biostudies-literatureUnknown14(1)Rafael MCortisol is a biomarker of grey wolf (<i>Canis lupus</i>) prey selection on wild ungulates. Throughout its range, wolves may prey on free-range livestock, leading to conflicts with humans. This can compromise wolf conservation through culling or poaching. We investigate whether glucocorticoid concentration could be a biomarker of individual prey selection by grey wolves that depredate on free-ranging cattle (<i>Bos taurus</i>). To achieve this, cortisol concentration in hair samples from live (<i>n</i> = 46) and wolf-preyed (<i>n</i> = 19) cattle was determined by enzyme-linked immunosorbent assays. The effects of intrinsic and extrinsic variables-namely age, sex and food availability-on hair cortisol concentration (HCC) were investigated through linear mixed models with farm as a random eConservation physiologycoag002https://www.ebi.ac.uk/biostudies/studies/S-EPMC12851633biostudies-literatureCould hair cortisol in free-ranging cattle be a proxy of wolf predation patterns?PMC12851633Nakamura MFonseca ERafael MSantos NfalseCould hair cortisol in free-ranging cattle be a proxy of wolf predation patterns?Cortisol is a biomarker of grey wolf (<i>Canis lupus</i>) prey selection on wild ungulates. Throughout its range, wolves may prey on free-range livestock, leading to conflicts with humans. This can compromise wolf conservation through culling or poaching. We investigate whether glucocorticoid concentration could be a biomarker of individual prey selection by grey wolves that depredate on free-ranging cattle (<i>Bos taurus</i>). To achieve this, cortisol concentration in hair samples from live (<i>n</i> = 46) and wolf-preyed (<i>n</i> = 19) cattle was determined by enzyme-linked immunosorbent assays. The effects of intrinsic and extrinsic variables-namely age, sex and food availability-on hair cortisol concentration (HCC) were investigated through linear mixed models with farm as a random e2026-01-01T00:00:00Z20262026-06-15T03:18:00.532Z2026-06-15T03:11:28.668ZS-EPMC128516334161304110.1093/conphys/coag002