add exercise

.gitignore

@@ -25,3 +25,6 @@ index_files/
 sections/*.html
 sections/*_files/
 /.quarto/
+PanTHERIA_*
+gadm*
+gbif*

sections/exercise.qmd

@@ -1,5 +1,24 @@
 # {{< fa user-clock size=1x >}} &nbsp;&nbsp;Exercise (20 min)
 
-## Coming soon
+## Cleaning data
 
-Work in progress...
+**Part 1** - Clean the [PanTHERIA database](https://esajournals.onlinelibrary.wiley.com/doi/10.1890/08-1494.1) from the [previous exercise](https://biodiversitydata.github.io/data-access/#/accessing-data)
+
+- use the function `readr::read_delim()` to import data
+- select columns `MSW05_Binomial`, `5-1_AdultBodyMass_g`, `8-1_AdultForearmLen_mm` & `3-1_AgeatFirstBirth_d`
+- rename columns in `pan_binomial_name`, `pan_adult_body_mass_g`, `pan_adult_forearm_len_mm` & `pan_age_at_first_birth_d`
+- replace `-999` by `NA`
+
+<br/>
+
+
+**Part 2** - Create a reference table from GBIF occurrences downloaded [previously](https://biodiversitydata.github.io/data-access/#/accessing-data)
+
+- remove all columns except `scientificName`
+- remove duplicated rows
+- clean binomial names (remove authors)
+
+<br/>
+
+
+**Part 3** - Merge this table with PanTHERIA (cleaned) to add trait values to these two species