Mozambique ‘sky island’ expeditions found 4 new species of chameleon – already at risk from forest loss

Male sylvan chameleon (Nadzikambia goodallae) from Mount Ribáuè, Mozambique. Krystal Tolley, CC BY Krystal Tolley, University of Johannesburg

Tropical rainforests are known for their unique biodiversity, with species found nowhere else on Earth. But nearly 30% of tropical rainforest has been destroyed or has become seriously degraded since 1990. Many of these forests have not been fully explored for their biodiversity. This means that the world may be losing species before they are even discovered by modern science.

In Africa, forest loss is rapid; about 25% of the continent’s tropical forest has been lost since 1990, against a backdrop of incomplete knowledge of where the biodiversity is located.

Greatly lagging in this respect are the “sky islands” of northern Mozambique: isolated granite mountains that rise sharply out of the savanna plains. They were left standing when softer rock around them gradually eroded, and can be as high as 3,000 metres elevation. Because they rise so steeply, the sky islands attract clouds and rainfall, feeding moisture to the tropical rainforests on their slopes within an otherwise arid terrain. Isolation has allowed unique species to evolve on each mountain, such as geckos, rodents, fishes, crabs, frogs, butterflies and bats.

Mount Inago. Krystal Tolley, CC BY
Small patch of remaining pristine rainforest at Mount Inago. Krystal Tolley, CC BY

From 2014 to 2018, a research team led by fellow herpetologist Werner Conradie and myself explored these sky island forests to catalogue the species of reptiles found there. We found that each sky island forest is home to a previously unknown species of chameleon within the genus Nadzikambia (forest-dwelling “sylvan chameleons”).

Unfortunately, these chameleons are already at risk of extinction due to the heavy slash-and-burn clearing of the forests, the only place they can call home.

We’ve described these new species, choosing four names to highlight pioneering women scientists whose work inspired us to strive towards new discoveries, but also to call attention to the losses of their forest habitat.

Hunting for chameleons

Over the course of several years, we explored four of Mozambique’s sky islands – Mount Namuli, Mount Inago, Mount Chiperone and Mount Ribáuè – with the aim of cataloguing all reptiles but also in the hopes of finding new species of chameleons. This was because a species of sylvan chameleon had been discovered on one of these mountains during the 1960s, but they were not known from any other mountains.

However, chameleons can be very difficult to find, given their ability to remain camouflaged against the background coupled with their slow movements. They are more easily spotted at night while they are sleeping, as they stand out against the vegetation when illuminated by a strong beam of light. Sylvan chameleons are even more difficult to spot than others, as they usually perch high in the thick forest canopy – tens of metres up.

The search meant dealing with some tough conditions: a long, arduous trek up the hot, arid slopes to reach the forest high up the mountain. Establishing a remote base camp was essential. All food, clothes and gear had to be packed into the camp, and we didn’t know how long it would take to find any animals.

At each of these mountains, we surveyed every night for chameleons – no trails to follow, no GPS signal to guide us, no cellphone signal to call for help.

Sometimes we were lucky and found chameleons on the first or second night. At other mountains we were not so lucky, with fruitless searches making it necessary to return another year.

Eventually these mountains revealed their secrets and we discovered four new species of sylvan chameleon, one on each of the four mountains.

Slash-and-burn clearing of rainforest at Mount Inago. Krystal Tolley, CC BY

We don’t know how big their populations are, but we assume they are in decline. Most of their habitat has been destroyed by forest clearing to make way for agriculture, with increasingly rapid losses in the last decade. We estimate that in some cases, 80%-90% of their habitat has been destroyed.

When parts of an ecosystem are lost, the whole becomes unstable and is eventually lost.

Choosing names for the new species

To highlight their predicament, we have described and named these chameleons and have forecast that three of these species are at high risk of extinction.

In particular, we highlight Nadzikambia goodallae from Mount Ribáuè. This species has been named in honour of the distinguished scientist Jane Goodall, whose own study species, the chimpanzee, is under similar pressures from loss of its rainforest habitat.

Female sylvan chameleon (Nadzikambia goodallae) from Mount Ribáuè. Krystal Tolley, CC BY

We also honour the renowned discoverer of the structure of DNA, Rosalind Franklin, by naming the species from Mount Namuli as Nadzikambia franklinae. The use of DNA data from these chameleons was essential to confirm them as new species.

Nadzikambia franklinae from Mount Namuli. Werner Conradie, CC BY

We have dubbed the species from Mount Inago as Nadzikambia evanescens, meaning “vanishing” in Latin, acknowledging the state of the forest destruction.

Male sylvan chameleon (Nadzikambia evanescens) from Mount Inago. Krystal Tolley, CC BY

The final species, Nadzikambia nubila, is named for the cloudy aspect of Mount Chiperone. This species has a lower risk of extinction given that the local community view the forest as sacred, and say it should be protected.

Female sylvan chameleon (Nadzikambia nubila) from Mount Chiperone. Krystal Tolley, CC BY

This latter case is significant, as it demonstrates that wholesale destruction of these forests is not an essential trade-off for local people to thrive. If encouraged and supported, community support and buy-in can be a solution to protect biodiversity in these sensitive ecosystems.The Conversation

Krystal Tolley, Principal Scientist, University of Johannesburg

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Johns Hopkins Team Develops Therapeutic, Nasally-Delivered DNA Vaccine for Tuberculosis

Artist’s illustration of tuberculosis bacteria (TB) – credit, US CDC

A research team at Johns Hopkins Medicine is developing a nose-delivered inoculation against tuberculosis, the world’s leading cause of death from infectious disease.

The approach fuses two tuberculosis genes with the goal of directing the immune system to fight drug-tolerant bacterial survivors that can endure antibiotic treatment to spread another day.

The paper on the vaccine was published last week in the Journal of Clinical Investigation, where JH Medicine researchers were joined by colleagues from the Johns Hopkins Bloomberg School of Public Health.

TB is estimated by the World Health Organization (WHO) to be spread asymptomatically by around 2 billion people. In 2024 , WHO reported that TB was the leading cause of death from a single infectious disease.

In recent years, WHO has called for therapeutic vaccines that can be used alongside drug therapies to shorten TB treatment regimens and improve outcomes, particularly because long multidrug courses are difficult to complete, and drug-resistant TB strains continue to emerge. The vaccine described in the new Johns Hopkins study shows promise for meeting that need.

The new Johns Hopkins vaccine, says study lead author Styliani Karanika, MD, fuses two genes: relMtb and Mip3α, and is given through the nose to take advantage of 3 beneficial biological activities.

“Administered together with first-line TB drug therapy, our intranasal DNA fusion vaccine helped infected mice clear the disease bacteria faster, reduced lung inflammation, and prevented relapse after treatment ended,” says Karanika, a faculty member of the Johns Hopkins Center for Tuberculosis Research.

“The vaccine also helped the powerful TB drug combination of bedaquiline, pretomanid, and linezolid work better, suggesting it could be used with treatments against drug-resistant TB to help the body fight the disease, even hard-to-treat cases.”

Dr. Karanika explained that TB bacteria possess a gene—relMtb—that produces a protein called RelMtb—which together help the microbes survive hostile conditions such as antibiotic exposure, low oxygen, and nutrient limitation by entering a drug-tolerant persistent state.

Fusing relMtb with another gene called Mip3α produces a signal that attracts immature human dendritic cells. These cells pick up TB proteins and ‘present’ them to T cells, the immune cells that help coordinate a targeted attack on the TB bacteria.

“Finally, intranasal delivery focuses vaccination on the respiratory mucosa in the lungs where TB infection occurs, helping generate long-lasting localized T-cell immunity in the airways and lungs, along with systemic immune responses,” says Karanika.

By combining these strategies, the investigators aimed to strengthen immune activity directly in the respiratory tract, where transmission most commonly occurs.

In the mouse studies, this approach both improved the quantity and organization of dendritic and T-cells in the lungs, and generated immune responses both locally and systemically. The improved response included to two types of T-cells, CD4 (also known as helper T-cells) and CD8 (also known as killer T-cells).

One study strongpoint was that it included tests on primates: in this case, rhesus macaques. The researchers found that their nose-delivered DNA vaccine prompted measurable TB‑focused immune responses in blood and in the airways similar to what led to lower bacterial counts in the lungs of the mice they studied.

These responses persisted for at least 6 months, suggesting durability for the vaccine’s action.

“These nonhuman primate data are encouraging because they show that the Mip3α/relMtb vaccine can generate durable, antigen-stimulated immune responses in an animal model whose immune system more closely resembles that of humans,” said Dr. Karanika. “That gives us an important translational bridge between the mouse efficacy studies and the additional preclinical work needed before human trials.”

Readers may recoil from the notion of primate testing, but Old World Monkeys are very susceptible to TB, and in fact spread it between themselves just as we do. Research has shown that TB has been spread among humans as far back as 70,000 years, and followed our migration out of Africa and across Asia.The authors say their findings support a broader strategy of targeting surviving TB bacteria with immunotherapy, rather than relying solely on antibiotics to eliminate actively replicating bacteria. Because DNA vaccines are relatively stable and can be manufactured efficiently, they may offer practical advantages if this approach ultimately proves effective in humans. Johns Hopkins Team Develops Therapeutic, Nasally-Delivered DNA Vaccine for Tuberculosis
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