Biological data: georeferencing Monica Papeş University of Kansas

Sources of occurrence data Natural history museum collections (many in distributed databases) – contains the bulk of species’ distribution information Literature citations (monographs, papers, etc) Surveys

Potential issues with NHM occurrence data Taxonomy: unidentified or wrong identifications; outdated taxonomy Sample bias Locality description too vague, misspelled, unreadable handwriting, etc. Faulty georeferencing

What is georeferencing? (simple response) Assigning geographic coordinates to a locality description USA, Georgia, Augusta, Wheeless Rd., 0.5 mi S of Gordon Hwy locality georeferenced to Latitude: Longitude:

Where to find coordinates? 1. Gazetteers - Paper based - Online databases

Where to find coordinates of localities? 1. Gazetteers - Paper based - Online databases GeoNet Names Server – worldwide coverage, no maps

GeoNet Names Server – worldwide coverage, no maps

Another example of online databases: Alexandria Digital Library – worldwide coverage, with maps

Where to find coordinates of localities 1. Gazetteers - Paper based - Online databases 2. Maps - Paper based - Electronic (digitized) *Exhaustive list of sources can be found on HerpNet website:

Georeferencing… more in depth look e.g.1: Lawrence e.g.2: Lawrence, Douglas Co, Kansas, USA e.g.3: 5 km E of Lawrence, DG, KS, USA e.g.4: 5 km SE of Lawrence, DG, KS, USA …

More in depth look… issues Assumptions: localities are accurate and complete Locality string has to be interpreted e.g. USA, KS, Dickinson Co, Jct I-70 & KS Hwy 15 in Abilene, 1 mi S, 3.5 mi W There are inherent uncertainties with each locality description (even with GPS coordinates!)

Causes of uncertainty: The extent of the locality – can be estimated using:The extent of the locality – can be estimated using: →bounding box method →bounding box method → point-radius method → point-radius method -... in future: shape method: complex, complete representation Imprecision in distance or direction measurements; map scale; unknown datum; GPS accuracy Imprecision in distance or direction measurements; map scale; unknown datum; GPS accuracy

Thus… we need to calculate a “confidence interval” for georeferencing done. Luckily, there is a CALCULATOR for this purpose!

Automated, batch processing tools (The future looks bright!) GEOLocate – georeferencing without error estimates designed for North America; recently expanded to include the whole world BioGeomancer – georeferencing with error estimates Still in the developing stage, but improving fast

Everything there is to know about georeferencing: Guide to Best Practices for Georeferencing Edited by Arthur D. Chapman and John Wieczorek (2006) Available for download:

Very bad localities…. REAL LOCALITIES FROM MaNIS project T-shirt: Requires specific knowledge Non-sensical Biologically unlikely Vague