Threat to crab-hunting chimps | Deforestation affects rainfall | Weather-predicting plant | A bee-eater farewell
Mining threat to crab-hunting Guinean chimpanzees
A team of international scientists has used a new genetic tool to measure the abundance and diversity of a population of critically-endangered western chimpanzees in the Mount Nimba Strict Nature Reserve.
The animals are famed for their unique ability to hunt for freshwater crabs in shallow streams.
The reserve they live in is a UNESCO World Heritage site, and the mountains in which it is located straddle the borders of Guinea, Liberia and Ivory Coast in West Africa.
There are plans to extract high-grade iron ore from an area on the Guinean side of the mountains that the chimpanzees regularly traverse. The international research team behind a recent study examined nearly 1,000 chimpanzee fecal samples collected over more than two decades from the western flanks of the mountains.
Through DNA analysis of these samples, they discovered that the area is home to at least 136 chimpanzees living in four separate communities.
Until now, it had been very difficult to gain accurate estimates of the population size. The terrain is rugged and the chimpanzees are still wary of humans.
The genetic census also found evidence of the recent migration of two females and a male between these four communities. Migration maintains the genetic viability of the chimpanzees, something that mining could disrupt, the researchers warn.
There is one piece of good news though.
On the Guinean side of the Nimba Mountains, the hunting of chimpanzees by humans was never witnessed by the research team. This, they say, is most likely because chimpanzees are the totem animal of the Manon community, one of the dominant ethnic groups in the region.
Rainforest and savanna in the Nimba Mts | Guy Debonnet | Wikimedia
Six decades of data shows how deforestation alters rainfall in DRC: study
A new study reveals the impact regional deforestation appears to be having on temperatures and rainfall in the east of the Democratic Republic of Congo, and it’s evident in the lack of blossoms on an iconic tree.
The study site was the landscape surrounding the Kahuzi-Biega National Park, in the country’s South Kivu Province.
Researchers from the Centre for International Forestry Research and World Agroforestry (CIFOR-ICRAF), dug into 60 years of climate data kept at the Lwiro Research Centre, five kilometers or so from the park.
They complemented those figures with data on forest loss compiled by Global Forest Watch (GFW) between 2001-2021. The GFW data showed that South Kivu lost over 640,000 hectares (1.5 million acres) of its forests over the last two decades alone.
“Our brief indicates a potential disruption of weather patterns in the Kahuzi-Biega National Park landscape,” the researchers wrote in a research paper published by CIFOR-ICRAF.
They said an increase in temperatures, reflected in records stretching back to 1981, was positively correlated with deforestation and reduced rainfall.
For humans, the impact has been seen in reduced harvests and shortages of edible caterpillars, mushrooms and honey.
But the authors of the study also noticed changes in the flowering pattern of one eye-catching species of tree, the Erythrina abyssinica or cigohwa, which typically loses its leaves and produces a blaze of fiery red flowers in July and August.
“Direct personal observations have shown that this phenomenon appears to be taking place much earlier or irregularly,” the authors note.
The eye-catching flowers of Erythrina abyssinica | sarahemcc | Wikimedia
South African succulent ‘predicts’ tomorrow’s weather
A species of succulent from South Africa is able to “predict” the weather and put in motion the process of flowering 16 hours before a warm day, according to new research.
The plant is Bulbine frutescens, also known as the snake plant or stalked bulbine. It is widely grown as a “waterwise” garden plant in California, where botanist Matthew Gilbert carried out the research in his garden during protracted periods of lockdown in 2020-2021.
He noticed that the plants outside his kitchen window would only flower a day after warm weather.
Unlike a number of other plants that open and close their flowers repeatedly in line with external temperatures, the stalked bulbine's flowers only last a day. That means the plant has just one crack at getting the timing right to ensure maximum chances of pollination by insects.
“The flowers need to predict whether to initiate final development based upon the previous day’s weather,” Gilbert writes in his study published in Functional Ecology.
The bulbine's weather forecasting ability appears to be an adaptation to the climate in South Africa’s Cape provinces, where it originates.
There, as in parts of California, most rain falls during the winter months.
“For winter rainfall areas in the USA and South Africa, the daily maximum temperature is highly predictive of the temperature the following day,” notes Gilbert.
After the lockdown was lifted, Gilbert’s bike rides to work confirmed that his own bulbines' flowering patterns were repeated among other populations of the plant that grew along his route.
He also got family members living in South Africa to observe and collect similar data from their flowering bulbines.
The ‘snake plant’ is a ‘waterwise’ garden plant | Stan Shebs | Wikimedia
Nature notes: A fond farewell
A large number of European bee-eaters spent Easter in Harare. The birds are prominent non-breeding migrants to Zimbabwe and the region during the southern hemisphere’s summer months.
They make their quick ‘hwiro-gwiro’ calls high up in the sky during long, hot afternoons.
Now the southern African autumn has arrived, and the leaflets from the flamboyant trees that line the streets of our northern Harare suburb are falling like confetti. The bee-eaters my daughter and I saw on Easter Monday were likely the last we’ll see and hear until September.
A small flock of around 30 birds was swooping around the top of a pine tree in our neighbour’s garden. Suddenly, as bee-eaters often do, they sped off like a shoal of airborne fish.
And that was that. We’ll miss them.
I’ll also miss the willow warblers. They too are non-breeding migrants from as far away as Russia. Each adult weighs less than 10 grammes (less than an ounce), yet will clock up distances of up to 13,000 kilometers (8,000 miles) to get here.
During our summer I often hear willow warblers calling when I pass beneath the branches of a paperbark acacia, or a Nyanga flat-top.
These trees are graced with broad canopies, delicately interlaced branches and peeling, papery bark: features that provide plenty of places for the insect-eating willow warblers to find their prey.
European bee-eaters are migrants to Africa | Pierre Dalous | Wikimedia