101 Amazing Frog Statistics

After writing over 300 frog-related articles on this blog, I can tell you that I have come across some very cool frog statistics from a wide variety of scientific studies.

In this post, I have compiled some of the top frog statistics from peer-reviewed frog research, as well as frog leg trade data, frog species-specific stats, frog conservation data, toad statistics, and pet frog industry statistics that I have come across through my research in writing for this blog.

Feel free to read more in the linked articles on our blog, as well as the primary sources found in the sources section below.

Let’s dive in 🙂

Number of Frogs in The World Statistics

• Amphibians consist of 3 orders: Anura (Frogs and Toads), Caudata (Salamanders), and finally, Gymnophiona (Caecilians). The current number of amphibians in the world totals about 8,479 species, 88% being frogs and toads, 9% newts and salamanders, and 3% caecilians as of June 2022 (AmphibiaWeb).

• As of June 2022, there are 54 frog families, 457 genera of frogs, and documented and known 7,556 frog species according to AmphibiaWeb.

• Hundreds of new frog species are discovered each year and according to AmphibiaWeb, as of June 2022, 155 new amphibian species were discovered in 2021, 166 in 2020, 154 in 2019, 166 in 2018 and 179 in 2017 (AmphibiaWeb).

• Since 1985 the total number of discovered amphibians has increased by over 60% (AmphibiaWeb).

• Observations provided by individual users of the iNaturalist and the HerpMapper platforms have respectively reported 405,390 and 5,609 observations of Anura since January 2021, for a total of about 411,000 documented frogs worldwide as of September 2021 (source).

Peer-Reviewed Frog Research Statistics

• On average, a frog’s tongue can be released from its mouth, grab prey, and return in a mere .07 seconds and pull items that weigh up to 1.4 times the frog’s body weight. Additionally, insects captured by the frog’s tongue can experience 12 times the acceleration of gravity or 12 Gs of force (Noel et al, 2017).

• A study into frog swimming patterns (Jizhuang et al. 2017) discovered that aquatic frog swimming styles are generally faster and more efficient in terms of energy consumption (43.11% propulsive efficiency while swimming) compared to terrestrial frog swimming patterns (29.58% propulsive efficiency while swimming) which are slightly less efficient and require more energy.

• Frogs need 74% more swallows to consume the prey without the assistance of their eyes (Levine, 2004). 

• A study on reptile and amphibian-related Salmonella infections was conducted at 5 Foodborne Diseases Active Surveillance Network (Mermin et al, 2004). The collected data estimated that an average of 74,000 annual Salmonella infections in the United States are due to amphibian or reptile association. 

• 12% of Nobel Prizes in Physiology and Medicine resulted from frog research.

• In 2015, scientists Hopkins and Brodie identified 124 frog species able to inhabit saltwater habitats. This number represents less than 2% of over 7,500 known frog species (Hopkins et al., 2015).

Species-Specific Frog Statistics

• Goliath Frogs (Conraua Goliath) are known as the largest and fastest frogs in the world to date, flaunting a hefty average leap of 10 ft forward. These frogs are enormous and are also known as the largest frogs on Earth. They grow to an average of 14 – 16 inches in length and weigh an average of 7 lbs.

• Goliath Frogs are currently endangered, according to accredited conservation lists. Their population has plummeted by over 50% in the last 15 years due to habitat loss, hunting, deforestation, commercial agriculture, and climate change.

• 90% of the bog where Florida Bog Frogs live is used as a military base and the USA considers “US national security has priority over wildlife.” However, bogs are fragile ecosystems that need to be protected.

• Golden Poison Dart Frogs are the most poisonous frogs on Earth as one frog has enough poison to kill 10 humans or 20,000 mice.

• Tree frogs that hibernate can freeze up to 60% of their bodies.

Frog Conservation Statistics

• Madagascar is the home of 374 recognized amphibian species representing 4.4% of global diversity as of June 2022, yet is only 0.4% of the World’s surface (AmphibiaWeb).

• Although Rainforests only cover approximately 2% of the earth’s total surface area, they are the perfect habitat for frogs with more than 1,000 frog species in the Amazon Basin alone. Many of the frogs living in tropical Rainforests are tree frogs with over 200 types of Poison Dart Frogs.

• A study found that for every millimeter increase in the snout to vent (SVL) length in an observed frog, the species is 2.8% more likely to eat other anurans, and invasive frogs are 40% more likely to eat anurans (Measey et al, 2015). 

• At least 104 amphibian species are invasive around the world, and more species are likely to be introduced in the future (Mohanty et al. 2019)

• According to the National Wildlife Federation (NWF), approximately 42% of endangered or threatened species are at risk due to invasive species on a broad scale.

• Over 50% of amphibian invasions are due to the pet trade and it is possible that future invasions will also include other frog species (Mohanty et al. 2019).

• Chytrid fungus (Batrachochytrium dendrobatidis) causes sporadic deaths endangering some amphibian populations, and can cause up to 100% mortality leading to extinction.

• Since 1980 over 200 species of frogs have gone extinct. That’s a lot of frogs in only 40 years. According to the USGS frogs are declining at a rate of 3.79% per year (source)

• Approximately 2% of frog eggs become tadpoles, 0.8% of tadpoles become froglets, and 0.1% of froglets become mature frogs capable of reproduction. However, these figures vary based on frog species, predation, and habitat. Some favorable environments may see higher average survival rates of 1 – 2% (Thurnheer et al. 2000).

• A scientific study found that there was only a 0.1% survival rate from the frog egg phase to maturity (Thurnheer et al. 2000).

• There are approximately 250 known frog species in Australia and about 93% of them are native (AmphibiaWeb).

Frog Leg Trade Statistics

• Between 1976 and 2007, the trade of frog eggs involved 2 species, 6152 eggs at 15 trade events with the last event having taken place in 2003 suggesting that this trade may have ceased (Carpenter, et al 2014).

• Between 1976 and 2007, the trade of frog skins included 4 species, 5790 individuals, and multiple import and export countries (Carpenter, et al 2014).

• Between 1976 and 2007, the trade in meat involved 2 species, 178 trade events, and over 26 million kilograms of frog legs. The study estimates 51 to 135 million Green Pond Frogs and 480 million to 1.2 billion Indian Bullfrogs were traded, for a total value of more than $111 million. This trade is thankfully showing signs it has slowed down (Carpenter, et al 2014).

• The frog leg trade represents US$40 million per year (Gratwicke et al., 2010).

• France, Belgium, and the US collectively imported more than 75% of all frog legs traded internationally. Data from 1996 through 2006 revealed that most countries throughout the world participated in the frog legs trade at some level (Gratwicke et al., 2010). 

• The scope and extent of international frog leg trade could facilitate the spread of pathogens, notably Batrachochytrium dendrobatidis which has been identified as a threat connected with the disappearance and possible extinction of over 90 amphibian species around the world (Gratwicke et al., 2010).

• The IUCN estimates that frog leg overharvesting is a serious threat, affecting 40% of the 54 declining true frog species in the family Ranidae (Stuart et al. 2004).

Pet Frog Industry Statistics

• Between 1976 and 2007, the trade in live amphibians included 18 genera, 27 species, and 482,292 individuals, with the top 3 genera being Dendrobates, Mantella, and Ambystoma (Carpenter, et al 2014).

• Just 10 species represented 78% of traded live animals between 1976 and 2007 of which 2 are on the IUCN Red List category of Critically Endangered (Mexican salamander, Panamanian Golden Frog). According to the study, the pet amphibian trade likely increasing with 60% of total trade recorded after 1996 (Carpenter, et al 2014).

• The Global Amphibian Assessment pegs 47 amphibian species to be predominantly threatened by unsustainable harvesting for the international pet trade (Mohanty et al. 2019).

• A study uncovered nearly 450 species of amphibians in the pet trade that were moved around the world in large numbers. The US alone imported 3.6 million pet amphibians between 2014 and 2019 (Mohanty et al. 2019).

• 17% of all amphibian species are being traded, representing almost 3x times previous recorded numbers. 345 species are threatened, with 100 being data deficient or unassessed. Most of the traded species originate from South America, China, and Central Africa (Hughes et al., 2021).

• Analysis of the origins of traded individuals showed that around 42% came from the wild (Hughes et al., 2021).

• The mean lag time is only 6.5 years for newly described species to be traded, including threatened and unassessed species (Hughes et al., 2021)

• “95% of the amphibians exported out of Madagascar and into the United States are native to Madagascar. Such countries may also have a higher percentage of their population living in relative poverty and who depend on the pet trade as their primary income […] and there is little monetary incentive to harvest sustainably” (Sinclair, et al., 2021).

• Japan’s import of live amphibians increased from 2005 to 2019 by 430% in value and by 230% in number (Kitade et al., (2022)

• Based on data compiled in the WCMC CITES database, over 63,000 dendrobatid frogs (of 32 species) were traded internationally (Nijman, 2010).

Top Toad Statistics

• A study found that 38% of toads hibernate in rodent burrows, 27% under large rocks, 19% under logs or root wads, and 15% under banks adjacent to streams or a lake (Bull, 2006).

• Toads are not freeze-tolerant and have been reported to die at temperatures between –1.5 to –5.2 °C or 29°F to 23°F (Swanson et al. 1996).

• The experiment found that 43% of the toads vomited Bombardier beetles after swallowing them within 12 to 107 minutes. Small toads vomited the beetles more often than larger toads did and all the beetles escaped alive and active (Sugiura et al, 2018).

Other Frog Statistics

• Frogs have been alive for 190 million years with few evolutionary adaptations. 

• 91% of frogs were dying trying to cross the road prior to installing an amphibian passage in a town in Quebec. Next to no frogs have died since the passage was created in the year 2000.

• Tree frogs, or arboreal frogs, are a diverse family with over 800 species around the world (CTNF).

• Many frog species are known to include intersex individuals that have changed gender or reversed their sex from male to female, or female to male. Generally, the number of individuals having experienced sex reversal represents 2 to 16% of the observed frog population.

• As a general rule, frogs lay 2 to 30,000 eggs once or twice per year depending on the species and climate.

• Frog tongues are muscle tissue used primarily for hunting prey. This extremely soft appendage is 10x softer than a human tongue, typically 1/3 the length of a frog’s body, and is coated in unique reversible saliva that can both liquefy and solidify in order to capture and maintain its grip.

• The speed that a frog’s tongue moves is 5 x faster than a human can blink.

After compiling all these stats together, I must admit it is hard reading about the intensity of the pet frog trade, the frog leg trade, and the dire need for conservation.

Our mission is to help spread better understanding of frogs by providing more education and promoting respect.

Hopefully these stats inspired in that direction as well.

Sources

Alexis C. Noel, Hao-Yuan Guo, Mark Mandica, David L. Hu. Frogs use a viscoelastic tongue and non-Newtonian saliva to catch prey. Journal of The Royal Society Interface, 2017; 14 (127): 20160764 DOI: 10.1098/rsif.2016.0764

AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 15 Sep 2021

Bull, Evelyn L. 2006. Sexual differences in the ecology and habitat selection of western toads (Bufo boreas) in northeastern Oregon. Herpetological Conservation and Biology. Vol. 1(1): 27-38

Carpenter, A., Andreone, F., Moore, D., & Griffiths, R.. (2014). A Review Of The International Trade In Amphibians: The Types, Levels And Dynamics Of Trade In Cites-listed Species. Oryx. 48. 565-574.

Gareth R. Hopkins and Edmund D. Brodie “Occurrence of Amphibians in Saline Habitats: A Review and Evolutionary Perspective,” Herpetological Monographs 29(1), 1-27, (1 December 2015). https://doi.org/10.1655/HERPMONOGRAPHS-D-14-00006

Gratwicke, B., Evans, M.J., Jenkins, P.T., Kusrini, M.D., Moore, R.D., Sevin, J. and Wildt, D.E. (2010), Is the international frog legs trade a potential vector for deadly amphibian pathogens?. Frontiers in Ecology and the Environment, 8: 438-442. https://doi.org/10.1890/090111

Hughes AC, Marshall BM, Strine CT. Gaps in global wildlife trade monitoring leave amphibians vulnerable. Elife. 2021;10:e70086. Published 2021 Aug 12. doi:10.7554/eLife.70086

Jizhuang F, Wei Z, Bowen Y, Gangfeng L. Propulsive efficiency of frog swimming with different feet and swimming patterns. Biol Open. 2017;6(4):503-510. Published 2017 Apr 15. doi:10.1242/bio.022913

Measey GJ, Vimercati G, de Villiers FA, Mokhatla MM, Davies SJ, Edwards S, Altwegg R. 2015. Frog eat frog: exploring variables influencing anurophagy. PeerJ3:e1204 https://doi.org/10.7717/peerj.1204

Levine RP, Monroy JA, Brainerd EL. Contribution of eye retraction to swallowing performance in the northern leopard frog, Rana pipiens. J Exp Biol. 2004 Mar;207(Pt 8):1361-8. doi: 10.1242/jeb.00885. PMID: 15010487.

Mohanty, Nitya & Measey, John. (2019). The global pet trade in amphibians: species traits, taxonomic bias, and future directions. Biodiversity and Conservation. 28. 10.1007/s10531-019-01857-x. 

Mermin J, Hutwagner L, Vugia D, Shallow S, Daily P, Bender J, Koehler J, Marcus R, Angulo FJ; Emerging Infections Program FoodNet Working Group. Reptiles, amphibians, and human Salmonella infection: a population-based, case-control study. Clin Infect Dis. 2004 Apr 15;38 Suppl 3:S253-61. doi: 10.1086/381594. PMID: 15095197.

Nijman, V., Shepherd, C.R. The role of Asia in the global trade in CITES II-listed poison arrow frogs: hopping from Kazakhstan to Lebanon to Thailand and beyond. Biodivers Conserv 19, 1963–1970 (2010). https://doi.org/10.1007/s10531-010-9814-0

James S Sinclair, Oliver C Stringham, Bradley Udell, Nicholas E Mandrak, Brian Leung, Christina M Romagosa, Julie L Lockwood, The International Vertebrate Pet Trade Network and Insights from US Imports of Exotic Pets, BioScience, Volume 71, Issue 9, September 2021, Pages 977–990, https://doi.org/10.1093/biosci/biab056

Kitade T, Wakao K. TRAFFIC (2022). Illuminating Amphibians: the amphibian trade in Japan.

Stuart SN, Chanson JS, Cox NA, et al. 2004. Status and trends of amphibian declines and extinctions worldwide. Science 306: 1783–86. 

Sugiura S, Sato T. Successful escape of bombardier beetles from predator digestive systems. Biol Lett. 2018 Feb;14(2):20170647. doi: 10.1098/rsbl.2017.0647. PMID: 29438051; PMCID: PMC5830659.

Swanson, D.L., B.D. Graves, and K.L. Koster. 1996. Freezing tolerance/intolerance and cryoprotection synthesis in terrestrially overwintering anurans in the Great Plains, USA. Journal of Comparative Physiology B 166:110–119

Thurnheer, Sylvie, Reyer, Heinz-Ulrich, Spatial distribution and survival rate of waterfrog tadpoles in relation to biotic and abiotic factors: a field experiment Zoological Institute, University of Zurich, 8057 Zurich, Switzerland, Corresponding author: H.-U. Reyer.