The Distribution, Density and Movements of Feral Pigeons Columba livia and their Relationship with People
Authors:   , Ryan Alice C. 
Published: November 2021

<p>Worldwide increases in the urban human population have led to a rise in human-wildlife conflict in cities. Mitigating human-wildlife conflict requires understanding of both wildlife and their relationship with humans. Feral pigeons (Columba livia), a ubiquitous commensal animal, are a source of human-wildlife conflict due to their waste which fouls and corrodes buildings and pavements, public health concerns and their tendency to forage in groups around people. Feral pigeons are abundant in Wellington City and information is needed to advise a new management strategy to reduce conflict. I aimed to measure the distribution and density of feral pigeons on a landscape scale in Wellington City and their movements in relation to artificial food. I also evaluated people's attitudes to feral pigeons and tolerance for control methods. I measured distribution using a resource use/availability study and density using distance sampling along eight line transects across the city centre in summer and winter. Variables measured for sites used and available to pigeons were assembled into models and compared using an Information Theoretic approach. Pigeon distribution was best explained by the model distance to pigeon feeder site, distance to public space, and landscape type (w = 0.696). Density was higher in winter (6.8 pigeons/ha) than summer (4.5 pigeons/ha), especially in commercial areas (17.8 pigeons/ha winter c.f. summer 5.9 pigeons/ha). Pigeons selected areas closer to pigeon feeder sites and to public spaces, and to landscape types with a higher human density, which suggests public feeding is the main influence on pigeon distribution in Wellington City and limitation of public feeding should form the basis of a management strategy. I observed the movements of 48 banded birds caught at five park capture sites over 38 search sites from June to December in Wellington City to construct minimum convex polygons for the 20 birds that had nine or more observations. The average activity area was 1.87ha, and activity areas ranged from 0.04ha to 10.26ha. Pigeons showed limited movement between sites, with 14 out of the 20 (70%) seen at three or fewer sites. The small activity areas suggest food is locally abundant as pigeons do not have to travel far to meet daily energy requirements. A significant food reduction may be required to decrease the population and should focus on major feeding sites. To investigate people's attitudes to feral pigeons and their control I hand-delivered 800 two page questionnaires to 50 residents at 16 stratified random sites around Wellington City. Questions were asked on residents' attitudes towards pigeons, their environmental knowledge, experiences and actions, and their support for control methods. Attitude towards pigeons was ranked on a scale of -1, 0, and 1 and tested using models composed of different variables. Respondents' attitudes towards pigeons were best explained by whether they fed birds and visited green space. Respondents who fed birds were less negative towards pigeons, while respondents who visited green spaces often were more likely to have a negative opinion. Bird feeders made up 21.5% of respondents while 5% of respondents stated they fed feral pigeons. Regulatory control methods for limiting pigeon population size had support over lethal methods. Survey respondents who fed pigeons had little support for control methods, yet their behaviour change is crucial to the success of a management programme. This shows the importance of consulting the public and allowing them to participate in the management decision making process. As regulatory methods were not considered practical, and banning bird feeding was not considered sensible due to its popularity and the appreciation for wildlife it provides, recommendations were made to use an education and social marketing campaign to reduce pigeon feeding and promote responsible bird feeding.</p>