Fifty-eight previously paired cockatiels were force-re-paired based on breeding history to determine the relationship between reproductive experience and nesting success. Males (M) and females (F) were assigned a breeding history that was 'experienced' (E) or 'inexperienced' (I), depending on whether they were part of a pair that had hatched at least one egg during the past two breeding trials. Re-pairing resulted in four groups designated EMEF, EMIF, IMEF, and IMIF. Nesting success was defined as incidence of, or latency to, nest inspection, nest-bowl formation, and egg laying, as well as hatchability of eggs. Additionally, age, pre-laying nestbox occupancy, and relative cage height were evaluated for relationship to nesting success. Eight weeks after re-pairing, birds were exposed to environmental stimuli for breeding, and nestboxes were checked dally for evidence of nest inspection, bowl formation, oviposition, and hatching. Videocameras recorded nestbox occupancy for 4 h every other day. Overall, groups differed significantly in the number of pairs that inspected nests and formed bowls; nest inspection was lowest for IMIF, and bowl formation was highest for EMEF. When groups were combined based on male breeding history, significantly more EM than IM inspected nests and formed bowls. Comparing groups based on female breeding history, significantly more EF than IF inspected nests and formed bowls. Only EF laid eggs, and mates of EF's that laid spent significantly more pre-lay time in the nestbox than did mates of EF's that didn't lay. Pairs in elevated cages inspected nests and initiated clutches significantly more than did lower tier pairs. Results of this study should be useful to aviculturists trying to select bird combinations and aviary design to maximize productivity.
- Nesting success