The Role of Intra-Clutch Variation of Magpie Clutches in Foreign Egg Rejection Depends on the Egg Trait Considered
| Autor: | Jesús Gómez, Marta Precioso, Jesús M. Avilés, Gustavo Liñán-Cembrano, Juan Gabriel Martínez, Mercedes Molina-Morales |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
egg phenotype and spottiness
Ecology Evolution Color color Variation (linguistics) Brood parasitism Statistics embryonic structures Trait QH359-425 Clutch Repeatability fractal dimensions repeatability Fractal dimension Egg phenotype and spottiness Ecology Evolution Behavior and Systematics brood parasitism QH540-549.5 Mathematics |
| Zdroj: | Frontiers in Ecology and Evolution, Vol 9 (2021) Digibug. Repositorio Institucional de la Universidad de Granada instname Digital.CSIC. Repositorio Institucional del CSIC |
| Popis: | MM-M and JA conceived the idea and analyzed the data. MM-M led the writing of the manuscript. MP and JGM performed the experiment in the field work. JG and GL-C carried out the images processing and performed the analyzes related to fractal dimension. All authors contributed critically to the drafts and gave final approval for publication. We thank Brian Peer for inviting us to contribute to this special issue. We are also indebted to Daniel Hanley and Vanina Dafne Fiorini for comments that greatly improved the manuscript. The existence of a coevolutionary process between avian brood parasites and their hosts predicts a lower intra-clutch variation in egg appearance of host eggs among rejecters as this would favor egg discrimination of parasite eggs by hosts once parasitic egg mimicry had evolved. So far empirical tests of this prediction have ignored the fact that different aspects of host egg phenotypes may differ in the relative role of environmental vs. genetic determination, and hence that the role of intra-clutch variation in egg rejection within a population cannot be invariant. Here, we estimated whether the intra-clutch variation in several aspects of host eggshell features is consistently associated to rejection of parasitic foreign eggs across years in a magpie host population parasitized by great spotted cuckoos. We innovatively estimated spottiness by means of the fractal dimension of eggs, which considers the homogeneity of spot pattern complexity in eggshells. Our results show that low intra-clutch variation in the blue-green coloration at the middle area of the eggs associated with a high chance of rejection, but only in one of the 3 years we conducted the study. In addition, females that rejected foreign eggs presented more homogenous spot patterns in their clutches as estimated by their fractal dimension than females that accepted experimental eggs, independently of the year of study. Finally, intra-clutch variation in egg volume of host eggs was not associated to rejection. Analyses at the individual level revealed that the relative role of genetic vs. environmental factors that determine egg phenotype would be feature-specific in magpies, females having a characteristic spottiness, but not color or volume, pattern. Our work stresses the importance of considering a holistic approach including several aspects of variation in host egg phenotype (size, color, and homogeneity of spot pattern), as some aspects might be more susceptible to selection through egg rejection than others, presumably because they are less influenced by variation in the environmental conditions. Moreover, our study highlights the importance of replication in studies on the adaptive value of host traits in egg rejection. This study was made possible through funding by the Spanish Ministry of Science through different projects (CGL2011-27561 and CGL2014-55362-P), a grant (BES-2015-075675), the Juan de la Cierva–Incorporación Fellowship (IJC2018-036411-I), and the Junta de Andalucía through a project (P06-RNM-01862). |
| Databáze: | OpenAIRE |
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