Blood feud in the dawn redwood

male-koel-neck-arched-square

Every year for the last seven years, I’ve heard koels calling, loudly and desperately, right outside my window, day and night, for the three months from the equinox to Christmas.  And for the whole of that time I’ve been trying to get a decent photograph.  A while back, I caught sight of a whopping great juvenile sitting around on a branch of the pine tree, whining for more food from his adoptive mum, a harassed looking red wattlebird. But that’s it.

I know they’re there, skulking in the trees, the males advertising their availability in an increasingly high pitched, eventually hysterical squeak from the cover of the leaves.  And there’s that duet that koel couples, both equally well concealed and well amplified, produce – the male exclaiming “wurru-wurru!” while the female interrupts with a simultaneous “keek keek keek!”.  But where are these potentially ear damaging exchanges coming from?  Who can say.  It’s like trying to locate a pair of shy and slightly drunk ventriloquists.

But that all changed in my backyard yesterday.  I’ve finally got my stash of koel shots.

Why did these cryptic birds let me get close enough to take a million pictures?  I reckon it was because there was a battle on in the branches.   The prospect of scoring, through combat, a romantic enounter with the iridescent, satan-eyed male seem to make the feuding females oblivious to all that clicking and crashing in the undergrowth.

The  sexual proclivities of koels are not well understood (by humans anyway.  You hope koels have a decent grip on it).  Brood parasites are inherently interesting critters, so koels’ interactions with the honeyeater “hosts”, whose nests they visit to lay their eggs, has been studied exhaustively. The changes in their migrating habits as the world warms up have been looked into a bit as well (eg Chambers et al 2014).  But how and with whom they do their coupling is all a bit of a mystery.

You can’t give the ornithologists too much grief about this.  Even the most avid twitcher is going to be a bit dubious about spending the three years of a PhD shinning up trees clinging to a GPS tracking device, in an attempt to pin down the sexual encounters of an intercontinental migrant of no fixed abode.  And that’s not even considering the koel’s antisocial habits: the fact that they are “typically wary and difficult to observe [remaining] in thick foliage, high in trees, calling from concealed positions” (Healy and Healey 2007).

female-koel-peeking-around-leaves-crop

So what did I see (or half see) in our metasequoia tree after breakfast yesterday?

Did I witness a female, already partnered however temporarily with Mr Shiny Feathers, being challenged by a youngblood for access to a mate?  Koel males are apparently “polygynous” – they mate with multiple females.  But those ventriloquist duets suggest some kind of short-term liaisons, since couples that sing together like this, apparently, often have some kind of ongoing arrangement (Maller and Jones, 2001).

Or just two females both keen to hook up with guy who had command of such a fine calling station, my beautiful dawn redwood?

 

The male was staying well out of it, watching cagily from the side lines.  At one point I spotted him passing somethinga nuptial gift of a berry? – to one of the warring females.  I didn’t see if him get anything in return, unlike the lucky Asian koel spotted by this Singapore based bird watcher. But then with bird couplings, blink and you could easily miss it.

koel-eating-a-seed-crop-for-amend

Female koel… with nuptial gift?

 

But if the male bird was playing favours, this was strictly a chick fight.

At first it was a rap battle.

Eventually the two females settled at opposites ends of a branch, studiously ignoring each other, like gunfighters in a Western pacing the far ends of Main Street.  And then it was on, with a flurry of feathers and a fanning of tails.

two-koel-on-branch-flipped-and-cropped

Two female koels about to tussle

 

Such chick fights aren’t as unusual as old-fashioned zoologists might think. Females that live in groups, it seems, often engage in “intense female-female competition over reproduction, dominance rank and other components of social-living” (Rubenstein, 2012, 2250). I’ve seen it with the chickens.  According to the implausibly named Clutton-Brock and Huchard, in a recent article for the Royal Society these fights “peak… during the reproductive season [81–83], and … can lead to wounding or death [28,84].”  And fights are not just about access to mates, but about protecting eggs or nesting sites, space or foraging territories (Tobias et al, 2012; Krieg 2016).

Intriguingly, competition between females seems to go along with good looks or “ornamentation”.  Or better still “ornamentation and weaponry”.  And female koels, while not obviously armed to the teeth, surely are beautiful birds; like most ornamental or colourful females both substantial in size and hailing from the tropics (Dale et al 2015).

sideish-female-koel-with-good-view-of-stain-include-square

Hang on, what is that mysterious red stain on that creamy chest?  Was this a battle involving “wounding or even death”?  Was I witnessing an injured female being challenged, in her moment of weakness, by a healthier rival?

In some of my photos it surely looks like it.

Is that a blood stained beak?  Was this a ghoulish outcome of a predator attack followed by a desperate battle for genetic survival?

female-koel-with-red-beak-squareOr is it just mulberry season?

References

Chambers, L E, Beaumont LJ, Hudson IL (2014) “Continental scale analysis of bird migration timing: influences of climate and life history traits” International Journal of Biometeorology 58 (6) 1147-62

Dale, J., Dey, C, Delhey, K, Kempenaers, B, Valcu, M. (2015) “The effects of life history and sexual selection on male and female plumage coloration” Nature Vol 527 pp.367-71

Healy, C and Healey, E (2007) “Diet and Roost-site Fidelity in the Common Koel
Eudynamys scolopacea in Suburban Darwin” Australian Field Ornithology 2007, 24, 184–186

Maller, C J and Jones, D N (2001)”Vocal behaviour of the Common Koel, Eudynamys scolopacea, and implications for mating systems” Emu, 2001, 101, 105–112

Rubenstein, D.R. (2012) “Sexual and social competition: broadening perspectives by defining female roles”  Philosophical Transactions: Biological Sciences, Vol 367 No 1600, 2274-2293

Tobias, J. et al (2012) “The evolution of female ornaments and weaponry: social selection, sexual selection and ecological competition” Philosophical Transactions: Biological Sciences, Vol 367 No 1600, 2274-2293

Krieg, CA, Getty, T. (2016) “Not just for males: females use song against male and female rivls in a temperate zone songbird” Animal Behaviour Vol 113 39-47

 

Thinking like a bird

One of the things I love about my regular walk to the the train station is the chance to check out the critters’ daily routines while I’m in the midst of mine.  I’m an everyday intruder, just passing through.  Through the carpark behind the panel beaters’ shed where the glossy black cockatoos do their acrobatics.   Over the slimy patch on the footpath that used to lure eastern waterdragons out to play chicken in the traffic (I stress “used to”. Sad face). Past the carefully tended brush turkey mound in the scrub by the library and round the the blind corner where butcherbirds find their roadkill.  So far I’ve never seen them pecking at the flattened remains of kids on skateboards but I worry.

I was trudging home a few months ago, when there was a kerfuffle in the shrubbery that even the most self-absorbed commuter couldn’t ignore. An aggravated bird was repeatedly hurling herself at an invisible enemy, and making a tremendous din.  I spotted a tail sliding behind the trunk of a halfway up a tree – was it a goanna? a snake?  No, a brush-tailed possum, having a late afternoon snack in a grey butcherbird’s nest. Mum was willing to fight for her eggs to her last breath.  I don’t have any pictures of the stramash, unfortunately, despite roaming around Berowra most days like some bumbling stalker, a chunky camera swinging around my neck.

However, I feel a bit less sheepish about my amateur-hour suburban birdwatching – and a little less clueless about butcherbirds – after  reading Gisela Kaplan’s fascinating book Bird Minds (CSIRO, 2015) this week.

Butcherbird in near silhouette crop

Grey butcherbird makes a rare appearance in the backyard

Bird Minds considers most aspects of avian cognition – social learning, mimicry, tool use, play, abstract thought and emotion  – with a particular focus on the locals.  This, as Kaplan points out, is no mean feat.  Aussie natives are under-discussed in the world of scholarly ornithology, it seems.  She tells (with secret delight, I reckon) how the international community were forced to reluctantly accept that songbirds evolved in the part of Gondwanaland that came to be Australia, overturning 200 years of northern hemisphere prejudice.  The oldest songbird fossil ever found came from here, and recently the discovery of heron footprints from the Cretaceous Era in southern Victoria showed that birds and those other, non-avian dinosaurs cohabited this part of the world, at least, for millions of years.

So, as well as summarising the work of researchers from around the globe, to fill the gap in the published research on Australian natives, Kaplan draws on anecdotes from bird watchers (like the amazing tales of fire-starting black kites that have done the rounds in the papers lately) and her own experience of studying, observing and hand-rearing birds over the decades.  My particular favourite is her story of the adopted 75 year old galah who liked to summon all four household dogs by name in a passable impression of Kaplan’s voice just for the fun of bossing them around.  Every week.  It’s this kind of jolly jape that keeps a bird young.

Galahs in the rain crop

Pair of galahs

Butcherbirds are just the type of birds that Kaplan is interested in, although her own research for the last 25 years has been on another member of the Artamidae family, the Australian magpie.  Currawongs, butcherbirds and magpies, like many other Australian natives, don’t fit a northern hemisphere perspective on avian lives.  Grey butcherbirds are wonderful mellifluous singers, for example (though their tunes are less feted than the improvisational outpourings of the pied butcherbird).  But their carolling doesn’t fit the familiar songbird story.

Kaplan points out, for instance, that while northern hemisphere songbirds are most vocal during the breeding season, the Australian bush is often quietest at that time.  Amongst the much studied birds of high latitudes, males sing as part of a courting display.  In comparison, she observes, “Australian species often seem rather ‘egalitarian’ “.  For many Aussie birds, including butcherbirds “there is often no difference in the song between male and female, no marked difference in plumage or size, brooding and feeding of youngsters and defence” (Kaplan 2015 114).  I have to confess, this whole line of argument really appeals to me.

Magpie with fluff horizontal smaller

Magpie in spring

I also get sneaky pleasure at Kaplan’s observations about the cleverness of Australian birds.  Smarts, she suggests, are one strategy for coping with harsh environments and unreliable climatic conditions.  The humble budgie, a desert dweller, for instance, has one of the largest bird brains for its size, along with Cape York’s palm cockatoo, a formidable tool user.  These clever cockies select, shape and stash particularly excellent sticks, some to use as percussion instruments and others to improve nest-hole drainage.  Behavioural flexibility is a sign of sophisticated thinking: I guess musician cum plumber fits that bill quite nicely.  Birds like this, Kaplan thinks, playful, inquisitive and social, fill the ecological niche of monkeys in an Antipodean environment.

Australian birds often live much longer lives than their northern hemisphere equivalents. Permanent pair bonding means that galahs, for instance, or sulphur crested cockatoos may end up in a 60 year partnership.  Kaplan suggests that these long-term pairings require social nous and a sophisticated communication repertoire.  Forget relationship counselling, it could be time to take advice from the local cockies!

Young Australian birds are also likely to spend a long time hanging around with their parents learning the ropes – an extra year for grey butcherbirds, as much as four for white-winged choughs. Which explains the whiny teenagers I’ve been hearing everywhere lately.

It’s hilarious watching great hulking juvenile wattlebirds, indistinguishable from adults to my untrained eye, sitting in the Japanese maple tree out back, calling plaintively and endlessly for parental attention until someone hops up and gives them a lerp.  And last week on the way home, as I passed Butcherbird Corner, I heard the sounds of a youngster calling out that all-too-familiar refrain: “Mum! Mum! Mum! Mum! Mum! Mum!”.  It drives me mad when my kids do it, but on this occasion, pester-power put a smile on my face.  The lumbering youngster was a survivor of the Possum Bloodbath of 2015, demanding quality time (and a take-away) from its weary parent.

The youngbloods may hang around with mum and dad for ages, but they do get off the couch and help with the housework.  Raising your chicks with the help of older siblings and even unrelated adults – “cooperative breeding” – is surprisingly common in Australia, in comparison to elsewhere. If refraining from tearing your life-partner limb from limb with your own beak during the course of 60 years together is a challenge to a bird’s emotional control, how much more so is long-term living with the extended family?

This is an idea that Kaplan toys with throughout the book – that “negotiated living” might  “require… changes in powers of perception: a watchful eye, powers of observation and careful scrutiny of others… watching others means awareness of others and such habits can change from behaviour reading into mind reading” (Kaplan 2015 122).  Complex social lives go along with complex minds.

I rather enjoyed the sly dig at northern hemisphere birds (they sound nice, but could well be dim) that runs alongside Kaplan’s argument for the evolutionary value of cooperation.

in the competitive mode, learning (in males) is for a well-rehearsed performance: an Eistedfodd of dance or song. In the cooperative model, learning is for communication (Kaplan 2015 119)

Old leftie that I am, I can’t help liking the idea that cooperation, “egalitarianism” of the sexes and general smarts go along together.

Long beaked corellas giving me a funny look long.jpg

Long billed corellas giving me a funny look

I can’t vouch for the rigor of Kaplan’s science, but I loved reading her stories of the cleverness of Australian birds – their “versatility, resourcefulness, complex social and individual problem solving abilities” (Kaplan, 2015, 193).  Reading Bird Minds has given me plenty to look out for as I make my workaday way through the suburban territory we share.