Native plants provide equal or better nutrition than crop plants in wildlife plantings

Abstract

As a wildlife biologist, I have often wondered about the tendency of land managers toward planting nonnative species for wildlife, purportedly because of superior nutritional characteristics. Therefore, I analyzed seeds of 26 species of plants for 3 key nutritional factors: gross energy, crude protein, and crude fat. Six of the species were nonnative (including 4 common agricultural crops), whereas the other 20 were native North American plants often reported in wildlife food habits studies. Two crop plants (Helianthus annuus L. [Asteraceae] and Glycine max (L.) Merr. [Fabaceae]), one nonnative plant (Lespedeza bicolor Turcz. [Fabaceae]), and 7 native species had the 10 highest values of crude fat. Glycine max, along with 2 nonnative Lespedeza species and 7 native species had the greatest values of crude protein. For gross energy, Helianthus annuus and Glycine max, along with 8 native species, ranked highest. When comparing the combination of gross energy, crude fat, and crude protein for all species, 4 nonnative and 6 native species ranked highest. This study, the first to test these species with identical procedures, provides comparative evidence that supports using native plants, rather than agricultural and other nonnative species, to supply wildlife winter food.