Findings · Biodiversity science

Are we still discovering
species at Saladita?

Insects: ~42% undocumented. Fungi: ~44%. Lagoon reptiles: ~70% (only conspicuous spp. on record). Fish: baseline undefined. Sea turtles: near-complete.

La Saladita · 17.5897°N, 101.4317°W · Guerrero, Mexico · Data: GBIF / iNaturalist 2000–2025

Species accumulation curves (Chao1 + jackknife) applied to GBIF/iNaturalist records, 2000–2025. Saturation ratio = observed ÷ Chao1 estimate. Sea turtles and whales: near-complete (small global pools). Insects and fungi: barely half documented. Fish: no baseline — we have not started.

How we measured this

The saturation method

Method

Chao1 (Chao 1984): Sobs + f₁(f₁−1)/2(f₂+1). First-order jackknife as cross-check. Saturation = Sobs ÷ Chao1. GBIF/iNaturalist 25–100 km study area, 2000–2025. All estimators assume equal detectability — violated here: charismatic species are over-represented. Read these ratios as lower bounds on the undocumented fraction.

Saturation ranking

Which groups have the most still undocumented?

Taxon Observed Chao1 estimate Saturation % undocumented
Fish 4 obs / 1 spp Undefined
~100% (no baseline)
Mushrooms 667 obs / 220 spp ~396 spp
~44%
Insects 5,350 obs / 1,514 spp ~2,630 spp
~42%
Lagoon reptiles
vs literature pool of ~10 spp
416 obs / 3 spp ~10 spp (literature)
~70% (conspicuous spp only documented)
Plants 3,645 obs / 671 spp ~952 spp
~30%
Birds
no current artifact
— no data —
Unknown — likely 30–50%
Whales & dolphins 889 obs / 4 spp (GBIF) ~8 spp regional pool
~37% (vs regional pool)
Sea turtles 256 obs / 4 spp 5 spp (Eastern Pacific)
~20% (1 species possible gap)
Per-taxon analysis

The detail behind each group

High gap · Insects
Insects (Insecta)
Records5,350
Species documented1,514
Chao1 estimate~2,630
Jackknife estimate~2,390
Saturation — documented fraction
58% documented · ~42% undocumented
Rarefaction curve (Coleman expected species)

With 5,350 records and 1,514 documented species, insects have the largest dataset — but the Chao1 estimator suggests roughly 1,100 additional species remain unseen. The accumulation curve is still climbing steeply: each new observation has a real chance of being a species not yet on record. Beetles and parasitic wasps are the most under-represented insect groups in citizen-science databases — both orders are enormously speciose and rarely photographed.

Caveats: singleton/doubleton ratio estimated from distributional assumptions. Butterflies (Lepidoptera) and dragonflies (Odonata) are over-represented by upload bias; beetles (Coleoptera) are substantially undercounted. Chao1 is a lower bound on true richness here.
High gap · Fungi
Mushrooms & Fungi
Records667
Species documented220
Chao1 estimate~396
Jackknife estimate~352
Saturation — documented fraction
56% documented · ~44% undocumented
Rarefaction curve — curve still rising steeply

With only 667 total records, fungi are the most data-scarce group in the survey. Chao1 projects 396 species against 220 documented — but the true number for a tropical dry-forest habitat like this likely exceeds 2,000 species, meaning the Chao1 estimate itself is probably too low. Post-rainy-season fruiting (August–October) is when mushrooms are most abundant and currently least observed.

Caveats: Chao1 becomes unreliable with only 667 total records. Singleton and doubleton counts estimated from distributional assumptions. Rainy-season bias inflates the proportion of species seen only once outside the main fruiting window.
Moderate gap · Plants
Plants (Plantae)
Records3,645
Species documented671
Chao1 estimate~952
Jackknife estimate~831
Saturation — documented fraction
70% documented · ~30% undocumented
Rarefaction curve — beginning to bend toward plateau

Plants have the best-developed baseline of any terrestrial taxon, but roughly 30% of the Guerrero dry-forest and mangrove-edge flora remains undocumented in GBIF/iNat for this area. Note that the dataset blends marine algae (dominant in June and November records) with terrestrial plants — the two have very different detectability profiles. Rainy-season ephemerals and orchids are highest-payoff targets.

Caveats: dataset blends marine macroalgae + terrestrial plants. Rainy-season ephemerals and orchids are systematically under-represented. Guerrero Pacific coast flora estimated at 3,000+ species regionally.
High gap · Reptiles
Lagoon Reptiles
Records416
Conspicuous spp documented3
Literature pool estimate~10 spp
Cryptic spp documented0
Saturation vs literature pool
30% of expected species documented · ~70% undocumented
The three documented reptile species — American crocodile (*Crocodylus acutus*), green iguana (*Iguana iguana*), and black spiny-tailed iguana (*Ctenosaura pectinata*) — are all large and conspicuous. The cryptic reptile fauna (geckos, skinks, boas, and colubrid snakes) is essentially absent from GBIF for this location. These species are almost certainly present: the habitat is right for them, and village residents report seeing snakes and geckos around the lagoon edge and stone walls. Chao1 is not useful here because all three documented species appear abundantly, leaving no singletons and doubletons for the estimator to work with; comparing against the literature-based expected pool (3 of ~10 species) gives a more honest picture.
Note: Chao1 collapses to the observed count when there are no singletons. Literature pool of ~10 species is an expert estimate for tropical Pacific coast lagoon and dry-forest habitat. Boa constrictor, Pacific ground boa, Phyllodactylus geckos, Hemidactylus geckos, and several colubrid snakes are expected but have no GBIF records here.
Near-complete · Sea turtles
Sea Turtles
Records256
Species documented4
E. Pacific pool5 spp
Chao1 estimate4 spp
Saturation vs Eastern Pacific pool
4 of 5 Eastern Pacific species documented · ~20% gap
Sea turtles are close to fully documented. Four of the five Eastern Pacific species are confirmed: Olive Ridley (*Lepidochelys olivacea*, 146 records), East Pacific Green (*Chelonia mydas*, 95 records), Hawksbill (*Eretmochelys imbricata*, 10 records), and Leatherback (*Dermochelys coriacea*, 5 records). The only realistic gap is the loggerhead (*Caretta caretta*) — an occasional stray on this coast, not a resident. The apparent near-saturation reflects a genuinely small global species pool, not comprehensive survey effort. Future value lies in nesting documentation, population monitoring, and careful ID of Hawksbill vs Green confusion records.
Note: Loggerhead occasional stray on Mexican Pacific coast — highest-priority gap. GBIF records do not distinguish nesting from at-sea encounters. Leatherback and Hawksbill records are sparse (n=5 and n=10); treat as presence indicators only.
Moderate gap · Cetaceans
Whales & Dolphins
Records (GBIF)889
Species documented4 + 1 lit.
Regional pool~8 spp
Humpback share94% of records
Saturation vs regional pool (~8 spp)
~62% of regional pool documented · ~38% gap
Cetacean records are dominated by Humpback whale (838 of 889 records). Four species are confirmed by GBIF records; Bryde’s whale is literature-confirmed but has zero GBIF records in the study area. Spinner dolphin, Blue whale, and Orca are plausible additions to the documented list. The GBIF saturation picture is misleading here: year-round resident dolphins (Bottlenose, Common) have 8–9 records each despite likely continuous presence, while Humpback has 838 records from a 4-month window.
Note: Humpback dominance (94% of records) makes Chao1 uninformative — it collapses to Sobs. Regional pool comparison (~8 expected inshore species) is more honest. Spinner dolphin is the highest-payoff gap: likely present year-round but not yet recorded in the study area.
Data gap · Birds
Birds (Aves)
Artifact statusNot generated
Expected regional spp450–500
Expected local pool200–280 spp
Saturation ratioUnknown

The _bird_climatology.js artifact has not been generated in the current build. The builder script (scripts/build_bird_climatology.py) targets GBIF class Aves (taxonKey=212) for a 25 km bounding box. From regional eBird data, the Guerrero Pacific coast hosts 450–500 bird species; the Saladita estuary and dry-forest interior likely support 200–280 species. Shorebird and wader diversity in the lagoon estuary is under-documented in GBIF, and migratory species (Oct–Mar) are likely under-counted. Run the builder to populate this entry.

Action: Run python3 scripts/build_bird_climatology.py to generate the artifact and enable quantitative saturation analysis for birds.
Baseline undefined · Fish
Fish (Actinopterygii + Elasmobranchii)
GBIF records (area)4 (roosterfish only)
Species documented1
FishBase expected400–600 spp
Saturation ratioUndefined

Fish have essentially no GBIF or iNaturalist records at La Saladita — 4 roosterfish observations in the lagoon artifact and nothing else. The saturation accumulation curve cannot be drawn because there is no baseline. The Guerrero coast sits within the Eastern Pacific Tropical biogeographic province; FishBase and WoRMS list 400–600 nearshore and reef species for this province. The correct framing is not “saturation analysis” but “baseline establishment.” Any underwater photograph uploaded to iNaturalist is a first record for this location.

Recommendation: A FishBase + WoRMS-driven reference species list for the Eastern Pacific Tropical province would establish what should be present. Citizen-science upload of fish photos (snorkeling, fishing) is the fastest path to a local record.
Where to focus

Citizen science priority ranking

Sources

GBIF API v1 + iNaturalist, 2000–2025, 25–100 km radius. Scripts: scripts/build_*_climatology.pyscripts/analyze_species_accumulation.pyfunctions/api/_findings_biodiversity_saturation.js. Rarefaction: Coleman (1981). Birds: no artifact yet — run python3 scripts/build_bird_climatology.py. Fish: no baseline — use FishBase Eastern Pacific Tropical province list. References: Chao (1984) Scand. J. Stat. 11:265–270; Coleman (1981) Math. Biosci. 54:191–211.