title: Expression of multiple sexual signals by fathers and sons in the East-Mediterranean barn swallow: are advertising strategies heritable?
abstract: The level of expression of sexually selected traits is generally determined by genes, environment and their interaction. In species that use multiple sexual signals which may be costly to produce, investing in the expression of one sexual signal may limit the expression of the other, favoring the evolution of a strategy for resource allocation among signals. As a result, even when the expression of sexual signals is condition dependent, the relative level of expression of each signal may be heritable. We tested this hypothesis in the East-Mediterranean barn swallow (Hirundo rustica transitiva), in which males have been shown to express two uncorrelated sexual signals: red-brown ventral coloration, and long tail streamers. We show that variation in both signals may partially be explained by age, as well as by paternal origin (genetic father-son regressions), but that the strongest similarity between fathers and sons is the relative allocation towards one trait or the other (relative expression index), rather than the expression of the traits themselves. These results suggest that the expression of one signal is not independent of the other, and that genetic strategies for resource allocation among sexual signals may be selected for during the evolution of multiple sexual signals.
authors: Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel; Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors: Yoni
authors: Y
authors: Vortman
authors: Department of Ecology and Evolutionary Biology, Univ. of Colorado at Boulder, Boulder, CO, United States of America.
authors: Rebecca J
authors: RJ
authors: Safran
authors: Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors: Tali
authors: T
authors: Reiner Brodetzki
authors: Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel; Department of Ecology and Evolutionary Biology, Univ. of Colorado at Boulder, Boulder, CO, United States of America; Fuller Evolutionary Biology Program, Cornell Lab of Ornithology, Ithaca, NY, United States of America.
authors: Roi
authors: R
authors: Dor
authors: Department of Zoology, Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors: Arnon
authors: A
authors: Lotem
mesh_terms: D000819:Animal Communication; D000818:Animals; D005260:Female; D008297:Male; D010641:Phenotype; D015203:Reproducibility of Results; D012725:Sexual Behavior; D046388:Swallows