Frog of the Week

Holdridge’s Toad (Incilius holdridgei)

Holdridge's Toad
photo by Juan G. Abarca

Common Name: Holdridge’s Toad
Scientific Name: Incilius holdridgei
Family: Bufonidae – True Toad family
Locations: Costa Rica
Size: 1.25 – 2 inches (32 – 53 mm)

The Holdridge’s Toad lives in the secondary montane forest of Costa Rica. They are an explosive breeder following the rains in April. Interestingly, the toad lacks vocal slits, making it impossible for the frog to call. The toads breed in forest pools filled by the recent rains and man-made ditches. Females lay between 45 to 137 eggs. The tadpoles take around a month to complete their metamorphosis.

Holdridge's Toad
photo by Juan G. Abarca

The International Union for the Conservation of Nature (IUCN) Red List assesses the Holdridge’s Toad as Critically Endangered. The toad was thought be extinct until it was spotted in 2009. The habitat of the toad has not been that distrubed, leading reasearchers to believe that Chytrid Fungus, a deadly fungal disease, wiped out most of their population. There is thought to be less than 50 total mature toads left. Luckily, the toads habitat falls into a protected area but researchers haven’t been able to captive bred the toad.

Frog of the Week

Spotted Poison Frog (Ranitomeya vanzolinii)

Spotted Poison Frog
photo by John P Clare

Common Name: Spotted Poison Frog and Brazilian Poison Frog
Scientific Name: Ranitomeya vanzolinii
Family: Dendrobatidae – Poison Dart Frog family
Locations: Brazil and Peru
Size: 0.65 – 0.74 inches (16.7 – 19 mm)

The Spotted Poison Frog is an arboreal poison dart frog, primarily living at least 6 feet (2 meters) off the ground. Juvenile frogs on the species can be found in the leaf litter.

The frogs mate in tree holes that are partially filled with water. If more than one egg is laid, male waits for the eggs to hatch and then carries each tadpole to its own tree cavity. Then, the male guides the female to each cavity where she lays unfertilized eggs for the tadpole to each.

The International Union for the Conservation of Nature (IUCN) Red List assesses the Spotted Poison Frog as Least Concern for Extinction. The frog has a wide range and a presumed large population.

The species is named after Paulo Vanzolini, a Brazilian herpetologist and music composer, specially sambas.

Frog of the Week

Mazatlan Narrow Mouthed Toad (Gastrophryne mazatlanensis)

Mazatlan Narrow Mouthed Toad
photo by Jim Rorabaugh

Common Name: Mazatlan Narrow Mouthed Toad or Sinaloan Narrow-mouthed Toad
Scientific Name: Gastrophryne mazatlanensis
Family: Microhylidae
Locations: Mexico and the United States – Arizona
Size: 1.6 inches (4 cm)

The Mazatlan Narrow Mouthed Toad was originally thought to be its own species before researchers merged it into the Great Plains Narrowed Mouth Toad (Gastrophryne olivacea). It sat as a subspecies for over 50 years before researchers decided to elevated back to its own species. Not much is known to be different in its life history than the Great Plains Narrowed Mouth Toad and it seems no one has really tried to study it. They spend most of their life underground which also doesn’t help with knowing what they are doing. However, the toads come to the surface to breed. They breed following the heavy spring and summer rains.

The International Union of the Conservation of Nature (IUCN) Red List has not assessed the conservation status of the toad.

Frog of the Week

Veragua Stubfoot Toad (Atelopus cruciger)

Veragua Stubfoot Toad
photo by Indiana Cristo

Common English Name: Veragua Stubfoot Toad and Rancho Grande Harlequin Frog
Local Name: Sapito Rayado
Scientific Name: Atelopus cruciger
Family: Bufonidae – True Toad family
Locations: Venezuela
Male Size: 1.1 – 1.3 inches (28.2–34.6 mm)
Female Size: 1.5 – 2 inches (39.5–49.9 mm)

The toads mate during the dry season, where they can be found on rocks and vegetation near fast moving streams. The males call out for the females and when the females arrive, the male grabs her from behind in the amplexus position. Then, the female carries the male over to the stream. Amplexus can last up to 19 days for the species. Next, the female lays her eggs and the male fertilizes them. The female lays between 150 – 270 eggs in several clutches. The eggs hatch into tadpoles that use their abdominal suckers to attach to rocks in the fast moving stream.

The International Union for the Conservation of Nature (IUCN) Red List assesses the Veragua Stubfoot Toad as Critically Endangered. The toads have disappeared from nearly all of its range. The culprit is Chytrid Fungus, a deadly fungal pathogen. Luckily, a few populations of the toad remain in some national parks and are surviving against the disease.

Frog of the Week

Large-Webbed Bell Toad (Bombina maxima)

Large-Webbed Bell Toad
photo by Benjamin Tapley

Common Name: Large-webbed Bell Toad and Yunnan Firebelly Toad
Scientific Name: Bombina maxima
Family: Bombinatoridae – Fire bellied Toad family
Locations: China
Size: 1.7 – 2 inches (44 – 51 mm)

The Large-webbed Bell Toad lives high in the mountains near swamps, ponds, and ditches. Like other fire bellied toads, they have a bright colored belly that shows off that they are toxic. When threatened, the toad arches its back to show off their stomach to warn off the predator. Also, they can secrete a white mucus to deter the predator from eating them. The toad breeds from May to June.

The International Union for the Conservation of Nature (IUCN) Red list assessed the Large-webbed Bell Toad as Least Concern with Extinction. The toad has a large range and are thought to be numerous throughout it.

Frog of the Week

Hot Creek Toad (Anaxyrus monfontanus)

Hot Creek Toad
photo by William Flaxington

Common Name: Hot Creek Toad
Scientific Name: Anaxyrus monfontanus
Family: Bufonidae – True Toad family
Locations: United States – Nevada
Size: 2.3 inches (60 mm)

The Hot Creek Toad is a new species to science. Once considered to be a population of the Western Toad (Anaxyrus boreas), they were elevated to full species status in 2020. Like most toads, the Hot Creek Toad is nocturnal. Not much about its life history has been confirmed but its probably similar to the Western’s Toad

The International Union for the Conservation of Nature (IUCN) Red List has not assessed the conservation status of the Hot Creek Toad. However, the toad is thought to be rather threatened. They live in a small area in the Hot Creek Canyon area.

Frog of the Week

Long-snouted Tree Frog (Taruga longinasus)

Long-snouted Tree Frog
photo by Milivoje Krvavac
Conservation status is Endangered

Common Name: Long-snouted Tree Frog, Sharp-snout Saddled Tree Frog, and Southern Whipping Frog
Scientific Name: Taruga longinasus
Family: Rhacophoridae – Asian Tree Frog family
Locations: Sri Lanka
Male Size: 1.6 – 1.8 inches (41-47 mm)
Female Size: 2.2 – 2.3 inches (57-60 mm)

The Long-Snouted Tree Frog lives in the tropical mountainous forests of southwestern Sri Lanka. The frog spends most of its life high up in the trees. They come down lower in the tree during mating season. The mating season coincides with the rainy season. The frogs make a foam nest on a branch overhanging a pool of water. The nest helps keeps the eggs from drying out. Eventually, the eggs hatch and tadpoles fall out of the tree and into the water below.

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Long-snouted Tree Frog as Endangered. The frogs live in a small area on the island. This area is threatened by increasing urban development, agricultural development, and harvesting wood in the area.

Frog of the Week

Iberian Midwife Toad (Alytes cisternasii)

Iberian Midwife Toad
photo by Benny Trapp

Common Name: Iberian Midwife Toad
Scientific Name: Alytes cisternasii
Family: Alytidae – Midwife Toad and Painted Frog family
Locations: Portugal and Spain
Size: Males – 1.4 inches (36 mm) | Females 1.7 inches (42 mm)

The Iberian Midwife Toad lives in the drier scrub-like environment of eastern Portugal and western Spain. The toad is rather fossorial, burrowing down into this loose dry soil.

Mating season lasts from September to March, peaking around October and November. The males call out every night on land to attract the females. Once the female arrives, the male grabs her from behind in the amplexus position. Next, she lays her eggs and the male fertilizes them. Now comes the interesting part. The male wraps the egg mass around his legs. He can then go out and mate with more females, capable of carrying up to 4 clutches at a time.

The International Union for the Conservation of Nature (IUCN) Red List assess the Iberian Midwife Toad as Least Concern for Extinction. The species has a wide range and are thought to be numerous throughout it. In some areas, the toads are disappearing due to destruction of their habitat.

Frog of the Week

Japanese Common Toad (Bufo japonicus)

Japanese Common Toad
photo by Yasunori Koide 

Common Name: Japanese Common Toad
Scientific Name: Bufo japonicus
Family: Bufonidae – True Toad family
Locations: Japan
Size: 3.1 – 6.9 inches (80 – 176 mm)

The Japanese Common Toad lives on the islands of Kyusyu, Shikoku, Hokkaido, and Honshu of Japan. They have also been introduced to the island of Izu Oshima. Additionally, they live in a wide range of habitats from coastal areas to high in the mountains. The toads vary in color from a dark green, yellowish brown, to dark brown. Like most toads, they are active during the night and hide during the day.

Two subspecies of the toads are recognized by some researchers. The subspecies are the Eastern Japanese Common Toad (Bufo japonicus formosus) and the Western Japanese Common Toad (Bufo japonicus japonicus). The western subspecies is slightly larger than the eastern.

Mating

The breeding season for the toads is late winter / early spring from February to March. The toads migrate to ponds and swamps to breed. They use odor cues to find their way to these water bodies. In the pond, the males outnumber the females, leading to fighting and scrambling for a mate. The males try to grasp the females from behind in the amplexus position. Next, the female starts to lay her eggs. The females lay between 1,500-14,000 eggs. Then, the male fertilizes the eggs. Neither parent provides any care for their offspring. The eggs hatch into tadpoles shortly after. Then, the tadpoles complete their metamorphosis in June.

Conservation for the Japanese Common Toad

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Japanese Common Toad as Least Concern for Extinction. The species populations are decreasing but not at an alarming rate. The main cause of the declines is habitat loss from the urbanization of their land.

Frog of the Week

Hurter’s Spadefoot Toad (Scaphiopus hurterii)

Common Name: Hurter’s Spadefoot Toad
Scientific Name: Scaphiopus hurterii
Family: Scaphiopodidae – American Spadefoot Toad family
Locations: United States and Mexico
US Locations: Texas, Louisiana, Arkansas, and Oklahoma
Size: 1.75 – 3.25 inches (4.4 – 8.3 cm)

The Hurter’s Spadefoot Toad is named after naturalist Julius Hurter, former curator of the St. Louis Academy of Science. They were once considered a subspecies of the Eastern Spadefoot Toad but was moved to being a full species. Like all Spadefoot Toads, the Hurter’s Spadefoot Toad is mostly fossorial, spending most of its time in burrows underground. They have keratonized sheaths on their rear feet that they use to help dig. Spadefoot toads can be distinguished from other groups of toads due to their vertical, cat-like eyes.

The easiest time to find a Hurter’s Spadefoot Toad is during the breeding season from late spring into summer. They breed following heavy storms that fill up temporary pools of water. Mating only lasts a day or two so you need to get out there quick. The males will call out from the shallows of the pools to attract a mate. Once the mate arrives, the male will grasp her from behind in the amplexus position. Then, the female will lay her eggs and then the male will fertilize. Neither parent provides any care for the offspring. The eggs hatch in 48 hours and the tadpoles complete their metamorphosis in two weeks. This is due to the limit time they have before the pond dries up. Surprisingly, the tadpoles will eat each other if there isn’t enough food in the ponds.

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Hurter’s Spadefoot Toad as Least Concern for Extinction. The toad has a wide range and presumed large population.