Causes of admission and outcomes of white-tailed eagles Haliaeetus albicilla in wildlife rescue centres in the Czech Republic during 2010–2020

Abstract

Admission records from wildlife rescue centres can help identify causes of morbidity for species of conservation concern, and to assess the effectiveness of rehabilitation. This study documents the causes of admission and outcomes of treatment in 68 white-tailed eagles admitted to rescue centres in the Czech Republic. We determine the factors that contribute to the outcome of rehabilitation. Most admitted birds were juveniles (1^st calendar year [CY]; n = 25), followed by immatures (2^nd–4^th CY; n = 23) and adults (≥5 CY; n = 17). We categorised admission causes into (1) trauma-related cases (most often unknown trauma, followed by collision and intraspecific fights), (2) non-trauma cases (weakness, toxicosis and becoming stuck in mud or entangled in rope) and (3) orphaned young birds. Trauma-related admissions were most numerous totalling 59%, non-trauma admissions accounted for 35% with the remaining 6% comprising orphaned young birds. At least a third of eagle admissions were caused by anthropogenic factors. In total, 40% of admitted eagles were released back to the wild, 35% died or were euthanized and 25% remained permanently in captivity. Eagles admitted due to non-trauma-related causes had a significantly higher probability of being released into the wild than those admitted due to trauma. Immature eagles were less likely to be released than juvenile individuals. Admissions data are valuable for conservation research, allowing for trends in threats towards species of conservation concern to be quantified, over time, throughout human-dominated landscapes.