Growth allometry in the Ring Ouzel, Turdus torquatus. Multivariate analysis

  • Marián Janiga National Park High Tatras, Research Coordination Centre, 069 60 Tatranská Lomnica, Czech and Slovak Federal Republic
Keywords: Growth allometry, Turdus torquatus, breeding responses, PCA, Low Tatras, Carpathians


The five-year study presents the results of statistical multivariate techniques which extend our knowledge on intraspecific differences in the growth pattern of Ring Ouzels. Because the chronological time has only an approximate relationship to biological age, the data is evaluated by the multivariate allometry without knowledge of nestling age. The allometric - first principal component from PCA is used to evaluate the influence of clutch adjustment, hatching asynchrony and brood size on the growth pattern of nestlings. Patterns of growth differ between the earlier and later hatched nestlings. Younger nestlings tend to be under weight for their primaries. Comparable analysis of different breeding responses shows that the allometric magnitude of developmental slowing is greatest among younger nestlings within a brood. The effect of brood reduction on the growth pattern is almost identical to this but the effect is probably less important than the effect ol asynchronous hatching. The examination of the effect of clutch adjustment on the growth pattern shows that the growth described in the form of body weight versus size skeletal index reflects the influence of exogenous factors, most likely because of the seasonal change in food.

How to Cite
Janiga, M. (1992). Growth allometry in the Ring Ouzel, Turdus torquatus. Multivariate analysis. Oecologia Montana, 1(1), 21-30. Retrieved from
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