Title

Heads Up! How Nuthatches Communicate Danger

Presenter Information

Nora Carlson

Presentation Type

Poster

Abstract

Predators are a major source of mortality for many species of birds. Many bird species produce alarm calls to warn conspecifics about predator presence, and these calls can also be interpreted by other animals sharing the environment. Alarm calls can encode information about predators such as size and threat level. One type of alarm call, a mobbing call, is produced in response to perched predators; they recruit other birds to assist in driving the predator away. In Montana there are three species of nuthatches (red-breasted, white-breasted, and pygmy). During winter they occur in mixed flocks with chickadees. Studies have shown that red-breasted nuthatches respond appropriately to threat levels encoded in chickadee mobbing calls, which is interesting because of the very different acoustic structure of chickadee and nuthatch calls. There is little information about whether nuthatches also encode such information in their own mobbing calls. I am in the process of examining the following questions: 1. What are the acoustic features of a nuthatch alarm call? 2. Is information about predator threat level/size encoded in their alarm calls? If so, then 3. How is information about predator threat level/size encoded in their alarm calls? To explore these questions I am experimentally presenting wild red-breasted nuthatches with live perched predators, playbacks of predator calls and chickadee mobbing calls given in response to known predators. I am recording the alarm calls with extremely sensitive microphones and analyzing the calls with bioacoustical software. If nuthatches do encode this specific type of information in their mobbing calls it would not only further support the idea that many bird calls encode much more information than previously thought, but it would give us a greater understanding of both eavesdropping and communication in bird communities.

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Apr 13th, 3:00 PM Apr 13th, 4:00 PM

Heads Up! How Nuthatches Communicate Danger

UC Ballroom

Predators are a major source of mortality for many species of birds. Many bird species produce alarm calls to warn conspecifics about predator presence, and these calls can also be interpreted by other animals sharing the environment. Alarm calls can encode information about predators such as size and threat level. One type of alarm call, a mobbing call, is produced in response to perched predators; they recruit other birds to assist in driving the predator away. In Montana there are three species of nuthatches (red-breasted, white-breasted, and pygmy). During winter they occur in mixed flocks with chickadees. Studies have shown that red-breasted nuthatches respond appropriately to threat levels encoded in chickadee mobbing calls, which is interesting because of the very different acoustic structure of chickadee and nuthatch calls. There is little information about whether nuthatches also encode such information in their own mobbing calls. I am in the process of examining the following questions: 1. What are the acoustic features of a nuthatch alarm call? 2. Is information about predator threat level/size encoded in their alarm calls? If so, then 3. How is information about predator threat level/size encoded in their alarm calls? To explore these questions I am experimentally presenting wild red-breasted nuthatches with live perched predators, playbacks of predator calls and chickadee mobbing calls given in response to known predators. I am recording the alarm calls with extremely sensitive microphones and analyzing the calls with bioacoustical software. If nuthatches do encode this specific type of information in their mobbing calls it would not only further support the idea that many bird calls encode much more information than previously thought, but it would give us a greater understanding of both eavesdropping and communication in bird communities.