Methodology
How CrocodileVsAlligator.com verifies sources, ranks data, sets refresh cadence, and handles corrections. The primary-source pattern, verification framework, scope, limitations, and contact details.
Wildlife emergency? For nuisance alligators in Florida call the FWC SNAP hotline on (866) FWC-GATOR / (866) 392-4286. For any life-threatening encounter call 911 (US) or the relevant national emergency service. This site is a reference, not a live response service.
Primary sources
Every numerical figure, species claim, and conservation-status assertion on the site traces back to a named primary source. The table below lists the authorities used, what the site takes from each, and the cadence at which each is reviewed.
| Source | Cadence | What we take from it |
|---|---|---|
| IUCN Red List of Threatened Species | On annual republish | The IUCN Red List is the primary source for conservation status on every species page. Each species profile cites the current IUCN listing: American alligator (Least Concern, conservation success), American crocodile (Vulnerable), saltwater crocodile (Least Concern), Nile crocodile (Least Concern), gharial (Critically Endangered), Chinese alligator (Critically Endangered), with caiman species listed per their current individual assessment. Where IUCN status revises, the site updates within the next monthly review. |
| IUCN SSC Crocodile Specialist Group | On revision | The Crocodile Specialist Group within IUCN's Species Survival Commission is the authoritative source for crocodilian-specific conservation framing. The site references the CSG for population estimate ranges, captive-breeding programme status (e.g. for the gharial recovery in the Chambal River), and the bridging context between IUCN listings and on-the-ground conservation reality. |
| Erickson et al. 2012, PLOS ONE | Fixed reference | Erickson, G.M., Gignac, P.M., Steppan, S.J., Lappin, A.K., Vliet, K.A., Brueggen, J.D., Inouye, B.D., Kledzik, D., Webb, G.J.W. (2012). Insights into the Ecology and Evolutionary Success of Crocodilians Revealed Through Bite-Force and Tooth-Pressure Experimentation. PLOS ONE 7(3): e31781. This is the single source for every bite-force figure on the site, measured across the full set of living crocodilians using a custom bite transducer. Figures are reported in pound-force (lbf) and newtons. |
| CrocBITE Worldwide Crocodilian Attack Database | Monitored quarterly | CrocBITE, hosted at Charles Darwin University, is the primary aggregated source for crocodilian attack and fatality data worldwide. The site cites CrocBITE for the per-species annual fatality estimates on /danger-ranking (Nile crocodile 200-300+/year, saltwater crocodile 20-50+/year, American alligator approximately 1/year). Figures are presented as estimates because attack reporting varies materially by country, region, and year. |
| San Diego Zoo Wildlife Alliance | On revision | San Diego Zoo Wildlife Alliance publishes vetted species fact sheets on every major crocodilian. The site cross-references SDZWA for life-history data (lifespan ranges, clutch size, growth rate) and behavioural framing. Where SDZWA framing differs from a peer-reviewed source, the site mirrors the peer-reviewed source and notes any material divergence. |
| Smithsonian National Zoo | On revision | The Smithsonian National Zoo's animal-facts pages are cross-referenced for behavioural and ecological context, particularly for the gharial recovery programme and American alligator population framing. The Smithsonian Tropical Research Institute publications are also consulted where they cover specific population studies. |
| Australia Zoo | On revision | Australia Zoo is referenced for saltwater crocodile context in the Indo-Pacific range, particularly population recovery in northern Australia following the 1971 hunting ban. The Steve Irwin Wildlife Reserve in the Cape York Peninsula publishes annual research updates on the Wenlock River population, which the site cites in context. |
| Florida Fish and Wildlife Conservation Commission | On revision | FWC is the primary source for American alligator US-population framing (approximately 1.3 million alligators in Florida alone, approximately 5 million across the southeastern United States), the Statewide Nuisance Alligator Program (SNAP) and the (866) FWC-GATOR hotline referenced in the /about and /where-to-see-alligators safety guidance, and the American-alligator-and-American-crocodile coexistence range in south Florida. |
| US Fish and Wildlife Service | On revision | USFWS is the federal authority on the American alligator's conservation history (removed from the federal endangered list in 1987, treated as a conservation success), the American crocodile's Endangered Species Act listing as Threatened in Florida (downlisted from Endangered in 2007), and federal regulations around crocodilian-leather trade and import. |
| National Geographic | On revision | National Geographic species pages and feature articles are cross-referenced for ecological framing, particularly for Nile crocodile behaviour at the Mara River wildebeest crossings and saltwater crocodile salt-gland physiology. The site cites NatGeo as a comparator authority; clinical numerical data (bite force, fatality counts, lengths) traces to the peer-reviewed primary source where possible. |
| Britannica | On revision | Britannica is cited for taxonomic and etymological framing (the Crocodylia order, family Alligatoridae vs Crocodylidae vs Gavialidae divergence in the late Cretaceous), and for cross-checking standard species accounts. Where Britannica framing differs from a peer-reviewed source, the site mirrors the peer-reviewed source. |
| Wildlife Conservation Society (WCS) | On revision | WCS publishes long-term field studies on crocodilian populations across South America, sub-Saharan Africa, and Southeast Asia. The site cites WCS for population framing in remote regions and for the in-situ conservation work on the gharial and Chinese alligator. |
| Peer-reviewed herpetology journals | Monitored quarterly | Journal of Herpetology (American Society of Ichthyologists and Herpetologists), Journal of Zoology (Zoological Society of London), and Copeia / Ichthyology & Herpetology (ASIH) are monitored quarterly for new measurement studies, taxonomic revisions, and population assessments. Where a new peer-reviewed measurement supersedes an existing site figure, the affected page is updated and the LAST_VERIFIED_DATE rolled forward. |
| Wikimedia Commons (Public Domain photography) | On revision | All photographs on the site are Public Domain images sourced from Wikimedia Commons, with attribution to the photographer and licence noted under each image. Specifically: Steve Hillebrand (US Fish and Wildlife Service, Public Domain) for the American alligator hero image; Tomas Castelazo (CC BY-SA 2.5) for the American crocodile hero image. No copyrighted or rights-managed imagery is used. |
In scope
- ◆Species comparison between Alligatoridae (alligators and caimans), Crocodylidae (true crocodiles), and Gavialidae (gharials), with the seven measurable differences on the home page and field-test ID logic on /identification.
- ◆Per-species conservation status from the current IUCN Red List assessment, with population estimates where the underlying data is published (e.g. approximately 5 million American alligators per USFWS / FWC; approximately 650 wild gharials per Crocodile Specialist Group).
- ◆Bite-force figures in pound-force (lbf) and newtons sourced exclusively from Erickson et al. 2012 PLOS ONE, ranked highest to lowest across measured species. No extrapolation beyond measured species.
- ◆Per-species annual human-fatality estimates from CrocBITE database, presented as ranges with the underlying reporting-completeness caveat.
- ◆North American crocodilian range, population, and management framing from Florida FWC and US Fish and Wildlife Service.
- ◆Travel and wildlife-viewing context: identifying ethical viewing locations (national parks, state wildlife management areas, accredited tour operators) and giving the safety guidance the site can responsibly provide.
- ◆Etymology, taxonomy, and natural history cross-referenced against Britannica, Smithsonian National Zoo, San Diego Zoo Wildlife Alliance, and National Geographic, with peer-reviewed herpetology literature as the tie-breaker where authorities differ.
Out of scope
- ×Live attack alerts, real-time animal tracking, or any service that would require operational on-the-ground intelligence. The site is a reference, not a live wildlife information service.
- ×Veterinary care advice or captive husbandry guidance for crocodilians kept in private or institutional collections.
- ×Captive-breeding husbandry guidance. Where the site discusses captive-breeding programmes (e.g. the Madras Crocodile Bank for gharial), it cites the institution rather than providing operational guidance.
- ×Extinct-taxon depth. The site mentions the late-Cretaceous divergence of Alligatoridae and Crocodylidae for context but does not cover extinct gavialids, mekosuchines, or pre-Cretaceous archosaurs in depth.
- ×Taxonomic revision proposals. Where current taxonomy is contested (e.g. the Tomistoma / false gharial family placement, with current molecular evidence favouring Gavialidae but morphological tradition favouring Crocodylidae), the site notes the disagreement and follows the most recent consensus revision.
- ×Tour booking, real-time availability, or guarantee of wild sightings. The /where-to-see pages identify locations and operators; they are not bookings.
Verification framework
Field identification (4-factor)
Field ID uses snout shape (V-shape narrow for crocodile, U-shape broad for alligator), dentition (interlocking lower fourth tooth visible for crocodile, only upper teeth visible for alligator with mouth closed), habitat (saltwater tolerance for crocodile via functional lingual salt glands, freshwater confinement for alligator), and geographic range (American alligator confined to SE USA and China; American crocodile in south Florida, Central America, Caribbean; Nile crocodile sub-Saharan Africa; saltwater crocodile Indo-Pacific). Where a single cue is ambiguous (e.g. juveniles, dim light), the four-factor combination resolves correctly.
Bite-force figures (Erickson 2012 only)
Every lbf and newton figure on /bite-force traces to Erickson et al. 2012 PLOS ONE. The study measured bite force in pound-force using a custom transducer across the full set of living crocodilians, and the site reports the maximum measured value per species with the published newton conversion. The site does not extrapolate to species not in the Erickson study, and does not compare to mammals or birds (whose measurement methodology differs).
Conservation status (IUCN Red List only)
Every conservation-status assertion (Least Concern, Vulnerable, Endangered, Critically Endangered) traces to the current IUCN Red List listing. Where local management (e.g. USFWS) classifies a species differently from the IUCN listing (e.g. American crocodile is IUCN Vulnerable globally but USFWS Threatened in Florida specifically), the site reports both and explains the divergence. Where IUCN re-assesses a species, the site updates within the next monthly review.
Danger ranking (CrocBITE annual ranges)
Per-species fatality estimates on /danger-ranking are annual ranges sourced from the CrocBITE Worldwide Crocodilian Attack Database. The framing makes explicit that under-reporting (particularly in rural sub-Saharan Africa) means actual fatalities may exceed the recorded range, and that any single-year figure is a snapshot not a trend. The site does not predict future attack rates or recommend behaviour beyond the safety guidance available from FWC, the relevant national wildlife authority, or accredited tour operators.
Refresh cadence
The IUCN Red List is checked on annual republish (typically late autumn for that calendar year's reassessments) and at the next monthly review cycle. Erickson 2012 PLOS ONE bite-force figures are fixed; no revisions expected. CrocBITE Worldwide Crocodilian Attack Database is monitored quarterly for newly aggregated regional data. Florida FWC and US Fish and Wildlife Service pages are reviewed on US-specific updates (e.g. SNAP programme changes, downlisting decisions). National Geographic, Britannica, San Diego Zoo Wildlife Alliance, and Smithsonian National Zoo are reviewed when their species pages republish.
The verification date is held in a single constant (LAST_VERIFIED_DATE in src/lib/schema.ts) imported by every page. Footer text, schema dateModified, and visible review timestamps all read from that single source so cosmetic refreshes are not possible without a content review. The current verified label reads May 2026.
Out-of-cycle refresh triggers: an IUCN status revision; a new peer-reviewed bite-force or population study in Journal of Herpetology, Journal of Zoology, or Copeia / Ichthyology & Herpetology; a recorded population shift in a CSG newsletter; a FWC or USFWS rule change; a flagged correction submitted via the corrections process.
Limitations
- !Bite-force figures are measured on captive specimens. Wild specimens of equivalent size may differ, but the Erickson 2012 study used wild-caught specimens of typical adult size for each species; the figures are the best available comparative data. The figures represent maximum measured bite force, not typical predatory force.
- !CrocBITE fatality counts vary by reporting completeness. Sub-Saharan African Nile crocodile attack reporting is incomplete; rural attacks frequently go unreported because the victim is unable to seek medical care. Published per-species annual estimates are floors, not ceilings.
- !IUCN Red List assessment lags real-time population shifts. Where a species is undergoing rapid population change (e.g. the gharial decline through the 2000s, or American alligator recovery), the current IUCN status reflects the most recent formal assessment, not the live population.
- !Species range descriptions on the site are simplified for editorial use. The actual range of each species is patchy and varies seasonally; the site identifies the principal regions but does not claim complete distribution mapping.
- !Taxonomy and etymology are occasionally revised. Where the consensus shifts (e.g. the Tomistoma family placement), the site reflects the most recent peer-reviewed revision and notes the historical context.
Corrections process
We correct factual errors promptly when identified. To submit a correction, email Digital Signet with the specific URL, the disputed claim, and the primary source you want the claim verified against. We aim to respond within 5 business days with either a correction (where the source supports the dispute) or an explanation (where the existing wording is correct).
Where a correction changes the substance of a factual claim, we note the change and the date on the affected page. The site LAST_VERIFIED_DATE is rolled forward only when a substantive review against the cited primary sources has occurred, not for cosmetic edits.
Do not email about a wildlife emergency
If you are dealing with a nuisance alligator in Florida call the FWC Statewide Nuisance Alligator Program (SNAP) on (866) FWC-GATOR / (866) 392-4286. For any other wildlife emergency call your local emergency services (911 in the US) or the relevant state or national wildlife authority. This site is a reference and does not provide live response or triage.