Search results for "mate competition"
showing 3 items of 3 documents
Implications of size‐selective fisheries on sexual selection
2019
Fisheries often combine high mortality with intensive size‐selectivity and can, thus, be expected to reduce body size and size variability in exploited populations. In many fish species, body size is a sexually selected trait and plays an important role in mate choice and mate competition. Large individuals are often preferred as mates due to the high fecundity and resources they can provide to developing offspring. Large fish are also successful in competition for mates. Fisheries‐induced reductions in size and size variability can potentially disrupt mating systems and lower average reproductive success by decreasing opportunities for sexual selection. By reducing population sizes, fisher…
Timing of reproductive effort as an alternative mating strategy in young black grouse (Tetrao tetrix) males
2014
Seksuaalivalinta aiheuttaa yksilöiden välille kilpailua parittelukumppaneista, minkä johdosta osa yksilöistä lisääntyy toisia enemmän. Elinkiertoteorian mukaan yksilöt eivät niukkojen resurssien vuoksi pysty tehokkaasti kohdentamaan energiaa samanaikaisesti useisiin toimintoihin, kuten kasvuun, selviytymiseen ja lisääntymiseen. Ikä, suuri koko ja näyttävät seksuaaliornamentit ovat seksuaalivalinnassa menestyvän yksilön merkkejä, sillä tällaisilla yksilöillä riittää energiaa elintärkeiden toimintojen lisäksi myös lisääntymiseen. Tavallisesti ne menestyvätkin parhaiten kilpailussa parittelukumppaneista. Nuoret tai huonokuntoiset yksilöt voivat kuitenkin turvautua vaihtoehtoisiin lisääntymisst…
Individual- and group-level sex ratios under local mate competition : consequences of infanticide and reproductive dominance
2023
Extremely female-biased sex ratios of parasitoid wasps in multiple-foundress groups challenges evolutionary theory which predicts diminishing bias as foundress numbers increase. Recent theory based on foundress cooperation has achieved qualitative rather than quantitative success in explaining bias among parasitoids in the genus Sclerodermus. Here, we develop an explanation, expanding the theory of local mate competition, based on the observation that male production seems dominated by some foundresses within groups. Two sex ratio effects arise from such reproductive dominance: an immediate effect via suppression of male production, and a long-term evolutionary response to reproductive skew…