Salamander female behavior

The main effect of courtship pheromones is to alter female behavior in such a way that insemination is more likely to occur. In the giant danaine butterfly, for example, the male produces courtship pheromones from specialized structures termed hairpencils. The pheromone is released onto the female s antennae as the male hovers above her. Following reception of the pheromone, the female assumes an abdomen-curling posture that apparently facilitates copulation (Nishida, Schulz, Kim, Fukami, Kuwahara, Honda Hayashi, 1996). A variety of other arthropod species also have courtship pheromones (e.g., Birch, 1974 Boppre, 1984 Grant, O Connell Eisner, 1989). These specialized chemosignals are not known for any vertebrate group, however, with the exception of salamanders (Houck, 1986). 

The delivery of male courtship pheromones is widespread among plethodontid salamanders (Houck and Arnold 2003), and other courtship pheromones are being discovered for this group (Houck, Palmer, Watts, Arnold, Feldhoff and Feldhoff 2007). The mode by which these pheromones are transferred to the female apparently has been modified from delivery via diffusion into the circulatory system to delivery that directly stimulates vomeronasal receptors (Fig. 20.1 Houck and Sever 1994 Watts et al. 2004 Palmer et al. 2005 Palmer et al. 2007). The behavior patterns and morphologies associated with these two delivery modes often remain static for millions of years. In contrast, evolution at the level of pheromone signals is apparently an incessant process that continuously alters the protein sequence and composition of pheromones both within and among species (Watts et al. 2004 Palmer et al. 2005 Palmer et al. 2007). 

Salamander courtship pheromones produced by male P. jordani share the basic characteristics of substances known to affect female reproductive behavior. The R jordani extract was comprised primarily of glycoproteins, including highly stable and non-volatile... 

Evidence from these three levels—courtship observations, morphology and experimental courtship manipulations—is summarized below. Most information is available for salamanders in three families (Ambystoma-tidae, Salamandridae, and Plethodontidae) which account for the majority of salamander species living today. The information below is not intended to duplicate detailed reviews of salamander reproduction and courtship behavior (e.g., Arnold, 1972, 1976, 1977 Houck, 1977, 1982 Joly, 1966 Organ, 1961 Salthe, 1967). Instead, I focus on specific examples that highlight the diversity of modes with which males deliver courtship pheromones to females. 

In summary, virtually all of the information on territorial pheromones (through behavioral inferences of their existence) comes from single species, Plethodon cinereus. Evidence to date indicates that at least males (and perhaps females) place chemical substances on the substrate, that these substances are contained in fecal pellets and are produced in or near the cloaca (though other glandular sources are not ruled out), that these substances tend to deter intruders from entering a marked (territorial) area, and that the aggressive and submissive interactions of territorial residents and intruders are governed in part by these substances (and in part by visual displays). Thus, pheromones, whatever they are, are used by Plethodon cinereus (and perhaps other species of salamanders) to advertise territorial possession. 

Forester, D. C., 1981, Parental care in the salamander Desmognathus ochrophaeus Female activity pattern and trophic behavior, Herpetol., 15 29. 

Forester, D. C., 1984, Brooding behavior by the mountain dusky salamander Can the female s presence reduce clutch desiccation Herpetologica, 40 105. 

Highton, R., and Savage, T., 1961, Functions of the brooding behavior in the female red-backed salamander, Plethodon cinereus, Copeia, 1961 95. 

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