Ardea
Official journal of the Netherlands Ornithologists' Union

login


[close window] [previous abstract] [next abstract]

Piersma T. (1984) Estimating energy reserves of Great Crested Grebes Podiceps cristatus on the basis of body dimensions. ARDEA 72 (1): 119-126
As a tool in evaluating the survival value of energy reserves, i.e. weight of labile fat and possibly protein stores in relation to the size of a bird, simple and cheap ways to estimate these reserves in Great Crested Grebes Podiceps cristatus are examined. Structural size, i.e. the dry fat-free weight of (starved) Great Crested Grebes with depleted reserves, was best approximated with a multiplication of keel-, wing- and total body length, even though obtained from a (mini-) sample of seven starved grebes. Fat content was best estimated from gross dry weight, but the weight of abdominal fat is the most practical estimator of total body fat in dead grebes. It is shown that in live grebes fat content can be well estimated from body weight when correcting for differences in structural size. Within both sexes, birds with larger structural size have the greater energy reserves and would survive longer when starving in winter.


[close window] [previous abstract] [next abstract]