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Black Caiman (Melanosuchus niger)

Black Caimen
photo by wikiuser Rigelus

Common Name: Black Caiman
Scientific Name: Melanosuchus niger
Family: Alligatoridae – Alligator family
Locations: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, and Peru
Size: 7.25 – 14.1 feet (2.2 to 4.3 meters) , can grow to 16.5 feet (5 meters)

The Black Caiman is the largest living species of caiman, capable of reaching 16.5 feet long and reaching over a thousand pounds! They live in the Amazon River Basin, where they are one of the apex predators there. Once the Black Caiman reaches full size, only humans attempt to hunt them. The caiman feeds on a variety of animals such as snakes, fish, monkeys, frogs, and even other caiman. They hunt at night, where their excellent night vision help out.

At the end of the dry season, the females start to build their nests of soil and vegetation. Additionally, these nests are almost 5 feet (1.5 meters) long and 2 and a half feet (0.75 meters) wide. At the start of the wet season (May – June), the caiman lays between 30 – 60 eggs. The mother protects her nests from predators until they hatch. The eggs hatch between 42 – 90 days after being laid. The mother helps dig the hatchlings out of the nest. Then, the offspring stick close to their mom. Even with their mom’s protection, a large number of the offspring die.

Black Caiman Conservation

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Black Caiman as Conservation Dependent. The IUCN Red List no longer uses this category. The caiman’s status hasn’t been reassessed since 2000 when they were placed there. Before, they were categorized as endangered due to over hunting of the species. Hunting of the species has slowed down thanks to legal protections.

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American Crocodile (Crocodylus acutus)

American Crocodile
photo by wikiuser Mattstone911

Common Name: American Crocodile
Scientific Name: Crocodylus acutus
Family: Crocodylidae – Crocodile Family
Locations: Belize, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Peru, United States, Venezuela, and Bolivia
US Location: Florida
Average Male Size: 9.5 – 13.1 feet (2.9 – 4 meters)
Average Female Size: 8.2 – 9.8 feet (2.5 -3 meters)
Maximum Size: 20 feet (6.1 meters)

The American Crocodile has the most widespread range of any crocodile in the Americas. They reach from southern Florida, through Central America, and down to northern South America. They live in fresh or brackish water of estuaries, lagoons, and mangrove swamps.

The American Crocodile breeds during the dry season. The males are highly territorial and fight other males for the best land. The courtship and breeding takes place in the water. The male’s main advertisement to females is 1 to 3 headslaps. If this is acceptable for the female, then she either puts her head on his back / head or performs some snout lifts. Next, the male lets out a low frequency noise that makes water blow up off of his back, called water dancing. Finally, the two mate in the shallows.

The female builds their nests on elevated, well drained soil. The female lays between 30 – 60 eggs. Temperature determines the sex of the offspring. Temperatures between 88- 91° F (31.1 – 32.7° C) produce mostly male offspring. Meanwhile, temperatures lower than 88° F (31.1° C) result in mostly females. The female parent protect the nest from scavengers such as raccoons and iguanas. The eggs hatch in 75 – 80 days at the start of the wet season. The female helps dig ups the hatched babies and carries them to the water.

American Crocodile Conservation

The International Union for the Conservation of Nature (IUCN) Red List classifies the American Crocodile as Vulnerable to Extinction. The Croc’s populations has improved than it previously had been. It was listed as Endangered before conservation work was done to help save them. Unfortunately, they were over-hunted for their hides before being listed on the US Endangered Species List in the 1970s. However, they moved from listed as federally endangered to federally threatened. Protections are still in place to help conserve the species from overharvesting. Unfortunately, their habitat is under threat of destruction to make room for more urban areas.

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Gharial (Gavialis gangeticus)

Gharial
Male Gharial – photo by Charles J Sharp

Common Name: Gharial, Gavial, and Fish-eating Crocodile
Scientific Name: Gavialis gangeticus
Family: Gavialidae – Gharial family
Locations: Bangladesh, India, and Nepal
Female Size: 8.5 feet (2.6 meters) – 14.75 feet (4.5 meters)
Male Size: 10 feet (3 meters) – 20 feet (6 meters)

The Gharial is known for their long, narrow snout that is adept at catching fish. Males of the species develop a gross looking growths called a ghara on the tip of their snouts once they reach sexual maturity. Ghara means Mud Pot in Hindi. They use the ghara to vocalize more loudly and blow bubbles during their mating displays.

The mating season for the frogs happens during the dry season, between March and April. The males stake out their territory and defend it from rival males. Females in the territory mate with the male and she then lays an average on 40 eggs. Their eggs are the largest eggs of all the living crocodilians, averaging over 5 ounces. The male provides no parental care for their offspring and will move onto reproducing with other females. The female stays to protect her nest from predators. The eggs hatch between 30 – 80 days. After hatching, the mom still protects the babies for weeks and even months.

Gharial Conservation

The International Union for the Conservation of Nature (IUCN) Red List classifies the Gharial as Critically Endangered. Their habitat has been drastically altered due to damming and diverting water from the rivers. Gharials don’t do well far away from the river. These alterations to the habitat causes them to have to travel farther on land when moving to new spots in their river, increasing their chance of dying. Overfishing is also rampant in rivers that the Gharial is found in. This reduces their food source and they get stuck or injured by nets.

Uncategorized

Saltwater Crocodile (Crocodylus porosus)

Saltwater Crocodile
photo by flickr user fvanrenterghem

Common Name: Saltwater Crocodile or Salties
Scientific Name: Crocodylus porosus
Family: Crocodylidae – Crocodile family
Locations: Australia, Bangladesh, Brunei, Cambodia, East Timor, India, Indonesia, Malaysia, Myanmar, Palau, Papua New Guinea, Philippines,, Singapore, Solomon Islands, Sri Lanka, Thailand, Vanuatu, and Vietnam
Size: 17 – 23 feet (5.1 – 7 meters)

The Saltwater Crocodile is the largest living crocodile species in the world. These crocodiles can reach 23 feet and over 2,200 pounds! They received their name due to their resistance to saltwater. Most crocodiles only enter the saltwater in emergencies while the Saltwater Crocodile just lives there. They are capable of living over 70 years in the wild and longer in captivity.

Saltwater Crocodile Reproduction

The Saltwater Crocodile breeds during the wet season when the water levels are the highest. The females select a nesting site where she and a male eventually mates. The male is a dead beat dad and doesn’t provide any care for his offspring. He leaves the mom and tries to find more potential mates. The female crocodile shows a high amount of parental care.

The mother guards her nest of eggs, even splashing water on the eggs to help prevent them from drying up. The eggs take 3 months to hatch. The sex of the offspring depend on the incubation temperature. Temperatures below 86 ºF (30 ºC) result in females. Meanwhile, temperatures above 89 ºF (32 ºC) results in male offspring. Once the eggs hatch, the female digs out the babies and carries them to the water in her mouth. Then, she protects the babies until they are able to take care of themselves. What a mom!

Conservation

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Saltwater Crocodile as Least Concern for Extinction. They have a fairly large range but the destruction of potential nesting sites is a concern. Another threat is hunting of the crocs for their pelts and meat. These threats are rather low though.

Frog of the Week

Holy Cross Frog (Notaden bennettii)

Holy Cross Frog
photo by wikiuser Tnarg 12345

Common Name: Holy Cross Frog, Crucifix Frog, and Crucifix Toad
Scientific Name: Notaden bennettii
Family: Myobatrachidae – Australian Ground Frog family
Locations: Australia
Size: 2.7 inches (6.8 cm)

The Holy Cross Frog is a fossorial species of frog found in the  black soil plains and semi-arid grassland regions of western New South Wales and Queensland. During the dry times, the frog burrows down in the ground and surrounds itself in a cocoon to preserve water. They are capable of digging down almost 10 feet (3 meters)! Due to their fossorial lifestyle, the frogs feed primarily on ants and termites. When threatened by predators, the frogs produce a sticky, glue-like substance that predators don’t want to eat. It is advised to wash your hands after handling the Holy Cross Frog and basically any frog.

Once the heavy rains come, the frog will emerge from the ground, ready to breed. The male frogs will move to temporary ponds created by the rains and start to call out to females. The call sounds like a woo. Once the female arrives at the pond, the male glues himself to her back due to his smaller size. Next, the female lays her eggs and the male will fertilize them. Neither parents provide any parental care for their offspring.

Holy Cross Frog
photo by flickr user eyeweed

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Holy Cross Frog as Least Concern for Extinction. The only threats to the species are habitat loss due to farming, climate change, and the introduction of the invasive Cane Toad (Rhinella marina). Researchers have been trying to get the frogs to breed in captivity just in case but have been struggling. Surprisingly, the answer to this problem was a Youtube Clip of a thunderstorm. This clip helps simulate heavy rain storms that gets the frogs in the mood.

New Species

2 New Species of Waterdogs

The Waterdogs are fully aquatic species of salamanders that are paedomorphic. This means that they retain their larval characteristics (gills, etc) throughout their life. They are often mysterious, often living at the bottom of drainages, ponds, and lakes.

Researchers, Craig Guyer, Christopher M. Murray, Henry Bart, Brian I. Crother, Ryan E. Chabarria, Mark A. Bailey, and Khorizon Dunn, have described two new Waterdog species from the southeastern United States. You can read the article here. The two waterdogs were considered to be Gulf Coast Waterdog (Necturus beyeri) but they are physically different than it. Also the researchers suggest changing the name of the Gulf Coast Waterdog to the Western Waterdog.

Escambia Waterdog – photo by Craig Guyer

The first of the new species is the Escambia Waterdog (Necturus mounti). The larvae lacks white spots which differs from the Gulf Coast Waterdog. The adults lack spots on their mandible chin and on the sides of their belly. Their belly is a bright white color as well.

Apalachicola Waterdog – photo by Craig Guyer

The second of the species is the Apalachicola Waterdog (Necturus moleri). They as well lack white spots on their larvae that differs it from the Gulf Coast Waterdog. The adults have spots on their mandible chin and on the sides of their belly. Their belly is dull white in color. Both of the new species can be found around the Florida – Alabama border.

Frog of the Week

Magdalena Giant Glass Frog (Ikakogi tayrona)

Common Name: Magdalena Giant Glass Frog
Scientific Name: Ikakogi tayrona
Family: Centrolenidae – Glass Frog family
Locations: Colombia
Size: 1.2 inches (28 mm)

The Magdalena Giant Glass Frog is found in the Sierra Nevada de Santa Marta mountain range in the Magdalena department of Colombia, at altitudes up to a mile (1790 meters) high. They are an arboreal species of frog, living up in the trees. During the day, the frogs will hide on the back of leaves, camouflaging in with their translucent skin. Glass Frogs are really small, so even a frog reaching not even 1.5 inches long is considered gigantic.

The males of the species will mark out territory in leaves over hanging a stream. They will fight other males that enter their territory. The males even have humeral spines on their arms that they use to fight the other males. Eventually, the males will start calling for the females. Once the females arrive, the male will grasp her from behind in the amplexus position. Then, the female will lay her eggs on the leaves and the male will fertilize them.

The Magdalena Giant Glass Frog is the only known Glass Frog known that females will provide parental care for their offspring. In the other species, parental care is either provided by the male or not at all. The females will brood the eggs, protecting the eggs from predators and keeping them hydrated. Eventually, the eggs will hatch and the tadpoles will fall into the stream.

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Magdalena Giant Glass Frog as Vulnerable to Extinction. They are found only in a small area where habitat destruction is an increasing problem.

Uncategorized

Crab-eating Frog (Fejervarya cancrivora)

photo by W.A. Djatmiko

Common Name: Crab-eating Frog, Mangrove Frog, Asian Brackish Frog, and Crab-eating Grassfrog
Scientific Name: Fejervarya cancrivora
Family: Dicroglossidae – Forked Tongued Frog family
Locations:  Brunei, Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand, and Vietnam.
Introduced Locations: Guam and Papua New Guinea
Size: 3.1 inches (80 mm) for females, 2.75 inches (70 mm) for males

The Crab-eating Frog is thought to be the most salt tolerant amphibians in the entire world. They are able to survive in brackish waters for extended periods of time and briefly survive swimming in salt water. With this species talent, they are able to feast upon crabs and other small crustaceans, hence their name. They are found along the shorelines, mangrove forests, and inland wetlands.

Reproduction for the frogs is pretty standard. They can breed year round but most activity is at the start of the wet season. At the start, the males will call for the females from a water body. Once the female arrives, the male will grasp her from behind in the amplexus positiion. Then, female will lay her eggs and the male will then fertilize them. Neither parent will provide any parental care for the offspring. The eggs will hatch into tadpoles that transform later into frogs.

The Crab-Eating Frog is listed by the International Union for the Conservation of Nature (IUCN) Red List as Least Concern of becoming Extinct. The frog has a wide range and is plentiful throughout it. They especially thrive in rice paddy fields. Potential threats to the survive of the frogs is the habitat destruction and over harvesting the frogs for food.

Frog of the Week

Tarahumara Frog (Rana tarahumarae)

Tarahumara Frog
photo by Jim Rorabaugh of USFWS

Common Name: Tarahumara Frog
Scientific Name: Rana tarahumarae
Family: Ranidae – True Frog family
Locations: United States and Mexico
US Locations: Arizona
Size: 2.5 – 4 inches (64 – 102 mm)

The Tarahumara Frog is found in the montane canyons of southern Arizona and down into Mexico. Their main habitat is rocky streams and plunge pools. They breed in these permanent bodies of water from April to May. The male frog will call out to the females though they lack vocal sacs like other frogs have. The female will arrive and the male will grasp her from behind in the amplexus position. Then, the female will lay her eggs and the male will fertilize them. Females can lay up to 2200 eggs at a time. Neither parent will provide any parental care for their offspring. The tadpoles can take over 2 years to complete their metamorphosis.

The International Union for the Conservation of Nature (IUCN) Red Lists categorizes the Tarahumara Frog as Vulnerable to Extinction. The frog is extinct in Arizona and is steadily disappearing from Mexico. Chytrid Fungus, a deadly disease, is believed to have caused large die offs of the frogs. Other reasons for the declines in their numbers include invasive species, pollution, and habitat destruction. Invasive species, such as the Blue Gill and American Bullfrog, feast upon the frog and their tadpoles. Much of the range of the Tarahumara Frog in Arizona has been taken over by Bullfrogs.

There are currently projects working to reintroduce the frogs into Arizona. The first reintroduction was done in 2004. All of the frogs sadly died out over the next 10 years due to Chytrid Fungus and flooding. In 2012 and 2013, frogs and tadpoles were once again reintroduced but a die off happened due to chytrid fungus again. There’s still hope enough survived to continue the population. More plans for reintroduction are being considered.

Frog of the Week

Western Chorus Frog (Pseudacris triseriata)

photo by Todd Pierson

Common Name: Western Chorus Frog or Midland Chorus Frog
Scientific Name: Pseudacris triseriata
Family: Hylidae – Tree Frog family
Locations: Canada and the United States
US Locations: Iowa, Illinois, Indiana, Kentucky, Michigan, New York, Ohio, and Tennessee
Size: .3 – 1.5 inches (10 – 37 mm)

The Western Chorus Frog is a poorly named frog, due to it not living anywhere close to the west. It used to be part of a species complex with other Chorus Frogs, such as the Upland Chorus Frog (Pseudacris feriarum), but they were eventually all split into their own species. The Western Chorus Frog is often confused with other species of chorus frogs. Differences between the chorus frog species have to do with location and leg size so it can be really confusing. While chorus frogs are a member of the tree frog family – Hylidae, they are not found climbing high in the trees but usually around ground level. Due to their small size, they can be rather hard to find. Best time to locate them is during the breeding season when they are calling.

 Ohio Department of Natural Resources Division of Wildlife

The Western Chorus Frog starts to breed in February or March, depending on when the snow melts. They will continue to breed until the end of April or early May. The males of the species will start to call from temporary bodies of water like flooded ditches, flooded fields, and ponds. Females will come to the water and choose a mate. Once that happens, the male will grasp the female from behind in the amplexus position. Then the female will lay her eggs and the male will fertilize them. The female can lay 300 eggs at a time. Neither parent provides any parental care for the offspring. The eggs hatch a week later and a tadpole emerges. The tadpole takes 3 months to complete their transformation into a juvenile frog.