I don't know how "Ontbird worthy" this is as I'm not really sure how "chaseable" this bird is. I'm mainly posting this because it's pretty rare for Ontario. I found an Audubon's Yellow-rumped Warbler amongst several Myrtles in Westminster Ponds in London.
There hasn't been one reported in Ontario on eBird since 2010 and there are very few reports in Ontario before that. To get to Westminster Ponds take the Wellington exit off the 401 and head north on Wellington Rd. You can park behind the Tourist Information Centre which is on Wellington just north of Southdale Rd. The bird was seen near the north shore of Tumblesons Pond. The trails can get very wet and muddy so bring appropriate footwear. https://www.flickr.com/photos/soundart/14051712612/in/photostream/ _______________________________________________ ONTBIRDS is presented by the Ontario Field Ornithologists - the provincial birding organization. Send bird reports to birdalert@ontbirds.ca For information about ONTBIRDS including how to unsubscribe visit http://www.ofo.ca/site/page/view/information.ontbirdssetup Posting guidelines can be found at http://www.ofo.ca/site/page/view/information.ontbirdsguide