Urbanization enhances body condition, but not innate immune defenses, in a common waterbird
Data files
Dec 17, 2024 version files 25.81 KB
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README.md
2.78 KB
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RSOS-241062_ESM_Raw_Data.xlsx
23.02 KB
Abstract
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.
README: 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.