We calculated the Manly-Chesson alpha index of selectivity for variable prey abundance and normalized it to get electivity
(-1 is complete avoidance and +1 is complete preference) (Chesson 1978) to determine prey preference when appropriate.
arduous with a weak positive electivity
value (D = 0.
Texas persimmon seeds had the highest electivity
The close agreement between taxa in fish stomachs and taxa in the water column is evidence for low electivity
for Salton Sea tilapia when feeding within the water column.
Here, we document spatial variation in electivity
in the Glanville fritillary butterfly, Melitaea cinxia (L.
index was used to determine herbivore preference for each species by ascertaining whether herbivory occurred at a rate predicted by species abundance (random selection; Jenkins, 1979; De Jager et al.
However, as is the case for electivity
indices which may be influenced by external food availability (Strauss, 1979; Gras & Saint-Jean, 1982), this is probably due to a high dominance in the pelagic community of the more frequent and abundant prey items found in the stomachs of this species.
Ivlev's index of electivity
was used to estimate natural prey preferences of C.
Reliability estimates for Ivlevs electivity
index the forage ratio and a proposed linear index of food selection.
Prey selectivity by juvenile salmon species was examined by using Ivlev's (1961) electivity
To determine gamekeepers' habitat selection of drive area, we used the Ivlev electivity
index (Krebs 1989).
The proportions of shells and species in the community were also used to calculate electivity
coefficients (E) based on the work by Ivlev (1961):