To run or to fly: low cost versus low risk escape strategies in blackbirds
Authors: Rodriguez-Prieto, Iñaki1; Fernández-Juricic, Esteban2; Martín, José1
Source: Behaviour, Volume 145, Number 8, 2008 , pp. 1125-1138(14)
Publisher: BRILL
Abstract:
When escaping from predators, ground-foraging birds could choose between two escape strategies with different costs: running or flying. We simulated predator attacks on blackbirds Turdus merula to investigate the factors influencing blackbirds to select between these strategies. The probability that blackbirds would fly increased as flight initiation distance decreased, suggesting that they may trade-off benefits of delaying escape with a costly escape strategy. The probability of flying also increased as the number of potential predators increased, indicating an increase in perceived predation risk with the number of non-attacking predators. Running was more likely to be used in the mornings and flying in the afternoons, suggesting a possible mass-dependent predation risk effect or restrictions in the use of costly escape strategies when energetic reserves are lower. Juvenile blackbirds tended to fly away more often than adults, probably to compensate for their less reliable risk assessments due to lack of experience. We conclude that different factors act independently on choosing an optimal escape strategy, and that the decision about when to escape (flight initiation distance) is associated with the decision about how to escape (escape strategy), which in turn can affect the decision about how far to escape (distance fled).Keywords: FLIGHT INITIATION DISTANCE; ESCAPE STRATEGY; DISTANCE FLED; LANDING DISTANCE
Document Type: Research article
DOI: http://dx.doi.org/10.1163/156853908784474489
Affiliations: 1: Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal 2, 28006 Madrid, Spain 2: Department of Biological Sciences, California State University Long Beach (MS 3702), 1250 Bellflower Boulevard, Long Beach, CA 90840, USA;, Email: efernand@csulb.edu
Publication date: 2008-08-01
- In this: publication
- By this: publisher
- In this Subject: Biology/Life Sciences , Zoology , Ecology
- By this author: Rodriguez-Prieto, Iñaki ; Fernández-Juricic, Esteban ; Martín, José

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