Egg-sequence rather than mating preference influences female egg investment in the red-legged partridge

Abstract

In precocial bird species, the eggs represent a strong maternal allocation of resources and constitute most of the maternal investment since parents do not feed the young after they hatch. Females can differentially allocate resources in their eggs as a response to the environment experienced during the laying period, including the quality of their mate. To assess the importance of female selection on egg composition in the red-legged partridge, we tested breeding females in a choice trial in which they were allowed to choose between males. After the choice trials, the females were mated with their preferred male (P group), with a non-preferred one (NP group) or with a randomly selected male (RND group). Eggs laid by females of the three groups did not differ significantly in mass, shape, yolk, albumen or shell weight. Moreover, there was no significant difference in egg lysozyme concentration (an important albumen antimicrobial component). There was a significant difference in egg characteristics in relation to position in the laying order, with last-laid eggs being heavier and more spherical. Last-laid eggs contained more albumen but their shell was lighter and the albumen contained less lysozyme. This study shows that partner attractiveness may not influence the characteristics of egg quality, and that in this partridge species the females are able to invest in large clutches without a decrease of egg size but with a progressive decrease of egg quality.

Shifts in Bacterial Communities of Eggshells and Antimicrobial Activities in Eggs during Incubation in a Ground-Nesting Passerine

“…In parallel, studies on wild birds have instead evaluated factors responsible for the albumen antimicrobial allocation among eggs, clutches or species. For instance, lysozyme concentration was shown to decrease with laying order—in barn swallows ( Hirundo rustica ) [ 30 ], red-legged partridges ( Alectoris rufa ) [ 31 ], and grey partridges ( Perdix perdix ) [ 32 ] (but see [ 33 ])—in line with the hypothesis that longer exposure to ambient conditions increases microbial invasion rates [ 1 ]. Despite the effort in describing antimicrobial deposition, how their activities vary during incubation remains unknown in wild birds.…”

Effects of experimentally increased in ovo lysozyme on egg hatchability, chicks complement activity, and phenotype in a precocial bird

“…Similarly, within species variability in egg white LSM concentration has been documented. For example, elevated egg white LSM have been observed in early‐laid eggs, where it also appears to improve hatchability due to antimicrobial protection (Cucco et al, ; Saino et al, ), and in eggs sired with attractive males, possibly enhancing the survival of such potentially high quality hatchlings (D'Alba et al, ; Giraudeau et al, ).…”

Avian Haemosporidian Diversity on Sardinia: A First General Assessment for the Insular Mediterranean

“…During the Pleistocene, the Western Mediterranean islands (i.e., Balearic Islands, Corsica, Tuscan Archipelago and Sardinia) acted as a glacial refugium for several organisms [29], and through subsequent isolation mechanisms became an important biodiversity hotspot in Europe [30]. Sardinia hosts a very rich avifauna including 163 breeding bird species [31], of which several are endemic taxa or have unique genotypes relative to mainland populations [32][33][34][35][36]. In addition, the breeding avifauna is comprised of both sedentary species (or populations) and migratory species.…”