Predation risk-induced adjustments in provisioning behavior for Horned Lark (Eremophila alpestris) in British Columbia

Abstract

ABSTRACT Parental provisioning rates influence nestling development with consequences for their survival and fitness as adults, but provisioning behavior can be disrupted by predation risk. For an alpine population of Horned Lark (Eremophila alpestris) on Hudson Bay Mountain, British Columbia, we tested the effects of perceived predation risk on parental provisioning behavior. Using a repeated measures experimental design, we presented nests with decoys representing 3 levels of predation risk: (1) a scent-oriented predator (red fox; Vulpes vulpes), (2) a visually oriented predator (Common Raven; Corvus corax), and (3) a noncompetitive sympatric species (Savannah Sparrow; Passerculus sandwichensis) as a control. We found that elevated perceived predation risk decreased parental nest visitation rate by 65.6% compared to the control rate (mean 0.64 [SE 0.04] visits per 10 min), with no difference in response to predators that use visual (raven: 0.17 [0.03]) or olfactory (fox: 0.27 [0.04]) cues after controll...