RTÉ box-set well worth viewing

EACH spring, RTÉ’s Mooney Show sets up nest-boxes at locations around Dublin.

The boxes are fitted with video cameras so that nests can be watched on the internet. In show-business, they say, you should never work with children or animals, so reality TV shows featuring birds are brave undertakings. Pit-falls abound and programme makers can suddenly be left with nothing to transmit.

The Mooney nest-box project, however, has been extraordinarily successful; the show’s first web-cam venture, featuring a jackdaw’s nest, won the prestigious Prix Europa prize in Berlin. Last year’s offering developed into a dramatic cliff-hanger as two blue tit broods ran foul of adverse weather and baby birds died.

Tits love nest-boxes and it’s fairly easy to film them but, this year, a pair of robins is nesting, an extraordinary stroke of luck. These miniature thrushes build in the most unlikely places but getting them to do so where there are cameras is a tall order. Blue tits have commandeered another box and, hopefully, they too will nest. Comparing the two families will be especially interesting.

They live in the same places but have radically different lifestyles. Tits spend their lives in trees and bushes, searching for insects and their larvae. Marvellous acrobats, they examine each leaf thoroughly and poke out little creatures hiding in crevasses. Tool use has been recorded twice.

Robins have a more opportunistic approach. Ground-feeders, they perch on branches and fly down to pick up insects they see moving in the grass or leaf litter. Pheasants have bills powerful enough to break open the soil in winter so robins follow them, hoping to grab the odd larva. There are no pheasants in the suburbs so the robins follow gardeners instead.

Whereas the gregarious blue tit spends the winter in flocks, pairing up as spring approaches, the robin leads a solitary anti-social life. Females hold territories in winter, singing as though they were males. As spring approaches, they move tentatively onto the properties of potential husbands. Rejection is common: pair formation in robins is a precarious process.

Tits nested traditionally in tree holes. These are hard to find nowadays, so cavities in walls and buildings are more widely used. An enclosed box, with an opening too narrow for predators to enter, is the bird equivalent of a Medieval bastion: for tits, fortification is the key to security. The nest, built by the female, is a grass cup lined with hair and feathers. Aromatic plants are brought in to ‘decorate’ the home. These probably help to deter parasites.

Robins approach nesting rather differently. Notoriously unconventional when choosing sites, they have been known to commandeer car and aircraft engines, railway wagons and discarded kettles. They can move indoors, building in drawers and on bookshelves. The choice of site may be capricious, but robins are very security conscious; nests are well concealed and camouflaged. The female, which does all the work, is careful not to give the location away. According to robin expert David Harper, ‘if watched too closely (a nest-building female) will ostentatiously carry material to a false site, then sneak to the real nest up to 50 metres away’. The final structure is an untidy cup of grass moss and leaves, lined with hair.

Tits and robins lay about the same number of eggs but tits, in Ireland at any rate, do so in a single clutch whereas robins spread them over two or three. Caterpillars are the mainstay baby-food of tits. These are only available in abundance for a brief period in May so all tit babies must hatch around then.

With their more laid-back approach to food, robins can afford a more extended breeding season. Tit and robin daddies feed their mates and young and, when the female robin starts her second clutch, the male may look after the first brood on his own.

Like their parents, robin youngsters are ferocious land-grabbers. They begin staking out territories a month or two after fledging. A migrant resting on a ship at sea may claim it as a territory, preventing other robins from boarding. Winter territories are defended and migrants visiting Spain maintain territories there, returning to them each winter.

* www.rte.ie/radio/mooneygoeswild/features/mooneycam.