Important aspects of courtship displays include male alert posture, approach and pursuit, the marking of the substrate trail, and tail undulations. and generally increase female receptivity towards the male's spermatophore and improve his chances of
reproductive success with her. In the
red-legged salamander (Plethodon shermani), males directly apply pheromones onto the female's nares. In the aquatic
smooth newt (
Lissotriton vulgaris), the pheromones are delivered indirectly; the male wafts them towards the female with his tail. In some species, it has been shown that the size a larger, more elaborate male's tail has played a role in the female's decision to mate. In the newt species of the
Italian crested newt (
Triturus carnifex), males that possessed large mid-dorsal body crests were more favorable to the females looking to mate. Female choice is the final step in the males attempt to reproduce; if the female does not find the male's traits desirable, reproduction will not be successful. As it is in most species, body size is an important and most common desired trait amongst females. Body size is indicative of fitness and/or genetic quality; and because it is easily observable, it can be an indicator for how a female will pick her mate. A larger body size positively correlates to higher paternity; thus larger males are more successful in siring more offspring than smaller males. Male salamanders also prefer larger females because they produce more ova than smaller females. In sexual coercion, a form of male sexual intimidation which includes forced copulations, repeated mating attempts with the same female, and punishing resisting females. even though prevailing scientific opinion is that sexual coercion is a manifestation of
sexual conflict, stemming out of the natural discord between males and females. In some species of salamanders, females that are territorial and aggressive also intimidate males.
Plethodon cinereus females aggressively punish males who are exhibiting social
polygyny. Males have been shown to punish females that partake in mating polyandry, forcing them into mating monogamously. Populations of salamanders tend to be heavily male-biased, which results in a higher number of males vying for access to the lesser number of females. Males will use different tactics in an effort to keep other males away from the female of interest and ensure their own paternity and reproductive success, such as sexual defense, which is used to steal other males
spermatophore, which may have already deposited into the female, and sexual interference, when a male pushes the female away from another courting male, a tactic for avoiding sperm competition. The male removes the sperm from a female who had mated with a previous male: many species of salamanders will remove the spermatophore from the previous male and insert his own; thus, ensuring his paternity. Sperm storage is a method by which females can control the sperm that fertilizes their eggs. Female salamanders and newts, most notably
Triturus vulgaris, possess sperm-storage glands called spermathecae in the walls of their cloacae. Sperm storage has evolved independently to control reproduction in response to the environment. Females have the ability to store multiple spermatophores until they are needed for fertilization. Spermatophores are composed of a cap containing the spermatozoa and a gelatinous support arrangement which fastens the spermatophore to a substrate. Spermatophores are very central to reproductive success; therefore, they are handled carefully. Mating success has a direct correlation to favorable phenotypic traits such as tail loss, adult body size, and age. == Vocal signaling in frogs ==