Behavior: Allometry of alarm calls: Black-capped chickadees encode information about predator size

Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
Science (Impact Factor: 33.61). 07/2005; 308(5730):1934-7. DOI: 10.1126/science.1108841
Source: PubMed


Many animals produce alarm signals when they detect a potential predator, but we still know little about the information contained in these signals. Using presentations of 15 species of live predators, we show that acoustic features of the mobbing calls of black-capped chickadees (Poecile atricapilla) vary with the size of the predator. Companion playback experiments revealed that chickadees detect this information and that the intensity of mobbing behavior is related to the size and threat of the potential predator. This study demonstrates an unsuspected level of complexity and sophistication in avian alarm calls.

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Available from: Christopher N. Templeton
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    • "Tadpoles of the frog Rana temporaria hide from predatory waterboatmen (Notonecta sp.), but not from aeshnid dragonfly larvae (Van Buskirk 2001). In chickadees (Poecile atricapilla), alarm calls encode information about predator size, which in turn mediates the intensity of the mobbing behavior directed toward the predator by the receivers (Templeton et al. 2005). The aquatic snail Physa acuta responds to different predators by taking appropriate evasive action, spending more time close the surface of the water when exposed to chemical cues from predatory crayfish, and more time beneath cover when they have detected predatory fish (Turner et al. 2006). "
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    ABSTRACT: Many species gain protection from predators by forming groups, but there is also evidence that some predators are better able to detect or more likely to attack grouped prey. Given this, it might pay prey to be flexible in their group behavior, forming groups on detecting certain predators, but dispersing when detecting others. In the first of 2 experiments, we found that flounders (Platichthys flesus) were more likely to attack larger groups of gammarids (Gammarus pulex) than smaller ones, whereas sticklebacks (Gasterosteus aculeatus) showed no such bias. This gave us the opportunity to test the idea that prey might show predator-specific grouping responses. Accordingly, our second experiment compared the grouping behavior of gammarids exposed to kairomones from either of the 2 predators, to conspecific injury cues (a nonspecific predation cue), to combinations of predator kairomone plus conspecific injury cues and finally to 2 control treatments. We predicted, based on our first experiment, that the gammarids would disperse in response to flounder kairomones, and group more cohesively in response to stickleback kairomones and conspecific injury cues. In fact, only the treatments including conspecific injury cues elicited a grouping response in the gammarids, whereas predator kairomones alone had no effect whatsoever on group cohesion or dispersal. We discuss possible explanations for these findings and briefly consider other systems that might be better suited to exploring predator-specific antipredatory grouping behavior.
    Full-text · Article · Jul 2015 · Behavioral Ecology
    • "Previous chickadee and titmouse studies using both live predators (Sieving et al. 2010; Templeton et al. 2005) and model or taxidermy mount predators (Bartmess-LeVasseur et al. 2010; Courter and Ritchison 2010; Pravosudov and Grubb 1998; Soard and Ritchison 2009) obtained similar patterns of response when the predator was detected. Typically, titmice and chickadees call more and sometimes modify the note composition of their chick-a-dee call, the greater the threat posed by the size or type of the predator stimulus. "
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    ABSTRACT: Although anti-predator behavior systems have been studied in diverse taxa, less is known about how prey species detect and assess the immediate threat posed by a predator based on its behavior. In this study, we evaluated a potential cue that some species may utilize when assessing predation threat-the predator's body and head orientation. We tested the effect of this orientation cue on signaling and predation-risk-sensitive foraging of a prey species, tufted titmice (Baeolophus bicolor). Earlier work revealed sensitivity of titmice and related species to the presence of predator stimuli. Here, we manipulated cat models to face either toward or away from a food source preferred by titmice and then measured titmouse calling and seed-taking behavior. Titmice showed greater feeder avoidance when the cat predator models faced the feeder, compared to when the models faced away from the feeder or when titmice were exposed to control stimuli. Titmouse calling was also sensitive to predator head/body orientation, depending upon whether titmice were from sites where real cats had been observed or not. This study experimentally demonstrated that both calling and foraging of prey species can be affected by the head and body orientation of an important terrestrial predator. Prey species may therefore signal in strategic ways to conspecifics not just about predator presence, but also urgency of threat related to the more subtle cue of the head and body orientation of the predator. These findings hold potential implications for understanding animal cognition and learning processes.
    No preview · Article · Jun 2015 · Animal Cognition
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    • "Various referential and risk-based alarm-calling systems play an adaptive role by eliciting a threat-appropriate response. Blackcapped chickadees, for example, adjust the length and intensity of their mobbing response in accordance with the level of threat encoded in conspecific mobbing calls (Templeton et al., 2005), and threat-specific alarm calls determine situation-specific escape responses in other passerines (Griesser, 2008; Suzuki, 2012). Specific information about a potential threat can thus increase the efficiency of antipredator responses and minimize energy expenditure. "
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    ABSTRACT: Recent studies have demonstrated the presence of risk-based variation in alarm calling in many vertebrate species. Most of the studies on birds, however, have focused on passerine systems perhaps due to the traditional view that passerine vocalizations are more complex. We investigated the presence of a risk-based alarm calling system in a nonpasserine, the herring gull, Larus argentatus, by recording birds presented with varying degrees of threat, and experimentally exposing and quantifying responses to manipulated alarm calls. We found that herring gulls communicate threat urgency in their alarm calls using both frequency and time parameters. Sound recordings indicated that herring gulls change centre frequency modulation patterns of their alarm calls, generate frequency discontinuities in notes and increase the rate of calling with increases in perceived threat level. Playback experiments showed that conspecifics pay attention to both frequency and time parameters and respond most urgently to play-backs of high-threat calls at a high call rate. A less urgent response to high-threat calls at a low call rate and to low-threat calls at a high call rate suggests that threat urgency information is reinforced by both call type and call rate in the herring gull system. This study is one of the first demonstrations of a risk-based alarm calling system in a nonpasserine.
    Full-text · Article · Jun 2015 · Animal Behaviour
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