Winter tick, Dermacentor albipictus, occurrence dataset

Data associated with Chenery E.S., N.J. Harms, H. Fenton, N.E. Mandrak, and P.K. Molnár. 2022. Revealing Large-scale Parasite Ranges: An Integrated Spatio-temporal Database and Multi-source Analysis of Winter Tick. We reconstructed the past and present distribution of the winter tick, <em>Dermacentor albipictus,</em> through compilation of a spatio-temporal database to create the first full baseline map of its occurrence throughout its North American range (WTOcc_data). Over 3,400 unique records of winter tick occurrence were compiled from multiple data sources, dating from 1869 to 2020 and spanning from 16.5 to 66.2 °N latitude. Both conventional, published sources and natural-history records were included along with new records from previously unpublished datasets and citizen-science observations to make this a comprehensive occurrence dataset for this species. Along with standardized location information and year of observation, the dataset includes associated host species and descriptive categorisation of the type and source of each record, providing new opportunities to examine host-parasite interactions in the winter tick system over time and space. A comprehensive metadata file (WTOcc_metadata) explaining compilation methods and source limitations, a file containing explanatory processing notes on each source included in the database (WTOcc_source_notes), and a full citation file (WTOcc_citations) of all records included within the database are also provided. In the associated paper, we present these data and discuss the potential sampling biases and lacunas in our integrated database records, particularly at the winter tick’s northernmost range. We also document changes in the types and sources of winter tick information from past to present, highlighting potential issues that should be considered before using these data in further analyses and when collecting ongoing records.