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Zimbabwean scientist explains rare discovery

by Staff reporter
30 Jul 2022 at 19:07hrs | Views
A TINY frog called the cave squeaker had not been seen for more than half a century and it had been placed on the international red list of threatened species.

Dr Robert Hopkins (80) of Parklands suburb who is an associate researcher at the Natural History Museum in Bulawayo and an internationally acclaimed frog research academic, led a team of researchers to find the frog species last seen in 1962.

After searching for 10 years they found it in December 2016, making headlines globally.

A man who had developed a strong passion for frogs from the age of six, had made history.

The ground breaking search team had Dr Hopkins' wife, Veronica, Francios Becker, who at the time was a MSc student at the University of Cape Town and Zimbabwean entomologist Herbst Scott, then a BSc student in entomology from Rhodes University.

The team also included Fungayi Mafudze and Tor Simonson who were guides from Outward Bound School with the help of the Conservation Club of Chimanimani.

Their mission was to find the existence of Cave squeakers, a breed of small frogs known by their scientific name: Arthroleptis troglodytes. Fifty-four years had gone by and successive annual searches had yielded no results. With funding from the Mohamed bin Zayed Conservation, Dr Hopkins made a breakthrough.

According to the scientific research, Cave squeaker are only found in their natural habitat in Chimanimani in the vicinity of Bundi River in an area covering 100 hectares.

Over the years, it was speculated that the rare frogs could be found across the river well into Mozambique, However, no specimen was found there.

In an interview, Dr Hopkins, who holds a doctorate degree in ecology from Rhodes University, said he was raised in a scientific family.

"I was born in a scientific family in East London in South Africa and my aunt Marjorie Eileen Doris Courtenay-Latimer was a director at the East London Museum. She would tell us that some years back when she was a young girl, she was called to the harbour to look at some fish," he said.

"She spotted some fish that she suspected had never been seen before. She placed it on a wheelbarrow and took it all the way to the museum."

Dr Hopkins said during that time, there was a Professor at Rhodes University by the name James Leonard Brierley Smith, who was an ichthyologist (a person who specialises in fish and frog biology)

"Prof Smith identified it as a fish that had gone extinct 60 million years ago and was found alive. As a result that fish was named after her," he said.

Dr Hopkins reminisced as a boy when they would go to the bush to catch snakes with his peers in South Africa and he moved to Zimbabwe in 1961.

"When I was about six years old in the Cape, I would go to the bush with other young black boys from the local Xhosa community and I was the only white boy. We used to play in the open and we used to catch snakes," he said.

"My father was impressed with my pastime and decided to support me. We had fish tanks where we would put snakes there and feed them with frogs."

Dr Hopkins said observing snakes eating frogs touched him and subsequently led to him researching more on frogs.

"I would feel sorry for the frogs and that is how I developed a passion for frogs and started researching on them from that age. When I came to Zimbabwe, which was Rhodesia then in 1961, the reasons were that there were no people that were actually working on frogs," he said.

Dr Hopkins secured a job to work for Government and his first research was on the African giant bullfrog whose scientific name is Pyxicephalus adspersus. It is the second biggest frog in the world.

"I remember being drawn to populations in Iminyela suburb in Bulawayo where I would encounter young boys playing soccer in an open space.

"When the rains came, the water used to gather there and Pyxicephalus adspersus used to reproduce and enjoy that kind of environment," said Dr Hopkins.

"During those days and that was sometime in November 1962, we counted something like 400 of these African giant frogs, but I have noticed that between that period and now, this species is disappearing in Matabeleland."

Dr Hopkins said due to the decline in the population of African giant frogs, South Africa has since declared them protected species and made sanctuaries for them.

Herpetologists attended a meeting in Cape Town in November 2015 and agreed that these frogs were part of the top 10 most endangered species.

"I was invited to South Africa where they now have a specialist in frogs in the mould of Prof Alan Channing whom I work closely with and he is probably the world's top authority on African frogs," he said.

"I went down to South Africa for a meeting with him (Prof Channing) in Cape Town and while there, we did research on frogs and made reports on abandoned species in different areas. There were some representatives from Mozambique, Angola Zambia, Malawi and I was representing Zimbabwe."

Dr Hopkins said he spent 10 years looking for the Cave squeaker but couldn't find it until November 2016.
The cave squeaker hadn't been seen for more than half a century in the rock-studded Chimanimani mountains where it used to be found.

The tiny frog only grows to around half the size of a thumb. An international red list of threatened species tagged the frog as critically endangered and possibly extinct.

With his face lighting up, Dr Hopkins recalled how excited he was upon discovering the Cave squeaker

"You can imagine the tremendous joy in me when news reached me that finally we had found the Arthroleptis troglodytes after 10 years of searching. In fact, I was supposed to climb up the mountain together with my team, but due to the fact that I had developed stomach cancer, I couldn't join them up there," he said.

Dr Hopkins said he received a phone call from Francois Becker while in bed shortly after 9pm.

"The first thing he (Becker) said on the phone was ‘Robert, I have found it' and I said ‘what?' I couldn't believe that something that we had been looking for years was finally found," he said.

The team found the first male specimen on December 3 in 2016 after following an animal call that they had not heard before," Dr Hopkins said.

They then discovered another two males and a female. Dr Hopkins said Becker came to his lodge and showed him the four Cave squeakers that he had found.

"Francois had done a great deal of work on similar species in South Africa, and had paid particular attention to their calls.
"He heard a call which he recognised as that of an Arthroleptis, but did not or could not identify it, so he tracked that call and ultimately found the first specimen," he said.

Dr Hopkins said researchers have been looking for the frog near water, which is where they were last seen in 1962.

The late Natural History Museum curator and renowned herpetologist, Dr Donald George Broadley, who first discovered the cave squeaker in 1962, had tried, but failed to relocate it. He died in March 2016 just months before the rediscovery.

Dr Hopkins said Dr Broadley was one of the greatest herpetologists in the world.

"He (Dr Broadley) saw this frog on the wall of a rock and realised that it wasn't anything he had seen before and called it Arthroleptis troglodytes after the cave. Its common name is Cave squeaker because it belongs to the family of squeakers," he said.

"The frog disappeared and couldn't be found and for 55 years we looked for that frog but could not find it. South African researchers and frog specialists came and we tried looking for it in the caves, but couldn't locate."

Dr Hopkins said there are 14 species of squeakers in Africa and Zimbabwe has four of the species.

"We changed the name and its now called the Chimanimani squeaker but you can't change the scientific name because it is registered in France unless more research is done," he said.

Dr Hopkins said Prof Channing flew into the country and took photographs of the cave squeaker and DNA samples.

The America Museum of Natural History including other countries across the world also contacted me.

Researchers plan to breed more of the frogs and then reintroduce them to the mountain summit.

"We need more black Zimbabwean researchers in the scientific world and that would help if we can get some young people to do that.

"My desire is to pass knowledge on frogs as much as I can to the younger generation," he said.

Source - The Chronicle