BLACK-BILLED MAGPIES (PICA HUDSONIA) CACHING FOOD IN SNOW

Abstract

I observed Black-billed Magpies (Pica hudsonia) in a residential backyard in Montana during November-December 2019 and February 2020, as they cached food 10 times in a snow cover 10- to 12-cm deep and recovered 3 caches from the snow. The magpies carried food items up to 7 m from a food source before caching them, and tended to cache more closely to the food source when alone rather than in the presence of other magpies. Most of the snow caches were on the ground, but 1 cache was made 1.5 m above ground in a snow-covered vine thicket, and a 2nd cache at the same height in snow accumulated on the roof of a parked trailer. Cached foods included chicken scratch (grains and cracked corn), sunflower seeds, crab apples, dried mealworms, and commercial suet. These observations appear to constitute the 1st report of Black-billed Magpies caching food in snow.