Gut Morphometrics in the Long-Tailed Duck Clangula Hyemalis Wintering on the Polish Baltic Coast

Abstract

Gut Morphometrics in the Long-Tailed DuckClangula HyemalisWintering on the Polish Baltic CoastThe study included guts of 140 individuals of the long-tailed duckClangula hyemalisobtained in autumn and winter of 1993-2000 in the western part of the Polish Baltic Coast. The following morphometric characters were analysed: duodenum length (DL), combined jejunum and ileum length (JIL), small intestine length (SIL), combined terminal intestine and cloaca length (TCL), and combined length (CBL) and weight (CBW) of both caeca. In the analysis the birds' sex and age were taken into consideration, as well as their body size characterised by body weight, body length, and sternum length. Ontogenetic differences in the gut morphometric characters were more pronounced in males than in females, and immature drakes were characterised by higher average values of JIL and CBW, compared to adult males. Besides the CBL and CBW, sexual dimorphism was manifest in the body size and other gut measurements - those parameters achieved higher average values in males than in females. No such differences were recorded with respect to relative parameters: DL, SIL, and TCL expressed as the percentage of the birds' body length. In case of JIL, CBL, and CBW no relation with any of the body size parameters was found. No relevant relations between SIL and JIL, and the measurements of CBL and TCL were noticed.