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.

Read More........

Heat with no end: climate model sets out an unbearable future for parts of Africa


Oluwafemi E. Adeyeri, Australian National University

People often think of a heatwave as a temporary event, a brutal week of sun that eventually breaks with a cool breeze. But as the climate changes globally, in parts of Africa, that level of heat is becoming a permanent part of the weather.

Research shows Africa’s exposure to dangerous heat is rising rapidly. Until now, estimating how severe this heat would become was challenging. This was because many widely used global climate models struggled to capture the local factors that shape heat in Africa’s diverse climate zones and habitats (humid tropics, dry savannas and rapidly changing agricultural areas).

It is very important to analyse how these different local factors cause dangerous heat because they all play a role in causing it. For example, rapid changes to the way land is used, such as deforestation, alter soil moisture and humidity. Turning forests into crop land therefore becomes a driver of extreme heat.

We are a team of hydroclimate and land-atmosphere scientists who study heat extremes, water resources, the way land use changes, and hydroclimate risk. We set out to produce reliable, locally relevant projections of future heatwaves. Our team realised that to understand the true heatwave risk in Africa, we had to look down as well as up. It is not only the warming atmosphere from above, it is also the way people are transforming the land below.

To better understand how heat is likely to affect African countries, and to avoid relying on any single climate model, we developed a framework built on four pillars:

  • To get the most accurate data, we studied 10 global climate models rather than betting on one model.

  • The global climate model outputs were adjusted so they matched observed heatwave patterns (the frequency, duration, magnitude, amplitude, number and timing of heatwaves) and showed the links between temperature, wind, radiation and humidity.

  • Artificial intelligence (AI) was used to quantify how much the different drivers of heat (such as temperature, humidity, soil moisture, wind, radiation, land use) contributed to heatwave changes. We also used AI to highlight how these drivers made heat worse when they interacted.

  • We compared what would happen in a high-pollution future as opposed to one where governments and industry managed to reduce carbon emissions.

Our research found that by the late 21st century, most regions in Africa will stop having occasional heatwaves and will suffer from extreme heat lasting most of the year. The study shows that by 2065-2100, many parts of Africa (apart from Madagascar) could experience heatwaves on 250-300 days per year.

Some areas, such as the western side of southern Africa, will experience heatwaves that are 12 times as long and frequent as they are now, even if global emissions are reduced. Many heatwaves will last longer than 40 days at a time.

This is not just a slight warming; it is a fundamental change in how people will have to survive on the continent. Once regions in Africa enter a state of almost continuous heatwaves, the human body will have no window of time to recover.

Africa’s heat risk comes from global emissions and local land choices. This means that cutting greenhouse gases matters, and so does protecting and restoring the land’s natural ways of cooling the planet down.

How heat will build dramatically across Africa

In places with intact forests that cool the air, heat and humidity usually remain below a deadly limit. Forests act like natural air-conditioners, preventing fatal heat.

But when forests are cut down and replaced with cropland, the local climate changes. Crops release large amounts of moisture into the air, raising humidity. Heat and moisture build, and the surface heats up faster during the day and stays warmer at night. The land becomes a heat trap. A hot spell that would have been tolerable under forest cover becomes a prolonged, hazardous heatwave.

Rising background heat can affect entire regions. Rural communities, including smallholder farmers, are also highly exposed because they work outdoors and often have limited access to cooling, healthcare or heat-resilient infrastructure.

Heatwaves will affect shack or informal settlement areas more because they generally lack trees and vegetation, and homes built from metal are harder to cool. Without shade, heat will build and linger.

A ‘deadly threshold’ will be reached

Our modelling shows that there is a specific combination of heat and humidity where conditions can intensify heatwaves very quickly, especially in landscapes dominated by cropland.

This is a different kind of heat risk. It is not the familiar “dry heat” driven by parched soils. It is a crop‑driven humidity effect that pushes the atmosphere into a danger zone. For example, in west Africa, extreme heat will peak at about 26.5°C-26.8°C with 74%-75% humidity, producing heatwaves that last 30-35 days.

In southern east Africa, heatwaves will happen even at lower temperatures (23.6°C-23.8°C) and humidity (70%-72%). The danger there is that even small increases in heat or moisture, including those caused by cutting down forests, will make heatwaves more common and longer.

Across all nine African climate regions, our research found that heatwaves will stop being rare events and start becoming a regular part of the year.

The good news is that local land choices will offer immediate protection. Keeping forests, restoring vegetation and using climate-smart farming (where animals and crops are farmed with trees) are not just environmental actions. They are public health defences that weaken the intensity and duration of heatwaves.

What needs to happen next

This research highlights something simple but powerful: a forest is a shield.

This study also shows how planning in cities and in rural areas can keep “nature’s air‑conditioner” working.

Protecting the continent means acting on two fronts. Globally, we need to keep reducing fossil fuel emissions, because even moderate cuts lower the chance of long, near-permanent heatwaves.

Locally, every land-clearing decision matters. Removing natural vegetation adds heat to communities, but keeping forests and cover on the land helps hold temperatures down.

The message is straightforward. Countries cannot control global warming on their own, but they can control how the land responds to it.The Conversation

Oluwafemi E. Adeyeri, Research Fellow in Climate Science, Australian National University

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

Read More........