Known predators include Spermophilus parryii and Mustela erminea which are most prevalent during the breeding season. Since nests are on the ground, Harris's sparrows provide an easy target for these terrestrial predators. Otherwise, Lanius excubitor and Falco columbarius are their main predators.
As an anti-predator adaptation, Harris's sparrows fly up into trees when startled by humans. They duck down to the ground when threatened by other birds. They also produce alarm calls when threatened to alert others. (Norment and Shackleton, 1993; Norment, 1993)
Anti-predator Adaptations: Cryptic