About the data

The observers

1,982observers

iNaturalist is a free, non-profit record of what people see outdoors: a photo or sound, a place, a date, and names agreed by other members. Goenche shows counts only. No observer is named and no photograph is shown.

The ten most active observers made 23 % of the records. Thank you to everyone in Goa who records what they see, and to the groups who run the Goa BioBlitz and the City Nature Challenge.

From the full record to the map

Counted for Goa but tied to no place: 7,351 position vaguer than 2 km; 6,215 outside every local body's outline (sea, estuary, edge); 3,001 position hidden by iNaturalist or the observer; 1,334 a species iNaturalist obscures.

The licences

Each observer chooses the licence on a record. The layer is built only from records whose licence allows reuse with changes; the faded rows are left out of every figure. Because most are non-commercial, the layer is not part of the paid print.

Records by year

42,851 of the 73,858 were made in 2025 and 2026. The map shows where recording has happened so far; it will fill in. 148 records are older than 2008.

By month

April stands out because of the City Nature Challenge, when many people record over one long weekend. The monsoon months are thin: fewer people are out.

What gets recorded

4,559 species in all; 2,692 have a record that two or more members agree on.

What is held back

126species never shown by place

iNaturalist hides the true position of species that could be harmed if people knew where they are, and of any record whose observer asks. Those records are counted for Goa as a whole and nowhere finer. A check runs before the file is published and stops it if a person or a hidden position could be read from it.

The biodiversity index, and when there is none

18 of 200places are surveyed well enough to carry one · values 82 to 346

A raw count of species mostly measures how much people have looked. The index allows for that. For each place we take every observer-day (one person, one day) as a sample and ask how complete the record is: the chance that the next record is of a species already seen there. That is its sample coverage. Each place is then thinned, by calculation, to the same completeness (60 %), and the variety of what remains is written as a number of equally common species (the Hill number of order 1). So 200 means "as varied as 200 equally common species", among places compared at the same completeness.

A place gets an index only if its own record is at least 60 % complete over 10 or more observer-days. Nothing is extrapolated. The other 182 are drawn grey and labelled "not surveyed enough to say", with their completeness where it can be worked out (140 places). That grey is the finding: it is where a day's recording would add most.

Why 60 %: taking all species together, 1 place reaches 80 % and none 90 %; 7 reach 70 %. It is a low bar, and the index describes the common species far better than the rare ones. Limits: observers favour birds, butterflies and places they can reach; a record is a sighting, not a count of animals, which is why samples are observer-days and not individuals; observer-days differ in length. Method: Chao and Jost, Ecology 93 (2012); Chao and others, Ecological Monographs 84 (2014); Hsieh, Ma and Chao, Methods in Ecology and Evolution 7 (2016), the iNEXT package, whose formulas ours follow.

Which groups can bear an index

Birds are the best recorded: 15 places carry a birds-only index at 80 % completeness, shown on their cards. Plants, fungi and fish are nowhere near; no index is given for them.

The check

Before each publish the code is run on the worked example that ships with iNEXT (ants at five elevations in Costa Rica, 98.5 % coverage) and must return the species and index figures printed in its manual. It does, to three decimals. If it ever does not, nothing is published.

How to cite, and how to add

For the layer: iNaturalist community. Observations from Goa, India. Exported from https://www.inaturalist.org on 25 Oct 2026.

For research, iNaturalist asks you to cite a download from GBIF, which carries its own DOI; the weekly GBIF copy holds the research-grade records with open licences. We have not made such a download yet. To add what you see in your own village: iNaturalist, Goa.