Zoosystematics and Evolution

What can we learn from vanishing wildlife species: the case of the Pyrenean Ibex

The sad history of the Pyrenean Ibex (Capra pyrenaica pyrenaica) is a powerful example of species loss due to causes related to human activity. DNA analyses of Pyrenean Ibex found evidence that, after a demographic expansion about 20,000 years ago, its population went through a bottleneck caused by hunting, inbreeding and other factors, which ultimately caused its extinction. Their research is published in the open-access, peer-reviewed journal Zoosystematics and Evolution.

*Only the French mountaineer and photographer Bernhard Clos managed to take a series of good photos of the Bucardo, as the Pyrenean Ibex is called on the Spanish side. Photo: Bernhard Clos*

Likely the first extinction event of the 2000s in Europe, the sad history of the Pyrenean Ibex (Capra pyrenaica pyrenaica) is a powerful example of the ever-increasing species loss worldwide due to causes related to human activity. It can, however, give us valuable information on what should be done (or avoided) to halt this extinction vortex.

The distribution of this subspecies of Iberian Ibex was limited to the French and Spanish Pyrenees. Its first mention in an official written document, dating back to 1767, already refers to it as extremely rare. Like many other mountain goats, it was almost hunted to extinction before its killing became prohibited in 1913. Neither the institution of a national park (Ordesa & Monte Perdido), nor a conservation project with European LIFE program funding could stop the extinction of the Pyrenean Ibex eventually officialised on January 6, 2000. But the story of this charismatic animal did not end there – a controversial cloning program was started instantly with no scientific agreement, nor support from regional environmental NGOs, claiming that de-extinction was possible even in the absence of further DNA studies.

Laña, the last surviving Pyrenean Ibex, returned as a mounted animal to Torla-Ordesa on the 6th November 2012 after its controversial cloning attempt. Her skin is now exhibited in the visitors centre of Ordesa & Monte Perdido National Park. Photo: Manolo Grasa

To find out more about the drivers of its extinction, an international team composed of 7 nationalities built a database of all known museum specimens and reconstructed the demographic history of the Pyrenean Ibex based on DNA evidence. Their research is published in the open-access, peer-reviewed journal Zoosystematics and Evolution.

The research found that after a population expansion between 14,000 and 29,000 years ago (which is quite recent from a genetic point of view), a significant loss of genetic diversity followed between approximately 15,000 and 7,500 years BP, and continued until present. By that time, the Pyrenean Ibex also lived outside the Pyrenean mountain chain, but, gradually, its distribution was reduced to only one valley in the Ordesa National Park in the Spanish Pyrenees.

*The adventures of the British hunter E.N. Buxton were published in 1893. This engraving represents a hunting party in the Ordesa Valley (Spanish Pyrenees).*

Written sources confirm hunting of the Pyrenean Ibex from as early as the 14th century, and during the 19th and 20th century it became a common target for trophy hunters. Undoubtedly, hunting played an important role in reducing its population numbers and distribution area, but it is not possible – with the information currently available – to pinpoint it as the straw that broke the camel’s back. Infectious diseases that originate from livestock (for instance, those caused by the bluetongue virus, BTV, and sarcopses) are capable of decimating other subspecies of Iberian Ibex in extremely short periods of time.

While the relative contribution of various factors remains largely unknown, it seems that hunting and diseases transmitted from other animals have been effective in drastically reducing the number of Pyrenean ibexes over the last two centuries, because they were acting on an already genetically weakened population. This low genetic diversity, combined with inbreeding depression and reduced fertility, brought the population beyond the minimum viable size – from that point onwards, extinction was inevitable.

This case study shows the importance of historical biological collections for genetic analyses of extinct species. A privately owned 140-year-old trophy preserved in Pau, France, was genotyped as part of this research, showing that private individuals may possess material of high value. As there is little knowledge of such resources, the authors call for the creation of an online public database of private collections hosting biological material for the benefit of biodiversity studies.

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Original source:
Forcina G, Woutersen K, Sánchez-Ramírez S, Angelone S, Crampe JP, Pérez JM, Fandos P, Granados JE, Jowers MJ (2021) Demography reveals populational expansion of a recently extinct Iberian ungulate. Zoosystematics and Evolution 97(1): 211-221. https://doi.org/10.3897/zse.97.61854

Highlands of diversity: Another new chameleon from the Bale region, Ethiopia

The Bale Mountains in south-central Ethiopia are considered to be one of the most unique centers of endemism, with an extraordinary number of plants and animals that can only be found there. Numerous species are already known from this Afromontane high-elevation plateau, making it a biodiversity hotspot, but ongoing research continues to reveal the presence of so far unknown and undescribed organisms.

The new chameleon species, *Trioceros wolfgangboehmei*
Credit: Koppetsch et al.

Zoologists Thore Koppetsch and Benjamin Wipfler of the Research Museum Alexander Koenig in Bonn, Germany, and Petr Nečas from the Czech Republic, describe one such species: a new small-sized chameleon living on the edge of the forest. Their findings were published in the open-access, peer-reviewed life science journal Zoosystematics and Evolution.

There were already two species of the chameleon genus Trioceros known to be restricted to the Bale region when Thore Koppetsch and his colleagues discovered another unique representative of this group from the northern slopes of the Bale Mountains. Interestingly, this new chameleon is considered to be part of a species complex of the wide-spread Ethiopian Chameleon Trioceros affinis. Previous studies have indicated divergence between its different populations across the Ethiopian Highlands – with some of them separated by the northern extension of the Great Rift Valley, which also shaped the evolution of early humans.

Living individual of *Trioceros wolfgangboehmei*
Credit: Koppetsch et al.

The new chameleon, Trioceros wolfgangboehmei, has a special name. It honours the scientific work of Wolfgang Böhme, senior herpetologist at the Zoological Research Museum Alexander Koenig in Bonn, and his passion for chameleons and other reptiles.

Apart from its biogeographical patterns, the new species also has a characteristic appearance, displaying enlarged spiny scales on its back and tail that form a prominent crest. It usually lives on small trees and bushes at an altitude of above 2,500 m above sea level.

Head detail of the new chameleon, *Trioceros wolfgangboehmei*
Credit: Koppetsch et al.

“Given the variation in colour patterns and morphology between different populations of these chameleons in Ethiopia, it is likely that these groups still bear a higher hidden diversity than expected, which might be revealed by further ongoing investigations.”
Thore Koppetsch

Furthermore, the research team urges for sustainable preservation and conservation of its habitat to mitigate the impact of human activity.

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Original source:

Koppetsch T, Nečas P, Wipfler B (2021) A new chameleon of the Trioceros affinis species complex (Squamata, Chamaeleonidae) from Ethiopia. Zoosystematics and Evolution 97 (1): 161–179. https://doi.org/10.3897/zse.97.57297

Life in the fast flow: Tadpoles of new species rely on ‘suction cups’ to keep up

The frogs living in the rainforest of Sumatra also represent a new genus

Indonesia, a megadiverse country spanning over 17,000 islands located between Australia and mainland Asia, is home to more than 16% of the world’s known amphibian and reptile species, with almost half of the amphibians found nowhere else in the world. Unsurprisingly, biodiversity scientists have been feverishly discovering and describing fascinating new animals from the exotic island in recent years.

Such is the case of an international team from the University of Hamburg, Germany, University of Texas at Arlington, USA, University of Bern, Switzerland and Bandung Institute of Technology, Indonesia, who came across a curious tadpole while collecting amphibian larvae from fast-flowing streams as part of an arduous expedition in the remote forests on the island of Sumatra.

To the amazement of the scientists, it turned out that the tadpoles possess a peculiar cup-like structure on their bellies, in addition to the regular oral disk found in typical tadpoles. As a result, the team described two new species and a genus in the open access journal Zoosystematics and Evolution. A previously known, but misplaced in an unsuitable genus, frog was also added to the group, after it was proved that it takes advantage of the same modification.

“This phenomenon where tadpoles display ‘belly suckers’ is known as gastromyzophory and, albeit not unheard of, is a rare adaptation that is only found in certain toads in the Americas and frogs in Asia,” explains lead author Umilaela Arifin.

The abdominal sucker, it is hypothesized, helps these tadpoles to exploit a very special niche – fast-flowing streams – where the water would otherwise be too turbulent and rapid to hang around. Gastromyzophorous species, however, rely on the suction provided by their modified bellies to secure an exclusive access to plentiful food, such as algae, while the less adapted are simply washed away.

When the scientists took a closer look at the peculiar tadpoles and their adult forms, using a powerful combination of molecular and morphological data, they realized that they had not only stumbled upon a rare amphibian trait, but had also discovered two brand new species of frogs in the process.

Moreover, the animals turned out so distinct in their evolutionary makeup, compared to all other frogs, that the scientists had to create a whole new genus to accommodate them. Formally named Sumaterana, the genus is to be commonly referred to as Sumatran Cascade Frogs.

“We decided to call the new genus Sumaterana after Sumatra, to reflect the fact that these new species, with their rare evolutionary adaptation are endemic to Sumatra’s rainforests and, in a sense, are emblematic of the exceptional diversity of animals and plants on the island,” says co-author Dr. Utpal Smart. “Tragically, all of them are in peril today, given the current rate of deforestation.“

The authors agree that much more taxonomic work is still needed to determine and describe Sumatra’s herpetofaunal diversity, some of which they fear, could be irreversibly lost well before biologists have the chance to discover it.

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Original source:

Arifin U, Smart U, Hertwig ST, Smith EN, Iskandar DT, Haas A (2018) Molecular phylogenetic analysis of a taxonomically unstable ranid from Sumatra, Indonesia, reveals a new genus with gastromyzophorous tadpoles and two new species. Zoosystematics and Evolution 94(1): 163-193. https://doi.org/10.3897/zse.94.22120