Plains zebra (Equal quagga) are an iconic African plains species, being easily identifiable by their distinctive black and white stripes. But plains zebra are now been seen with more unusual coat patterns. Instead of stripes, some have spotted or large, black splotches, and even golden coats with lighter stripes. In 2019, researchers in the Masai Mara National Reserve, Kenya, recorded a polka-dotted foal, which had white spots covering its darker brown body
These rarely found coat patterns are often caused by genetic mutations in which the production of melanin (a natural pigment) has been altered. Scientist Brenda Larison, has found an unusually high number, about 5%, of plains zebra with abnormal coat patterns, near Lake Mburo, Uganda.
In an interview with National Geographic, Larison said that “the observation [of the oddly patterned zebras] led me to wonder: is part of the reason that I’m seeing so many is because this population is inbred?”
To discover more, Larison along with fellow researchers, investigated population genetic health and genetic structure in plains zebra. They ran genetic analyses on 140 plains zebras from nine different locations, including Etosha and Kruger National Parks. Their analysis included seven individuals who had unusual coat patterns. The data was then analysed to find out the relationships between population structure, genetic diversity, inbreeding and abnormal phenotypes.
Not surprisingly, they found that smaller, more isolated zebra populations had lower genetic diversity. But, they also found that these isolated groups were more likely to produce abnormally striped zebras. This suggested that these genetic mutations are caused by poor genetic diversity, with one of the reasons these herds are isolated from other zebra populations might be due to a result of habitat fragmentation.
Although their study only included seven zebras with these odd patterns, their results could indicate a highly visible warning about the future of plains zebra.
Concern for plains zebra long-term survival
It is thought that by not having stripes, unusually patterned zebra are more vulnerable to predators, as researchers only found polka dotted foals, but no mature dotted adults. Larison is also researching the link between a zebra’s stripes and biting insects – do their stripes help to avoid them been bitten by tsetse flies, and if so, does this help them to avoid sleeping sickness?
Larison’s study found that zebras are becoming genetically closer within their own populations. In turn, these isolated populations are growing more genetically distant from other zebra populations. This means that these isolated populations could eventually lead to new subspecies of plains zebra.
“We found that there are populations that are possibly diverging more than they would under normal circumstances, because of human population pressure.”
Brenda Larison
This is of conservation concern. Inbreeding, with a lack of gene flow, can cause infertility, disease and other genetic defects. If isolated zebra populations become too genetically different from each other, then the opposite of inbreeding can occur – outbreeding – which can also cause abnormalities from genes being too dissimilar. The only way to make sure that this does not happen is through conservation strategies, such as translocating zebra, so that new genes are brought into a herd, ensuring their long-term survival.
Plains zebra are the least threatened of the three zebra species, but it is thought that their numbers have dropped by 25% since 2002, with around 500,000 plains zebra across the whole of Africa.
Habitat fragmentation is caused by human development, such as putting up fencing, which squeezes mammal populations into small pockets of land. This prevents them from migrating to other areas, and also stops them from breeding with other herds.
Find out more
Brenda Larison works at the Department of Ecology and Evolutionary Biology, University of California, Los Angeles. She researches Zoology, Ecology and Evolutionary Biology with her interests including the evolution of phenotypic diversity and conservation genetics. Her current research projects focus on the genomic and evolutionary basis of striping in plains zebras, and conservation genomics in Grevy’s and plains zebras and common loons.
Today, 2nd February, is World Wetlands Day. This year’s theme is ‘Wetlands and Water’, highlighting their importance as a source of freshwater and encouraging people to restore them to stop them from disappearing.
“We are facing a growing freshwater crisis that threatens people and our planet. We use more freshwater than nature can replenish, and we are destroying the ecosystem that water and all life depend on most – Wetlands.”
Wetlands contribute to the quantity and quality of our freshwater and are essential for the health of people and our planet. The 2nd February also marks the date of the adoption of the Convention on Wetlands which took place in 1971, at the Iranian city of Ramsar, on the shores of the Caspian Sea.
What are wetlands?
Wetlands are areas of land that are naturally saturated or flooded with water, either seasonally or permanently. Inland wetlands include marshes, ponds, lakes, fens, rivers, floodplains, and swamps. There are also coastal wetlands, which include saltwater marshes, estuaries, mangroves, lagoons and even coral reefs. Human –made wetlands include fishponds, rice paddies, and saltpans.
Only 2.5% of water on Earth is fresh water – most of this is stored in glaciers, ice caps and underground aquifers:
Less than 1% of freshwater is usable
Rivers and lakes hold 0.3% of our planet’s surface water
Why wetlands are essential
Both fresh and saltwater wetlands sustain nature and humans, supporting our social and economic development through:
Store and clean water – wetlands capture, hold and provide us with most of our fresh water, naturally filtering out pollutants, cleaning the water for us
Provide a safe habitat for many wildlife species – 40% of the world’s species live and breed in wetlands. Annually, around 200 new fish species are discovered in freshwater wetlands
Keep us safe – they provide protection from flooding as each acre of wetland absorbs up to 1.5 million gallons of floodwater. They also help regulate our climate – peatlands store twice as much carbon as forests whilst saltmashes, mangroves and seagrass beds also hold vast amounts of carbon
Keep us fed – Aquaculture is the fastest growing food production section and inland fisheries provide millions of tonnes of fish a year. 12 million tonnes of fish in 2018 whilst rice paddies feed 3.5 billion people each year
Underpin our global economy – wetlands are out most valuable ecosystem, providing services worth US $47 trillion a year globally whilst more than a billion people around the worked rely on wetlands for their income
Our freshwater consumption
Around the world we use 10 billion tons of water every day. 70% is used in agriculture and food cultivation, whilst 22% is used for industry and energy. Our water usage has increased six-fold in the last 100 years, with an annual increase of 1% each year. This is due to population growth, urbanisation and unsustainable consumption patterns which has put pressure on wetlands and their water. By 2050 our earth’s population is estimated to reach 10 billion people – 14% more water is therefore needed to produce 70% more food to feed everyone on earth.
Impact of losing our wetlands
Our increasing water consumption means there is less water for our nature and wildlife. The loss of wetlands, along with pollution, has intensified a water crisis, threatening all life.
Since the 1700s, nearly 90% of the world’s wetlands have been lost, with those remaining now disappearing at a rate three times faster than our forests
A quarter of all our wetland species, and 1 in 3 freshwater species, face extinction
The impacts of climate change is reducing surface and groundwater in already dry regions, resulting in increased competition for limited water supplies
Solutions – water for everyone
Start restoring our wetlands rather than destroying them
Stop damming rivers and over extracting from rivers and aquifers
Clean up freshwater sources and tackle pollution, poaching and overfishing
Increase water efficiency and use water and our wetlands wisely
Integrate water and wetlands into resource management and new development plans
Wetlands in Zambia
Our wetlands are home to huge range of biodiversity, including large concentrations of resident and migratory waterbirds, high densities of raptors along with rare Shoebill and endangered Wattled Crane. They are also an important habitat for a wide variety of mammals, including sitatunga and our endemic species of Kafue and Black Lechwe and the Bangweluu Tsessebe.
We have 8 designated wetlands of international importance within Zambia, making up approximately 14-19% of our total area. These were ratified in the Ramsar Convention, 50 years ago, in 1971: Kafue Flats Wetlands; Bangweulu Swamps; Barotse (Zambezi) Floodplains; Luangwa Floodplains; Busanga Swamps; Lukanga Swamps; Lake Mweru-wa-Ntipa and Lake Tanganyika.
We directly depend on these wetlands for our fisheries, agriculture and livestock, as well as for tourism, water transportation, energy and our cultural values and ceremonies. According to WWF, the Kafue Flats Wetlands alone provide us with approximately 50% of the nation’s hydroelectricity; 44% of Lusaka’s water supply to 3 million domestic and industrial users; nearly 90% of sugarcane for domestic and export markets; support an estimated 20% of the national cattle herds; produce maize for small-scale farmers; and, sustain one of Zambia’s most productive wild fisheries. So despite the Flats geographical remoteness, it plays a crucial role for a large percentage of our population who live in urban areas, including Lusaka.
Find out more
To find out more about the importance of Wetlands, what other countries are doing to protect them and how you can join in, then visit the World Wetlands Day website at www.worldwetlandsday.org
Performing wildlife counts from space might sound like something from science fiction, but a team, led by Isla Duporge from Wildcru, have now developed an exciting new technology.
With populations of African elephants (Loxodonta africana) declining due to habitat loss and poaching, and whilst communities lose crops before being able to harvest them, it is essential for conservationists to have up to date data on elephant populations – on population sizes, to monitor trends and to understand their movements across large areas. Accurate information is essential so that conservations can make decisions on how to protect our elephants and our farmers.
Traditional monitoring methods are prone to errors. The most common survey techniques in savannah habitats are done by performing aerial counts from small planes, on the ground transect surveys and dung counts. Due to human error and other factors such as poor visibility, these methods can be inaccurate. They are also costly to undertake, so only take place sporadically. Inaccurate data can lead to the wrong conservation decisions being made about elephant populations, which is also a waste of funds and resources.
This is why a team from the University of Oxford (WildCRU and the Machine Learning Research Group) along with Dr Olga Isupova from the University of Bath and Dr Tiejun Wang from the University of Twente, collaborated in order to resolve these monitoring problems. They came up with a new method to survey elephants by remote sensing using satellite imagery along with automation detection using deep learning.
“Satellites can collect upward of 5,000 km² imagery in one pass captured in a matter of minutes, eliminating the risk of double counting. Repeat surveys are also possible at short intervals.”
This unobtrusive technique requires no ground presence, so does not disturb wildlife and there is no element of risk for on the ground researchers whilst they are collecting data. Areas which are inaccessible by vehicle or small planes can be easily surveyed, along with cross-border areas which normally need the requirement of permits in order that surveys can be undertaken.
There are challenges in using satellite monitoring. These include the processing of huge quantities of images. But the team has come up with a process of automated detection, so checking images, that would have taken months, can now be done in just a few hours. This technology also is less prone to errors.
Using photos from an Earth-observation satellite, orbiting 600km above the planet’s surface, the researchers created a customised training dataset They used Addo Elephant National Park, South Africa as their study site, then tested it with images from known elephant populations in the Maasai Mara, Kenya. Addo has a high concentration of elephants who move between open savannah and woodland habitats, so this technology had to take into consideration that elephants constantly change shape and colour. Elephants adopt a range of postures when playing and foraging, with mud and dust bathing meaning that they are not always a standard colour.
To develop this new monitoring method, the team created a customised training dataset, feeding data into a Convolutional Neural Network. They then compared results with human surveys. It was found that elephants can be detected in satellite imagery, with accuracy as high as human detection capabilities. Once their model was trained to find adults, it was then also able to identify calves. This new method is able to survey up to 5,000 sq km of elephant habitat on a cloud-free day.
The researchers believe that by using this new technology it will go a long way to assist in elephant conservation:
“Satellite remote sensing and deep learning technologies offer promise to the conservation of these majestic mammals. Conservation technologies open a new world of possibilities, to be embraced with the urgency necessitated by the sixth mass extinction and the global plight of biodiversity”.
The second Annual Southern Zambia Birding Festival starts today in Southern Province. For more information and to follow what is happening during the Festival over the next two weeks then check out Birdwatch Zambia’s Facebook page.
Scientists, from Bat Conservation Intentional, have discovered a new species of bat which has bright orange fur and black wings. They described this new dichromatic species, of Myotis (Chrysopteron) which was discovered in the Nimba Mountains in Guinea in the journal American Museum Novitates.
The new discovery has been named Myotis nimbaensis, after the Guinea mountain range where it lives.
“Discovery of this new taxon increases the number of Myotis species known from mainland Africa to 11 species, although patterns of molecular divergence suggest that cryptic species in the Chrysopteron clade remain to be described. This discovery also highlights the critical importance of the Nimba Mountains as a center of bat diversity and endemism in sub-Saharan Africa.”
Simmons et al 2021.
Jon Flanders, Director of endangered species intervention at Bat Conservation International, lead the expedition with eight other researchers. They were looking for the critically endangered Lamotte’s roundleaf bat (Hipposideros lamottei) in abandoned unstable mineshafts in the Nimba Mountains. As these are not safe to enter, the scientists tossed nets at the entrances of the mineshafts, trapping bats as they flew out. Amongst the dark-furred bats that they caught, one brightly coloured bat stood out.
In an interview in The Washington Post, Flanders said this new species has phenomenal colouring – “Its wings are black with these orange fingers. There aren’t a lot orange bats in the world. I don’t tend to work with that many brightly coloured bats. It’s definitely an unusual one for me.”
At first, they thought it might be an unusual colour variation of an already-known species, but after checking through identification guides, textbooks and online for a species match, they realised they might have discovered a new species. In order to be sure, they re-captured the first bat that they had found, a male, along with a female.
They then contacted Nancy Simmons, Chairwoman of the bat taxonomy group at the International Union for Conservation of Nature. She then contacted the American Museum of Natural History, New York, the Smithsonian National Museum of Natural History, Washington and the British Museum of Natural History, London to find out if they could match the brightly coloured bat’s genetic blueprint or its physical features in their collections. They could not and it was concluded that Myotis nimbaensis is at least 5% different from its closest-related species.
The scientists hope to study more about Myotis nimbaenis’ ecology and habitat to find out where it lives, what it eats and what it needs to survive. Bat Conservation International, along with the mining company SMFG, are working together to build new tunnels to help the survival of the Lamotte’s roundleaf bat. With more research these joint efforts will probably ensure the survival of Myotis nimbaensis as well.
The Nimba Mountains are also known as the ‘sky islands’. These isolated mountain peaks lie a mile above sea level in sub-Saharan Africa. Their habitat is significantly different from the surrounding lowlands.
From the approximately 1,400 world wide bat species there are only a few known species of orange furred bats – found in China and South America, far from the Nimbia Mountains in West Africa. Over the past few years more than 20 new bat species have been discovered.
