Jan Mertens

Hemeleilanden en Spinnen: een verhaal over twee ontdekkingen in zuidelijk Afrika

tekst in het Engels, geschreven door BROGAN PETT @BroganConBio


I first got involved with BINCO through fieldwork in north-western Madagascar in 2017 surveying spiders in the enigmatic dry forests. From here on, I started working with Merlin and was very interested in the work that BINCO carries out, joining later in the year after my first Madagascar visit. I have so far visited the Madagascar field site twice. As well as an initial visit to the collection at the RMCA in Tervuren. I was invited on my second visit, onto the Xevioso project.

The two newly described species of Xevioso have a captivating appearance, the palps are certainly beautiful and incredibly intricate in their structure. I spent around two weeks in the lab at the RMCA on my second visit, with plenty of evening work sprinkled in, looking through each of the Mozambique pitfall samples and extracting all of the Xevioso material. There was a substantial sex bias in the collections in favour of males. Making female specimens eight-legged gold! In fact, we only found two females, which lends itself towards “conventional” sex roles in these spiders: the males are out searching for mates.

We had a lot of comparative material to work with; the types of the most closely related species and a few others in the genus really helped elucidate the key diagnostic features for me. Then there was three or so months of back and forth developing the manuscript with Rudy Jocqué (co-author and mentor), finessing the descriptions along the way (Pett & Jocqué, 2020)!

These two new species exhibit very interesting distributions. Xevioso cepfi, from the Njesi expedition, was found at each of the mountain plateaus, potentially suggesting its prevalence as a montane specialist. Contrastingly, the male holotype and female paratype of Xevioso megcummingae were collected in an urban garden in Harare, Zimbabwe. Following my museum visit, Rudy identified a much smaller male specimen of X. megcummingae whilst digging through material from Malawi. Its presence in the Viphya mountains (Malawi), a truly remarkable range expansion! This makes me guess it is present in a wide suite of areas in between its currently known distribution.

The discovery of Xevioso cepfi actually represents the second new spider discovery from the BINCO Njesi expedition, with Cicynethus mossambicus (see Jocqué & Henrard, 2018), also representing the most northerly limit of a species of its genus (as in X. cepfi). These results further augment the incredible value that such expeditions can have for biodiversity knowledge in poorly studied regions of the world.

The 2016 Njesi expedition was funded by the Critical Ecosystem Partnership Fund (CEPF). In honour of the fantastic work they do to help protect biodiversity and our natural capital in this world, we named X. cepfi after the organisation.

 

References

Jocqué R. & Henrard, A. (2018) A revision of the genus Cicynethus Simon, 1910 (Araneae, Zodariidae), a tale of colour patterns. European Journal of Taxonomy 465: 1–35.
Pett B.L. & Jocqué R. (2020) Description of two new species of Xevioso (Araneae: Phyxelididae) from Southern Africa, with the northernmost localities for the genus. European Journal of Taxonomy 636: 1–18.


Omvang van bedreigde vogelpopulaties langs de Mekongriver neemt af

tekst in het Engels geschreven door Erik Sandvig @eriksandvigc
afbeeldingen van John Mittermeier @johnmittermeier


In May 2018, together with an interdisciplinary team of biologists put together by BINCO, we did a rapid biodiversity assessment along the central section of the Mekong River in Cambodia. The goal for John Mittermeier and I, the ornithologists of the team, was to determine the avian diversity in the study area, which had been proposed by WWF as a protected area for the critically endangered Hog Deer (Axis porcinus). Luckily for us, a previous survey of the area had been done in 2008 by Robert Timmins who had surveyed birds along the river near our study site over the course of several weeks. This work set the groundwork for us to compare how things might have changed over the last decade. Our findings from this expedition were recently published in BirdingASIA (volume 32: 80-89). Here we share some additional details about our findings and a brief behind the scenes of the expedition. For more detailed information, feel free to get in touch for a copy of the published article.

After a few days of preparations and logistics in Phnom Penh our group set out to Kracheh (also spelled Kratie), located on the central section of the Mekong River. The plan was to establish four base camps over the next three weeks, all not far from the river, focusing on four distinct types of habitat. These were: sandy riverine islands, wet grassland, dry Dipterocarp forest, and semi-evergreen forest. One of our primary goals was to establish the presence and relative abundance of species of conservation concern. Of particular interest in this area are the endangered ibises and vultures.

Motoring into the Mekong we reached the islands where we were to set up camp for the next three days. From Timmins’ survey we knew White-shouldered Ibis (Pseudibis davisoni) was possible here and our boat driver assured us they were seen sporadically in some big trees in the river. Over the next days we covered the innumerable branches of the river separating the small islands in search of them, spotting a group of 7 on one day, and 5 another. A good sign to at least confirm their continued presence in the area. Of note was also finding the fourth record of Green-backed Flycatcher (Ficedula elisae) for Cambodia in the dense forest of one of the islands.

However, we also got our first glimpse of the direct threats that birds are facing along the Mekong at this first site. Exploring one of the islands we stumbled upon a couple of boys digging into a sandbank. Approaching them, they proudly showed us their bounty; eggs and nestlings of Blue-tailed Bee-eaters (Merops philippinus), apparently a local delicacy.

Our second camp was located just west of the river, in an area with wet grasslands and patches of dipterocarp woodland, where Hog Deer had been sighted some time back. In regard to birdlife, the area looks quite disturbed. So, we weren’t expecting much when we happened upon a skulking Acrocephalus warbler in the long grasses. After a challenging photo-op, John managed to take some half-decent pictures, confirming the ID as a White-browed (Manchurian) Reed Warbler (Acrocephalus tangorum). In total we saw at least four individuals in the area. Classified as Vulnerable, with only one known wintering area around Tonle Sap (much further west) in Cambodia, this record, close to the second camp, comprises a new wintering ground for the species.

The third camp was located on a large river island about 40km north of our previous camps. The habitat was mostly semi-evergreen forest, with good quality dry dipterocarp forest a short boat ride away on the other side of the river. The local WWF team had been running a ‘vulture restaurant’ in this dipterocarp forest for some years, in hopes of aiding the diminishing populations of Red-headed (Sarcogyps calvus), White-rumped (Gyps bengalensis) and Slender-billed Vultures (Gyps tenuirostris). These species are all Critically Endangered, so we were keenly interested in assessing their continued presence since Timmins’ survey in 2008. The team arranged for a cow to be set out in a clearing about a week before we arrived, and a local man, employed by WWF, kept close tabs on the carcass in case any vultures arrived. None came. We later learned that it had been many months since any had been seen, despite their efforts in placing a fresh carcass out every month. Although this doesn’t necessarily mean they are completely gone, it does paint a very worrying picture for these species.

While at this camp we also made a couple boat trips up the Mekong to a river island with breeding River Terns (Sterna aurantia), a species that is now highly threatened in Southeast Asia, where two tern nests were being monitored by a local couple employed by WWF and WCS. Unfortunately, predation by rats is a real problem on these small islands and one of the tern nests failed shortly after our visit. But not all was doom and gloom, as on one of the visits we recorded a couple greenshanks on a sandbank. Upon later inspection we were able to identify one of them as a Spotted (Nordmann’s) Greenshank (Tringa guttifer) – the first record for interior Cambodia. This finding provides evidence that the Mekong could be an important north-south corridor for this migratory species.

Now starting the third week of the expedition, we established our last camp in semi-evergreen forest in an area protected by the local village west of our last camp. Before even arriving at the spot we were struck by the widespread clearing of the forest in the area. Not far from the camp, commercial loggers were bulldozing roads into the forest. Perhaps one of the most haunting memories of the trip comes from these forests, when John and I spotted a pair of Great Hornbills (Buceros bicornis) displaying in a large tree. We were awe-struck by these majestic birds, rolling their heads back and making their guttural calls, but our heart sank hearing chainsaws roaring nearby.

After three weeks of surveying we were able to record 219 species in these four habitats, more than a third of the total species known from Cambodia. Among these were four globally threatened and eleven near threatened bird species. Worryingly, we did not find several species of waterbirds that had been recorded by Timmins in 2008 and we never saw any of the threatened vultures despite the feeding efforts of local conservationists. This suggests continued population declines of several of these birds along the Mekong. But heart-lifting news came after the expedition when the Cambodian government announced that the areas we had surveyed will be established as two new protected areas. More recently, more reassuring announcements were made including the government scrapping plans to build damn on the Mekong, close to the Laos border. These developments provide a glimmer of hope that the species recorded during the expedition will continue to persist in this area, and that those absent may one day return.


MyrmEcoDex – Cusuco National Park

afbeeldingen en tekst, in het Engels, door MATT HAMER @entohamer


 

Cloud forests are some of the most biodiverse ecosystems on the planet, being sites of high endemism that are heavily threatened from human-caused pressures. Cusuco National Park (CNP), located in Honduras, is no exception. The park holds considerable biodiversity and has been designated as one of the 137 irreplaceable protected areas in the world (Le Saout et al., 2013). Cusuco was allocated protection after a sweeping decree issued by the Honduran Government in 1987 that gave all mountainous habitats above 1800 m protection. In reality, however, the park is heavily threatened by illegal logging, deforestation and encroaching agriculture. 

Relatively little is known of the insect biodiversity of CNP, particularly the ant (Formicidae) diversity. Ants are an ecologically dominant group, comprising of species scattered throughout the food web from herbivorous leaf-cutting ants (Fig 1) to the highly predaceous army ants (Fig 2) that consume huge numbers of arthropods and vertebrates on the forest floor. Ants are also fantastic indicators of habitat change because many species are highly sensitive to ecological alterations allowing for the study of fine scale diversity and community patterns throughout an ecosystem (Underwood and Fisher, 2006; Tiede et al., 2017; Lessard, 2019). It is therefore important to document this rich community and the impact of occurring human-associated pressures.

MyrmEcoDex, the ant work group of BINCO, investigates the ant diversity present in CNP using inventories from previous expeditions to the park, alongside museum reference specimens and further sampling in collaboration with Operation Wallacea. Five members, based in Belgium, are currently involved in mounting, identifying, and databasing of the specimens. At this time, the team has prepared 251 specimens on point mounts and identified the majority of these, at least eight of them being new to the park already. These samples originate from opportunistic sampling by MyrmEcoDex volunteers in 2018 and 2019 and are also collected from pitfall samples from by-catch during dung beetle monitoring surveys conducted by Operation Wallacea. 

Ants occupy a variety of habitats throughout CNP and so multiple collecting methods will be needed to sample their biodiversity effectively. A significant number of species occupy the leaf-litter layer between the soil and vegetation - this diversity has previously been explored by the LLAMA project in 2010 (Longino et al., 2014). However, further surveys in areas not sampled by the LLAMA project may reveal new records and potentially new species. Additionally, it will be interesting to document whether ants found during the LLAMA project are recovered during current survey work. Ants also reside above ground where particular species dominate over others; it can be easy to overlook more subtle and secretive species, therefore methods such as bait-trapping together with more extensive pitfall trapping could be used to broaden our knowledge on ant diversity. 

MyrmEcoDex hopes that this initial survey work will galvanise further ant surveys in other remote and threatened parts of the world allowing for the inventories of these ecological important organisms and help to understand and document the impacts of anthropogenic pressures.

 

References

Lessard, J. P. (2019) ‘Ant community response to disturbance: A global synthesis’, Journal of Animal Ecology, 88(3), pp. 346–349. doi: 10.1111/1365-2656.12958.
Longino, J. T., Branstetter, M. G. and Colwell, R. K. (2014) ‘How ants drop out: Ant abundance on tropical mountains’, PLoS ONE, 9(8). doi: 10.1371/journal.pone.0104030.
Le Saout, S. et al. (2013) ‘Protected areas and effective biodiversity conservation’, Science, 342(6160), pp. 803–805. doi: 10.1126/science.1239268.
Tiede, Y. et al. (2017) ‘Ants as indicators of environmental change and ecosystem processes’, Ecological Indicators. Elsevier Ltd, 83, pp. 527–537. doi: 10.1016/j.ecolind.2017.01.029.
Underwood, E. C. and Fisher, B. L. (2006) ‘The role of ants in conservation monitoring: If, when, and how’, Biological Conservation, 132(2), pp. 166–182. doi: 10.1016/j.biocon.2006.03.022.


Checklist van de bladhaantjes (Coleoptera: Chrysomelidae) van El Salvador

Bladhaantjes, een keverfamilie, zijn een taxonomisch complexe maar economisch relevante groep. Veel soorten binnen deze familie zijn pestsoorten op gewassen. Toch is de kennis over de verspreiding van deze soorten in vele regio’s zoals de tropen heel beperkt. Bovendien is het in vele landen niet evident om een staalname-campagne te organiseren. Historische collecties uit musea zijn een waardevol startpunt bij het invullen van soortenkennis van een bepaalde regio.

In het koninklijk Belgisch Instituut voor Natuurwetenschappen (KBIN) te Brussel ontdekte BINCO een grote collectie bladhaantjes uit El Salvador van wijlen Jan Bechyné, een befaamd wetenschapper die historisch veel onderzoek deed naar deze familie. Bechyné leefde van 1920 tot 1973 en na het behalen van zijn doctoraat in 1948 werkte hij onder andere in het natuurhistorisch museum te Praag, het museum G. Frey en het KBIN. In 1959 vertrok hij met zijn vrouw Bohumila op reis naar Centraal en Zuid Amerika waar hij onder andere werkte in El Salvador en eindigde in Venezuela. Samen met zijn vrouw schreef hij 188 publicaties over bladhaantjes, werken die tot op heden nog zeer relevant zijn. De collectie van Bechyné in het KBIN bestaat uit 18 volle insectendozen en werd in de periode juni – september 2017 gedigitaliseerd door BINCO. In deze collectie bevinden zich 2.797 specimens van in totaal 89 soorten. BINCO koppelde deze soortdata met records uit de literatuur om zo tot een checklist te komen van de bladhaantjes van El Salvador.

Op dit moment zijn er 420 soorten gekend van El Salvador waarvan er 33 konden worden toegevoegd door dit digitalisatieproject. Met deze studie creëert BINCO een nieuwe basis voor onderzoek naar Centraal-Amerikaanse bladhaantjes.

De resultaten werden gepubliceerd in het wetenschappelijke tijdschrift ZooKeys en kan hier worden gelezen.


Verspreiding en identificatie van graanhaantjes in Vlaanderen

Graanhaantjes, een genus binnen de bladhaantjes (Coleoptera: Chrysomelidae – Oulema spp.) zijn welgekende pestsoorten van graangewassen in het noordelijk halfrond. Door zeer kleine verschillen in morfologie tussen de soorten in dit genus blijft soort identificatie een uitdaging. Aangezien deze soorten een differentiële fenologie kunnen hebben en dus de datum van bestrijding afhankelijk is van de dominante soort, is het nochtans belangrijk om de soortsamenstelling te kennen. Hierdoor kan ook worden gezocht naar selectieve controlestrategieën zonder een overdaad aan pesticiden te gebruiken.

BINCO bestudeerde mee de verspreiding en soortsamenstelling van graanhaantjes in Vlaanderen. De soortsamenstelling in graanvelden werd bemonsterd overheen drie opeenvolgende jaren. We vonden drie soorten die frequent aanwezig zijn; O. melanopus, O. duftschmidi en O. obscura. Door middel van discriminantanalyse toonde we aan dat deze soorten vrij betrouwbaar geïdentificeerd kunnen worden op basis van metingen van lichaamsdelen (zoals lengte en breedte van het dekschild), maar dat controle aan de hand van genitaliënstructuur nog steeds wenselijk is.

De populatie-densiteiten waren zeer variabel binnen en tussen jaren. Dit zal gerichte controle vermoeilijken en vereist een adequaat grote en spatiaal en temporeel gespreide staalname.

De resultaten van dit project werden gepubliceerd in het wetenschappelijk tijdschrift Environmental Entomology en kunnen hier worden bekeken.

Foto: Hilde Christiaens, dit project werd gefinancierd door VLAIO-LA


Boek: Orchids of the Maltese Islands - een beschrijvende veldgids

In 2016 startten BINCO en Greenhouse Malta het Malta Biodiversity Initiative (MABIMO). MABIMO streeft naar het opstellen van een gestandaardiseerd biodiversiteitmonitoringsnetwerk op de Maltese eilanden. Via dit netwerk zullen we de nodige informatie kunnen verzamelen om na te gaan welke soorten op de eilanden aanwezig zijn, waar ze voorkomen en hoe de populaties evolueren in de tijd om zo de verschillende soortgroepen gericht te kunnen beschermen indien nodig.

MABIMO werd opgestart met de monitoring van een selectie soortgroepen, waarvan de orchideeën er één zijn.  Vrijwilligers werden ingeschakeld bij het verzamelen van verspreidingsgegevens van orchideeën om zo de basis te leggen voor het opstellen van een rode lijst van bedreigde soorten in Malta.

Het boek ‘Orchids of the Maltese Islands - a descriptive guide’, geschreven door Stephen Mifsud in samenwerking met Greenhouse en BINCO, is een product van dit ‘citizen science’ project en kan beschouwd worden als een zeer waardevolle bijdrage aan de actuele kennis van de orchideeën van Malta. Deze veldgids omvat alle gekende soorten orchideeën van de Maltese eilanden waarvan enkele tot dusver onbekend voor deze eilandengroep. Naast gedetailleerde morfologische beschrijvingen en identificatiesleutels aangevuld met fotomateriaal, bevat het boek ook informatie over verspreiding, morfologische variatie, geschiedenis, bloeiperiode, gekende bestuivers etc.

Als je ooit van plan bent om Malta te bezoeken in de lenteperiode, dan kan dit boek een waardevolle gids zijn om je te helpen bij het op naam brengen van de vele prachtige soorten orchideeën die bloeien op de Maltese eilanden.

Het boek kan online besteld worden bij grotere verkopers van veldgidsen zoals NHBS en BDL.


Intensification of forest for coffee production affects mammals in Ethiopia

Onze verontschuldigingen, dit bericht is alleen beschikbaar in het Engels.


Een nieuwe soort boktor van Cusuco National Park – Honduras

Cusuco National Park ligt in het noordwesten van Honduras in de Sierra del Merendón en bestaat voornamelijk uit nevelwoud. Zoals het geval in grote delen van Honduras vormt ontbossing ook hier een grote bedreiging voor de biodiversiteit, waaronder vele endemische soorten. De beschrijving van nieuwe soorten zoals Derobrachus cusucoensis, een charismatische nieuwe soort boktor, draagt bij aan de ecologische valorisatie van het gebied.

Derobrachus cusucoensis is zelfs voor een boktor een indrukwekkende verschijning en komt vaak af op de lichtvallen die gebruikt worden als deel van de jaarlijkse multisoorten-monitoring door Operation Wallacea. BINCO werkt samen met Operation Wallacea in hun projectgebieden en specialiseert zich daar in het documenteren van de kleinere en minder bestudeerde soortgroepen. Het doel is om deze elementaire soortgegevens op verschillende niveaus in te zetten om unieke ecosystemen zoals de nevelwouden van Cusuco beter te kunnen beschermen. De soort werd beschreven in het wetenschappelijke tijdschrift Zootaxa en kan hier worden bekeken.