Aircraft strikes are a significant safety hazard on airports worldwide. Wildlife management at airfields is the most effective tactic to reduce airstrike risk – to modify the habitat to be undesirable to animals. Tall fescue grasses containing a fungal symbiont may serve that purpose. They produce alkaloids that convey resistance to some grass-feeding invertebrates, which might in turn reduce incidence of insectivorous birds. A commercial endophytic grass (Avanex™) consisting of ‘Jackal’ tall fescue infected with a unique endophyte (AR 601) is purported to contain especially high levels of alkaloids and to reduce bird populations if planted at airports. I evaluated it against the common KY31 tall fescue with its wild-type endophyte for invertebrate and vertebrate deterrence. Invertebrate abundance, survival, growth, and development were generally similar on Jackal E+ or KY31 E+. Spanish goats and wild birds showed no avoidance of Jackal E+, nor did Jackal E+ contain significantly higher levels of alkaloids than did KY31 E+. The Avanex™ tall fescue was not any better than KY31 in deterring herbivores but the concept is sound. However, better understanding of the relationship between grass, endophyte, alkaloid, and herbivore is needed to inform how such grasses might be used to reduce bird strike hazard.