Project Highlights:

  • This project examines major habitat and supplemental food availability drivers of productivity of garden birds in a major city
  • The project is highly interdisciplinary using a range of innovative field methodologies and experimental approaches to investigate breeding success of garden birds  
  • The project provides a strong outreach component through interactions with private garden owners and schools in the city who will assist in collecting data that might in the latter case shape lesson plans.

The world is urbanising rapidly and by 2050 it is predicted that 60% of the global human population will be living in urban areas. Urbanisation inevitably results in changes in habitat as well as in the availability of natural food to wildlife. Given that such changes can have profound impacts on both human and non-human populations, and given the increasing concerns about climate change under intensifying urbanisation scenarios, it is timely that we learn lessons from wildlife that is adapting to city life and its concomitant ever-changing environmental challenges.

Traditionally, ecologists have used thoughtful study design to attempt experimentally to manipulate single extrinsic variables while holding all others constant within a scientific ‘arena’. This is particularly true of manipulations of food availability through supplementary feeding of urban-adapted birds (Fig. 1) that have mimicked urban bird feeding but within a rural setting. A multi-year feeding study carried out in a rural homogeneous deciduous woodland 12 km outside of the city of Birmingham revealed a consistent advancement in laying but reduced clutch and brood sizes produced by Blue Tits (Cyanistes caeruleus) and Great Tits (Parus major). However, applying findings from such studies to urban environments remains problematic because experimental feeding treatments are not replicable by the bird-feeding public in cities, especially when single birds can feed in numerous city gardens during the breeding season.

In this project we will not change what and how citizen scientists are feeding birds in their gardens and at schools. Instead, we will test the hypotheses that avian breeding performance is positively related to: (i) food supplement availability, and (ii) the availability of habitat that supports invertebrate prey for adults and nestlings. Previous research has revealed that suburban areas of Birmingham show spikes in avian productivity and this PhD will identify a potential mechanism through which this finding is mediated.     

Mean first clutch size (± 1 SE) of supplemented and unsupplemented (control) Florida Scrub-Jays (Aphelocoma coerulescens) nesting in two successive years in south-central Florida. Significant differences within years among treatment groups are indicated by different lowercase letters (Source: Reynolds et al. 2003).


The project will focus on Blue Tits breeding in nestboxes at 100 sites at schools and homes where 100 weather stations will have been established along the urban gradient as part of the Birmingham Urban Observatory Project (https://birminghamurbanobservatory.com/). We will test the hypothesis that breeding performance of birds will be higher at sites where habitat supports a high natural prey base and supplemental food is more available. We will use PIT tags on leg rings on birds to monitor their nest attendance through innovative and new PIT tag readers on nestboxes. Breeding outcomes will be determined through regular nestbox monitoring by both the student and resident citizen scientists while supplemental food availability at study sites will be determined by the latter who will also document such food availability in the neighbourhood accessible to birds from the nestbox.   

Training and Skills

The proposed project has a strong multidisciplinary component, combining aspects of avian biology, behavioural ecology, spatial statistics and educational outreach. Thus, subject-specific training will be offered in each of these areas. It will comprise a mix of appropriate postgraduate level training and external training. The former will include biostatistical training in analysis of complex spatial environmental and biological datasets and the use of Geographic Information Systems (GIS) in elucidating pattern and process in habitats across an urban gradient. The candidate will also be trained in bird handling skills working with city ringers to obtain a British Trust for Ornithology ringing licence with a PIT-tagging endorsement.


Year 1: Project development and DR training (e.g. statistics, modelling, bird handling) leading to the first field season working in Birmingham at sites in private gardens and schools. This will expose the candidate to outreach activities with citizen scientists of all ages including teaching them about how we monitor ongoing breeding attempts in nestboxes as well as how we monitor food availability at study sites.

Year 2: Secondment to CASE partners to learn about the importance of urban trees and how scientific findings are used to develop bird foods and inform the bird-feeding general public. Continued fieldwork. National conference attendance and presentation.

Year 3: Data analysis, fieldwork, conference attendance (international) to showcase research outputs, paper- and thesis-writing.

Further Details

Dr Jim Reynolds +44 (0)121 414 3639