Frog of the Week

Green and Golden Bell Frog (Litoria aurea)

photo by LiquidGhoul

Common Name: Green and Golden Bell Frog
Scientific Name: Litoria aurea
Family: Hylidae – True Frog family
Locations: Australia
Introduced Locations: New Caledonia, New Zealand, and Vanuatu
Male Size: 2.2 – 2.7 inches (57 – 69 mm)
Female Size: 2.5 – 4.2 inches (65 – 108 mm)

While the Green and Golden Bell Frog is a member of the tree frog family, they are a semi-aquatic species of frog. They like to perch on vegetation around water. The frogs breed during summer time from October through March. Reproduction is pretty standard for these fellas. The males will call from the water and the female will select a mate. Then the male will grasp her from behind in the amplexus position and she will lay her eggs. The female frog lays between 3 – 10 thousand eggs. The male will then fertilize the eggs. Neither parent provides any care for their offspring.

The Green and Golden Bell Frog is naturally found along the southeastern coast of Australia but has expanded its range to other Pacific Islands including New Zealand. In New Zealand, they are found on the northern half of North Island. It’s hard to tell if these frogs are causing any problems in these new habitats.

The Green and Golden Bell Frog is listed as Vulnerable by the International Union for the Conservation of Nature (IUCN) Red List. The frogs face a variety of threats. The wetlands that the frogs live in are being drained to make room for more houses. The Mosquito Fish (Gambusia holbrooki) has been introduced to the wetlands as well to control mosquito populations. Sadly, these fish also feed on tadpoles of frogs. Also Red Foxes (Vulpes vulpes) has been introduced to Australia and they can feed on adult frogs. Chytrid Fungus, a deadly fungal pathogen that is devasting frog populations around the world, has been found in the frogs. This is likely causing some declines in the species.

Frog of the Week

Marsh Frog (Pelophylax ridibundus)

photo by Charles J Sharp

Common Name: Marsh Frog
Scientific Name: Pelophylax ridibundus
Family: Ranidae – True Frog Family
Locations: Afghanistan, Albania, Armenia, Austria, Azerbaijan, Bahrain, Belarus, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Hungary, Iran, Islamic Republic of, Iraq, Israel, Italy, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Luxembourg, Macedonia, Moldova, Montenegro, Netherlands, Poland, Romania, Russia, Saudi Arabia, Serbia, Slovakia, Slovenia, Tajikistan, Turkey, Turkmenistan, and Ukraine.
Introduced Locations: Belgium, Spain, Switzerland, and the United Kingdom
Female Size: 6.7 inches (17 cm)
Male Size: 4.7 inches (12 cm)

The Marsh Frog is the largest frog native to Europe. Its found around the edges of rivers, lakes, ponds, and streams. They rarely ever move away from these shores. The frogs will start to breed at the beginning of spring. Like most frogs, the male Marsh Frogs will call to the female frogs from the shallows of the water. Once the female selects a mate, the male frog will grasp her from behind. The female will then lay her eggs and the male will then fertilize them. The female can lay between 670-13,000 eggs. Neither parent will provide any care for their offspring.

Marsh Frogs were introduced to Kent, England in the 1930s. Other populations of the frog have popped up in western London and the southwestern part of the country. Due to their size, they prey on native wildlife, potentially having problematic effects on the native populations. The frogs could also be spreading chytrid fungus, a deadly pathogen, around the country.

Frog of the Week

Coquí Llanero (Eleutherodactylus juanariveroi)

photo by the USFWS

Common Name: Coquí Llanero, Plains Coquí, or Puerto Rican Wetland Frog
Scientific Name: Eleutherodactylus juanariveroi
Family: Eleutherodactylidae
Locations: Puerto Rico
Average Male Size: .58 inches (14.7 mm)
Average Female Size: .62 inches (15.8 mm)

The Coquí Llanero was only recently described in 2005 by Neftalí Rios. It is found only in the wetlands in a old navy base in Toa Baja, Puerto Rico. Sadly, it is already listed as a federal endangered species and as critically endangered by the International Union for the Conservation of Nature (IUCN) Red List. They are listed due to their small habitat that is threatened by development. The wetlands have been designed as critical habitat but that offers little protection.

Now onto the biology of the frog. Like all members of the family Eleutherodactylidae, the Coquí Llanero lays eggs that directly develop into froglets, skipping the tadpole stage. Though, they lay one of the smallest clutches of eggs, ranging from 1 to 5. Interestingly, they only lay their eggs on the leaves of the Bulltongue Arrowhead (Sagittaria lancifolia). Breeding can happen year round though more clutches are produced in the warmer, wetter months. The call of the Coquí Llanero is the highest frequency of all amphibians on Puerto Rico, ranging between 7.38 and 8.28 kHz. This makes the calls nearly impossible to hear over all the other noises in the wetlands.

Frog of the Week

Canyon Tree Frog (Hyla arenicolor)

photo by Zion National Park

Common Name: Canyon Tree Frog
Scientific Name: Hyla arenicolor
Family: Hylidae – Tree Frog family
Locations: United States and Mexico
US Locations: Arizona, Colorado, New Mexico, Nevada, Texas, Utah
Size: 1.25 – 2.25 inches (32-57 mm)

The Canyon Tree Frog is an arboreal frog found on boulders and rocks near streams not in the trees like most tree frogs are. They range in color from tan to gray to dark olive and try to blend in with rocks that they sit on to avoid predators. The frogs are inactive during the day but during the night, they will hunt for prey such as insects. During the hot summer days, they will hide in rock crevices to escape the heat.

The Canyon Tree Frog mates during late spring and summer. Males can be distinguished from females due to their darker throats. The males of the species will call from the edges of streams to attract the females. Once the female comes and selects a mate, they will embrace in the amplexus pose. Female can lay more than 100 eggs at a time. The tadpoles take only two months to complete their metamorphism where they will leave the water and ascend the rocks.

Frog of the Week

Common Lesser Escuercito (Odontophrynus americanus)

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photo by Raul Maneyro

least concern
Common Name: Common Lesser Escuercito or American Ground Frog
Scientific Name: Odontophrynus americanus
Family: Odontophrynidae
Locations: Argentina, Brazil, Paraguay, and Uruguay
Size: 1.75 inches (4.6 mm)

The Common Lesser Escuercito is a nocturnal frog found in semi arid and humid forests. They are a fossorial species, living underground, only coming to the surface to breed. Breeding happens after heavy rains. They can breed in permanent or temporary bodies of water. Males are highly territorial and will even fight each other for the best calling spot. They will call from the shallows to attract the females and then breed. After breeding, both parents leave and perform no parental care.

 

Frog of the Week

Chiriqui Harlequin Frog (Atelopus chiriquiensis)

Chiriqui_harlequin_frog_-_Atelopus_chiriquiensis
photo by Brian Gratwicke

critically endangered

Common Name: Chiriqui Harlequin Frog and Lewis’ Stubfoot Toad
Scientific Name: Atelopus chiriquiensis
Family: Bufonidae – True Toad family
Locations: Costa Rica and Panama
Female Size: 1.9 inches (49 mm)
Male Size: 1.3 inches (34 mm)

The Chirique Harlequin Frog is sadly, probably extinct. While still listed as critically endangered by the IUCN redlist, it has not been seen since the 1990s. What happened to this beautiful frog? There are multiple different reasons for the decline. Chytrid Fungus, a deadly pathogen, has wiped out a majority of the population. The Chiriqui Harlequin Frog is not the only frog to be killed off by the fungus. Other frogs to become extinct from the fungus includes the Panamanian Golden Frog. The rest of the frogs didn’t do well against introduced trouts and the destruction of their habitat.

Frog of the Week

Carvalho’s Surinam Toad (Pipa carvalhoi)

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photo by Renato Augusto Martins
least concern

Common Name: Carvalho’s Surinam Toad
Scientific Name: Pipa carvalhoi
Family: Pipidae – Tongueless Frog family
Locations: Brazil
Female Size: 2.6 inches (68 mm)
Male Size: 2.2 inches (57 mm)

The Carvalho’s Surinam Toad is a highly aquatic frog, only leaving the water to escape drying ponds. Males of the species are territorial, chasing away and even wrestling male frogs that invade their territory. Just like its cousin the Surinam Toad (Pipa pipa), the Carvalho’s Surinam Toad gives “birth” to their young out of their back. To accomplish this task, the male grasps around the female’s waist (inguinal amplexus). The female swims upward to the surface and releases her eggs. She then turns down and the male then fertilizes the eggs and pushes them into the female’s back The couple does this repeatable until all the eggs are released from the female. After 2 to 4 weeks, tadpoles emerge from the mother’s back, slightly different than the Surinam Toad who has froglets emerge.

Frog of the Week

Sierra Nevada Yellow-legged Frog (Rana sierrae)

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photo by William Flaxington

Conservation status is Endangered

Common Name: Sierra Nevada Yellow-legged Frog
Scientific Name: Rana sierrae
Family: Ranidae – True Frog Family
Locations: United States – California and Nevada (probably extinct there)
Size: 2 – 3 inches (5 – 7.6 cm)

The Sierra Nevada Yellow-legged Frog is a federally listed endangered species by the United States. One study found that 92% of the population have become extinct. There are two primary causes for the decline: Chytrid Fungus and introduced non-native species.  Chytrid Fungus is a deadly pathogen that has affected frogs around the world. It causes the skin of the frog to harden preventing air flow in the frog. Introduced trouts have preyed on the tadpoles of the frogs, causing declines. Experiments of complete removal of the trouts in lakes have shown to increase the Sierra Nevada Yellow-legged Frogs. Other smaller threats to the frog are climate change, pollution, and habitat destruction due to cattle grazing.

 

Frog of the Week

Sanguine Poison Arrow Frog (Allobates zaparo)

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photo by Santiago Ron

least concern

Common Name: Sanguine Poison Arrow Frog, Zaparo’s Poison Frog, and Sanguine Poison Frog
Scientific Name: Allobates zaparo
Family: Dendrobatidae – Poison Dart Frog family
Locations: Ecuador and Peru
Size: 1.2 inches (30.5 mm)

The Sanguine Poison Arrow Frog is a diurnal (active during the day) species of frog. It can move around during the bright daylight without fear due to their bright colors that warn predators that they are poisonous. Surprise! They aren’t actually poisonous. They use batesian mimicry, where they look similar to other poisonous frogs but actually aren’t. The frog species it mimics are the Ecuador Poison Dart Frog (Ameerega bilinguis) and the Ruby Poison Dart Frog (Ameerega parvulus).  Interestingly,  in areas where both of the frogs inhabit, the Sanguine Poison Arrow Frog mimics the coloration of the Ecuador Poison Dart Frog, the less poisonous of the two.

The breeding for the Sanguine Poison Arrow Frog is pretty typical for any poison dart frog. The frogs lay their eggs on leaves and when the eggs hatch, the parents carry the tadpoles on their back to a body of water. It isn’t known which parent or if both parents carry the eggs over to the water.

 

Frog of the Week

Johnstone’s Whistling Frog (Eleutherodactylus johnstonei)

Johnstone

least concern

Common Name: Johnstone’s Whistling Frog or Lesser Antillean Whistling Frog
Scientific Name: Eleutherodactylus johnstonei
Family: Eleutherodactylidae
Locations: Anguilla, Antigua and Barbuda, Barbados, Dominica, Grenada, Guadeloupe, Martinique, Montserrat, Netherlands Antilles, Saint Kitts and Nevis, Saint Lucia, and Saint Vincent and the Grenadines
Introduced Locations: Aruba, Bermuda, Brazil, Colombia, Costa Rica, French Guiana, Guyana, Jamaica, Panama, Trinidad and Tobago, and Venezuela
Size:  .6 – 1.3 inches (17-35 mm)

The Johhnstone’s Whistling Frog is named after Robert S. Johnstone, the Chief Justice of Grenada, who helped collect the first specimens. These small frogs live on many of the islands in the eastern Caribbean and have spread to other areas. They can stow away easily on boats and are great at adapting to new areas.

The frogs breed throughout the year but mostly during the wettest months, June to August. Males produce whistling calls to attract females. Once the female finds the male, the male will back away while continuing to call. The female will follow and they move to a breeding site. The female will lay between 10 – 30 eggs. The male or the female protects the eggs until they hatch. The eggs hatch directly into froglets, skipping the tadpole stage.