Weekly round-up: March 28

African elephants have officially been divided into two separate species

African elephants will now be officially identified as two separate species – the African forest elephant and African savanna elephant – following new genetic evidence. Both are at risk of extinction. 

As a single species the African elephant was classified as Vulnerable on the International Union for the Conservation of Nature’s Red List, but division of the species has resulted in a categorisation of Critically Endangered for the forest elephant and Endangered for the savanna elephant.

Poaching and habitat loss pose the biggest threats to both species – African forest elephant populations have fallen by 86 per cent over three decades, while African savanna elephant numbers have declined by at least 60 per cent over the past 50 years. The 2016 IUCN African Elephant Status Report estimated the total population at around 415,000.

Dr Bruno Oberle, IUCN director general, said: “Africa’s elephants play key roles in ecosystems, economies and in our collective imagination all over the world. [The] new IUCN Red List assessments of both African elephant species underline the persistent pressures faced by these iconic animals.

“We must urgently put an end to poaching and ensure that sufficient suitable habitat for both forest and savanna elephants is conserved. Several African countries have led the way in recent years, proving that we can reverse elephant declines, and we must work together to ensure their example can be followed.” 

Successful conservation efforts, anti-poaching measures and reduction in human-wildlife conflicts have resulted in stabilising forest elephant numbers in Gabon and the Republic of Congo. Savanna elephant populations have also been stable or growing for decades, especially in the Kavango-Zambezi Transfrontier Conservation Area.

Dr Dave Balfour, member of the IUCN Species Survival Commission African Elephant Specialist Group, said: “While the results of the assessment place the continental population of savanna elephants in the Endangered category, it is important to keep in mind that at a site level, some subpopulations are thriving. For this reason, considerable caution and local knowledge are required when translating these results into policy.”
Source IUCN

The newly-identified Xingu screech owl (Kleiton Silva)

The world of taxonomy has been a busy one this week, with two new owls, one chameleon and 13 moth species also making headlines.

In Brazil, researchers from the University of Helsinki and Chicago Field Museum identified two new species of screech owl previously thought to belong to existing groups – the Xingu screech owl, named after the river near where it is found in the Amazon, and the Alagoas screech owl, primarily found in areas of Atlantic forest in the state of the same name.  

Co-author John Bates, curator of birds at the Field Museum in Chicago, said: “Screech owls are considered a well-understood group compared to some other types of organisms in these areas. But when you start listening to them and comparing them across geography, it turns out that there are things that people hadn’t appreciated. That’s why these new species are being described.

“They’re cute little owls, probably five or six inches long, with tufts of feathers on their heads. Some are brown, some are gray, and some are in between.”

Previously the owls had been classed as the tawny-bellied screech owl and the black-capped screech owl, but while their positive identification is a boon for science, it also reveals both species are at risk of extinction.

The Alagoas screech owl (Gustavo Malacco)

Co-author Jason Weckstein said: “Both new species are threatened by deforestation. The Xingu screech owl is endemic to the most severely burned area of the Amazon by the unprecedented 2019 fires, and the Alagoas screech owl should be regarded as critically endangered given the extensive forest fragmentation in the very small area where it occurs.”

The Atlantic forest, which runs along the eastern coast of South America from Brazil to Argentina and inland to Paraguay, once covered 1,000,000km2 of the continent, but is now just seven per cent of its original size.

In Ethiopia’s Bale Mountains, a team of researchers discovered a new member of the chameleon genus Trioceros, the third found in a region famed for its vast array of biodiversity and endemism.

Trioceros wolfgangboehmei has a distinctive row of spiny scales along its back and tail (Koppetsch et al.)

The new species, small in size and varying from yellow/brown to vivid green, has been named Trioceros wolfgangboehmei in honour of Wolfgang Böhme, senior herpetologist at the Zoological Research Museum Alexander Koenig in Bonn. Found in small bushes and trees, the chameleon is also separated from its close relatives by a row of spiny scales along its back and tail, forming a prominent crest.

Meanwhile in Hawaii, the rediscovery of a moth thought to have gone extinct prompted extensive exploration by a team of researchers across the state’s major volcanic islands, leading to the discovery of 13 species new to science.

It all started when entomologist Akito Kawahara chanced upon an individual from the Philodoria genus, thought to be extinct.

“That was the beginning’” said Kawahara, associate curator at the Florida Museum of Natural History’s McGuire Center for Lepidoptera and Biodiversity. “It opened my eyes to the fact that at least one species had not gone extinct. Were there others?”

Now, after eight years of research, Kawahara and the team have compiled a complete natural history of the genus, revealing 13 new species – including Philodoria obamaorum, named after the state’s most famous resident, President Barack Obama, and his wife Michelle.

However, the moths’ restricted range and the scarcity of their host plants place them in danger of extinction. The researchers were unable to find living representatives of ten Philodoria species known from museum specimens, and another 12 could be severely threatened, based on how scant their food sources are. Around 80 per cent of Philodoria species feed exclusively on a single plant genus – more than half of the plant genera they eat contain threatened or endangered species, and three-quarters of the moth species themselves are restricted to one island or volcano.
Publications Zootaxa/Zoosystematics and Evolution

Humpback whale numbers are increasing

A quarter of marine mammals are now at risk of extinction, while others are showing signs of recovery due to conservation efforts.

An international research team, led by the University of Exeter, reviewed the status of 126 species including whales, dolphins, seals, sea otters and polar bears, and identified bycatch, pollution and climate change as the main drivers of decline. The vaquita, the world’s smallest porpoise, is most at risk, with a population estimated to be fewer than 20 mature individuals.

However, successful conservation efforts have resulted in increasing numbers of other species, including the northern elephant seal, humpback whale and Guadalupe fur seal.

Lead author Dr Sarah Nelms, of the Centre for Ecology and Conservation on Exeter’s Penryn Campus, said: “We have reached a critical point in terms of marine mammal conservation. Very few marine mammal species have been driven to extinction in modern times, but human activities are putting many of them under increasing pressure. Our paper examines a range of conservation measures – including marine protected areas (MPAs), bycatch reduction methods and community engagement – as well as highlighting some of the species that are in urgent need of focus.”

Of the 126 species, 21 per cent are listed as ‘data deficient’ by the IUCN, making it difficult to identify threats and conservation needs.
Publication Endangered Species Research

Red kites were found to have toxic levels of rat poison in their liver tissue

Rat poison has been found in more than half of the birds of prey sampled in a long-running German study, highlighting the pervasive effects of chemical use on wildlife.

Over 22 years, a team from Leibniz Institute for Zoo and Wildlife Research, the Julius Kühn Institute and the German Environment Agency collected the carcasses of red kites, northern goshawks, Eurasian sparrowhawks, white-tailed sea eagles and ospreys.

Rodenticides were found in the liver tissues of more than 80 per cent of northern goshawks, with 18 per cent exceeding the threshold level of 200 ng per gram body mass for acute toxic effects – 14 per cent of red kites exceeded the figure, while rodenticides were also found in 40 per cent of white sea eagles. Exposure in sparrowhawks and ospreys was low to zero.

“Rodenticide poisoning represents an important cause of death for birds of prey,” the team concluded. “Species that facultatively scavenge have shown to be at high risk for rodenticide exposure.”
Publication Environmental Research

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