Drastic reduction of the population distribution of White Storks predicted in absence of landfills

Abstract

Organic waste production has greatly increased following human sprawl and led to the development of landfills in recent decades. This abundant and reliable anthropogenic food source has favored several species, some of which consequently became overabundant. Landfills present hazards to wildlife, which may suffocate on plastic materials, tangle on cords, and get exposed to pollutants and pathogens. In response to environmental and public health concerns over the maintenance of landfills, the European Commission proposed to close the landfills. Our objective was to determine the impact of Landfill European Directive on the White Stork (Ciconia ciconia) whose population recovery and growth was linked to landfill exploitation. We implemented species distribution models to project future distribution in the absence of landfills in the Community of Madrid (Spain). Habitat suitability was estimated based on nest occurrence and we included data from land cover types, human population density, and two different climate change scenarios (i.e., emissions in low and high shared socioeconomic pathways). Given that protection measures, particularly implemented in protected areas, were associated with population recovery, we also evaluated the overlapping degree between protected areas and projected distribution. Our models predicted a sharp decline in breeding population distribution with landfill closure, reaching values similar to the 1984 breeding census when the species was categorized as threatened. Our results also suggest a decrease in maximum habitat suitability. Climate change also contributed to a reduction in breeding population distribution given model predictions for the extreme emission pathway (ssp5). Measures such as gradual change in landfill management, continuous monitoring of breeding populations, and evaluation of the White Stork use of natural feeding areas before and after landfill closure, should be considered.

Promoting urban ecological resilience through the lens of avian biodiversity

“…Thus, urban landfills can play a crucial role in preserving avian diversity and resilience despite posing hazards to wildlife through exposure to plastics, toxic compounds, and pathogens (Figure 5; Plaza and Lambertucci, 2017). Populations of some species of conservation concern, like white storks (Ciconia ciconia) are predicted to decline if urban landfills are closed (Loṕez-Garcıá et al, 2023). However, closed landfills can be reclaimed as open urban green spaces (Hoefer et al, 2016).…”

Birds are not the only ones impacted by guidance to cease bird feeding

“…To date, there are no direct tests of whether ceasing of intentional bird feeding influences disease prevalence and/or population levels of feeder species. However, studies of bird species that lose access to unintentional feeding sites (landfills, garbage dumps) find that reduced access to such sources of food is associated with lower apparent survival for young Yellow-headed gulls Larus michahellis (Delgado et al, 2021), reduced numbers of breeding pairs of Rooks Corvus frugilegus (Olea & Baglione, 2007), and predicted declines in breeding populations of White Storks Ciconia ciconia (López-García et al, 2023). Interestingly, Yellow-headed gulls also appear to expand their foraging ranges when access to refuse is reduced (Arizaga et al, 2014).…”