DOI: 10.5061/dryad.05qfttfcp
title: Urbanization enhances body condition, but not innate immune defenses, in a common waterbird

description: There is a growing body of evidence that urbanization can affect body
 condition and immune function in wild birds, although these effects may be
 complex and taxa specific. Here, we assessed the effects of urbanization
 on body condition (size-corrected body mass and haemoglobin concentration)
 and innate immune defences (haemolysis-haemagglutination assay,
 haptoglobin concentration, and bacterial killing assay) in 136 Eurasian
 coots (Fulica atra) from three urban and three nonurban populations across
 Poland. We also quantified the heterophil to lymphocyte ratio to control
 for the potential effect of physiological stress on immune defences. We
 found that urban coots showed significantly better condition than nonurban
 ones. At the same time, we found no relationship between any immune
 defence and urbanization or condition. Thus, our study offers no support
 for condition-dependent immune function. Our analyses also revealed
 significant differences between male and female coots in both condition
 and immune defences; however, we found no evidence for sex-specific
 responses to urbanization. In conclusion, our study provides correlative
 evidence that urban habitat enhances condition but not immune defenses in
 the Eurasian coot.
description: # Urbanization enhances body condition, but not innate immune defenses, in
 a common waterbird ## Description of the data and file structure Data were
 collected for 136 Eurasian coots from six populations (three urban and
 three nonurban) across Poland during two breeding seasons (years: 2021 and
 2022). Files and variables File: RSOS-241062_ESM_Raw_Data.xlsx
 Description: Variables * Urbanization The level of urbanization
 ("urban" - an individual was sampled from one of the three urban
 populations, "nonurban" - an individual was sampled from one of
 the three nonurban populations) * Population The population from which the
 individual was sampled. * Year The year in which the individual was
 sampled. * Sex The sex of the individual (F-female, M-male). *
 Haemagglutination The score of haemagglutination (an agglutination of
 cells dependent on the interaction with NAbs) assessed using scans of the
 assay plates (made 20 min after incubation). When the two scores differed
 by 0.5, a mean value was assigned as a final score. When the two scores
 differed by more than 0.5, the sample was scored for the third time and a
 median value was used. * Haemolysis The score of haemolysis (a cell lysis
 response dependent on the interaction between NAbs and complement)
 assessed using scans of assay plates (made 90 min after incubation). When
 the two scores differed by 0.5, a mean value was assigned as a final
 score. When the two scores differed by more than 0.5, the sample was
 scored for the third time and a median value was used. * Haptoglobin
 concentration [mg/ml] The concentration of haptoglobin in plasma sample
 measured with colorimetric assay (PHASE Haptoglobin Assay, Ireland). *
 Bacterial killing capacity The plasma killing capacity was calculated
 dividing the mean number of bacterial colonies on duplicated sample plates
 by the mean number of bacterial colonies on the corresponding duplicated
 positive control plates. * Haemoglobin concentration [g/l] Haemoglobin
 concentration (used as a condition index) was measured with HemoCue Hb
 201+ portable photometer. * Body mass [g] Body mass (used as a condition
 index) was measured with an electronic scale (± 1 g). * Wing length [mm]
 The wing length was measured from the carpal joint (the bend of the wing)
 to the tip of the longest primary feathers with a stopped ruler (± 1 mm).
 Wing length was included as a linear predictor of body mass in the
 statistical models. * Log H/L ratio The H/L ratio (used as the
 physiological stress index) was calculated for each individual as a
 proportion of heterophils to lymphocytes and log-transformed. Missing
 values marked as "NA". ## Code/software All computations were
 performed in R v.4.0.3 statistical environment and Statistica v13.1
 software.