Tuesday, December 13, 2011

I think I'm going cuckoo


Thrice welcome, darling of the Spring!
Even yet thou art to me
No bird, but an invisible thing
A voice, a mystery.

                     Wordsworth (who clearly didn't live around here)


Firstly, let me point out that this post is not about lemurs.
In fact it isn’t even about Madagascar.

I’m taking a break from my lemur litany to indulge in a bit of a gripe.

I need it.

You see my neighbourhood ‘invisible thing’ is driving me to distraction.


I’m sure you know how it feels to be assailed by an apparently innocuous sound, endlessly repeated.
Whether it’s the plink of a dripping tap or a tune circling in your mind, incessant repetition can push the sanest of us into madness. (And after eight years as a recluse, sanity is not my strong suit.)

My own personal bugbear comes feather-coated. He swept in about a month ago, all fresh and perky after a winter vacation in equatorial Africa. Dressed elegantly in soft grey, with a waistcoat of pinstripes and salmon cravat, he’s far too dapper for his slightly embarrassing moniker: the red-chested cuckoo (Cuculus solitarius).

 
Like other cuckoos, the red-chested (Cuculus solitarius) is dressed to impress. His slick hawk-like shape, raptorish eye-ring and sparrow-hawk chest stripes are no accident. Experiments show that the stripes alone are enough to intimidate potential cuckoo-rearers, allowing the wearer access to nests. Photo by Johann du Preez.

My red-chested cuckoo is out for a good time.
Having staked out a bachelor pad in the trees along the river, he dallies at special ‘song posts’ hidden in the foliage (essential, to avoid the shot-gun blasts of irate listeners) and sends forth his message. Repeatedly.

Now his descending, three-note call is not unpleasant per se (you can listen to it here).
But repeated stridently - at one second intervals – for hour after hour after hour, it’s simply soul destroying. And don’t imagine that nightfall brings relief. Mere darkness is no deterrent to a red-chested cuckoo on the make.

Tossing and turning sleeplessly, I’ve had plenty of time to ponder the purpose of his incessant advertising. Is he warning off rivals or serenading the ladies? At the risk of eroding your sympathy, I’ll admit (solely for scientific purposes) that he does occasionally take a break; sometimes for several days at a stretch (ah, blessed relief).
But this is weird behaviour for a bird that defends its territory with song. Does he only engage in operatics when he has an audience?
I’ve come to the conclusion that what he’s really shouting is,
“Have I got a nest for you!”

You see, in red-chested cuckoo society, it’s the male who screens prospective foster parents. When not driving innocent bystanders insane, he skulks about spying on the neighbours. Once he spots a happy couple preparing their nursery, he hurriedly leads (one of) his true loves to the spot and helpfully distracts the parents-to-be while she sneaks in and lays an egg. To make the crime scene less conspicuous, she then scoffs a resident egg (why waste a good egg?).


Like all his kind, this cute red-chested cuckoo chick won his spoiled, only-child status by murder (struggle, push, shove... ‘Oh look, chick/egg overboard. Now how did that happen?’).
Photo by Arno & Louise Meintjes.

As I’m sure you know, cuckoos produce eggs that look similar to those of their victims to assist them in their evil egg-switching.
This is all good and fine if you’re a cuckoo species that freeloads on only one type of bird. But my annoying red-chested cuckoos don’t put all their eggs in one basket (that way, they could become extinct... or so I fantasize).
No, my cuckoos foist their ankle-biters off on to 18 different species of sucker, all of whom produce very different looking eggs. So how do the cuckoos mix and match?

Well not all red-chested cuckoos are born equal. In any one place, you’ll find several different races (called gentes), each of which specialises in hoodwinking just one particular host, and produces the eggs to match.
But how do the cuckoos maintain this racial purity? What happens when a girl from the Cape robin gens (gens is the singular of gentes) is swept off her feet by a boy from the wagtail gens. Will the couple’s daughters ever find a suitable nest for their miscegenated eggs?
Alternatively if maiden cuckoos always abide by family tradition and only choose lovers from within their own gens (i.e. there’s no racial mixing), surely the races are really different species?

The answer is devious. Unlike mammals - where it’s the male who totes the whacky, sex-defining Y chromosome - birds do things the other way around. Macho birds carry two Z chromosomes while the ladies are ZW. Egg colour is craftily encoded on the W chromosome, so it’s always passed on – unadulterated - from mother to daughter regardless of what or whom Dad is (as he can only ever contribute a Z chromosome).

A recent study of greater honeyguides (OK, not a cuckoo but employing the same nefarious means of reproduction) found that their gentes are extremely ancient. When the researchers looked at the honeyguides’ mitochondrial DNA (which comes only from Mum) they found that the gentes had remained entirely separate and unsullied for millions of years. But when they looked at the chromosomal DNA (which comes from both Mum and Dad) they could find no difference between gentes (because everyone happily interbreeds).


The eye of the beholder. Some gentes of red-chested cuckoo lay eggs that don’t match those of their target species. So why do the victims accept them? Unlike us, birds are able to see near ultraviolet wavelengths. When researchers examined the eggs using ultraviolet-visible spectrophotometery, they found that they were similar. Oops.
Photo by Johann du Preez.


Among their other weird traits, cuckoos are renowned for their fondness for hairy caterpillars (they munch them, not keep them as pets). They develop this predilection only in adulthood because no sensible foster parent offers a chick such noxious fare. Furred caterpillars are eschewed by almost all birds thanks to their urticating hairs (I love that word; it means ‘stinging like a nettle’). The tips of these hairs are detachable and dispense irritating poison. Although cuckoos scrub their dinner thoroughly (you can see footage here), the lining of their gizzard still ends up bristling with cactus-like spines. To rid themselves of these, European cuckoos slough off and regurgitate bits of mucous membrane lining (a trick most of us employ only after dining on dodgy prawns).


Local cuckoo food.
Who wouldn't want one as a pet?

It was perhaps this ability to stomach noxious things that encouraged our ancestors to link cuckoos with wedlock. The sceptre of the ancient Greek goddess of marriage is normally topped by a cuckoo rampant, and folklaw stipulates that to hear a cuckoo is good luck for those about to tie the knot, and a portent of adultery for those already wed. Since I fall into neither category, I’ll opt for the alternative claim: the number of cuckoo calls you hear signifies the number of years until you marry or die (whichever comes first).

By my calculation, I should still be going strong in 9011.
How long my sanity will last is another question entirely.




12 comments:

  1. Lydia, I always love your posts but this one—madness! cons! marriage!—is an especial delight. I love cuckoos. I think I'd like you, too.

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  2. Lynda, I found your blog whilst researching a bird I'd photographed in my garden on the Bluff, Durban. (I think it's a Trumpter Hornbill.) I've bookmarked your site and it will become a favourite I'm sure. So well written! By the way I came across a family of mongoose living in the bush near Anstey's beach the other day. I think you are very brave! Margot

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  3. Pin-tailed whydahs also do the cuckooo thing. Are they also geared to a particular species? Ours sings, but it's a pleasant background noise. And he stops at dinnertime, quiet at night!

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  4. Eep! Apologies for totally bungling your name this morning. Pre-coffee commenting should not be allowed. I meant what I said, though. :)

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  5. Africa has a surplus of monotonous cuckoos, and equally monotonous barbets and tinkerbirds. Luckily most of them give it a rest at night.
    The sparrowhawk-like bands on some cuckoos is an interesting trait. I remember watching a Jacobin Cuckoo (which lacks breast bands) being pursued relentlessly by a Common Bulbul, trying to keep the cuckoo away from it's nest. Maybe the Red-chested Cuckoo would have intimidated the bulbul more asily.

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  6. High on the night time annoyance chart has to be my resident fruit bat's continuous and loud "Ping! Ping! PING!!!".

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  7. You poor creature. =(

    oh, how I was hoping there was an etymological tie-in. From your description, I wondered if the fact that the cuckoo's call makes you nutty relates to our use of the word to describe such a nutty person.

    From http://www.etymonline.com

    cuckoo
    mid-13c., from O.Fr. cocu "cuckoo," also "cuckold," echoic of the male bird's mating cry (cf. Gk. kokkyx, L. cuculus, M.Ir. cuach, Skt. kokilas). Slang sense of "crazy" (adj.) is Amer.Eng. 1918, but noun meaning "stupid person" is first recorded 1580s, perhaps from the bird's unvarying, oft-repeated call. The O.E. name was geac, cognate with O.N. gaukr, source of Scottish and northern English gowk. The Germanic words presumably originally were echoic, too, but had drifted in form. Cuckoo clock is from 1789.

    In any case, the southern California version is the mocking bird. Happily their song, pretty much all mimicry of other birds, frogs, car alarms, is MUCH more varied, but WOW is it loud, and they will sing, as far as my exhausted brain could track, ALL NIGHT LONG. I imagined the males could not possibly live long with all that energetic expenditure, tho' I have no idea.

    I lived in San Diego, and at 3 a.m. the city is finally very, very quiet (you can actually hear the train and a fog horn from miles away, only then), save for the spring-time LOUD, incessant calls of this loquacious creature.

    The sleepy visages of co-workers and their groggy, one-word explanation, "Mocking bird," as they grabbed yet another cup of coffee, never failed to bring about sincere, sympathetic murmurings.

    Super interesting post, esp. the fuzzy toxic dressed caterpillars as food. I'd like to know if there was any sort of other benefit conferred to the consumers other than caloric. Don't suppose caterpillar-hair-infused breath wards off potential predators? Or makes the birds untasty?

    Thanks, as ever, for the lovely post. Please, never hesitate to whinge. =) It's delightful.

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  8. Happy holidays folks as I'm just visiting different blogs. Richard from Amish Stories

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  9. I would appreciate any advice on how to keep neighborhood mongooses (mongeese?) from using my front yard as their latrine. It's disgusting. Thanks. NM in Kapolei HI

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  10. Meera,
    Thank you for your encouragement. I'm glad your liking of this post (and cuckoos)isn't merely a product of caffeine withdrawal; otherwise I'd have to start sabotaging coffee manufacturers.

    Margot55,
    Hi! I also have those 'pinging' fruit bats. It's amazing that something quite small can make such a racket. Actually I find their prolific 'output' more annoying than their call. I don't know if it's the fruit pulp that they spit out after extracting the juice, or their actual droppings (apparently the juice only takes half an hour to pass through them), but the outside of my house is entirely bespattered with sticky red stains.

    Elephant's Eye,
    Your pin-tailed whydahs sound much more civilised than cuckoos. Their chicks don't indulge in murder for a start, happily sharing a nest with their foster siblings (usually common waxbills but sometimes swee or orange-breasted waxbills). To help win bouts of sibling rivalry, their begging performance and the pattern on the insides of their mouths (which stimulates Mum and Dad to cough up the grub) are almost identical to that of their foster siblings.

    John,
    Barbets and tinkerbirds are a blessing compared to red-chested cuckoos! It would be interesting if people responded to a barred chest in the same way. Maybe sailors are on to something...

    Biobabbler,
    Thank you for the interesting info. How did mockingbirds come by their name? Was it because they mock people's attempts to sleep??
    I haven't heard of any secondary advantage to guzzling furry caterpillars. Maybe cuckoos wield an urticating tongue against predators or rivals (Oh no, I've been licked by a cuckoo!). Or maybe their sore throats keep them up at night, so they call to pass the time (gaining a reproductive advantage over sound sleepers).
    You can't imagine how pleasant it feels to be given sanction to whinge!

    Amish Stories,
    Thanks for dropping by. I hope you have a great Xmas.

    NM,
    If your Small Indian mongooses are anything like the mongoose species I've worked with, they'll be strongly attracted to defecate in places where they can smell mongoose droppings. If they're using a particular place, I'd suggest removing all droppings, hosing the area very thoroughly and sploshing about something seriously smelly (e.g. antiseptic, eucalyptus oil, etc) to mask any remaining odours. Remember that they'll probably also have scent-marked any prominent landmarks near their latrine (rocks, logs, etc.) so you'll need to clean or remove these too.
    If this doesn't put them off, you can try shifting the latrine. Move their droppings about 1 or 2 feet, in the direction of your nearest fenceline, and clean the smell from the old spot. They're very likely to now use the new place, and - if you don't make the increments too large - you should be able to gradually move their latrine off your property (you may not be too popular with your neighbour however).
    If they're scattering droppings randomly all over your garden, I'm not sure what to suggest (are you sure it's the mongooses doing it?). You could try discouraging them from coming into your garden by leaving evidence of predators around (e.g. dogs' droppings). Hmm, on second thoughts, maybe not a great solution...

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  11. I just love your posts Lynda. Have a wonderful break and we all look forward to reading your adventures next year!

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  12. Brian,
    Thank you for your encouragement. I hope you're having a fun day and that the coming year is full of adventure for you too.

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