Tag: habitats

Human activities degrade hippopotamus homes at Bui National Park, Ghana

Researchers found that the number of hippopotamus in the Bui National Park declined by about 70% after the construction of a hydroelectric dam in the reserve.

The Bui National Park is one of the few areas where the common hippopotamus resides in Ghana. The combined resources of the Black Volta River and the abundance of grasses make the area very suitable for hippopotamus. However, in an attempt to solve the electricity crisis the country faced in 2007, the government of Ghana constructed a hydroelectric dam in the heart of their home.

Farmers clearing trees along the rivers to begin cultivation at Bui National Park.

Knowing the consequence of dam creation on aquatic species, scientists Godfred Bempah, Martin Kobby Grant, Changhu Lu, and Amaël Borzée from Nanjing Forestry University, China, wanted to understand how the hippopotamus, a mega semi-aquatic species, was impacted by this project. The results have been published in the journal Nature Conservation. Assessing the impact of the dam construction can advise policy and decision making in future projects like this.

The researchers spent 24 days (2 days per month for 12 months) at the Bui National Park to estimate the number of hippopotamus individuals and understand local migratory activities, as well as to assess changes in land cover in the area after the dam was constructed. They then compared this information with historical data to understand the ecological changes within the area.

A hippopotamus in the Zoologico de Vallarta at Mismaloya south of Puerto Vallarta, Mexico. Photo by David Stanley under a CC BY 2.0 license

To complement the field surveys, the researchers spoke to local people familiar with the reserve before and after the dam construction. These included fishermen, canoe operators and park rangers. During the interactive discussion, all of them stated that the numbers of hippopotamus have declined compared to periods before the dam construction. They attributed the decline to poaching and habitat destruction.

The results indicated a decline in hippo numbers of about 70%: from 209 individuals in 2003 to 64 individuals in 2021.

A seized skull of Hippopotamus amphibius at the Bui national Park.

The study revealed noticeable changes in land cover after the dam construction, and, most importantly, a decline in forest cover, as well as destruction of riparian grasses, the habitat preferred by the hippopotamus. The increase in water levels flooded the areas where the animals used to reside, forcing them to disperse to other suitable areas. As they dispersed, the animals became vulnerable to poaching, which combined with habitat loss eventually led to a decline in hippopotamus numbers. It is possible that some of the animals might have successfully moved to other areas outside the reserve.

The hippopotamus is listed as Vulnerable to extinction by the IUCN Red List of Threatened Species.

In conclusion, the authors note that the number of common hippopotamus individuals in the park has declined following the dam construction, in connection with habitat destruction and poaching. Once these threats are removed, the hippopotamus can survive in the medium to long term, when effective management plans are implemented.

Research article:

Bempah G, Kobby Grant M, Lu C, Borzée A (2022) The direct and indirect effects of damming on the Hippopotamus amphibius population abundance and distribution at Bui National Park, Ghana. Nature Conservation 50: 175-201. https://doi.org/10.3897/natureconservation.50.87411

Journal Alpine Entomology calls for contributions in a new topical collection

“Trends in Arthropods of Alpine Aquatic Ecosystems” is the first topical collection for the journal of the Swiss Entomological Society

The open-access, peer-reviewed scholarly journal Alpine Entomology, published by Pensoft on behalf of the Swiss Entomological Society, announced its very first topical collection of articles, which will be focusing on arthropods associated with aquatic ecosystems in mountainous regions.

The journal is currently inviting scientists, working on aquatic fauna from alpine habitats, to openly publish their research articles and short notices that provide evidence how arthropods’ biogeography, species communities, distribution, behaviour and morphology have changed in recent times.

“Aquatic invertebrates are key indicators of global or local changes. Furthermore, many aquatic ecosystems are closely linked to mountains because they originate in them. Many valuable unpublished datasets on aquatic arthropod fauna may therefore be available from mountainous regions,”
explain the rationale behind the newly opened topical article collection guest editors Dr. Jean-Luc Gattolliat (Museum of Zoology, Lausanne and University of Lausanne, Switzerland) and Dr. David Muranyi (Eszterházy Károly Catholic University, Hungary).

The aim of the “Trends in Arthropods of Alpine Aquatic Ecosystems” collection is to bring together data and findings about what many agree is the most impacted type of environment on Earth: aquatic ecosystems, especially running waters.

The collection will remain open for submissions for the next two years. In the meantime, the accepted manuscripts will be published on a rolling basis, as soon as they are ready for publication.

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Visit the journal’s website at: https://alpineentomology.pensoft.net/
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Eleven new species of rain frogs discovered in the tropical Andes

One of the newly described species: *Pristimantis chomskyi*.
Its name honors Noam Chomsky, a renowned linguist from ASU.
Image by David Velalcázar, BIOWEB-PUCE.

Eleven new to science species of rain frogs are described by two scientists from the Museum of Zoology of the Pontifical Catholic University of Ecuador in the open-access journal ZooKeys. Discovered in the Ecuadorian Andes, the species are characterized in detail on the basis of genetic, morphological, bioacoustic, and ecological features.

On the one hand, the publication is remarkable because of the large number of new species of frogs. Regarding vertebrate animals, most studies only list between one and five new to science species, because of the difficulty of their collection and the copious amount of work involved in the description of each. To put it into perspective, the last time a single article dealt with a similar number of newly discovered frogs from the western hemisphere was in 2007, when Spanish scientist Ignacio de la Riva described twelve species from Bolivia.

The Rain frogs comprise a unique group lacking a tadpole stage of development. Their eggs are laid on land and hatch as tiny froglets.
Image by BIOWEB-PUCE.

On the other hand, the new paper by Nadia Paez and Dr Santiago Ron is astounding due to the fact that it comes as part of the undergraduate thesis of Nadia Paez, a former Biology student at the Pontifical Catholic University, where she was supervised by Professor Santiago Ron. Normally, such a publication would be the result of the efforts of a large team of senior scientists. Currently, Nadia Paez is a PhD student in the Department of Zoology at the University of British Columbia in Canada.

Unfortunately, amongst the findings of concern is that most of the newly described frog species are listed as either Data Deficient or Threatened with extinction, according to the criteria of the International Union for Conservation of Nature (IUCN). All of the studied amphibians appear to have very restricted geographic ranges, spanning less than 2,500 km2. To make matters worse, their habitats are being destroyed by human activities, especially cattle raising, agriculture, and mining.

Amongst the newly described species, there is the peculiar Multicolored Rain Frog, where the name refers to its outstanding color variation. Individuals vary from bright yellow to dark brown. Initially, the studied specimens were assumed to belong to at least two separate species. However, genetic data demonstrated that they represented a single, even if highly variable, species.

Variations of the Multicolored Rain Frog. Its name makes reference to the outstandingly varied colorations within the species.
Image by BIOWEB-PUCE.

The rest of the previously unknown frogs were either named after scientists, who have made significant contributions in their fields, or given the names of the places they were discovered, in order to highlight places of conservation priority.

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Original source:

Paez NB, Ron SR (2019) Systematics of Huicundomantis, a new subgenus of Pristimantis (Anura, Strabomantidae) with extraordinary cryptic diversity and eleven new species. ZooKeys868: 1-112. https://doi.org/10.3897/zookeys.868.26766.

How did coyotes conquer North America?

Coyotes now live across North America, from Alaska to Panama, California to Maine. But where they came from, and when, has been debated for decades.

Using museum specimens and fossil records, researchers from the North Carolina Museum of Natural Sciences and North Carolina State University have produced a comprehensive (and unprecedented) range history of the expanding species that can help reveal the ecology of predation as well as evolution through hybridization. Their findings are published in the open access journal ZooKeys.

The geographic distribution of coyotes has dramatically expanded since 1900, spreading across much of North America in a period when most other mammal species have been declining. Although this unprecedented expansion has been well-documented at the state/provincial scale, continent-wide picture of coyote spread been coarse and largely anecdotal. A more thorough compilation of available records was needed.

“We began by mapping the original range of coyotes using archaeological and fossil records,” says co-author Dr. Roland Kays, Head of the Museum’s Biodiversity Lab and Research Associate Professor in NC State’s Department of Forestry and Environmental Resources. “We then plotted their range expansion across North America from 1900 to 2016 using museum specimens, peer-reviewed reports, and game department records.”

In all, Kays and lead author James Hody, a graduate student at NC State University, reviewed more than 12,500 records covering the past 10,000 years for this study.

Their findings indicate that coyotes historically occupied a larger area of North America than generally suggested in the literature. Previous maps, as it turns out, had ancient coyotes only located across the central deserts and grasslands. However, fossils from across the arid west link the distribution of coyotes from 10,000 years ago to specimens collected in the late 1800s, proving that their geographic range was not only broader but had been established for hundreds, perhaps thousands of years, which also contradicts some widely-cited descriptions of their historical distribution.

It wasn’t until approximately 1920 that coyotes began their expansion across North America. This was likely aided by an expansion of human agriculture, forest fragmentation, and hybridization with other species. Eastern expansion, in particular, was aided by hybridization with wolves and dogs, resulting in size and color variation among eastern coyotes.

Before too long, coyotes may no longer be just a North American species. Kays notes that coyotes are continually expanding their range in Central America, having crossed the Panama Canal in 2010. Active camera traps are now spotting coyotes approaching the Darien Gap, a heavily forested region separating North and South America, suggesting that they are at the doorstep of South America.

“The expansion of coyotes across the American continent offers an incredible experiment for assessing ecological questions about their roles as predators, and evolutionary questions related to their hybridization with dogs and wolves,” adds Hody.

“By collecting and mapping these museum data we were able to correct old misconceptions of their original range, and more precisely map and date their recent expansions.”

“We hope these maps will provide useful context for future research into the ecology and evolution of this incredibly adaptive carnivore,” he concludes.

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(Originally published on Eurekalert! by North Carolina Museum of Natural Sciences.)

Original source:

Hody JW, Kays R (2018) Mapping the expansion of coyotes (Canis latrans) across North and Central America. ZooKeys 759: 81–97. https://doi.org/10.3897/zookeys.759.15149

The Alps are home to more than 3,000 lichens

Historically, the Alps have always played an emblematic role, being one of the largest continuous natural areas in Europe. With its numerous habitats, the mountain system is easily one of the richest biodiversity hotspots in Europe.

Lichens are curious organisms comprising a stable symbiosis between a fungus and one or more photosynthetic organisms, for example green algae and/or cyanobacteria. Once the symbiosis is established, the new composite organism starts to function as a whole new one, which can now convert sunlight into essential nutrients and resist ultraviolet light at the same time.

A common fruticose lichen in the Alps (Flavocetraria nivalis). Photo: Dr Peter O. Bilovitz — *A common fruticose lichen in the Alps (Flavocetraria nivalis).*
*Photo: Dr Peter O. Bilovitz*

Being able to grow on a wide range of surfaces – from tree bark to soil and rock, lichens are extremely useful as biomonitors of air quality, forest health and climate change.

Nevertheless, while the Alps are one of the best studied parts of the world in terms of their biogeography, no overview of the Alpine lichens had been provided up until recently, when an international team of lichenologists, led by Prof. Pier Luigi Nimis, University of Trieste, Italy, concluded their 15-year study with a publication in the open access journal MycoKeys.

Sunrise in the Julian Alps. Photo: Dr Pier Luigi Nimis — *Sunrise in the Julian Alps.*
*Photo: Dr Pier Luigi Nimis*

The scientists’ joint efforts produced the first ever checklist to provide a complete critical catalogue of all lichens hitherto reported from the Alps. It comprises a total of 3,138 entries, based on data collected from eight countries – Austria, France, Germany, Italy, Liechtenstein, Monaco, Slovenia and Switzerland. In their research paper, the authors have also included notes on the lichens’ ecology and taxonomy.

A common lichen in the Alps (Xanthoria elegans). Photo: Dr Tomi Trilar — *A common lichen in the Alps (Xanthoria elegans).*
*Photo: Dr Tomi Trilar*

They point out that such catalogue has been missing for far too long, hampering research all over the world. The scientists point out that this has been “particularly annoying”, since the data from the Alps could have been extremely useful for comparisons between mountainous lichen populations from around the globe. It turns out that many lichens originally described from the Alps have been later identified in other parts of the world.

“It was a long and painstaking work, which lasted almost 15 years, revealing a surprisingly high number of yet to be resolved taxonomic problems that will hopefully trigger further research in the coming years,” say the authors.

“We think that the best criterion to judge whether a checklist has accomplished its task for the scientific community is the speed of it becoming outdated,” they conclude paradoxically.

The new checklist is expected to serve as a valuable tool for retrieving and accessing the enormous amount of information on the lichens of the Alps

A widespread alpine lichen (Thamnolia vermicularis). Photo: Dr Peter O. Bilovitz — *A widespread alpine lichen (Thamnolia vermicularis).*
*Photo: Dr Peter O. Bilovitz*

that has accumulated over centuries of research. It offers a basis for specimen revisions, critical re-appraisal of poorly-known species and further exploration of under-explored areas. Thus, it could become a catalyst for new, more intensive investigations and turn into a benchmark for comparisons between mountains systems worldwide.

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Original source:

Nimis PL, Hafellner J, Roux C, Clerc P, Mayrhofer H, Martellos S, Bilovitz PO (2018) The lichens of the Alps – an annotated checklist. MycoKeys 31: 1-634. https://doi.org/10.3897/mycokeys.31.23568