Loggerhead Shrike predation

• In Event: Poster Presentation and Judging for: Anthropology; Botany; Conservation Ecology; Environmental Science; Freshwater Science; Geosciences; Mathematics & Computer Science; Neuroscience; Physics & Eng; Science Education; Terrestrial Ecology & Management.
  In Poster Session: Terrestrial Ecology Poster Session

Abstract

The loggerhead shrike (Lanius ludovicianus) is a predatory passerine found throughout the United States. These birds are well known for their tendency to impale prey on sharp objects, allowing easy assessment of their predatory tendencies without disturbing the birds. We conducted a weekly inventory of prey items taken by loggerhead shrikes over the course of a year to analyze prey preference, impaled prey turnover rate, and to test whether shrikes leave prey as territorial markers. We surveyed a shrike larder that consisted of a mile length of barbed wire fence along a rural road in west Texas. Once a week we noted what types of prey were found on the fence and how often specific prey items were still present during the next survey; all prey specimens present were collected once a month for further analysis. A grid system and photos were used to keep track of impaled prey along the barbed wire fence. Prey were more frequently found in the fall and early winter months and begins to wane during nesting and breeding season, which is inconsistent with the hypothesis that prey items are used as territorial markers. Only 1% percent of the prey was left on the fence over the course of a month, suggesting a rapid turnover rate for prey impaled on the barbed wire fence. These results suggest that most prey are primarily impaled for temporary storage and are removed for complete consumption within a month.

Authors

• Morgan Seiler, Sul Ross State University

• Sean Graham, Sul Ross State University