1. Introduction
The purpose of this chapter is to discuss the evolution of long-distance
acoustic signals through the atmosphere (Bass and Clark, Chapter 2,
address problems in underwater communication). We are especially interested in signals that are used in mate recognition. In most cases, these
signals are produced by males to attract potential mates and repel male
competitors, and they are evaluated by females when they make a mating
decision. Although there are cases of females attracting males and males
choosing females, we will tend to concentrate on the more typical case.
1.1. Long-Distance Signals, Selection, and Evolution
Sounds that have evolved to attract mates over relatively long distances are
common throughout diverse taxa. These signals are often subject to strong
natural selection imposed by the environment and by unintended receivers,
such as predators and parasitoids, as well as sexual selection imposed by
intended receivers, such as potential mates and competitors for those mates.
The importance of these signals in reproduction implicates them in two
processes central to evolutionary biology—speciation and sexual selection.
These are the processes primarily responsible for increasing biodiversity
through multiplying and diversifying species.
Long-distance communication signals occur in many taxa, such as
mammals and fish, but are especially prevalent and well-studied in insects,
frogs, and birds. Within each of these taxa, long-distance signals are betterstudied than acoustic signals used in other contexts (see taxon-specific
reviews cited below). There are several taxon-specific reviews of various
aspects of long-distance communication (e.g., insects: Ewing 1989; Michelson 1998; Römer 1998; frogs: Fritzsch et al. 1988; Gerhardt 1994; Zelick et
al. 1998; Ryan 2001; birds: Kroodsma and Miller 1982, 1996; Catchpole and
Slater 1995) as well as reviews in more general texts on animal communication (Hauser 1996; Bradbury and Vehrencamp 1998; Owens and Morton
225
5
Selection on Long-Distance
Acoustic Signals
Michael J. Ryan and Nicole M. Kime
The purpose of this chapter is to discuss the evolution of long-distance
acoustic signals through the atmosphere (Bass and Clark, Chapter 2,
address problems in underwater communication). We are especially interested in signals that are used in mate recognition. In most cases, these
signals are produced by males to attract potential mates and repel male
competitors, and they are evaluated by females when they make a mating
decision. Although there are cases of females attracting males and males
choosing females, we will tend to concentrate on the more typical case.
1.1. Long-Distance Signals, Selection, and Evolution
Sounds that have evolved to attract mates over relatively long distances are
common throughout diverse taxa. These signals are often subject to strong
natural selection imposed by the environment and by unintended receivers,
such as predators and parasitoids, as well as sexual selection imposed by
intended receivers, such as potential mates and competitors for those mates.
The importance of these signals in reproduction implicates them in two
processes central to evolutionary biology—speciation and sexual selection.
These are the processes primarily responsible for increasing biodiversity
through multiplying and diversifying species.
Long-distance communication signals occur in many taxa, such as
mammals and fish, but are especially prevalent and well-studied in insects,
frogs, and birds. Within each of these taxa, long-distance signals are betterstudied than acoustic signals used in other contexts (see taxon-specific
reviews cited below). There are several taxon-specific reviews of various
aspects of long-distance communication (e.g., insects: Ewing 1989; Michelson 1998; Römer 1998; frogs: Fritzsch et al. 1988; Gerhardt 1994; Zelick et
al. 1998; Ryan 2001; birds: Kroodsma and Miller 1982, 1996; Catchpole and
Slater 1995) as well as reviews in more general texts on animal communication (Hauser 1996; Bradbury and Vehrencamp 1998; Owens and Morton
225
5
Selection on Long-Distance
Acoustic Signals
Michael J. Ryan and Nicole M. Kime