Doi: https://doi.org/10.13157/arla.72.1.2025.ra1
Authors: Jorge GARCíA-MACíA, Laura GARCíA, Carlos TORRALVO, Miguel FERRER and Virginia MORANDINI
E-mail: jgarcia@fundacionmigres.org
Published: Volume 72.1, January 2025. Pages 3-13.
Language: Spanish
Original Title: Human-induced mortality causes affecting a newly established population of Ospreys Pandion haliaetus in southern Iberia
Keywords: biological conservation, fish farms, population dynamics and raptor
Summary:
Local populations of birds contribute to genetic diversity and influence population dynamics at broader scales. Thus, studying the causes of mortality of threatened birds at a local scale is particularly important. In the western Mediterranean the Iberian mainland breeding population of Ospreys Pandion haliaetus was extinct by the 1980s but, following a reintroduction project during 2003-2012 in Andalusia (southern Iberia), a small breeding population has settled in the territory. Furthermore, southern Iberia is an important migratory passage and wintering destination for western palearctic Ospreys. We present mortality data of Ospreys from two decades (2001-2021) to analyse Osprey in Andalusia (southern Spain), including its year-to-year evolution, seasonal patterns, spatial differences and causes of mortality. In total 121 mortality events were reported (6.7 ± 3.8 individuals per year) during 2001-2021. These increased from 2001 to 2021, in parallel with the increase of the migratory, wintering and breeding population in the region. Deaths were higher during the migration and wintering periods, and within the provinces of Cádiz and Huelva, where the populations were also larger. Three main causes of mortality should be highlighted: entanglement in fish farm nets (n = 38, 31%), collision with wind turbines (n = 24, 20%) and electrocution at powerlines (n = 18, 15%). The last two affect many bird groups, especially soaring-gliding raptors, but fish farms only affect piscivorous birds and specific measures should be implemented there to protect Ospreys.
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