More on the validation of fecal samples for the large-scale study of dietary differences between two sympatric carnivores

Abstract

S. 2007. More on the validation of fecal samples for the large-scale study of dietary differences between two sympatric carnivores. Acta Theriologica 52: 307-315.Prey occurrence from stomach and fecal samples were compared in American marten Martes americana Turton, 1806, and fisher M. pennanti Erxleben, 1777. Diets were analyzed from stomach and fecal contents in four sex-age marten groups and four fisher groups, and dietary differences tested between species, sex, age and sample sources. Prey richness was compared between the two sample sources. Relative occurrence of dominant or co-dominant prey items did not differ between stomach and fecal samples in any of the groups. However, both series revealed inter-specific contrasts. Binomial correlations of prey occurrence between sample sources were significantly negative for most prey items. Correlations of prey richness between samples sources were not significant except in larger marten sample. Our results failed to reveal a bias in using fecal sample source. Thus we suggest that diet analyses using either sample source are valid when diets are assessed in a relatively large number of animals.

Assessing carnivore diet by faecal samples and stomach contents: a case study with Alpine red foxes

“…In contrast, mammalian hairs are well preserved during the digestive process and easily found in the faecal samples [11]. Conflicting results have been reported for digestion processes found in other small mammals such as martens [6,8], suggesting that the separation of feather fragments could be a peculiarity of the physiology of digestion of foxes.…”

“…Although the correct interpretation of the results requires that the limits of each method are disclosed and accounted for, multiple techniques have been applied and compared in only a few studies, yielding contrasting conclusions: no method-related differences in diet composition have been found comparing stomach and intestine contents of martens Martes americana and M. pennanti [8,9], while differences have been reported for prairie dog Cynomys ludovicianus [10] and red fox Vulpes vulpes [11,12].…”

Distinctive diets of eutherian predators in Australia

“…There are significant biases in the analysis of diet from scats compared with stomach contents due to differential digestibility of particular diet items (but see [ 214 ]). The identification of less plant [ 215 , 216 ], and the underreporting of amphibians [ 23 , 32 ] from scats has been identified previously.…”