Golden Mole Hunt | Volcano Toad | Honeyguide Signals | River of Time
Researchers in SA use eDNA, scent-trained dog, to rediscover ‘lost’ golden mole
A border collie that was trained to find iridescent golden moles in South Africa helped scientists track down a species of the tiny mammals that hadn’t been seen for close on 90 years and was thought to be extinct.
“Jessie” sniffed out mole trails alongside researchers from the Endangered Wildlife Trust as they surveyed up to 18 kilometres (11 miles) of sand dunes every day for a month between Lambert’s Bay and Visagiesfontein on South Africa’s western coastline.
There were known to be three other species of golden mole living in the dunes along the same stretch of coastline, which made the search for the missing De Winton's mole extremely complicated.
The researchers spent months teasing apart the different kinds of mole DNA they found in soil samples taken from mole tracks, before finally confirming the existence of De Winton’s golden mole for the first time since 1936.
The research team got a strong hint they were on the right trail when their dog, which had been trained to detect the scent of the three other golden mole species, didn’t respond to mole tracks on the beach at Port Nolloth.
It suggested the tracks were made by the missing mole, whose scent was unknown to the dog.
Until now, eDNA has mostly been used to hunt for missing aquatic animals, not terrestrial ones.
The researchers say in a study describing their discovery that alluvial diamond mining, agriculture and residential development threatens golden mole habitat along the western coast, and that all four species “may be considered flagship species for these coastal dune ecosystems.”
A De Winton’s golden mole | Nicky Souness | EWT
Kenyan volcano toad represents a new species and genus
A forest toad, caught in a pitfall trap on the slopes of Mount Kenya one misty morning in 2015, has been identified as not only a new species, but a new genus.
It’s been named the Kenyan volcano toad in honour of its volcano home, which is no longer active.
The find has raised more questions than answers. Only a male specimen of the new toad was found. Subsequent efforts to find more during an expedition in 2017 failed.
The researchers have had to speculate on the species’ breeding biology, given that they didn’t find any female frogs to examine.
They think that, like a closely-related genus of forest toads living in similar habitat in neighbouring Tanzania, the Kenyan volcano toad might have a very long gestation period, and give birth to froglets, rather than eggs that go through a tadpole phase.
The Kenyan volcano toad was found by a team from the National Museums of Kenya (NMK) surveying a patch of forest known as the Chogoria Forest Block, that is a fair distance from human settlement.
So, at the moment, its forest home does look safe.
Patrick Malonza, a NMK herpetologist who led the search for more specimens in 2017, says that neighbouring forest blocks are still in good condition and could also provide suitable habitat for the toad.
Christoph Liedtke, the lead author of a new study describing the volcano toad, says its physical appearance is surprising because the specialised group of toads it belongs to usually have a more drab appearance to help them blend into dense, humid forests.
“They tend to be small and brown and well-camouflaged, so to see this rather large, greenish and conspicuous animal is quite curious.”
An artist’s rendition of the Kenyan volcano toad | Paula Martin
Greater honeyguide birds prefer the signals of their cooperating humans
Greater honeyguide birds that lead human honey hunters to wild bees’ nests in Africa learn unique signals used by hunters to initiate the search, and these signals differ between cultures.
The partnership between honey hunters and greater honeyguides is a rare form of human-animal mutualism that persists in only a few places and cultures, including among the Hadza of northern Tanzania, and the Yao of northern Mozambique.
Both parties benefit: humans get honey, and honeyguides get to feast on beeswax that they wouldn’t otherwise have access to.
To demonstrate the preference that honeyguides have for the distinct calls of their preferred human partners, researchers undertook dozens of transects at study sites in both regions, and played recordings of both Hadza and Yao signals, as well as control sounds.
The Kidero honeyguides responded to recordings of the familiar, birdlike whistles of the Hadza in 81% of tests, compared to 24% when Yao sounds were played. Similarly, honeyguides in Mozambique's Niassa Special Reserve, where the Yao live, responded to nearly 75% of Yao trill-grunts compared to just 25% of unfamiliar Hadza whistles.
Members of the honey-hunting communities told the researchers that the calls they used were learned from fathers and other elders, and that no-one diverges from these traditions because they will find less honey if they do.
Likewise, the honeyguides themselves probably engage in their own social learning of the human signals of serious honey hunters worth cooperating with.
"Our experimental data show that a mosaic of interspecies communication traditions exist between people and birds, underpinned by learning in both species," the authors state.
A male honeyguide bird in Niassa Special Reserve, Mozambique | Claire Spottiswoode
Nature Notes: River of Time
Halfway up the Mupata Gorge, we stop to survey the trees. I’m on a well-worn elephant trail winding its way along the side of a cliff.
The way is rocky, narrow and uneven. I realise how agile the elephants must be to use this path. One misstep would send me tumbling into the Zambezi River below. How does a three-tonne elephant cope?
I was last in this gorge 30 years ago: a teenager, nearing the end of a long canoe journey with my Dad.
One day a pack of African wild dogs appeared on the Zambian side of the river, opposite our camp, and lapped at the water’s edge.
With its ancient jackal-berry trees rubbed smooth by passing elephants, this landscape – the trees, the rocks, the rugged hills – look unchanged. I take leaf samples to press between the pages of my notebook.
We drift back down the Zambezi. A yellow-billed kite glides out from somewhere in the gorge and on dark, unbeating wings follows us. It perches in the branches of a rain-tree, right above my head, when we stop for shade. Biding its time. Waiting for a chance to snatch food.
