Female Attraction to Conspecific Chemical Cues in the Palmate Newt Triturus helveticus

Abstract

Although chemosignals are largely used in sexual communication in urodeles, olfactometer studies in newts provided contrasting results about the sex specificity of female behavioural responses. Because long-range sexual advertisement is believed to be costly, some species might restrain this activity to close interactions with conspecifics. We tested chemical-mediated sexual attraction in female palmate newt (Triturus helveticus) by measuring the attraction to male and female odours in a linear water olfactometer. Unexpectedly, females were attracted towards conspecifics regardless of sex. They did not show attraction towards Limnaea stagnalis, a common sympatric aquatic gastropod. These results do not support the use of long-range male sexual signalling in the palmate newt. Instead, conspecific attraction is likely to promote aggregation of males and females in breeding ponds. Observations in the field and in the laboratory tend to support the aggregative behaviour of this species. We discuss the possible function of conspecific attraction in this context. Heading towards any conspecific would increase the probability of finding potential mates. Chemical cues do not need to be sex-specific at that stage so that long-range sexual advertisement might be unnecessary. This work emphasizes the need for studies investigating the evolutionary relationships between sexual signalling systems and population-distribution patterns.

Preference for the other sex: Olfactory sex recognition in terrestrial fire salamanders (Salamandra salamandra)

“…Chemical signals such as pheromones produced by specialized glands and volatile substances from unspecialized epidermal secretions as well as faecal material have been shown to be involved during basic communication processes both between (Halliday, 1990;Houck and Arnold, 2003) and within species (Kikuyama et al, 1995(Kikuyama et al, , 2002Verrell, Strand, and Hanson, 2001;Gautier, Léna, and Miaud, 2004;Secondi, Haerty, and Lodé, 2005).…”

Leaf extracts from an exotic tree affect responses to chemical cues in the palmate newt, Lissotriton helveticus

“…Consequently, the ability to detect ponds containing females should be advantageous for males due to increased mating opportunities (Aragón, López, & Martín, 2000). Similarly, using chemical cues to detect and then avoid ponds with predators would be advantageous due to increased survival (Mathis & Vincent, 2000;Secondi, Haerty, & Lodé, 2005). For experiments 1 and 2 we captured the males in the morning and maintained them in laboratory conditions in groups of 10 individuals/10 litres of original pond water during the afternoon until the experiment started.…”

Love Is Blind: Indiscriminate Female Mating Responses to Male Courtship Pheromones in Newts (Salamandridae)

“…Using experiments with sponges [3], [25]–[27], these molecules were shown to work as sex attractants. In other salamandrids, experiments with linear olfactometers [28], Y-mazes [21], [29] and two-choice aquaria [30], [31] also suggest the presence of attractant pheromones. However, since a male only starts tail-waving in front of the female after an initial investigation [1], [2], [4], [5], [32], the pheromones emitted during this behavior are expected to be courtship rather than attractant pheromones [23], [24], and a straightforward function for these chemical cues therefore remains unknown.…”