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Urban Birds of Ontario


The primary aim of the citizen science component of our Urban Birds of Ontario project is to generate a comprehensive list of all of the bird species that breed in Ontario’s 15 metro areas (defined by Stats Canada). To accomplish this, we are tapping into the wealth of expertise and knowledge possessed by Ontario’s birders and naturalists, and asking them to complete surveys for any cities with avifaunas that they know well. One of the most important unanswered questions in urban ecology is: why do some species thrive in cities, while so many others do not? To address this and related questions, we first need to identify those species that appear to tolerate urban habitat, as well as those that do not.


We have put a lot of thought into the methods we are using, and we have used similar methods successfully in a previous global study, which was published in the Proceedings of the National Academy of Sciences in 2018. We know that survey participants often have questions about our methods, and so we have answered four of the most commonly asked questions below. If you have a question that is not answered here, please feel free to contact us.


Why aren’t you using eBird, Breeding Bird Survey, or Breeding Bird Atlas data?  

We are familiar with all of these great resources (and others), and even used BBA and eBird data to generate our surveys, but the structure and method of collection of those data aren't suitable for the goals of our study. In part, this is because these other data sources aren’t urban-focused and cannot give a nuanced description of breeding occurrence specifically in urban habitats. They also cannot document absence of a species from all urban habitats within a city.

How do you define “urban habitat”? (Why didn’t you provide a clearer definition?)  

We have chosen not to provide a rigid definition of “urban habitat” or to specify a strict geographic area to include for each survey, and instead provide a description of habitats that should not be included (conservation areas, wildlife preserves, isolated patches of natural habitat, and farmlands). We want to generate a list that includes birds that can breed in truly urban (or suburban) areas. We do not want this list to include birds that persist within the city limits, but require native habitat or farmland, which can be found, generally in small patches, inside the limits of some cities.


How did you select which species to include on each city’s survey?  

We started with the Ontario Field Ornithologists' checklist of breeding birds of Ontario as the broadest list of candidate species that could be found breeding in Ontario’s cities. We then cross-referenced that list with maps of the breeding ranges of each species (primarily from the Atlas of the Breeding Birds of Ontario, 2001-2005, as well as the Birds of North America species accounts and eBird, especially for species showing recent range shifts). We wanted to err on the side of inclusion, and so included any species with a recorded breeding occurrence within ~25km of the city's downtown core. We consider this to indicate that the species has the “geographic opportunity” to breed in the city, even if its occurrence in the city is highly unlikely (e.g., because of aspects of its ecology).

How did you select which cities to include in your study?  

We used data from Statistics Canada's 2011 census to identify the 15 metropolitan areas in Ontario that we are including in this study.




Dr. Fran Bonier, Associate Professor

Queen's University Biology Department

Kingston, ON K7L 3N6 Canada

phone: +01.613.533.6000 x 77024


photo credits

Derek Zaraza: Urban peregrine

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