The nature conservation group of New Acropolis in Budapest has been placing and maintaining bird boxes in the Danube-Ipoly National Park for ten years now. This spring, in the twenty bird boxes that were placed out over the years, volunteers found several newly built nests, 2 or 3-week-old tit nestlings and the eggs of tits and flycatchers. Participants of an outing organized by the group, in addition to assessing the condition of the bird boxes, also collected the rubbish off the ground, as materials released from aluminium and plastic bottles can damage wildlife.