To feed or not to feed wild birds?
Background – Bird feeding is a widespread practice in urban areas across North America, Europe, Australia, and New Zealand, aimed at aiding birds in finding food amidst concrete landscapes. However, this intervention alters the type of food and its spatial distribution, impacting habitat quality for garden birds differently depending on whether they can forage from feeders. Therefore, bird feeding is expected to influence competition for nesting grounds as well as the quality of the environment for chick development. Specifically, it may lead to increased garden disturbance due to higher bird visitation rates, elevated predation risks, greater pathogen prevalence, and reduced diet quality. Given that private gardens constitute around 50% of urban greenspaces, bird feeding can significantly affect the breeding success and welfare of urban avian populations.
Methods – The study will take place in Innsbruck (Austria). We will carry out a two-year natural semi-experiment at about 30 urban gardens, half of them providing yearlong supplementary food. In each garden, we will set up two nestboxes, one targeting great tits (a common user of feeders), and another targeting black redstarts (a common garden species that does not use feeders). First, we will use nestbox occupancy rate as a way to gauge the level of competition for nesting sites among both target and non-target bird species, and assess how bird feeding impacts the social stress levels experienced by these birds. Second, we will use a panel of complementary measurements (e.g. corticosterone metabolites in droppings, growth rate, ectoparasite load, etc.) to assess the consequences of bird feeding on nestling welfare.
Impact – Given the global prevalence of bird feeding, it is imperative to evaluate its impact on birds. This project will assess the impact of bird feeding on the welfare of both target and non-target bird species during the breeding season. By doing so, it will provide scientific-based arguments for building trusted recommendations on bird feeding to avoid species exclusion and improve nest site quality.
People involved – Marion Chatelain (PI - University of Innsbruck), Frédéric Angelier (Centre d’Etude Biologique de Chizé, CNRS, France).
Funding – Seed Grant 2023 to Marion Chatelain from the Wild Animal Initiative
Project updates
6 new projects selected for research grants from Wild Animal Initiative
"To feed or not to feed wild birds" is one of the six projects funded by the Wild Animal Initiative in 2024 under the Seed Grant scheme. In their blog post, they explain why they chose to fund this project: "With the widespread popularity of bird feeding and the density of private gardens in cities, identifying the pros and cons of bird feeding could be crucial for understanding and ultimately improving the welfare of urban birds. We especially appreciate that this project will consider both target and non-target bird species and that it focuses on the welfare of juveniles."
9th of July 2024