Found this intresting note on breeding the Black-cheeked by Raymond Sawyer at Chestut Lodge :
Not many woodpeckers were imported and few have been bred in captivity here in the UK, but one which was bred successfully at Cobham is the Black-cheeked Woodpecker Melanerpes pucherani from Central and northern South America. The male and female look similar to each other, except that the male's cap is a stronger shade of red. This species was first bred there in 1992. The pair nested in the trunk of a Silver Birch Betula pendula, cut into three sections for ease of handling and moveability. Once the pair had excavated the nest hole, there was nothing further to do but wait and hope until they saw lots offood being taken into the nest and then knew the pair had young. Eventually four emerged. Raymond believed they remained in the nest for about three weeks. The pair went on to breed successfully on numerous other occasions, including in 1996. Over the years Raymond found that woodpeckers enjoy nectar and always ensured that it was available for them. He added, that as well as nectar, the Black-cheeked Woodpeckers liked softbill food, fruit and livefood. At the time, the pair shared the flight with a Scarlet-chested Sunbird Nectarinia senegalensis and Raymond got pleasure from watching the sunbird and woodpeckers drinking from the same dish of nectar. He found it is not a particularly aggressive species. When the pair first bred, it was sharing the flight with a pair of Black-naped Fruit Doves Ptilinopus melanospila.