ebird, a project of the Cornell Lab of Ornithology and the National Audubon Society, collects data about bird sightings from observers around the world. In addition to providing many ways of viewing this data online, it also allows downloading of data for use in non-commercial projects. To access the data you will need to set up a free account (or use your Project FeederWatch or Great Backyard Bird Count account) and request access to the data.
I requested data about bird sightings in Ontario and a smaller file of sightings of Snowy Owls in Ontario . The data comes with terms of use, a recommended citation format and metadata information.
This map was created using the ebird data and CartoDB. I uploaded the dataset, created a query to extract a subset of the data relating to the winter of 2014/2015 and created a torque map using the CartoDB map wizard. The map shows a time-lapse of reported sightings of Snowy Owls in Ontario from October 1, 2014 – April 29, 2015.
Data retrieved from: eBird Basic Dataset. Version: EBD_relMay-2015. Cornell Lab of Ornithology, Ithaca, New York. May 2015.