Why holes and hollows are prime properties for some avian species.
For a large number of bird species,holes and hollows are hot property. Whether they are in walls,in boles or branches,in cliff-faces or mountainsides,or even in the ground they are snapped up pronto and ugly brawls over property rights may occur. Woodpeckers,barbets,parakeets,mynas,hoopoes,hornbills,owls,chats,magpie robins,bee-eaters,and kingfishers are just some of the everyday species that bring up their babies in such places. Think of the advantages of raising a family in such accommodation: usually,its readymade; all you need to do is to put in the soft furnishings. Of course,some DIY hard hats like woodpeckers and barbets personally drill holes in tree trunks,but many trees have natural holes and hollows,as do walls,cliff-faces and crumbling monuments. Besides,if you belong to the Mafiosi mynas,you can always turf out a righteous resident and move in.
I once discovered a hole that had been painstakingly excavated by a coppersmith that looked like it was going to settle down it kept going in and popping its head out in an approving sort of way,looking this way and that; when I visited the site the following week,a blackrumped flameback (golden-backed woodpecker) had taken possession and like any new tenant was making modifications; shards of wood flew out thick and fast as it went about its work. The next time I went there,there was no sign of any birds,but bees were humming around it possessively,so that was that. It would have been interesting to see how the bees actually turfed out the flameback.
But usually from a security point of view holes are top-class. Theyre completely sheltered from the elements (and prying predators usually),the wind wont blow your home and babies away,and you can,if you are a grey hornbill,up the security to Z+ by sealing up the entrance with mud and excreta (leaving just a slit for feeding purposes) while your wife sits on the eggs and broods. Later of course,when the eggs hatch,shell break free but seal the kids inside and both mom and pop feed the brats until such time as they are grown enough to leave home. A magpie robin I met on the Delhi Ridge had another trick up its sleeve (probably inadvertent). I used to see it fly out of its hollow,but never saw it fly in. Then I walked around the tree and sure enough,there was a backdoor through which,she was entering a convenient escape route in case a snake slithered in.
Indeed,these are so hot,that sometimes a whole bunch of expectant moms will lay their eggs in the same hole,with or without the approval of the rightful matron. Forty-seven eggs have been discovered in one such hole occupied by a (obviously very maternal) comb-duck; fortunately ducklings are chilled-out babies and can look after themselves as soon as they hatch so they jump out into the water below and paddle off happily. For some ground nesters like burrowing owls (in wanton California for example),who live in underground burrow colonies,the cheek-by-jowl proximity of the neighbours (the hunk next door or the golden-eyed dumpling) makes for very interesting if salacious suburban soap-operas and lots of little half-sibling owlets.
Cities like Delhi,for example,with its crumbling ruins and walls and parks are good places for hole-nesters. Parakeets occupy niches and holes in every old fort or monument or wall,hornbills and owls nest in the hollows of big trees peepul,banyan,tamarind in gardens,parks and along the avenues of New Delhi,barbets and woodpeckers drill their own neat round holes in acacias,rock chats move into old abandoned structures,and mynas occupy weep-holes in walls everywhere.
The weep-holes in a wall opposite Delhis Indra Prastha College,used to be full of apartment dwelling bank mynas,who would stick their heads out and gossip: the wall was taken down for the construction of the Metro and the mynas lost their homes,but later it was reconstructed and theyre back now,lively and loquacious as ever. Theyre hardcore urbanites and have also moved into the holes in the walls along flyovers.
More rural perhaps,are kingfishers and bee-eaters which nest in holes drilled into soft earth banks. Kingfishers excavate holes by diving head-first into the soft mud banks along the river for example and bee-eaters excavate holes and tunnels in soft-earth banks. Both have to finish chick-rearing by the monsoons,when their homes would literally turn to mud. Dead trees too are relatively easy to drill holes into,(by woodpeckers and barbets) and make popular nesting sites and so are better left standing,unless of course theres a danger of them falling.
The biggest danger,of course,comes from us. If you spot the nesting hole of a parakeet or owl or hornbill,do not stand and gawp. Youll be spotted immediately by urchins or sleazy undesirables. The parakeet babies will promptly be taken for sale as pets,the owlets and hornbills used for hideous black-magic rituals or the making of medicinal potions. No bird will ever be able to nest in that hole safely again.
Ranjit Lal is an environmentalist and bird watcher