Age-based mate choice and characters displacements
Age based mate choice in Rana dalmatina and Alytes obstetricians
Regarding the advertisement call in anuran as a sexually selected trait, we investigated the effects of male call parameters on reproductive success (both clutch size and hatching success) in Agile and water frogs and in midwife toad Alytes obstetricians.
Alytes obstetricans produced single repeated short calls (mean duration: 132:4 ms; mean interval: 1:44) with a relatively low fundamental frequency (mean frequency: 1341 Hz). Call frequency is associated with the male body size, thus with age, and may act as cues for genetic advantages, as an age-based indicator. Large males obtained more matings, having successive amplexus with several partners, and showed a higher hatching success. Female choice for dominant frequency may be regarded as a related fitness trait. Anyway, the male size and the female choice for low calls result in a same evolutionary trend favouring a best fitness.
Male breeding success is predicted by call frequency in the territorial agile frog (Rana dalmatina). The males having the lowest fundamental call frequency enjoyed better breeding success than those with higher fundamental call frequency. The male call in the agile frog is both a sexually selected trait and a trait associated with the territorial behaviour of this species.
Ecological and reproductive character displacements
Character displacement is an evolutionary mechanism which increases phenotypic differences between species living in sympatry rather than in allopatry, thus leading to a possible speciation process. We studied character displacement in polecat, mink, agile and water frogs (see publications), but here, the page focalized on newts and on Neuroptera (Chrysoperla).
Although chemical cues are largely used in sexual communication in urodeles, palmate newt (Lissotriton helveticus) showed no sex specificity of female responses. Unexpectedly, females were attracted towards conspecifics regardless of sex. Females of L. helveticus expressed a deeper tail when in the presence of the other species, a pattern consistent with reproductive character displacement.
Thus, the evolution of mate recognition systems could occur at a microgeographical scale within a sympatric area…
Generalist predators such as chrysopids may play a key role in crop protection (Conservation Biological Control). The adult chrysopids feed on a narrow range of pollen species, that occur mainly in the habitats in which they spend most time. Studies carried on different Chrysoperla from the complex carnea should provide new results on their sympatric differentiation, including both ecological and reproductive characters …
Pollen (Asteracees) in Chrysoperla (Photo J Villenave)
JOHANET A, SECONDI J, PAYS O, PAGANO A, LODÉ T. & LEMAIRE C 2009. A case of reproductive character displacement in female palmate newts (Lissotriton helveticus). C. R. Biologies, 332: 548-557
LESBARRERES D., LODÉ T & J. MERILA. 2008. Male breeding success is predicted by call frequency in a territorial species, the agile frog (Rana dalmatina). Canadian Journal of Zoology 86, 1273-1279
VILLENAVE J, DEUTSCH B, LODÉ T & RAT-MORISS E, 2006, Pollen preference of the Chrysoperla species (Neuroptera: Chrysopidae) occurring in the crop environment in western France, European Journal of Entomology 103 (4): 771-777
VILLENAVE J., THIERRY D., AL MAMUN, LODÉ T. & RAT-MORRIS E. 2005. The pollens consumed by common green lacewings Chrysoperla spp. (Neuroptera: Chrysopidae) in cabbage crop environment in western France, European Journal of Entomology 102 (3): 547-552
SECONDI J., HAERTY W., & LODÉ T. 2005. Female attraction to conspecific chemical cues in the palmate newt Triturus helveticus. Ethology 111:726-735
VILLENAVE J., CANARD M., LODE T. & RAT-MORIS E. 2005, Ecological and biological notes on lacewing species Psectra diptera in we'stern France (neuroptera: Hemerobiidae), Entomologia generalis 28: 183-192
SECONDI J, HAERTY W, LODE T. 2004. Is there alternate male sexual strategies in the Palmate newt Triturus helveticus? International Society of Behavioural Ecology 2004, Jyväskulä Finland
LODÉ T & D. LE JACQUES 2003. Influence of advertisement call on reproductive success in Alytes obstetricans Behaviour 140: 885-898,
LESBARRÈRES D; & LODÉ T. 2002 Variations in male calls and response to unfamiliar advertisement call in a territorial breeding anuran, Rana dalmatina: evidence for a dear enemy effect. Ethology Ecology & Evolution 14: 287-295
LODÉ T.& PAGANO A. 2000 - Variations in call and morphology in males water frog : taxonomic and evolutionary implications. Compte-Rendus Académie des Sciences Vie/Life Sciences 323 : 995-1001.