'Extinct' tree rediscovered | Bats regenerating forests | Tourism disturbing dolphins | Tarantula tale

‘Extinct’ ebony tree rediscovered in Madagascar 

There’s good news from Madagascar, where an ebony tree thought to have gone extinct has been rediscovered. 

Only 17 survivors of the species known to science as Diospyros ketsensis were found growing in four forest fragments that are currently threatened by annual wild fires and wood harvesting.

This is the first confirmation of the tree’s existence in nearly a century. 

It was first described for science in 1926 from another fire-threatened fragment of forest, near Mahatsinjo, in the Malagasy Highlands. It hadn’t been seen by botanists since then.

The International Union for Conservation of Nature lists the tree as critically endangered. It’s a status that’s unlikely to change, since the region the remnant trees were found growing in doesn’t fall within a protected area. 

“A few seeds were collected and eight individuals of this species are now growing in the field gene-bank,” the research team said. 

You can read about the hunt for the elusive ebony tree in the latest edition of Cultivate, the journal published by Botanic Gardens Conservation International. 

Diospyros ketsensis — known only from the type specimen collected in 1926 — is unique to Madagascar | Rod Waddington | Wikimedia 

Fruit bats in South Africa have minimal impact on valuable litchi crops 

A new study suggests that three species of fruit-eating bat in South Africa’s Limpopo Province have a negligible impact on litchi crops grown on farms there, and in fact are responsible for a valuable ecosystem service: dispersing the seeds of indigenous fruit trees. 

The fruit bats — Wahlberg’s epauletted, Peters’ epauletted and Egyptian — were captured in mist nets and samples of their faeces were collected by keeping them in cotton bags for a couple of hours. 

Their diet was found to consist mainly of the fruit of wild growing species, including various types of fig, quinine trees, mobola plums, water berries and forest fever trees.

In all, these fruits made up 95% of their diets; litchis comprised just 2%. 

Bats are often erroneously targeted by farmers in retaliation for their perceived damage to commercial crops. Yet the epauletted fruit bats were likely dispersing the seeds of wild figs that are an important natural food resource for bats and other frugivores, the authors state. 

“We recommend that it is vital to educate farmers on the ecological benefits of having fruit bats around their orchard habitats.”

A Peters’ epauletted fruit bat in South Africa’s Kruger National Park | Bernard Dupont | Wikimedia

Tourists in Mozambique disrupt ‘activity budgets’ of bottlenose dolphins 

Tourism may be disturbing dolphins in a key marine protected area in southern Mozambique. 

A study finds that the peak of the local tourism season in December coincides with the height of the calving season for Indo-Pacific bottlenose dolphins in the Ponta do Ouro Partial Marine Reserve. 

The researchers were able to compare data from 2007-2009 (when swim-with-dolphin tourism was still relatively low) with data from 2017-2019 (when the industry was a lot more vibrant). They found that an increase in tourist vessels seeking out and interacting with dolphins was having a negative impact on the dolphins’ “activity budget” – the way they partition key tasks necessary for their survival: feeding, interacting with their calves and mating. 

In December individual operators conduct 3-4 tourist trips per day on average. This, the study calculates, uses up 67% of daylight hours. This is the time when dolphins should be engaged in their own social interactions. 

“There is a misconception that because dolphins often approach and interact with humans there are no negative consequences,” the researchers say. 

They recommend stricter regulation of swim-with-dolphin operations along the Mozambican coast and islands.

Research for the dolphin study was carried out at Ponta do Ouro Partial Marine Reserve | Hein Waschefort | Wikimedia 

Nature Notes: tarantulas are no match for spider-hunting wasps 

One rainy Sunday afternoon recently I took my family for a walk in a park in Harare and we found a tarantula, or baboon spider as they’re known here due to their furry appearance, lying immobile beside its burrow. 

A spider-hunting wasp, with a dark blue body and wings, was busy widening the tunnel. It was evidently preparing to inter the spider in the burrow after laying its eggs in the spider’s abdomen. Once the wasp’s larvae hatch, they feed on the spider’s body. 

I posted a picture of the spider, probably a cranial horned baboon spider, on a WhatsApp group I belong to. It prompted some discussion. 

One member of the group asked what would happen to the spider if the wasp came to grief? Would the immobilizing toxin wear off and the spider recover? 

The administrator said he’d heard of a few cases in which people had “rescued” a spider from a spider-hunting wasp. The spiders did eventually recover, but they were never the same afterwards, he said.

They were slower and less active. 

“The chances of them recovering in the wild are very slim,” he added.  

Baboon spider immobilized by a sting from a spider-hunting wasp | Ryan Truscott