Archive for the ‘brood parasites’ category

The forcibly adopted child!

21 October 2009

I have a great respect for the God of Lesser Things! The actual God, not the book, I mean. He is kind, he is just and he is fair. Since he rewards us in suitable measure, we should indeed proclaim him as the deity of all amateur naturalists.

To the compulsive lister of species, he sends hordes of small warblers, difficult and challenging to identify and extremely satisfying to record. To the casual bird watcher, who wants to enjoy nature without too many hassles,  he will direct a mother Spotbill with ducklings swimming across his binocular’s view. A beginner will be blessed with a Paradise Flycatcher which will surely make him gaga about the rare wonderful bird that he saw! But this God is especially kind to that least and most obscure community of birdwatchers –  the kitchen window birdwatchers.

To be a member of this club you have to be a hard-working housewife and the glances through the kitchen-window or from the balcony or terrace are the only ornithological indulgences that are allowed  in between the drudgery of chores. I really respect these kitchen-window bird watchers. My mother, my aunt, my wife, my cousin sister – they are all members of this venerable clan.

The gracious God sends them ‘Tit-bits’ (pun intended) to lighten their long labour. My mother was rewarded with the sight of a Jungle Crow with overlong curved upper beak which she attempted to feed to the great happiness of the squirrels. My aunt enjoyed the sight of sunbirds nesting year after year in the bush outside her kitchen window. My sister saw a Spotted Owlet in Pune city in the tree opposite her verandah which wasn’t – it was a Scops Owl which all will agree is a rare and delicious find!

Just a few days ago, my wife, who has a keen eye for sound, heard a harsh call amidst the noisy cackle of the babblers.

The babblers are a familiar feature of Maharashtra’s landscape.  They are earthy-brown, generally unkempt and noisy birds which are always seen in a flock, hence their colloquial name of “Saat bhai” or “Saat behen” (‘seven brothers’ or ‘seven sisters’ in Hindi).

Large Grey Babbler (Turdoides malcolmi)

Large Grey Babbler (Turdoides malcolmi)

The babblers in our garden are the Large Grey Babblers (Turdoides malcolmi). They squabble around our courtyard and never seem to leave our garden. Who can blame them? Here they find – a neatly tended lawn, profusely bloomed flower beds with interesting flowers (both coloured and fragrant), din -k- raja, raat -ki-rani, plumeria, papaya, a small pond deliberately run wild with bulrushes all around it, a variety of trees all around the fence both inside and outside, an interesting garbage heap, a neglected garden patch, a servant’s quarter with its associated fireplace and litter, and long weedy verges aside the driveway. Though they  deign to favour our neighbours from time to time,  its ””’our””’ garden they occupy and I proudly call this flock ”mine”.

Since they are such a constant part of the background, I tend to take them for granted. “Ghar ki murgi dal barabar” so goeth the old adage ( a rough translation of this Hindi proverb is – the delicious chicken dish if cooked at home is considered equal only to the lowly lentil! ).

After all, they are only ”babblers”; virtually the first bird a new birdwatcher learns about and soon tires of. They aren’t as gaudy as the Golden Oriole which flies across our clearing. Or as distinct as the Bharadwaj  (Coucal) that struts across the fence-lawn-pond-papayas route four times a day in his tireless, rapacious search for food! Or as spectacular as the Grey Hornbills which play catch-me-if-you-can amongst the ”Gliricidia” trees. They are plain ashy-coloured biscuit brown birds who cackle and perform but soon tire you of their antics.

But all of a sudden that day, they pulled a rabbit out of a hat. In this case, it was an adopted child! And it was my beloved kitchen window-birdwatcher (my better 99% – for those joining in now) who spotted it!

A forlorn squawk drew her attention to the branches above where the flock foraged on the ground. Above, on the branch of the tree in our backyard, was perched a grey bird heavily striated on its chest. It was a juvenile “Brainfever bird“!

My wife caught her breath, because just then a babbler flew up and deposited a meal in the gaping maw of the young ‘un. The babblers were feeding the bird.

The 'adoped child' and his mom (?).

The 'adoped child' and his mom (?).

There is a simple explanation for this! The “Brainfever bird” is a cuckoo. Most of us will know it as the “papeeha” while birdwatchers call it the Common Hawk-cuckoo (Heirococcyx varius) because it resembles very closely our resident Indian sparrow-hawk – the Shikra.

The Brainfever Bird adult.

The Brainfever Bird adult.

The Shikra (Accipiter badius) which the hawk-cuckoo resembles.

The Shikra (Accipiter badius) which the hawk-cuckoo resembles.

The papeeha is a brood parasite of the Turdoides babblers. When the female babblers are not looking, the female Hawk-cuckoo will deposit its egg in their nest.

Cuckoos are known to roll off some or all of the genuine eggs to make place for their egg. Usually a cuckoo’s egg resembles the host species’ egg very closely in colour and pattern though it may be larger in size. Sometimes birds recognise the eggs as ‘strange’ and eject them but in the majority of the cases they do not.

Looking away - the adopted child's orange bill and indistinct eye-ring are visible.

Looking away - the adopted child's orange bill and indistinct eye-ring are visible.

In some species, the cuckoo’s egg hatches earlier and the young cuckoo fledgeling kicks off the eggs or nestlings of the host species and makes itself the lord of the nest.

The cuckoo sibling is ravenous. Its gaping maw resembles that of the babbler’s nestlings and the plaintive cries trigger the feeding instinct in the babblers. Though it grows larger and looks different from the babblers, the hosts are trapped in their instinctive response which the cuckoo has evolved to take advantage of.

This phenomenon is called “brood parasitism” and is considered a form of “kleptoparasitism” where birds steal resources from others to gain an advantage in  propagating their kind.

A very poor photo with cuckoo and babbler in the same frame.

A very poor photo with cuckoo and babbler in the same frame.

Our brain-fever bird is quite large now. It is larger than its adopted parents but yet it follows the pack around positioning itself at a vantage point above where the babblers forage. Soon it will be able to fend for itself and the babblers will be free from feeding such a hungry brute. Lets hope the next time they are able to raise their own kind.

Fortunately Large Grey Babblers are irregular in habit in breeding while cuckoos breed as per season so they have a far chance of raising their kind. The breeding season of the Common Hawk Cuckoo varies from place to place and is very dependent not only on its hosts but its very competitive cousin, the Pied Crested Cuckoo (Clamator jacobinus) who also parasitises the same hosts – the babblers.

Brainfever birds are relatively benign parasites. On many occasions the host is able to raise its own chicks as well as that of the cuckoos. The babblers are known to collectively rear the young. Parent babblers often rejoin the flock after the fledgelings have flown. However, the adopted child of the Brainfever bird is dependent for much longer and hence our observations in CME. As per T.C. Jerdon, Brainfever birds often do not eject the eggs or young and permit the host to breed its children alongwith them.

This is not so in the case of its relative, the Great Spotted Cuckoo (Clamator glandarius) of Europe. The female of this species exhibits an extreme form of aggressive brood-parasitism, referred to as the “Mafia hypothesis“. She revisits the nests of the host birds where she has laid an egg. If that egg has been ejected, she lets loose her anger and destroys the nest. This is a very good move on her part – if a nest is destroyed early in a season,  the nesting pair of the host species may rebuild the nest and lay another clutch. This will give her a chance to breed once again. She will again visit the new nest repeatedly to ensure her egg is safe and repeat her destruction if the egg is mising.

This is however an extreme case of animal behaviour and shared by one another species only – the Brown-headed Cowbird of subtropical North America.

Great Spotted Cuckoo, a.k.a. the Mafia cuckoo

Great Spotted Cuckoo, (clamator glandarius) a.k.a. the Mafia cuckoo

Before you get all furious over our cuckoos, remember enough of their hosts breed so as to maintain a large enough population to bring up the next generation of cuckoos. Too high a success rate in nest-parasitism is its own death knell.

Besides, the host birds develop behavioural patterns to reduce the effectiveness of the brood-parasites – an evolutionary battle constantly rages between the hosts and the brood parasites.

Most of all we should not denigrate these birds because it is they who provide the beautiful bird calls which warn of the onset of India’s summer, monsoon or spring.

The koel’s crescendo and the “brain-fever brain-fever” call of the papeeha are known to all.

My favourite memory of cuckoo-calls is that of   the liquid four notes of the Indian Cuckoo in the Himalayan spring which remind me of the first four notes of the popular Ventures tune “Popcorns’ which once accompanied Sports Roundup in the good old days of black and white TV! Many’s the time I returned tired from a run at the Indian Military Academy when the Indian Cuckoo luled me to sleep.

Listen to it here!

Besides this, we have the Plaintive Cuckoo, the Drongo-Cuckoo and so many, many more.

They too are the gems of Indian biodiversity.

Some references.

1.    Gaston, AJ & Zacharias VJ. (2000). “Hosts of the Common Hawk Cuckoo”. Forktail Vol 16, pg 182. Pulication of the Oriental Bird Club.[url=http://www.orientalbirdclub.org/publications/forktail/16pdfs/Gaston-Cuckoo.pdf].

2.    Jerdon, T.C. (1862). “The birds of India”. Volume 1 (pg 330). Pub – Military Orphan Press. Calcutta.[http://www.archive.org/stream/birdsofindiabein01jerd#page/330/mode/1up].

3.  Payne, R.B. (2005). “The Cuckoos”. Oxford University Press. ISBN 0198502133.

Credits

* All pix of “forcibly adopted child” and that of the Large Grey Babbler mine. See my license publicly declared on the blog.

* Brainfever Bird adult – nidhingpoothully Creative Commons Attribution License 2.0 . On Wikimedia Commons here.

* Shikra – J.M. Garg. Creative Commons Attribution ShareAlike 3.0 license On Wikimedia Commons here.

* Great Spotted Cuckoo (Clamator glandularius). 1905 Naumann encyclopaedia. Public domain. Wikimedia Commons link.


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