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PhD Thesis I Demographic processes of the Eurasian Spoonbill in the face of global change

Hugo Ferreira, a PhD candidate at Tour du Valat since 2020, defended his thesis and was awarded an honorary distinction on March 13, 2025, in Aveiro, Portugal. The thesis is entitled:

« Demographic processes of the Eurasian Spoonbill in the face of global change »

Hugo conducted his PhD under the scientific supervision of Dr. José Alves, principal researcher at CESAM, University of Aveiro, co-supervised by Jocelyn Champagnon, research director at Tour du Valat, and in collaboration with Tamar Lok from the NIOZ Royal Netherlands Institute for Sea Research.

Hugo Ferreira’s thesis defence in Portugal on 13 March 2025. ©Tour du Valat

Abstract :

Global changes are occurring at an alarming rate due to continued and increasing human development. Anthropogenic activities not only have a profound direct impact on the ongoing loss of habitats and thus biodiversity, but also have indirect effect, for example on the ability of species to respond to global changes. Migratory birds, which are currently experiencing high and fast global declines, are among the taxa most affected by both climate global changes and habitat loss. However, not every species in this group is declining and some appear to be recovering, at least locally, such as several waterbird species in Europe. Understanding how these recovering species are able to cope with ongoing environmental changes, both in terms of climate and habitat, can provide insights into their resilience.

©Tiziana Annesi / Hans Lucas

 

A notable example of population increase after years of decline is the Eurasian spoonbill,

a partial-migratory species that ranges from the East-Atlantic Coast to the Southeast Asia. In this thesis, Hugo investigated the role of environmental conditions, behaviour and experience in influencing the response of this waterbird to global and local changes driven by direct and/or indirect anthropogenic factors. Specifically, this thesis is comprised of six empirical chapters aiming at (i) exploring how breeding performance is associated with environmental conditions experienced locally; (ii) assessing the impact of anthropogenic factors throughout the annual cycle and across age groups; and (iii) understanding the effect of migratory behaviour on survival and productivity.

 

 

This thesis explores how a moderately specialised waterbird species can benefit from current global changes by exploiting new opportunities, such as using invasive species as new food sources and using wetlands managed for economic and recreational activities. It also highlights how improved performance (e.g., breeding and migration), driven by age and social cues from older conspecifics, further enhances spoonbill’s ability to thrive in changing environments. Finally, it discusses how quickly a currently positive scenario displayed by waterbirds may change in the face of severe wetland degradation or of a lack of adaptive flexibility to ongoing global changes.

 

⬇️ Download the full thesis at the bottom of the page.

 

Hugo also wrote six articles in his thesis, three of which have already been published:

1) Ferreira HRS, Alves JA, Jiguet F, Duriez O, Blanchon T, Lok T, Champagnon J. 2024. Role of protected areas for a colonial-breeding waterbird in a fragmented landscape throughout its annual cycle. Landscape Ecology 40:6. https://doi.org/10.1007/s10980-024-02017-5  [1]> Plus d’info ici [2]

2) Ferreira HRS, Hadden AC, Champagnon J, Lok T, Vittecoq M, Alves JA. 2025. Presence and potential impact of anthropogenic nesting materials on a colonial breeding waterbird. Science of The Total Environment 964:178588. https://doi.org/10.1016/j.scitotenv.2025.178588 [3].

In this study, we quantified the presence of anthropogenic nesting materials (plastics) in spoonbill nests. Several data collection efforts were conducted, the main one using photographs to limit disturbance. Plastics were primarily found in the spoonbill’s nest lining and consisted mainly of plastic sheets. The proportion of plastic increased throughout the season. No link was found between the plastic proportion and breeder age or hatching success.

3) Ferreira HRS, Champagnon J, Alves JA, Lok T. 2024. Relationship between wintering site and survival in a migratory waterbird using different migration routes. Oecologia. https://doi.org/10.1007/s00442-024-05518-x [4].

A study used ringing data to assess survival differences in Eurasian Spoonbills based on their wintering areas. Long-distance migrants had the lowest survival, independently of the flyway taken. Additionally, as they age, spoonbills seem to better cope with migratory challenges and wintering conditions as no differences in apparent survival among wintering strategies were detected during subsequent years.