Physical and Migration Metrics of White Storks (Ciconia ciconia) and the influence that landfills play in their variation

This is a Preprint and has not been peer reviewed. This is version 2 of this Preprint. You must log in to post a comment. There are no comments or no comments have been made public for this article. This is a Preprint and has not been peer reviewed. This is version 2 of this Preprint. Add a Comment You must log in to post a comment. Comments There are no comments or no comments have been made public for this article. 1. White storks (Ciconia Ciconia) are a traditionally fully migratory species and their numbers in western Europe were decimated in the last century. Their numbers have since boomed and they have altered their migratory strategy to have become a partially migratory species. This change has been ascribed in large part to anthropogenic food subsidies, particularly in the form of landfill sites. 2. We measured the size, and using GPS logger data monitored the movement, of 73 juvenile white storks in their first migration from southern Portugal to the Sahel. We compared their sizes and migration timings and movement metrics with each other and compared all with the minimum distance between their nest and a landfill site. 3. Birds were larger and left their nests later the closer to a landfill they were raised. Some variations in migration were noted in north Africa and crossing the Sahara. Birds raised closer to landfills traversed from Tangiers south across the Atlas Mountains more efficiently, but then crossed the Sahara more slowly, than those raised farther from landfills. Additionally, based on landfill distance, variations in easting whilst crossing the Sahara were noted. 4. We conclude that landfill proximity impacts on the fitness of a bird and that fitter birds successfully complete more migrations. The impact of removal of landfill food subsidies could severely impact the annually resident population of white storks within western Europe but is unlikely to cause serious issues to the migrant populations. https://doi.org/10.32942/X20646 Comparative and Evolutionary Physiology, Ecology and Evolutionary Biology, Life Sciences, Ornithology, Zoology White stork (Ciconia ciconia) Migration ecology Anthropogenic food sources Landfill foraging GPS tracking Movement ecology Bio-logging Juvenile bird migration You c, swap one of the species-specific ones for: Animal movement Avian ecology Human–wildlife interactions, White stork (Ciconia ciconia), Migration ecology, Anthropogenic food sources, Landfill foraging, GPS tracking, movement ecology, bio-logging, Juvenile bird migration, animal movement, Avian ecology, Human–wildlife interactions Published: 2025-07-25 00:19 Last Updated: 2025-07-25 00:19 CC BY Attribution 4.0 International Conflict of interest statement: None Data and Code Availability Statement: Open data/code are not available. Language: English