DOI: 10.5061/dryad.44j0zpcq5
title: Phylogenetic relationships of immune function and oxidative physiology with sexual selection and parental effort in male and female birds

description: Sexual differences in physiology are widely regarded as potential
 proximate mechanisms that underlie sex differences in mortality, life
 history, and disease risk of vertebrates. However, little is known about
 the causes of sex-specific variation in physiology. Sexual selection and
 parental workload are two key components suggested to play a role. Theory
 predicts that, within males, species with stronger male sexual selection
 (greater sexual dichromatism and more frequent social polygyny) and higher
 male parental effort should have lower immune capacity and stronger
 oxidative imbalance. Within females, a weak or no direct effect of male
 sexual selection on physiology is expected, but species where females
 invest more in parental care should have lower immune capacity and higher
 oxidative imbalance. We tested these predictions by phylogenetic
 comparative analyses conducted separately for the two sexes and based on
 11,586 physiological measurements of samples collected in the field from
 2,048 individuals of 116 and 106 European species for males and females,
 respectively. For males, we found that the degree of dichromatism,
 polygyny and male parental effort correlated negatively with multiple
 immune indices, and the level of antioxidant glutathione correlated
 positively with polygyny score. In contrast, female immune and oxidative
 variables were unrelated or weakly related to both male sexual selection
 or female parental effort. We conclude that sex roles can drive
 inter-specific variation in immune function (primarily in male birds), but
 less so in oxidative physiology. These findings support earlier claims
 that males pay higher physiological costs of sexual selection than
 females, but apparently also of caregiving. We discuss how females might
 avoid such costs.
description: All morphological, behavioural, and ecological parameters
 provided in Table 1 and used in the analyses were extracted from published
 articles as stated in the Methods. For all physiological traits, species-
 and sex-specific average physiology measures as best linear unbiased
 estimates (BLUEs) are provided. The blood samples for physiological
 measures were collected from wild birds captured during the breeding
 season.
description: # Phylogenetic relationships of immune function and oxidative physiology
 with sexual selection and parental effort in male and female birds ##
 Description The dataset contains species-specific values for body mass and
 parental effort of males and females, sexual dichromatism, male polygyny
 score, extra pair paternity, diet and average physiology measures
 (heterophils, lymphocytes, white blood cells, heterophile: lymphocyte
 ratio, agglutination, lysis, bacteria-killing activity, total antioxidant
 status, uric acid, total glutathione, reactive oxygen metabolites,
 malondialdehyde) of males and females provided as best linear unbiased
 estimates (BLUE scores) and sample sizes for each measured physiological
 parameters. Note that cells from Table 2 with NA represent missing values.
 Physiological measures were collected from 116 and 106 European bird
 species for males and females, respectively, captured at various sites
 across Romania during the breeding season between 2011 and 2013, and
 between 2016 and 2019. The sources of all morphological, behavioural, and
 ecological traits from Table 1 are provided in the Methods. ## Data Files
 ## dryad_table1.csv Data on body mass (g) of males and females, the amount
 of parental effort of males and females, sexual dichromatism based on
 plates in the Handbook of the Birds of the World Alive (del Hoyo, Elliott,
 & Christie, 2017), male polygyny score (0 - no or very rare polygamy
 (&lt; 0.1% of individuals), 1 - rare polygamy (0.1–1%), 2 - uncommon
 polygamy (1–5%), 3 - moderate polygamy (5–20%), and 4 - common polygamy
 (&gt; 20%)), extra pair paternity (% offspring) and diet. See Materials
 and methods for further information. ## dryad_table2.csv Data on species
 and sex-specific sample sizes and BLUE scores for each measured
 physiological parameter. ## Variable Dictionary – dryad_table2
 **Heterophils_Male** – Mean BLUE score for the heterophil cell count for
 males. **Heterophils_Nmale** – Sample size for male heterophil cell count
 (number of individuals). **Heterophils_Female** – Mean BLUE score for the
 heterophil cell count for females. **Heterophils_Nfemale** – Sample size
 for female heterophil cell count (number of individuals).
 **Lymphocytes_Male** – Mean BLUE score for the lymphocyte cell count for
 males. **Lymphocytes_Nmale** – Sample size for male lymphocyte count
 (number of individuals). **Lymphocytes_Female** – Mean BLUE score for the
 lymphocyte cell count for females. **Lymphocytes_Nfemale** – Sample size
 for female lymphocyte count (number of individuals).
 **White_blood_cells_Male** – Mean BLUE score for the total white blood
 cell count for males. **White_blood_cells_Nmale** – Sample size for male
 white blood cell count (number of individuals).
 **White_blood_cells_Female** – Mean BLUE score for the total white blood
 cell count for females. **White_blood_cells_Nfemale** – Sample size for
 female white blood cell count (number of individuals).
 **Heterophile_Lymphocyte_ratio_Male** – Mean BLUE score for the heterophil
 to lymphocyte ratio for males. **Heterophile_Lymphocyte_ratio_Nmale** –
 Sample size for male heterophil to lymphocyte ratio (number of
 individuals). **Heterophile_Lymphocyte_ratio_Female** – Mean BLUE score
 for the heterophil to lymphocyte ratio for females.
 **Heterophile_Lymphocyte_ratio_Nfemale** – Sample size for female
 heterophil to lymphocyte ratio (number of individuals).
 **Agglutination_Male** – Mean BLUE score for the natural antibody
 agglutination titre for males. **Agglutination_Nmale** – Sample size for
 male agglutination score (number of individuals). **Agglutination_Female**
 – Mean BLUE score for the natural antibody agglutination titre for
 females. **Agglutination_Nfemale** – Sample size for female agglutination
 score (number of individuals). **Lysis_Male** – Mean BLUE score for the
 complement-mediated lysis titre for males. **Lysis_Nmale** – Sample size
 for male lysis score (number of individuals). **Lysis_Female** – Mean BLUE
 score for the complement-mediated lysis titre for females.
 **Lysis_Nfemale** – Sample size for female lysis score (number of
 individuals). **Bacteria_killing_activity_Male** – Mean BLUE score for the
 bactericidal activity for males. **Bacteria_killing_activity_Nmale** –
 Sample size for male bactericidal activity (number of individuals).
 **Bacteria_killing_activity_Female** – Mean BLUE score for the
 bactericidal activity for females. **Bacteria_killing_activity_Nfemale** –
 Sample size for female bactericidal activity (number of individuals).
 **Total_antioxidant_status_Male** – Mean BLUE score for the total
 antioxidant status for males. **Total_antioxidant_status_Nmale** – Sample
 size for male total antioxidant status (number of individuals).
 **Total_antioxidant_status_Female** – Mean BLUE score for the total
 antioxidant status for females. **Total_antioxidant_status_Nfemale** –
 Sample size for female total antioxidant status (number of individuals).
 **Uric_acid_Male** – Mean BLUE score for the uric acid concentration for
 males. **Uric_acid_Nmale** – Sample size for male uric acid concentration
 (number of individuals). **Uric_acid_Female** – Mean BLUE score for the
 uric acid concentration for females. **Uric_acid_Nfemale** – Sample size
 for female uric acid concentration (number of individuals).
 **Total_glutathione_Male** – Mean BLUE score for the total glutathione
 concentration for males. **Total_glutathione_Nmale** – Sample size for
 male total glutathione concentration (number of individuals).
 **Total_glutathione_Female** – Mean BLUE score for the total glutathione
 concentration for females. **Total_glutathione_Nfemale** – Sample size for
 female total glutathione concentration (number of individuals).
 **Reactive_oxygen_metabolites_Male** – Mean BLUE score for the reactive
 oxygen metabolites for males. **Reactive_oxygen_metabolites_Nmale** –
 Sample size for male reactive oxygen metabolites (number of individuals).
 **Reactive_oxygen_metabolites_Female** – Mean BLUE score for the reactive
 oxygen metabolites for females. **Reactive_oxygen_metabolites_Nfemale** –
 Sample size for female reactive oxygen metabolites (number of
 individuals). **Malondialdehyde_Male** – Mean BLUE score for the
 malondialdehyde concentration for males. **Malondialdehyde_Nmale** –
 Sample size for male malondialdehyde concentration (number of
 individuals). **Malondialdehyde_Female** – Mean BLUE score for the
 malondialdehyde concentration for females. **Malondialdehyde_Nfemale** –
 Sample size for female malondialdehyde concentration (number of
 individuals). ## Contact For questions about this dataset, please contact:
 Peter Laszlo Pap – Babes-Bolyai University –
 [peterlpap@gmail.com](mailto:peterlpap@gmail.com)