Date: June 12, 2018
Source: British Ecological Society
Complete brood failure in blue tits is almost always associated with the sudden and permanent disappearance of one of the parents. Scientists show in their study that the remaining parent substantially increased its effort to raise at least some of the chicks, which turned out to be successful in two thirds of the nests.
Single parent males generally do worse, probably because they are not able to keep their chicks warm. Their findings are published today in the Journal of Animal Ecology.
Apart from being a popular garden feeder visitor, blue tits have been the focus of much research on the causes and consequences of variation in reproductive success. Blue tits typically lay between 8-15 eggs, of which a varying number of young will survive to leave the nest. In some nests, however, all the offspring die before they are old enough to leave the nest.
Finding out what causes these cases of complete brood mortality has proven challenging. Does one parent leave all the care to its mate? Can a single parent not cope with the demands? Do both parents decide to desert their brood? To find out, we need to know exactly when parents stop bringing food and when the offspring perish.
Therefore, Peter Santema and Bart Kempenaers from the Max Planck Institute for Ornithology in Seewiesen equipped all adult blue tits in their study site with a tiny, passive integrated transponder.