Differences in Bone Mineral Content and Density between Male and Female Budgerigars during the Non-reproductive Season

Source: ZULAUF-FISCHER, A. LIESEGANG, M. HAESSIG, M. CLAUSS, J.-M. HATT (2006), Journal of Veterinary Medicine Series A 53 (9), 456–457
It is known that female birds increase medullary mineral stores in long bones shortly before egg laying.
Here, we present results from two groups of budgerigars (Melopsittacus undulatus), in both of which females had significantly higher bone mineral contents and densities, as measured by peripheral quantitative computed tomography of the tibiotarsus, during a reproductively dormant period. The results could indicate that female birds can accumulate mineral stores outside of the breeding season.