Morphology and Morphometry of Caeca in the Tufted Duck Aythya Fuligula

Morphology and Morphometry of Caeca in the Tufted Duck Aythya Fuligula In this study, we examined the caeca of 44 individuals of Tufted Duck (Aythya fuligula): 29 males (23 adult and 6 young) and 15 females (8 adult and 7 young). We analyzed the correlations between lengths of left (CLL) and right (CRL) caeca vs. the dimensions of the bird's body: body weight (BW), body length (BL), sternum length (SL) and tarsus length (TL), in relation to the sex of the animals. We also analyzed the asymmetry of caeca and determined its direction and strength, using a fluctuating asymmetry coefficient. Despite the observed sexual dimorphism in the body size, we found neither sex-related differences in the length of caeca, nor any significant correlation between the CLL and CRL vs. body size (BW, BL, SL, TL). 42 birds (94.5%) were asymmetrical with respect to the length of caeca, and in 37 (84.1%) the left caecum was longer. The fluctuating asymmetry coefficient for the length of these organs in the examined group was 0.413.