Assessing Feeding Preferences of a Consumer Guild: Partitioning Variation Among versus Within Species.

In this study, we examine feeding preference through repeated laboratory choice feeding assays of 444 wild-caught individuals of eight invertebrate grazer species on rocky reefs in northern California. Between-species variation accounted for 25%-33% of the total variation in preference for the preferred resource, while between-individual variation accounted for 4%-5% of total variation. For two of the eight species, between-individual variation was significantly different from zero and on average contributed 14% and 17% of the total diet variation, even after accounting for differences due to size and sex. Therefore, even with clearly distinguishable between-species differences in mean preference, diet variation between and within individuals can contribute to the dietary niche width of species and guilds, which may be overlooked by focusing solely on species' mean resource use patterns. PMID: 30125236 [PubMed - in process]
Source: The American Naturalist - Category: Biology Authors: Tags: Am Nat Source Type: research