Rare Feeding Behavior of Great-Tailed Grackles () in the Extreme Habitat of Death Valley

ABSTRACT

During the twentieth century, the Great-tailed Grackle (Quiscalus mexicanus) underwent a rapid and largescale range expansion, extending its northern limits from Texas in 1900 to 21 states in the US and 3 Canadian provinces by the end of the century. This explosive growth correlated with human-induced habitat changes. To investigate adaptations that might explain their expansion into even extreme habitats, a small number of Great-tailed Grackles were observed in Death Valley, CA. We noticed that these birds displayed a rare feeding behavior, i.e. picking dead insects from the license plates of parked vehicles. All birds used the same technique in obtaining the food and the behavior was displayed by both males and females. It was estimated that this food resource has a major contribution to the daily food intake. No other bird species sharing the same habitat showed this behavior although American crows (Corvus brachyrhynchos) had the possibility to watch the Great-tailed Grackles behavior.