NEST BOX SELECTION BY FLOOR LAYING AND REPRODUCTIVELY NAIVE CAPTIVE COCKATIELS (NYMPHICUS-HOLLANDICUS)

These experiments examined the effects of offering captive cockatiels a choice of two types of nest boxes which differed primarily in type o f nest entrance. The nest entrance to cavity-type boxes was circular a nd relatively small (6.4 cm diameter), while that to shelf-type boxes was rectangular and relatively large (15.2 cm x 26 cm). Cockatiels wit h histories of laying in cavity-type boxes tended to choose cavity-typ e boxes for their first and subsequent clutches. Cockatiels with histo ries of either laying on cage floors or not laying in the previous bre eding trial were more likely to choose shelf-type boxes for first clut ches but then switched to cavity-type boxes for subsequent clutches. A pproximately one-third of reproductively naive cockatiels also chose s helf-type boxes for first clutches but increasingly used cavity-type b oxes for subsequent clutches. Cockatiels that laid in cavity-type boxe s never switched to shelf-type boxes. Fertility, hatchability and hedg ing success (survival to 3 weeks of age) were all greater in cavity-ty pe boxes, resulting in greater chick production. These results indicat e that chronic floor laying can be corrected by offering cockatiels sh elf-type boxes and that shelf-type boxes may be useful for improving c aptive reproductive performance of non-layers and naive layers as well .