Abstract

Research focused on evaluating how human food subsidies influence the foraging ecology of scavenger species is scarce but essential for elucidating their role in shaping behavioral patterns, population dynamics, and potential impacts on ecosystems. We evaluate the potential role of humans in shaping the year‐round distribution and habitat use of individuals from a typical scavenger species, the yellow‐legged gull (Larus michahellis), breeding at southwestern Spain. To do this, we combined long‐term, nearly continuous GPS‐tracking data with spatially explicit information on habitat types and distribution of human facilities, as proxied by satellite imagery of artificial night lights. Overall, individuals were mainly associated with freshwater habitats (mean proportion, 95% CI: 40.6%, 36.9%–44.4%) followed by the marine‐related systems (40.3, 37.7%–42.8%), human‐related habitats (13.5%, 13.2%–13.8%), and terrestrial systems (5.5%, 4.6%–6.5%). However, these relative contributions to the overall habitat usage largely changed throughout the annual cycle as a likely response to ecological/physiological constraints imposed by varying energy budgets and environmental constraints resulting from fluctuations in the availability of food resources. Moreover, the tight overlap between the year‐round spatial distribution of gulls and that of human facilities suggested that the different resources individuals relied on were likely of anthropogenic origin. We therefore provide evidence supporting the high dependence of this species on human‐related food resources throughout the annual cycle. Owing to the ability of individuals to disperse and reach transboundary areas of Spain, Portugal, or Morocco, international joint efforts aimed at restricting the availability of human food resources would be required to manage this overabundant species and the associated consequences for biodiversity conservation (e.g., competitive exclusion of co‐occurring species) and human interests (e.g., airports or disease transmission).

Highlights

  • Over millennia, humans have altered ecosystems through habitat destruction, pollution, species extinctions, and biological invasions, these impacts have been exacerbated recently during the Anthropocene (McCauley et al, 2015; Rockström et al, 2009; Steffen et al, 2011)

  • The efficient exploitation of anthropogenic food subsides has directly contributed to the expansive dynamics of scavenger populations all over the globe (Newsome et al, 2015)

  • Our understanding on the behavioral patterns of scavenger species, their population dynamics and their potential impacts on highly anthropogenic landscapes necessarily pass through a proper comprehension on their degree of dependence on human food subsides (Oro et al, 2013)

Read more

Summary

| INTRODUCTION

Humans have altered ecosystems through habitat destruction, pollution, species extinctions, and biological invasions, these impacts have been exacerbated recently during the Anthropocene (McCauley et al, 2015; Rockström et al, 2009; Steffen et al, 2011). We evaluated how human activities in a widely transformed and heterogeneous landscape can shape the foraging ecology of a typical scavenger species in both space and time Besides their ecological interest within the current context of human impacts on ecosystems' structure and functioning (Oro et al, 2013), these results may have important management implications, such as providing information about those habitats, and food subsidies, that may contribute the most to the expansive dynamics of this species (Martínez-Abraín & Jiménez, 2016; Payo-Payo et al, 2015; Vidal, Medail, & Tatoni, 1998)

| MATERIALS AND METHODS
| Fieldwork procedure
Findings
| DISCUSSION

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.