Biodiversity & Species Data

A map of occurrence records is a map of where people looked.

The biodiversity path, from what an occurrence record is to richness, models and ranges. every record is a presence, and there are no absences1what a record isfields and flags2bias & uncertaintymeasured, not assumed3richness & effortgrids and rarefaction4models & rangesand honest evaluationStage two is the turn: after it, every later number is reported with what it rests on

Species occurrence records are the largest open spatial dataset about life on earth and the most misread. Every record is a presence — there are no absences — the coordinates carry a radius that is usually ignored, and the density of records tracks roads and weekends more closely than it tracks the species. These guides start with what a Darwin Core record contains and how badly it is biased; then download and clean GBIF records, build richness grids and correct them for effort, thin records for modelling, fit and honestly evaluate a distribution model, draw ranges, and join species to protected areas — with the fixes for truncated downloads, records in the ocean, richness maps that are effort maps, models that score well and predict badly, and ranges that cover a quarter of the planet.

Step two is the one that changes how the rest reads: once the bias is measured rather than assumed — an elevenfold over-representation within ten kilometres of a town — every later step is about what the records can and cannot support.

The full path, in order

The concepts underneath the work, then each task, then the errors that task produces. Work down, or jump to the step you need.

  1. Sampling Bias in Occurrence Data Explained sampling bias occurrence data 🧭 Concept
  2. Coordinate Uncertainty Explained coordinate uncertainty in meters 🧭 Concept
  3. Species Distribution Models Explained species distribution model explained 🧭 Concept
  4. Biodiversity Metrics Explained biodiversity metrics richness diversity 🧭 Concept
  5. Protected Area Data Explained protected area data wdpa 🧭 Concept
  6. How to download GBIF occurrences in Python download gbif occurrences python ⚙️ How-To
  7. How to clean species occurrence records clean species occurrence records ⚙️ How-To
  8. How to build a species richness grid species richness grid python ⚙️ How-To
  9. How to correct richness for sampling effort rarefaction sampling effort richness ⚙️ How-To
  10. How to thin occurrence records spatially spatial thinning occurrence records ⚙️ How-To
  11. How to fit a species distribution model in Python species distribution model python ⚙️ How-To
  12. How to draw a species range from occurrence points species range map alpha hull ⚙️ How-To
  13. How to find which species occur in protected areas species in protected areas python ⚙️ How-To
  14. How to extract climate covariates at occurrence points worldclim covariates at points python ⚙️ How-To
  15. A GBIF download is missing records gbif download missing records 🔧 Fix
  16. Occurrence records fall in the ocean occurrence records in the ocean 🔧 Fix
  17. A richness map is a map of sampling effort richness map sampling effort 🔧 Fix
  18. A species distribution model scores well and predicts badly sdm auc spatial cross validation 🔧 Fix
  19. A range polygon has the wrong shape range polygon wrong shape 🔧 Fix

Topics this path covers

A path is a route; a topic is everything the site has on a subject. Open a topic to see the guides this path skips.

Other ways in