The Strange Big-eared Brown Bat, Histiotus alienus, was first described by science in 1916, by the British zoologist Oldfield Thomas. The description of the species was based on a single specimen captured in Joinville, Paraná, in southern Brazil.
For more than 100 years, the species had never been captured, being known only by its holotype—the specimen that bears the name, and represents morphological and molecular traits of a species—deposited in The Natural History Museum in London, United Kingdom. Now, after a century, the species has been rediscovered. Scientists Dr Vinícius C. Cláudio, Msc Brunna Almeida, Dr Roberto L.M. Novaes, and Dr Ricardo Moratelli, Fundação Oswaldo Cruz, Brazil and Dr Liliani M. Tiepolo, and Msc Marcos A. Navarro, Universidade Federal do Paraná, Brazil have published details on the sighting in a paper in the open access journal ZooKeys.
During field expeditions of the research project Promasto (Mammals from Campos Gerais National Park and Palmas Grasslands Wildlife Refuge) in 2018, the researchers captured one specimen of big-eared bat at Palmas Grassland Wildlife Refuge. To catch it, they used mist-nets—equipment employed during the capture of bats and birds—set at the edge of a forest patch. When they compared it to the Tropical Big-eared Brown Bat (Histiotus velatus), commonly captured in the region, they found it was nothing like it.
The unidentified big-eared bat specimen was then collected and deposited at the Museu Nacional in Rio de Janeiro, Brazil, for further studies.
After comparing this puzzling specimen against hundreds of other big-eared brown bats from almost all the species in the genus, the researchers were able to conclusively identify the bat as a Strange Big-eared Brown Bat and confirm its second known record. “Since the description of several the species within the genus is more than one hundred years old and somewhat vague, comparisons and data presented by us will aid the correct identification of big-eared brown bats,” they say.
The Strange Big-eared Brown Bat has oval, enlarged ears that are connected by a very low membrane; general dark brown coloration in both dorsal and ventral fur; and about 100 to 120 mm in total length. This combination of characters most resembles the Southern Big-eared Brown Bat (Histiotus magellanicus), in which the membrane connecting ears is almost absent.
The only known record of the Strange Big-eared Brown Bat until now was from Joinville, Santa Catarina state, southern Brazil, which is about 280 kilometers away from where it was spotted in 2018. So far, the species is known to occur in diverse terrains, from dense rainforests to araucaria and riparian forests and grasslands, at altitudes from sea level to over 1200 m a.s.l.
This increase in the distribution of the species, however, does not represent an improvement on its conservation status: the species is currently classified as Data Deficient by the International Union for the Conservation of Nature. Its habitat, the highly fragmented Atlantic Forest, is currently under pressure from agricultural activity.
But there is still hope: “The new record of H. alienus in Palmas is in a protected area, which indicates that at least one population of the species may be protected,” the researchers write in their study.
Research article:
Cláudio VC, Almeida B, Novaes RLM, Navarro MA, Tiepolo LM, Moratelli R (2023) Rediscovery of Histiotusalienus Thomas, 1916 a century after its description (Chiroptera, Vespertilionidae): distribution extension and redescription. ZooKeys, 1174, 273–287. doi: 10.3897/zookeys.1174.108553
Between 2010 and 2019, total imports of frog’s legs into the EU numbered 40.7 million kg, which equals to up to roughly 2 billion frogs. While Belgium is the main importer, France is the main consumer. These insights are part of a new study, published in the journal Nature Conservation, which found “inexplicable volatility” in the trade of frog legs and an extreme dependency of the EU on other countries to meet its demand.
Leading author Dr. Auliya of the Leibniz Institute for the Analysis of Biodiversity Change in Bonn, Germany, outlines the manifold uncertainties underlying this trade: “The international trade in frogs’ legs is a black box, whether it is the lack of species-specific trade data, which would be needed to ensure sustainability, or the large-scale mislabeling in trade and the challenges to identify species when it comes to processed, skinned and frozen frogs’ legs.”
Frogs’ legs from large ranids at a large-scale reptile collector in North Sumatra, Indonesia. Photo by Mark Auliya
Frogs have a central role in the ecosystem as insect predators – and where frogs disappear, the use of toxic pesticides increases. Hence, the frogs’ legs trade has direct consequences not only for the frogs themselves, but for biodiversity and ecosystem health as a whole. The extent to which pesticide residues in frogs’ legs are traded internationally remains unclear.
In the 1970s and 1980s, India and Bangladesh were the top suppliers of frogs’ legs to Europe, but when their wild frog populations collapsed, both countries banned exports. Since then, Indonesia has taken over as the largest supplier. In the Southeast Asian country, as now also in Turkey and Albania, large-legged frog species are dwindling in the wild, one after the other, causing a fatal domino effect for species conservation. This increasingly threatens frog populations in the supplier countries.
“The EU is by far the world’s largest importer of frogs’ legs, and large-legged species such as the crab-eating grass frog (Fejervarya cancrivora), the giant Javan frog (Limnonectes macrodon) and the East Asian bullfrog (Hoplobatrachus rugulosus) are in particular demand among supposed gourmets in Europe”, points out co-author Dr. Sandra Altherr, a biologist and wildlife trade expert of the Germany-based charity Pro Wildlife.
Frozen frogs’ legs on sale in a French supermarket, August 2022. Photo by Sandra Altherr / Pro Wildlife
While commercial frog farms, like those operated in Viet Nam, may at first glance seem to be an alternative that can relieve the pressure from wild frog populations, ongoing restocking of frog farms with native species from the wild and, in the case of non-native species, such as the American bullfrog (Lithobates catesbeianus) the risk of escape, invasion and potential risk of disease spread, are serious risks for the environment.
The harvest of wild frog populations and species produced at commercial frog farms for the purpose of consumption also leaves disease control and hygiene measures by the wayside; additionally, the cross-border trade of species for consumption has led to genetic pollution and hybridization between species.
Limnonectes blythii species complex from a large-scale collector in North Sumatra. Photo by Mark Auliya
„During the course of this study, it became clear just how difficult it is to obtain concrete data on the current international trade in frogs’ legs. Specifically, relevant data are scattered across different unconnected databases,“ the researchers write in their paper.
In the course of their review, they were not able to find any published data out whether pesticide residues and other potentially toxic substances in (processed) frogs or their legs imported into the EU have been monitored. “This in itself is shocking and in view of the situation in exporting countries and the lack of transparency and management in the application of agrochemicals and veterinary medicinal substances within commercial farms, we strongly recommend that this monitoring become an urgent near-future task for importing countries,” they write.
“The complexity of issues underlying the frogs’ legs trade is not a priority policy item for the EU,” the authors conclude. They add that a listing of the most-affected frog species under CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, would help to monitor trade and ensure its sustainability, and the EU as the main destination should take the lead on that.
Research article:
Auliya M, Altherr S, Nithart C, Hughes A, Bickford D (2023) Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer. Nature Conservation 51: 71-135. https://doi.org/10.3897/natureconservation.51.93868
Choloepus hoffmanni capitalis is a poorly known subspecies of two-toed sloth that inhabits coastal southern Colombia and Ecuador(Hayssen 2011). In Ecuador, according to local reports from rehabilitation centers and events recorded by the press, this species is apparently not widely trafficked for pet trade, but it is known to be illegally hunted and consumed, the impact of which is difficult to trace and evaluate. Nevertheless, the conservation status of the two-toed sloths C.h. capitalis Ecuadorian coast keeps leaning towards more threatened categorizations, and nowadays is established as vulnerable (Tirira, 2021).
The sloths Bravo and Linda during rehabilitation.
Its habitat is a hotspot for conservation in all its extent, as it is threatened. In addition, due to multiple origins of impact, it has been recorded as the second most abundant mammal (from the list of animals subjected to wildlife traffic and bushmeat consumption according to Environment Ministry reports) received in the busy rehabilitation center of Guayaquil, Ecuador (Villalba-Briones et al., 2021).
Xenarthrans have been relatively poorly studied, specially sloths (Superina and Loughry 2015), and due to the species’ inconspicuous strategy, it is also difficult to detect and perform population evaluations (Martínez et al. 2020). Taking in account the slow reproduction rate of Choloepus gen., having one offspring every 3 years (Hayssen 2011), it is critical to consider the importance of reintroductions (Paterson et al. 2021, Villalba-Briones et al. 2022), but, to all effects, nothing can substitute the implementation of efficient regulation to cease hunting and bushmeat consumption.
In-situ studies, understanding its ecology, behavior, abundance etc., could provide the necessary tools to estimate its populations, and evaluate its conservation status. Alternatively, non-invasive opportunistic studies in ex-situ programs during rehabilitation procedures could provide improvements in the aspects as diets and health, increasing the survival rate and fitness to release of rehabilitated sloths.
Bravo, the two-toed sloth moving through the trees on the day of release with a biodegradable backpack that supported the Bluetooth detection device (Day 1). Photo by R. Villalba-Briones
We suggest considering follow-up activities to check the animals’ safety during their adaptation to the natural environment. We also propose the inclusion of a follow-up term to redeem the post-release supportive monitoring, develop its scope, and to rely on the presence and readiness of the caregivers or researchers to help the animal during the first weeks after release.
In order to track Bravo after his release, a handmade biodegradable backpack with Bluetooth signal transmission capacity was fitted to his body. The lightweight Tile Bluetooth device did not pose any harm to the sloth, and after some heavy rains cardboard-made attachment just disintegrated, releasing the device.
Motionless defensive behavior of Bravo, the two-toed sloth, under threat from an owl (Night 6). Photo by R. Villalba-Briones
In our work, the presence in the area of a territorial carnivore individual led to the end of the follow-up activity. Consequently, in the case of probable undesired situations, we propose the use of devices to track the animals and monitor their presence daily. Alternatively, accounting for the relationship between movement patterns of the individual and detection probability, we propose 7 pm as the best time for observations of this mainly nocturnal species.
Due to the difficulty monitoring nocturnal animals, economic constraints in conservation, accessibility, and safety of the animals, biodegradable Bluetooth-based backpacks are recommended to ease the location of the animal and support its survival in the wild. The range of detectability of the device used indicates its suitability for tracking low-mobility animals.
Map showing the movements and tree use of the rehabilitated two-toed sloth (Choloepus hoffmanni) in a dry tropical forest in the coastal region of Ecuador.
This first record of the follow-up of a rehabilitated Choloepushoffmanni and the detectability analysis offer valuable information for the future release and follow-up of individuals belonging to the genus Choloepus, and sloths in general.
The knowledge about released animals’ survival could help in clearing rehabilitation uncertainties, and, always, can give the animals the second chance they deserve. Monitoring animal survival after release is essential for recording whether the rehabilitation process has been accomplished, but it is rarely done in practice, given the amount of funds required. It can, however, be substantially cheaper and affordable if the right techniques are used. These activities are more feasible when strategic planning and support exist.
Nowadays, the scarcity of funds to fulfill the needs of conservation projects on sloths (Superina and Loughry 2015, Choperena-Palencia and Mancera-Rodríguez 2018) seems to be an important obstacle. However, with a sensitized population, management effort, and support, it could be possible to understand and preserve the Choloepus hoffmanni capitalis.
References:
Choperena-Palencia MC, Mancera-Rodríguez NJ (2018) EVALUACIÓN DE PROCESOS DE SEGUIMIENTO Y MONITOREO POST-LIBERACIÓN DE FAUNA SILVESTRE REHABILITADA EN COLOMBIA. Luna Azul: 181–209. https://doi.org/10.17151/luaz.2018.46.11
Hayssen V (2011) Choloepus hoffmanni (Pilosa: Megalonychidae). Mammalian Species 43: 37–55. https://doi.org/10.1644/873.1
Martínez M, Velásquez A, Pacheco-Amador S, Cabrera N, Acosta I, Tursios-Casco M (2020) El perezoso de dos dedos (Choloepus hoffmanni) en Honduras: distribución, historia natural y conservación. Notas sobre Mamíferos Sudamericanos 01: 001–009. https://doi.org/10.31687/saremNMS.20.0.25
Paterson JE, Carstairs S, Davy CM (2021) Population-level effects of wildlife rehabilitation and release vary with life-history strategy. Journal for Nature Conservation 61: 125983. https://doi.org/10.1016/j.jnc.2021.125983
Superina M, Loughry WJ (2015) Why do Xenarthrans matter?: Table 1. Journal of Mammalogy 96: 617–621. https://doi.org/10.1093/jmammal/gyv099
Villalba-Briones R, Molineros E, Monros, J. S. (2021). Estudio retrospectivo de rescates y retenciones de especies de fauna silvestre sujetas a tráfico de fauna en guayaquil, Ecuador. Comité científico.
Villalba-Briones R, Jiménez ER, Monros JS (2022) Release and follow-up of a rehabilitated two-toed sloth (Choloepus hoffmanni) in a tropical dry forest in Ecuador. Neotropical Biology and Conservation 17(4): 253-267. https://doi.org/10.3897/neotropical.17.e91332
Tirira, D. G. (ed.). 2021. Lista Roja de los mamíferos del Ecuador, en: Libro Rojo de los mamíferos del Ecuador (3a edición). Asociación Ecuatoriana de Mastozoología, Fundación Mamíferos y Conservación, Pontificia Universidad Católica del Ecuador y Ministerio del Ambiente, Agua y Transición Ecológica del Ecuador. Publicación Especial sobre los mamíferos del Ecuador 13, Quito.
With more than 7000 individuals populating the Carpathian Mountains and neighboring areas, Romania has the highest density of brown bears in Europe. As they often inhabit human-dominated landscapes, conflicts with people are not uncommon.
“The media play an influential role in how the public perceives brown bears, thus, it can promote human-wildlife coexistence or exacerbate future conflicts”, they say.
Brown bear waiting on the roadside for food scraps (National Road 2D, Vrancea, Romania). Photo by Dr Silviu Chiriac (EPA Vrancea)
The study found that news stories related to brown bears became common in Romanian media only after 2016, following the instatement of a provisional one-year ban on culling, and increased abruptly in 2021 following the whistleblowing of an alleged trophy hunting event.
The majority of reports were about human-bear interaction, hunting, and poaching, offering little context and information on how to avoid conflicts. Articles on the ecology and biology of brown bears were rare, which indicates less consideration of the ecological significance and the impact of human activities on their conservation status.
Focusing on alarming messages without offering evidence or advice can increase fear and undermine efforts to protect the species and the welfare of society.
The attitude towards brown bears, perceived from the studied articles was predominantly negative (53%; 380 articles). In these articles, the authors used phrases such as: “At any moment the people can find themselves in front of a hungry bear;” “Beyond the horror they live with every day, they have lost their patience and trust in the authorities;” and “People are afraid of the worst.”
Even when reporting sightings of bears near populated areas and encounters with no casualties, Romanian media promoted a negative image of bears to their readership. “Focusing on alarming messages without offering evidence or advice can increase fear and undermine efforts to protect the species and the welfare of society,” the researchers said.
Importantly, the team found that media did not consult wildlife and conservation biologists when reporting on human-bear interactions or bear hunting and poaching events. “This can be because the experts are reluctant to be part of the debate, or because the media may not be interested in bringing more scientific context to their reports,” they reason.
Rescuing a bear trapped in wire-snare in an orchard (Vrancea, Romania). Photo by Dr Silviu Chiriac (EPA Vrancea)
“In conclusion, increasing the frequency of reporting interaction events with alarming messages can only lower the level of tolerance for wildlife and negatively influence political decisions regarding the management of the brown bear population.”
The researchers call for publishing detailed and evidence-informed news as a means to educate people to avoid conflict and facilitate the implementation of effective wildlife conservation and management strategies.
“Evidence-informed news can help authorities better understand conflicts and create bottom-up pathways toward an optimistic future for brown bears and Romanian society”, they conclude.
Research article:
Neagu AC, Manolache S, Rozylowicz L (2022) The drums of war are beating louder: Media coverage of brown bears in Romania. Nature Conservation 50: 65-84. https://doi.org/10.3897/natureconservation.50.86019
Researchers recorded an individual at the Canoas Airbase, one of the last remaining green spaces in a densely urbanized area of a large city in southern Brazil.
You may assume that metropolitan areas are devoid of wildlife, but that is very far from the truth. The remaining green spaces within the urban matrices of large cities can serve as corridors or stepping stones for wild animals. Sometimes, even threatened mammal species end up using them.
On August 12, 2020, a research team from Brazil recorded a South American coati in Canoas, the fourth most populous and densely urbanized city in the southernmost state of Brazil, Rio Grande do Sul. The animal was detected with a camera trap during a Masters research project conducted at the Canoas Airbase, one of the last green spaces remaining in the municipality.
South American Coati at the Canoas airbase in Rio Grande do Sul, Brazil. Video by Diego Floriano da Rocha, Thaís Brauner do Rosario and Cristina Vargas Cademartori
Widely distributed throughout the continent, the South American coati is a medium-sized carnivore living on trees and feeding mainly on small invertebrates and fruits. The species is classified as Vulnerable in Rio Grande do Sul, and it’s considered threatened mainly because of the loss of its forest habitats.
The study that recorded an individual in the urban area was conducted as part of a partnership between the Canoas Airbase and La Salle University. Led by Dr Cristina Vargas Cademartori from La Salle University, the research team was made up of Diego Floriano da Rocha (Doctoral student), Thaís Brauner do Rosario (Masters student), Ana Carolina Pontes Maciel (biologist at the Canoas Airbase), and Duana Suelem Alves (undergraduate student). They described in detail the record and the study area in a paper in the open-access journal Neotropical Biology and Conservation.
The researchers were surprised to find the coati in the midst of a dense urban area. Although the species is not considered threatened in the majority of its area of distribution, its populations have been in decline because of habitat loss and hunting.
“This record confirms the capacity of this species to use environments that have been changed by anthropic activity,” the researchers write in their paper, adding that, because of all the food that humans leave behind, urban environments can in fact favor the establishment of more adaptable species like the coati.
The discovery highlights the importance of urban green spaces for wildlife conservation. “This is very important for defining appropriate conservation measurements for endangered species, especially beyond protected areas,” the authors conclude.
Research article: da Rocha DF, do Rosario TB, Maciel ACP, Alves DS, Cademartori CV (2022) Record of occurrence of Nasua nasua (Linnaeus, 1766) (Carnivora, Procyonidae) in a densely urbanized area of the city of Canoas, southern Brazil. Neotropical Biology and Conservation 17(2): 111-116. https://doi.org/10.3897/neotropical.17.e81824
“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems.
“Is it the road that crosses the habitat, or does the habitat cross the road?” ask scientists at Gauhati University (Assam, India) before agreeing that the wrong road at the wrong place is bound to cause various perils for the local wildlife, habitats and ecosystems. Furthermore, some of those effects may take longer than others to identify and confirm.
This is how the research team of doctoral research fellow Somoyita Sur, Dr Prasanta Kumar Saikia and Dr Malabika Kakati Saikia decided to study roadkill along a 64-kilometre-long stretch of one of the major highways in India: the National Highway 715.
What makes the location a particularly intriguing choice is that it is where the highway passess between the Kaziranga National Park, a UNESCO World Heritage site in Assam and the North Karbi Anglong Wildlife Sanctuary, thus tempting animals to move to and from the floodplains of Kaziranga and the hilly terrain of the Sanctuary to escape the annual floods or – on a daily basis – in search for food and mating partners.
In the beginning, they looked into various groups, including mammals, birds, reptiles, and amphibians, before realising that the death toll amongst frogs, toads, snakes and lizards was indeed tremendous, yet overlooked. Their findings were recently published in the peer-reviewed scholarly journal Nature Conservation.
“To our surprise, the death toll within that 64-kilometre stretch of the highway was indeed dramatic. We estimated that it has been over 6000 animals that have fallen under the wheels of motor vehicles within a single year. Prior to our study, similar research had focused on big charismatic species like the tiger, elephant and rhino, so when we took into account also the smaller animals: frogs, toads, snakes and lizards, the count went through the roof. Thus, we decided to make smaller species the focus of our work,”
comments Sur.
In conclusion, the scientists agree that roads and highways cannot be abandoned or prevented from construction and expansion, as they are crucial in connecting people and transporting goods and necessities.
“Yet, we can definitely put some effort into designing and constructing them in a scientifically sound, eco-friendly and sustainable manner, so that they don’t become the bane for our ecosystems,”
the team concludes.
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Research article:
Sur S, Saikia PK, Saikia MK (2022) Speed thrills but kills: A case study on seasonal variation in roadkill mortality on National highway 715 (new) in Kaziranga-Karbi Anglong Landscape, Assam, India. In: Santos S, Grilo C, Shilling F, Bhardwaj M, Papp CR (Eds) Linear Infrastructure Networks with Ecological Solutions. Nature Conservation 47: 87-104. https://doi.org/10.3897/natureconservation.47.73036
In a first for science, researchers set out to analyze over 10 years of roadkill records in Flanders, Belgium, using data provided by citizen scientists.
The road is a dangerous place for animals: they can easily get run over, which can seriously affect wildlife diversity and populations in the long term. There is also a human economic cost and possible injury or even death in these accidents, while crashing into heavier animals or trying to avoid them on the road.
Making roads safer for both animals and people starts with a simple first step: understanding when, where, and how many animals get run over. This knowledge can help protect specific species, for example by using warning signs, preventing access to the roads for animals, creating overpasses and underpasses, or closing roads. Wildlife roadkill data can also help monitor other trends, such as population dynamics, species distribution, and animal behavior.
Thanks to citizen science platforms, obtaining this kind of data is no longer a task reserved for scientists. There are now dozens of free, easy-to-use online systems, where anyone can record wildlife collision accidents or roadkill, contributing to a fuller picture that might later be used to inform policy measures.
One such project is the Flemish Animals under wheels, where users can register the roadkill they saw, adding date, time and geolocation online or by using the apps. The data is stored in the online biodiversity database Waarnemingen.be, the Flemish version of the international platform Observation.org.
Between 2008 and 2020, the project collected almost 90,000 roadkill records from Flanders, Belgium, registered by over 4,000 citizen scientists. Roadkill recording is just a small part of their nature recording activities – the multi-purpose platform which also allows the registration of living organisms. This is probably why the volunteers have remained engaged with the project for over 6 years now.
In a first for science, researchers from Natuurpunt Studie, the scientific institute linked to the largest Nature NGO in Flanders, with support from the Department of Environmental and Spatial Development, set out to analyze over 10 years of roadkill records in the region, using data provided by citizen scientists. In their study, published in the peer-reviewed journal Nature Conservation, they focused on 17 key species of mammals and their fate on the roads of Flanders.
The researchers analyzed data on 145,000 km of transects monitored, which resulted in records of 1,726 mammal and 2,041 bird victims. However, the majority of the data – over 60,000 bird and mammal roadkill records – were collected opportunistically, where opportunistic data sampling favors larger or more “enigmatic” species. Hedgehogs, red foxes and red squirrels were the most frequently registered mammal roadkill victims.
In the last decade, roadkill incidents in Flanders have diminished, the study found, even though search effort increased. This might be the result of effective road collision mitigation, such as fencing, crossing structures, or animal detection systems. On the other hand, it could be a sign of declining populations among those animals that are most prone to being killed by vehicles. More research is needed to understand the exact reason. Over the last 11 years, roadkill records of the European polecat showed a significant relative decrease, while seven species, including the roe deer and wild boar, show a relative increase in recorded incidents.
There seems to be a clear influence of the COVID-19 pandemic on roadkill patterns for some species. Restrictions in movement that followed likely led simultaneously to fewer casualties and a decrease in the search effort.
The number of new observations submitted to Waarnemingen.be continues to increase year after year, with data for 2021 pointing to about 9 million. Even so, the scientists warn that those recorded observations “are only the tip of the iceberg.”
“Citizen scientists are a very valuable asset in investigating wildlife roadkill. Without your contributions, roadkill in Flanders would be a black box,”
the researchers conclude.
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Research paper:
Swinnen KRR, Jacobs A, Claus K, Ruyts S, Vercayie D, Lambrechts J, Herremans M (2022) ‘Animals under wheels’: Wildlife roadkill data collection by citizen scientists as a part of their nature recording activities. In: Santos S, Grilo C, Shilling F, Bhardwaj M, Papp CR (Eds) Linear Infrastructure Networks with Ecological Solutions. Nature Conservation 47: 121-153. https://doi.org/10.3897/natureconservation.47.72970
Researchers developed a method to determine which amphibians inhabit a specific area. The new technique will resolve some of the issues with conventional methods, such as capture and observational surveys.
Ryukyu Sword Tailed Newt, or Firebellied Newt. Photo by Neil Dalphin via Creative Commons CC0.
An international collaborative research group of members from seven institutions has developed a method to determine which amphibians (frogs, newts and salamanders) inhabit a specific area. Their work was published in the open-access, peer-reviewed journal Metabarcoding and Metagenomics (MBMG).
To do so, the scientists amplified and analysed extra-organismal DNA (also known as environmental DNA or eDNA) found in the water. This DNA ends up in the water after being expelled from the amphibian’s body along with mucus and excrement.
The newly developed technique will resolve some of the issues with conventional methods, such as capture and observational surveys, which require a specialist surveyor who can visually identify species. Conventional surveys are also prone to discrepancies due to environmental factors, such as climate and season.
The researchers hope that the new method will revolutionise species monitoring, as it will enable anyone to easily monitor the amphibians that inhabit an area by collecting water samples.
While monitoring in general is crucial to conserve the natural ecosystems, the importance of surveying amphibians is even more pressing, given the pace of their populations’ decline.
Amongst major obstacles to amphibian monitoring, however, are the facts that they are nocturnal; their young (e.g. tadpoles) and adults live in different habitats; and that specialist knowledge is required to capture individuals and identify their species. These issues make it particularly difficult to accurately survey amphibians in a standardised way, and results of individual efforts often contradict each other.
On the other hand, eDNA analysis techniques have already been established in programmes targeted at monitoring fish species, where they are already commonplace. So, the researchers behind the present study joined forces to contribute towards the development of a similar standardised analysis method for amphibians.
First of all, the researchers designed multiple methods for analysing the eDNA of amphibians and evaluated their performance to identify the most effective method. Next, they conducted parallel monitoring of 122 sites in 10 farmlands across Japan using the developed eDNA analysis along with the conventional methods (i.e. capture surveys using a net and observation surveys).
As a result, the newly developed method was able to detect all three orders of amphibians: Caudata (the newts and salamanders), Anura (the frogs), and Gymnophiona (the caecilians).
Furthermore, this novel eDNA analysis method was able to detect more species across all field study sites than the conventional method-based surveys, indicating its effectiveness.
Research Background
Amphibian biodiversity is continuing to decline worldwide and collecting basic information about their habitats and other aspects via monitoring is vital for conservation efforts. Traditional methods of monitoring amphibians include visual and auditory observations, and capture surveys.
However, amphibians tend to be small in size and many are nocturnal. The success of surveys varies greatly depending on the climate and season, and specialist knowledge is required to identify species. Consequently, it is difficult to monitor a wide area and assess habitats. The last decade has seen the significant development of environmental DNA analysis techniques, which can be used to investigate the distribution of a species by analysing external DNA (environmental DNA) that is released into the environment along with an organism’s excrement, mucus and other bodily fluids.
The fundamentals of this technique involve collecting water from the survey site and analysing the eDNA contained in it to find out which species inhabit the area. In recent years, the technique has gained attention as a supplement for conventional monitoring methods. Standardised methods of analysis have already been established for other species, especially fishes, and diversity monitoring using eDNA is becoming commonplace.
However, eDNA monitoring of amphibians is still at the development stage. One reason for this is that the proposed eDNA analysis method must be suitable for the target species or taxonomic group, and there are still issues with developing and implementing a comprehensive method for detecting amphibians. If such a method could be developed, this would make it possible for monitoring to be conducted even by people who do not have the specialised knowledge to identify species nor surveying experience.
Hopefully, this would be established as a unified standard for large-scale monitoring surveys, such as those on a national scale. This research group’s efforts to develop and evaluate analysis methods will hopefully lay the foundations for eDNA analysis to become a common tool for monitoring amphibians, as well as fish.
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Follow Metabarcoding and Metagenomics (MBMG) journal on Twitter and Facebook.
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Research article:
Sakata MK, Kawata MU, Kurabayashi A, Kurita T, Nakamura M, Shirako T, Kakehashi R, Nishikawa K, Hossman MY, Nishijima T, Kabamoto J, Miya M, Minamoto T (2022) Development and evaluation of PCR primers for environmental DNA (eDNA) metabarcoding of Amphibia. Metabarcoding and Metagenomics 6: e76534. https://doi.org/10.3897/mbmg.6.76534
Spending time outdoors is good for a person’s body and soul, but how good is it for the wildlife around us?
Outdoor recreation has become a popular activity, especially in the midst of a pandemic, where access to indoor activities might be limited. Long known to have negative behavioural and physiological effects on wildlife, outdoor recreation is one of the biggest threats to protected areas. Human disturbance to animal habitats can lower their survival and reproduction rates, and ultimately shrink populations or eradicate them from areas where they would otherwise thrive. Still, park planners and natural resource managers often can’t find clear recommendations on how to limit these impacts.
Human recreation and wildlife often overlap. Here an American black bear and hikers use the same trail hours apart in Sonoma County, California, USA. Image by the Wildlife Conservation Society
A new scholarly article in the open-access, peer-reviewed journal Nature Conservation from researchers at the Wildlife Conservation Society looked at nearly 40 years of research on recreation impacts on wildlife to try to find the point where recreation starts to impact the wildlife around us. Knowing when and to what extent a species is being disturbed can ultimately allow for more informed and effective management decisions and increase the chances of its successful conservation.
The researchers found that the impact or uncomfortable distance to humans, vehicles or trails for shorebirds and songbirds was as short as 100 meters or even less, whereas for hawks and eagles it was greater than 400 meters. For mammals, it varied even more widely, with an impact threshold of 50 meters for medium-sized rodents. Large ungulates – like elk – would rather have to stay 500 to 1,000 meters away from people.
While human disturbance thresholds can vary widely, large buffer zones around human activities and controlled visitation limits should always be considered during planning and maintenance of parks and protected areas. Based on their findings, the authors recommend that human activities should be considered to be impacting wildlife at least 250 metres away. Further, they call for future research to explicitly identify points where recreation begins or ends to impact wildlife.
Bird diets provide a real treasure for research into the distribution and conservation of their prey, conclude scientists after studying the Eurasian Eagle Owl in southeastern Bulgaria. In their paper, published in the open-access, peer-reviewed journal Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa”, they report the frequent presence of the threatened Big-Bellied Glandular Bush-Cricket, and conclude that studies on the Eurasian Eagle Owl could be used to identify biodiversity-rich areas in need of protection.
Male specimen of the Big-Bellied Glandular Bush-Cricket (Bradyporus macrogaster) Photo byDragan Chobanov
Bird diets provide a real treasure for research into the distribution and conservation of their prey, such as overlooked and rare bush-cricket species, point out scientists after studying the diet of the Eurasian Eagle Owl (Bubo bubo) in southeastern Bulgaria.
While the Balkan Peninsula has already been recognised as the area with the highest diversity of orthopterans (grasshoppers, crickets and bush-crickets) in Europe and one of the generally most biologically diverse areas in the whole Palearctic realm, it is also home to a worrying number of threatened species. Additionally, a thorough and updated country assessment of the conservation status of the orthopterans found in Bulgaria is currently lacking. This is why the Bulgarian team undertook a study on the biodiversity of these insects by analysing food remains from pellets of Eurasian Eagle Owls, collected from 53 breeding sites in southeastern Bulgaria.
As a result, the scientists reported three species of bush crickets that have become a significant part of the diet of the studied predatory birds. Curiously enough, all three species are rare or threatened in Bulgaria. The case of the Big-Bellied Glandular Bush-Cricket is of special concern, as it is a species threatened by extinction. Meanwhile, the local decline in mammals and birds that weigh between 0.2 and 1.9 kg, which are in fact the preferred prey for the Eurasian Eagle Owl, has led the highly opportunistic predator to increasingly seek large insects for food. The researchers even suspect that there might be more overlooked species attracting the owls.
Taking into account the hereby reported interconnected inferences of conservation concern, as well as the vulnerability of the Big-Bellied Glandular Bush-Cricket, a species with a crucial role in the food chain, the scientists call for the newly provided data to prompt the designation of a new Natura 2000 site. Additionally, due to the species’ requirements for habitats of low disturbance and high vegetation diversity, and its large size and easy location via singing males, they point out that it makes a suitable indicator for habitat quality and species community health.
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Original source:
Chobanov D, Milchev B (2020) Orthopterans (Insecta: Orthoptera) of conservation value in the Eurasian Eagle Owl Bubo bubo food in Bulgaria. Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 63(2): 161-167. https://doi.org/10.3897/travaux.63.e53867
