DOI: 10.5061/dryad.6q573n65f
title: Young male blackcaps with blood parasite coinfections cope with oxidative stress favouring anthocyanin-rich food during migratory fattening

description: Parasites may alter host physiology, which may promote behavioural
 adaptations to counteract their effect. Adaptive feeding may help
 individuals to cope with infection, especially during physiologically
 demanding life stages. For instance, migrating birds need fuel for
 long-distance flights and to repair oxidative damage caused by intense
 aerobic exercise, and parasites may influence how individuals balance
 these needs. Infected birds may face increased oxidative challenges, which
 could induce them to favour antioxidant defences over other needs, such as
 fattening. We tested whether migrating birds can adaptively choose food
 according to their needs, favouring dietary antioxidants to cope with
 oxidative stress caused by haemosporidian blood parasites during
 migration. During autumn migration, we mist-netted young male Eurasian
 blackcaps (Sylvia atricapilla) stopping over in central Spain. We placed
 the birds in cages where they were offered fat and anthocyanin-enriched
 food alternatives. We measured preference for each food offer. We tested
 their infections with haemosporidian parasites by PCR techniques and their
 parasitaemia by blood smear inspection. We also measured physiological
 variables that account for nutritional and oxidative status in red blood
 cells and plasma. We found that birds with multiple infections favoured
 anthocyanin-enriched food controlling for an effect of body mass on food
 preference (lean blackcaps preferred anthocyanins, likely because they are
 urged to repair oxidative damage upon arrival on stopover with depleted
 energy reserves). Haemosporidian-infected birds had a lower antioxidant
 capacity of plasma, although no effect of infections on oxidative damage
 was detected, and individuals with more oxidative damage preferred
 anthocyanin-enriched food. Our results suggest that haemosporidian
 infections may increase individuals’ antioxidant needs, which could affect
 migratory performance if the urge to find dietary antioxidants reduces the
 rate of fuel consumption.
description: # Young male blackcaps with blood parasite coinfections cope with
 oxidative stress favouring anthocyanin-rich food during migratory
 fattening Authors:
 Jiménez-Gallardo, Lucía; López-Arrabé, Jimena; Pérez-Tris, Javier;
 Remacha, Carolina Journal: Journal of Avian Biology Paper
 DOI:10.1111/jav.03214 ## Description of R SCRIPT files (A) DATABASE
 PREPARATION: \- Filename = "MS_SYATDIET_db.qmd". PREVIOUS to
 perform any ANALYSES this script must be run to generate adequately
 transformed behavioural, physiological and biological data. This script
 generates a ready for use database for analyses save as
 "SYATDIET_db_test.csv". (B) TEST ANALYSES: \- Filename =
 "MS_SYATDIET_test.qmd". Script with the code to reproduce all
 the analyses and results of the manuscript. It can be run with the
 database file previously generated "SYATDIET_db_test.csv". ##
 Description of variables in the DATA files:
 "MS\_SYATDIET\_db.csv" and "SYATDIET\_db\_test.csv" \*
 order = correlative order \* LAB_SAMPLE_CODE = individual identity code \*
 year = 2019 and 2020 \* weight1 = body mass of the bird \* tarsus = tarsus
 length (mm) \* nbeh.peckfat = number of times the bird peck the fat \*
 nbeh.intfat = number of times the bird is interested in the fat \*
 nbeh.peckattfat = number of times the bird tries to peck the fat \*
 nbeh.peckantiox = number of times the bird peck the antioxidant \*
 nbeh.intantiox = number of times the bird is interested in the antioxidant
 \* nbeh.peckattantiox = number of times the bird tries to peck the
 antioxidant \* INFnLIN = number of haemosporidian lineages \* INF_P_CILO =
 2 categories of infection by Plasmodium parasites following Ciloglu et al.
 2019 protocol (0 = not infected, 1 = infected) \* INF_H_CILO = 2
 categories of infection by Haemoproteus parasites following Ciloglu et al.
 2019 protocol (0 = not infected, 1 = infected) \* INF_L_CILO = 2
 categories of infection by Leucocytozoon parasites following Ciloglu et
 al. 2019 protocol (0 = not infected, 1 = infected) \* INF_P5000 = number
 of infected erytrocytes by Plasmodium parasites in 5000 erytrocytes \*
 INF_H5000 = number of infected erytrocytes by Haemoproteus parasites in
 5000 erytrocytes \* INF_L5000 = number of infected erytrocytes by
 Leucocytozoon parasites in 5000 erytrocytes \* Haemoglobin = level of
 haemoglobin (g/dL units) \* CV.Haemoglobin = coefficient of variation of
 haemoglobin level \* Plate.Haemoglobin = plate of the sample in the
 haemoglobin assessment \* GSH = level of glutathione in RBC (GSH) (μmol
 g-1 units) \* CV.GSH = coefficient of variation of glutathione levels in
 RBC (GSH) \* Plate.GSH = plate of the sample in the glutathione levels in
 RBC (GSH) assessment \* prot = level of protein (g/dL units) \* CV.prot =
 coefficient of variation of protein level \* Plate.prot = plate of the
 sample in the protein assessment \* TAS = level of total antioxidant
 status (TAS) (mM Trolox units) \* CV.TAS = coefficient of variation of TAS
 level \* Plate.TAS = plate of the sample in the TAS assessment \* uric =
 level of uric acid (mg dL-1 units) \* CV.uric = coefficient of variation
 of uric acid level \* Plate.uric = plate of the sample in the uric acid
 assessment \* MDAplas = level of malondialdehyde (MDA) in plasma (μmol
 mL-1 units) \* CV.MDAplas = coefficient of variation of MDA level in
 plasma \* MDARBC = level of malondialdehyde (MDA) in red blood cells
 (RBC)(μmol mL-1 units) \* CV.MDARBC = coefficient of variation of MDA
 level in red blood cells (RBC) \* TG = level of triglycerides (mg dL-1
 units) \* CV.TG = coefficient of variation of triglycerides level \*
 Plate.TG = plate of the sample in the triglycerides assessment \*
 Haemolysis = level of blood haemolysis, 3 categories (0 = no haemolysis,
 1=low level, 2 = high level) \* nfatbehav = total number of behaviours
 towards fat \* nantioxbehav = total number of behaviours towards
 antioxidant \* nprefbehav_tot = total n behaviours towards a food offer \*
 npref = factor determining if the bird had some preference \* nprefbehav =
 preference towards fat in behaviour taking into account the peckings,
 pecking attempts and interest. Higher values account for a preference
 towards fat \* infected = factor determining the general infection status
 (0 = not infected; 1 = infected) \* coinfected = factor that distinguish
 the level of infection (0 = not infected; 1 = single infected; 2 =
 multiple infected) \* INFintensity = intensity of infection of the 3
 parasite genera \* INFintensityLog = log transformed intensity \*
 nbeh.peckfatlog = log transformed nbeh.peckfat \* nbeh.intfatlog = log
 transformed nbeh.intfat \* nbeh.peckattfatlog = log transformed
 nbeh.peckattfat \* nbeh.peckantioxlog = log transformed nbeh.peckantiox \*
 nbeh.intantioxlog = log transformed nbeh.intantiox \*
 nbeh.peckattantioxlog = log transformed nbeh.peckattantiox \* resBM =
 residual body mass calculated as the residuals of the regression between
 log transformed weight and tarsus \* stdresBM = standardized resBM \*
 stdINFintensityLog = standardized INFintensityLog \* GSHcor = GSH
 corrected by protein concentration \* MDARBCcor = MDARBC corrected by
 protein concentration \* MDAplaslog = log transformed MDAplas \*
 MDAplassqrt = squareroot transformed MDAplas \* TGlog = log transformed TG
 \* TGsqrt = squareroot transformed TG \* stdHaemoglobin = standardized
 Haemoglobin \* stdprot = standardized prot \* stdGSH = standardized GSH \*
 stdGSHcor = standardized GSHcor \* stdTAS = standardized TAS \* stduric =
 standardized uric \* stdMDAplaslog = standardized MDAplaslog \* stdMDARBC
 = standardized MDARBC \* stdMDARBCcor = standardized MDARBCcor \* stdTGlog
 = standardized TGlog \* RBChorm = hormetic effect between stdMDARBCcor and
 stdGSHcor. Higher values correspond with higher values of both variables
 \* RBCstress = gradient of oxidative stress in red blood cells measured
 between stdMDARBCcor and stdGSHcor. Higher values correspond with more
 oxidative damage \* TAScor = TAS values corrected by uric acid levels.
 Residuals of the regretion between TAS and uric \* stdTAScor =
 standardized TAScor