Scientists Discover Three New Toad Species That Give Birth to Live Young
In a remarkable discovery, scientists have identified three new species of toads that give birth to fully formed “toadlets” rather than laying eggs — an exceptionally rare trait among amphibians.
All three belong to the Nectophrynoides genus, commonly known as tree toads, a group already famous for this unusual reproductive strategy. Instead of going through a tadpole phase, their young emerge from the mother as miniature adults.
Until now, these toads were believed to be part of a single widespread species. But new research reveals that what was once considered one population is actually four distinct species, each with a smaller and more isolated habitat — a finding that could have major implications for their conservation.
“Live-bearing is extremely rare among frogs and toads — less than 1% of species do it,” said Dr. H. Christoph Liedtke, an amphibian evolution researcher at the Spanish National Research Council. “That makes these new species particularly fascinating.”
A Closer Look at Tanzania’s Tree Toads
The Nectophrynoides genus has long intrigued scientists. Of the more than 7,000 known frog and toad species worldwide, only 17 are known to give birth to live young, with most belonging to this group. The new study, published on November 6 in Vertebrate Zoology, adds three more names to that short list.
The original Nectophrynoides viviparus was described in 1905, and for over a century it was thought to range widely across Tanzania’s Eastern Arc Mountains and Southern Highlands. But a 2016 genetic analysis hinted that there might be more to the story — that several distinct species were hiding under one name.
To test that theory, researchers reexamined hundreds of museum specimens, analyzed field recordings of their mating calls, and used museomics — extracting DNA from century-old preserved samples — to compare their genetics.
Their results revealed that the toads once lumped together as N. viviparus actually represent four species, three of which were previously unknown to science:
- Nectophrynoides saliensis
- Nectophrynoides luhomeroensis
- Nectophrynoides uhehe
Though they look similar at first glance, subtle differences in head shape, shoulder gland structure, and DNA distinguish them.
“Some of the specimens we studied were collected over 120 years ago,” said Dr. Alice Petzold, an evolutionary biologist at the University of Potsdam. “Our genetic work helped us trace exactly which populations those old specimens came from — something that wasn’t possible until now.”
New Discoveries, New Conservation Concerns
The finding reshapes scientists’ understanding of these toads’ distribution — and their vulnerability. What was once considered a single, stable species now appears to be multiple smaller populations, each restricted to limited areas of forest.
That’s worrying news, as many of these habitats are already shrinking due to deforestation, agriculture, and climate change.
“The forests these toads depend on are disappearing fast,” warned Dr. John Lyakurwa of the University of Dar es Salaam.
One close relative, Nectophrynoides asperginis, went extinct in the wild in 2009 after a dam construction project and a fungal disease outbreak devastated its population — a stark reminder of how fragile these species can be.
The researchers hope their findings will help shape conservation plans to protect these unique live-bearing amphibians before it’s too late.
“Every new discovery like this reminds us how much biodiversity is still hidden — and how quickly it can vanish,” said Liedtke.