Negative correlation between nuptial throat colour and blood parasite load in male European green lizards supports the Hamilton–Zuk hypothesis

Abstract

During female mate choice, conspicuous male sexual signals are used to infer male quality and choose the best sire for the offspring. The theory of parasite-mediated sexual selection (Hamilton-Zuk hypothesis) presumes that parasite infection can influence the elaboration of sexual signals: resistant individuals can invest more energy into signal expression and thus advertise their individual quality through signal intensity. By preferring these males, females can provide resistance genes for their offspring. Previous research showed that nuptial throat colour of male European green lizard, Lacerta viridis, plays a role in both inter- and intrasexual selections as a condition-dependent multiple signalling system. The aim of this study was to test the predictions of the Hamilton-Zuk hypothesis on male European green lizards. By blood sampling 30 adult males during the reproductive season, we found members of the Haemogregarinidae family in all but one individual (prevalence = 96%). The infection intensity showed strong negative correlation with the throat and belly colour brightness in line with the predictions of the Hamilton-Zuk hypothesis. In addition, we found other correlations between infection intensity and other fitness-related traits, suggesting that parasite load has a remarkable effect on individual fitness. This study shows that throat patch colour of the European green lizards not only is a multiple signalling system but also possibly acts as an honest sexual signal of health state in accordance with the Hamilton-Zuk hypothesis.

Effects of energy and thermoregulation time on physiological state and sexual signal in a lizard

“…Since our data do not allow setting up cause‐causative links among the traits affected by our treatments, we can only say that this pattern is suggestive of a direct costs of sexual signaling both in terms of general (ROMs) and specialized (suppressed immunocompetence) decrease in physiological performance. We have shown earlier that this sexual signal is linked to parasite infection intensity in line with the parasite‐mediated sexual selection (Molnár et al., ). The present results further support the notion that the UV‐blue nuptial throat patch is an honest signal in male L. viridis .…”

“…Additionally, suboptimal environmental temperature significantly decreased UV color development (Bajer et al., ). Different throat color components act as a condition‐dependent multiple signaling system (Molnár et al., ), conveying information about blood parasite infection (Haemogregarinidae) (Molnár et al., ) and spatial strategies (Molnár, Bajer, Szövényi, Török, & Herczeg, ). Hence, it is an ideal model to study how environmental factors may simultaneously affect sexual signal intensity and physiological state, helping us to form testable hypothesis about the physiology–sexual signal link.…”

A Comparison of Multiple Methods for Estimating Parasitemia of Hemogregarine Hemoparasites (Apicomplexa: Adeleorina) and Its Application for Studying Infection in Natural Populations

“…Iberolacerta monticola [43], P. lilfordi [51] and Lacerta viridis [91]). Body size has been used as an estimator of age in reptiles [92], [93], with older individuals of the same species usually being larger in size.…”

Morphological and molecular characterization of Karyolysus ¿ a neglected but common parasite infecting some European lizards

“…Therefore several authors classified detected parasites only as "haemogregarines" or "blood parasites" [9,[11][12][13][14]. The presence of blood parasites was detected in various European lizards including Algyroides nigropunctatus, Iberolacerta horvathi, Podarcis muralis and P. melisellensis from Austria and Croatia [3], Podarcis lilfordi from Balearic Islands [11], L. agilis and Zootoca vivipara from Poland, Denmark and Sweden [4,5,9], L. viridis from Hungary [15], Podarcis bocagei and Podarcis carbonelli from Portugal [16], L. agilis chersonensis from Romania [2] and Iberolacerta monticola, P. muralis and Timon lepidus from Spain [12][13][14].…”