birds.”

So, it turns out, the avian brain is a su­per-clever smart­phone be­side the desk­top com­puter that f ills the mam­malian skull.

In re­sponse, the me­dia lit up with head­lines about “feath­ered apes” and birds not be­ing bird-brained af­ter all.

In his 2016 book, Bird Brain: An Ex­plo­ration of Avian In­tel­li­gence, Nathan Emery, a cog­ni­tive psy­chol­o­gist at Queen Mary Univer­sity in Lon­don, de­scribes birds as “Ein­steins of the air”. Some birds should be con­sid­ered as in­tel­li­gent as apes and dol­phins, and may match our ear­li­est hu­man an­ces­tors in cog­ni­tive prow­ess. He adds that “rooks, jays and New Cale­do­nian crows are at least as com­pe­tent and, in some cases, more com­pe­tent than chil­dren younger than eight years old in tasks in­volv­ing tool in­no­va­tion and causal rea­son­ing”.

How­ever, it’s clear that, where brain­power is con­cerned, not all birds are equal, and avian cog­ni­tive skills vary enor­mously. Our smartest birds are cock­a­toos and par­rots, with palm cock­a­toos and bud­gies in the lead.

Close be­hind are ravens, crows, bower­birds and mag­pies. Even some smaller birds, such as wrens and hon­eyeaters, score sur­pris­ingly well on the in­tel­li­gence scale.

BE­FORE THE 1960S, tool use was thought to be the ex­clu­sive pre­serve of hu­mans; a mark of su­pe­rior in­tel­lect that sep­a­rated hu­man­ity from other life forms. But that no­tion came crash­ing down when pri­ma­tol­o­gist Jane Goodall dis­cov­ered in 1960 that wild chim­panzees mod­ify twigs to catch ter­mites. Since then, birds have joined the top ranks of tool-mak­ing and tool-us­ing an­i­mals. Sev­eral species fashion sticks for reach­ing and hook­ing food and also for use as weapons or play­things.

The New Cale­do­nian crow is a cham­pion maker and user of tools, metic­u­lously fash­ion­ing a range of barbed sticks with which it ex­tracts grubs from tree bark.

Bi­ol­o­gist, au­thor and AG con­trib­u­tor Tim Low de­scribes in his latest book, Where Song Be­gan, how he watched a young crow in a New Cale­do­nian rain­for­est us­ing a tool to fish out a cricket from a tree hole. “I was as­ton­ished,” Tim told me. “The young bird was so smooth, so deft in its op­er­a­tion. There was noth­ing ten­ta­tive or clumsy about it; it knew ex­actly what it was do­ing.

“When you’ve been watch­ing birds all your life, to see a bird op­er­at­ing at a level of so­phis­ti­ca­tion that is just way above any­thing you’ve seen be­fore, you have a sense of awe,” he con­cluded.

Pub­lished the year be­fore Gisela’s book came out, Where Song Be­gan ex­plores com­pre­hen­sively the view that more than half of the world’s birds orig­i­nated in the Aus­tralian re­gion and ex­plains why so many of our birds are un­usu­ally in­tel­li­gent, so­cial and noisy.

Avian tool users in Aus­tralia in­clude the male palm cock­a­too, which fash­ions sticks with which to drum on tree trunks. Sci­en­tists aren’t sure why, but be­lieve it’s ei­ther to warn off in­trud­ers or sig­nal his readi­ness to mate. He may carry a good drum­stick around to dif­fer­ent trees and also re­moves leaves and twigs from sticks that he then cuts to a pre­cise size for build­ing a nest in a tree hol­low. His tool-mak­ing skills are equal to – some say more so­phis­ti­cated than – those of the New Cale­do­nian crow.

Like corvids and rap­tors else­where in the world, Aus­tralian birds may use stones for a va­ri­ety of pur­poses. The black-breasted buz­zard wields a stone with its beak to crack open eggs and a group of mag­pies re­port­edly dropped stones on the tin roof of a farm­house in the morn­ing if the res­i­dents were late in

Our smartest birds are cock­a­toos and par­rots, with palm cock­a­toos and bud­gies in the lead.

putting out food for them. Abo­rig­i­nal peo­ple in the North­ern Ter­ri­tory tell of rap­tors spread­ing bushf ires to f lush out prey.

Bob Gos­ford, an NT lawyer who has worked with Abo­rig­i­nal peo­ple in cen­tral and north­ern Aus­tralia, has heard talk of rap­tors pick­ing up smoul­der­ing or burn­ing sticks and f ly­ing as far as 50m to drop them on un­burnt patches of dry grass to start new f ires.

“There is com­pelling ev­i­dence that at least two raptor species – the brown fal­con and the black kite – act as prop­a­ga­tors of fire within the Aus­tralian sa­vanna wood­lands,” Bob wrote in the dig­i­tal mag­a­zine Crikey.

For mil­len­nia, the wildf ires that shaped the Aus­tralian land­scape were started ei­ther by light­ning or by hu­mans. Bob be­lieves that rap­tors may be a third f ire-pro­mot­ing force and he’s re­search­ing Abo­rig­i­nal ac­counts of this be­hav­iour.

AG PHOTOGRAPHER DON FUCHS once had an en­counter with a raven in an aviary in Aus­tria that gave him food for thought. “The bird looked at me and I looked at it and then it picked up a twig and pushed it through the mesh to­wards me,” Don says. “So I took it and im­me­di­ately the bird lifted a wing to ex­pose its un­der­side. It seemed to be in­di­cat­ing that it wanted me to scratch it. So I did and the bird half-closed its eyes and its head went back a little and it was quite clear to me that it was en­joy­ing what I was do­ing.”

Af­ter a while, Don stopped scratch­ing and pushed the stick back inside. “The bird was not happy. It grabbed the stick and pushed it out again, ba­si­cally or­der­ing me to keep go­ing,” he re­calls. “What was amaz­ing was that I re­ally felt that there was clear com­mu­ni­ca­tion be­tween us.”

The raven had com­mu­ni­cated with Don through ges­ture, ex­pres­sion and the ma­nip­u­la­tion of a tool. But as Gisela says in her book, one of the hall­marks of bird com­mu­ni­ca­tion is vo­cal­i­sa­tion. “Apart from hu­mans, no other class of an­i­mals has de­vel­oped such a plethora of vo­cal sig­nals as have birds,” she writes.

Com­plex calls seem to go with co­op­er­a­tive living and in­tel­li­gence. Sci­en­tists are now f in­d­ing that many bird calls have a fixed mean­ing; in other words, they show the be­gin­nings of a vo­cab­u­lary. Pro­fes­sor Dar­ryl Jones, a be­havioural ecol­o­gist at Queens­land’s Griff ith Univer­sity, has stud­ied ur­ban crows and mag­pies. A re­search project he ran on the vo­cal com­mu­ni­ca­tion of Tor­re­sian crows re­vealed that they em­ployed as many as 200 dif­fer­ent el­e­ments.

“They gen­uinely ap­pear to have what you’d have to call lan­guage,” he says. “They don’t make noise for no rea­son and they talk to each other all day, ev­ery day, and so some­thing is go­ing on. There are enough bits to it and they talk to each other enough for us to spec­u­late that they may even have sen­tences.

“That’s the kind of thing that al­ways makes me think that these are smart birds,” he con­tin­ues. “They’re com­mu­ni­cat­ing in a re­ally so­phis­ti­cated way.”

Deep in the wilds of Tas­ma­nia, ravens and cur­ra­wongs ex­ploit a dif­fer­ent form of in­tel­li­gence to great ad­van­tage. At two sites on the Overland Track, bush­walk­ers reg­u­larly dis­card their back­packs to make short side trips. Once the walk­ers have set off, the birds de­scend on the packs. They’ve learnt not only

Com­plex calls seem to go with co­op­er­a­tive living and in­tel­li­gence.

which outer pock­ets walk­ers usu­ally store their day snacks in, but also how to un­zip them.

“They’ve got keen eyes and can eas­ily spot that little metal zip­per tag,” says Rob Arm­strong, a dis­cov­ery ranger with Tas­ma­nia’s Parks and Wildlife Ser­vice.

“They’ll pull out ev­ery­thing un­til they f ind food. They’re mainly af­ter zi­plock bags, where peo­ple keep their scrog­gin mix – fruit and nuts and things like that. Once they find what they want, they don’t put the other stuff back in, of course, so a lot of rub­bish gets spread around those sites.”

In a bid to re­duce the mess, the ser­vice has put up signs that warn: “PRO­TECT YOUR PACK! Cur­ra­wongs can undo zips – and they know where you keep your snacks!”

DO BIRDS LIKE TO HAVE FUN? Do they play? Some bird species do, but they rep­re­sent only a tiny frac­tion of the world’s 10,000 species of bird. Par­rots, corvids and Aus­tralian mag­pies top the list of imag­i­na­tive play­ers, although sci­en­tists keep f in­d­ing other species to in­clude.

The­o­ret­i­cally, in evo­lu­tion­ary terms, play should of­fer a sur­vival ad­van­tage. So birds that live in tight so­cial groups may play with one an­other be­cause it pro­motes so­cial skills and bonds the group.

Chas­ing, tus­sling, hid­ing or tug-of-war games may hone brain synapses, mus­cles and mo­tor skills, and play­ing with ob­jects may nur­ture in­ven­tive­ness or build handy ex­per­tise that will one day pro­vide food.

But then per­haps play could just be for fun. I’ve watched a f ly­ing wedge-tailed ea­gle play­ing with a dead rab­bit, drop­ping it and then div­ing and catch­ing it, over and over. I’ve seen ravens launch them­selves re­peat­edly from a cliff to per­form wild aer­o­bat­ics, wheel­ing, tum­bling, div­ing, rolling and loop­ing in the up­draft. I once saw a pel­i­can take off on a hot day and spi­ral up in a ther­mal to the cloud base be­fore re­turn­ing to its orig­i­nal rest­ing place.

I as­sumed it had gone up to cool off but then maybe it was for the sheer plea­sure of free f light.

Gisela has watched young mag­pies play hide-and-seek, dur­ing which one mag­pie f inds a de­sir­able ob­ject such as a leaf and runs off with it and hides while oth­ers chase and search.

“It’s a game of dis­ap­pear­ance and reap­pear­ance,” she says. “They of­ten vo­calise while they’re do­ing this, and when they find the other, they squeak and squeal and have won­der­ful fun. Sig­nif icantly, they un­der­stand that an ob­ject that was ini­tially in their f ield of vi­sion and then dis­ap­peared is ac­tu­ally still there. Hu­man chil­dren don’t de­velop such con­cepts un­til they’re three to f ive years old.”

BIRDS ARE ALL AROUND US. We see and hear them ev­ery day. That may be why we take them for granted and dis­miss them as just an­other el­e­ment of our en­vi­ron­ment. Although we’re com­ing to un­der­stand how in­tel­li­gent some of them are, we’re a long way from hav­ing the full pic­ture. It’s clear, how­ever, that hu­mans have long un­der­es­ti­mated birds’ ca­pac­i­ties and com­plex­ity, and grossly over­es­ti­mated their own. A lot more work needs to be done.

We could start by us­ing the term bird brain as a com­pli­ment rather than an in­sult.

For smart birds such as Aus­tralian mag­pies, hav­ing fun is a big part of grow­ing up and may help in­stil be­hav­iours use­ful in adult life. Here three young­sters play-fight in a game of their own in­ven­tion.

Grip­ping a stick he’s shaped for the pur­pose, a male palm cock­a­too pre­pares to drum on a branch. If he likes the stick, he’ll carry it with him to his next drum site.

Be­ware of smart birds! This sign be­side Tas­ma­nia’s Overland Track warns walk­ers about the pil­fer­ing skills of local birdlife.

Many bird species around the world use stones to crack open eggs. Here an Aus­tralian black-breasted buz­zard tack­les an emu egg with a stone ‘tool’.

Birds of prey, such as this wed­getailed ea­gle, seem to en­joy play­ing with ob­jects, in­clud­ing an­i­mals they have hunted and killed.

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