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Publications
Publications (55)
First report of Ophidiomyces ophidiicola in wild barred grass snakes
(Natrix helvetica) in the Netherlands
Ophidiomyces ophidiicola is the causative agent of ophidiomycosis (also
called snake fungal disease) and has been associated with mycosis in
individual snakes and population declines in several North American
snake species. While cases of ophi...
On the occurrence of Pituophis hybrids in the Dutch coastal dunes Since 2013 Pituophis hybrids have been observed in Natura2000 site Meijendel & Berkheide annually. These animals must have been purposely introduced by private persons. A total of 129 observations have been registered from a maximum of 91 individuals. Fourteen specimens have been enc...
In een eerder artikel noemden wij dat er in het Westduinpark bij den Haag met behulp van mtDNA-barcoding twee verschillende uitheemse boomkikkersoorten zijn aangetroffen, namelijk de oostelijke boomkikker (H. orientalis) en de Italiaanse boomkikker (H. intermedia). Bij nader onderzoek kan alleen de aanwezigheid van H. intermedia in het Westduinpark...
Ophidiomyces ophidiicola is the causative agent of ophidiomycosis (also called snake fungal disease) and has been associated with mycosis in individual snakes and population declines in several North American snake species. While cases of ophidiomycosis from North America have been numerous in the past two decades, reports from Europe remain sparse...
In 2019 werd langs een amfibieënscherm tegen de duinen bij Callantsoog volstrekt onverwachts een knoflookpad in een valemmer gevonden. Een jaar later maakten gerichte luister-en zoekacties duidelijk dat zich hier een populatie gevestigd had. In 2021 is daarom aanvullend onderzoek uitgevoerd. Aandachtspunten daarbij waren de verspreiding, de voortpl...
Many herpetofauna species have been introduced outside of their native range. MtDNA barcoding is regularly used to determine the provenance of such populations. The alpine newt has been introduced across the Netherlands, the United Kingdom and Ireland. However, geographical mtDNA structure across the natural range of the alpine newt is still incomp...
Van boomkikkers, vroedmeesterpadden en kamsalamanders zijn duinpopulaties van dubieuze herkomst bekend in Nationaal Park Hollandse Duinen. Leidse biologiestudenten hebben aan de hand van DNA de geografische oorsprong van deze populaties getraceerd. Hun resultaten zijn onlangs gepubliceerd als een reeks artikelen in het wetenschappelijke tijdschrift...
In Nederland komen van nature drie groene kikkersoorten voor: de meerkikker (Pelophlylax ridibundus), poelkikker (P. lessonae) en bastaardkikker (P. klepton esculentus). De bastaard-kikker is een (stabiele) hybride soort tussen de meerkikker en de poelkikker. Er wordt ook wel gesproken over het 'groene kikker complex'. Het geslacht Pelophylax omvat...
Omstreeks 2000 deed de 'boomkikker' haar intrede in de duinen van Meijendel. Sindsdien is de soort enorm uitgebreid, zowel in aantal als verspreiding. De complete duinstrook tussen Katwijk en Scheveningen is in 15 jaar gekoloniseerd. Met name Meijendel werd voor liefhebbers en fotografen een populaire bestemming vanwege de mogelijkheid om boomkikke...
In Nationaal Park Hollandse Duinen komen verschillende amfibieën voor waarvan vermoed wordt dat ze door de mens geïntroduceerd zijn. Het gaat hier om de 'boomkikker', de Vroedmeesterpad en de Kamsalamander. In het voorjaar van 2021 gingen Leidse biologen de duinen in om DNA-monsters te verzamelen. Het doel van hun onderzoek was om te achterhalen wa...
Invasive species are considered one of the main drivers of the sixth mass extinction. Conservation solutions depend on whether a species is also indigenous to the country it invades (i.e., beyond its native range). In the case of invasive cryptic species, genetic tools are required to establish their identity. We illustrate these issues with the hu...
Species that are threatened in their native range may actually prosper as introduced populations. To investigate how such introduced populations were established involves determining from where within the natural range the founder individuals originated. This can be accomplished through mtDNA barcoding. The common spadefoot toad (Pelobates fuscus)...
The North American terrapin, the red-eared slider, has globally recognized invasive status. We built a new extensive database using our own original and literature data on the ecology of this reptile, representing information on 1477 water bodies throughout Eurasia over the last 50 years. The analysis reveals regions of
earliest introductions and l...
For most if not all European herpetofauna, range-wide mtDNA phylogeographies have been published. This facilitates establishing the provenance of introduced populations. However, precision is contingent on the spatial genetic structure across the range of the taxon under study and, in particular, from where within that range the introduction was so...
Isolated distribution patches may represent local remnants of a formerly wider range or could have originated by human-mediated expansion beyond the natural range. Distinguishing between these two scenarios is not always straightforward. Northern crested newts ( Triturus cristatus ) in the Dutch coastal dunes are disconnected from the main species...
Smaragdhagedissen hebben een wijde verspreiding in Zuid-en Centraal-Europa en Klein-Azië. De meest noordelijke populaties bevinden zich in het oosten en westen van Duitsland. Dit zijn geïsoleerde relictpopulaties van respectievelijk de oostelijke smaragdhagedis (Lacerta viridis) en de westelijke smaragdhagedis (L. bilineata). Enkele losse waarnemin...
Chelonian reproduction in the Netherlands
Fertility of eggs from free-ranging exotic Trachemys scripta ssp. in the
Netherlands has been recorded with (minimum) fertility rates between
0 and 100%. Additionally , embryonic development has been detected
up to phase 21 (of 27). The finding of a freshly hatched juvenile T. scripta
is considered a likely...
The Netherlands harbours seven autochtonous reptile species and 16 amphibian species. Several invasive alien species have established in recent years. Lacerta bilineata seems to have disappeared again, due to spatial developments. The American bullfrog (Lithobates catesbeianus), has been eliminated successfully. Some of the exotics that survive, ar...
Biological invasions are recognized as one of the global problems accompanying the development of human civilization. The red-eared slider, Trachemys scripta elegans, originates from North America. This freshwater terrapin is one of the most popular pet reptiles in Eurasia. Young red-eared slider individuals are small and brightly colored, making t...
Reptiles contribute to the global process of biological invasions, one of the problems
accompanying the development of human civilization. The red-eared slider, Trachemys
scripta elegans is one of the most popular pet reptiles in the world. Uncontrolled releases of this animal into outdoor water bodies represents a conservational issue. We combined...
In 1994 an unknown number of captive bred Russian rat snakes, Elaphe schrenckii (Strauch, 1873) were introduced near Groningen Airport Eelde (Drenthe Province), the Netherlands. Research in 2016/2017 confirmed that the species has become established and is expanding slowly, as recent sightings are known at distances up to 5.3 km from the initial re...
Striped grass snakes in the Netherlands - Genetics, background and
risks
The barred grass snake Natrix helvetica is native to the Netherlands. The
closely related grass snake N. natrix was long suspected to have been
introduced at multiple sites in the Netherlands, based on observations
of individuals that possess lateral stripes (characteristic of...
Trachemys scripta is widely distributed in The Netherlands. All three subspecies (Trachemys scripta elegans, T. s. scripta and T. s. troostii) are encoutered. How are these subspecies faring in the Netherlands?
We determined the occurrence of multiple paternity and minimum number of fathers in eight clutches of the endangered E. schrenckii in South Korea using offspring obtained from a captive breeding program between 2014 and 2016. By examining five microsatellite loci and comparing the result with the characteristics of mother, egg and offspring we foun...
Captive rearing programs have been initiated to save the European common spadefoot (Pelobates fuscus), a toad species in the family of Pelobatidae, from extinction in The Netherlands. Evaluating whether this species needs ultraviolet B (UVB) radiation and/or dietary supplementation for healthy bone development is crucial for its captive management...
Ranavirus is a genus of viruses, in the family Iridoviridae, that are known to have the potential to adversely affect fish, amphibians, and reptiles. Ranaviruses are associated with large-scale die-offs and rapid population declines in amphibians. The development and progression of an outbreak, however, varies greatly depending on the host species...
Translocation of reptiles before widening motorway
Special attention had to be given to reptile species present in the road verges of the A12 when plans were made by Rijkswaterstaat (organization responsible for design, construction, management and maintenance of the main infrastructure in the Netherlands) to widen the motorway that runs through t...
Ranavirus is a genus of viruses, in the family Iridoviridae, that are known to have the potential to adversely affect fish, amphibians, and reptiles. Ranaviruses are associated with large-scale die-offs and rapid population declines in amphibians. The development and progression of an outbreak, however, varies greatly depending on the host species...
![Fig. [Abb.] 1: Geographical distribution of Cuora mouhotii (Vietnam...](profile/Richard-Struijk/publication/318653735/figure/fig1/AS:614402780835840@1523496446899/Fig-Abb-1-Geographical-distribution-of-Cuora-mouhotii-Vietnam-trade-records-are_Q320.jpg)
A case of intergradation in captivity between the two currently recognized subspecies of Cuora mouhotii is described. Parental specimens are a male C. m. mouhotii and a female C. m. obsti. Two examined intergrades show intermediate features, especially with regard to plastral colour patterns. This case represents the first reliable characterization...
“Cuora serrata” is a collective noun for hybrids between members of the galbinifrons-complex and C. mouhotii sensu lato. However, hybrids with C. picturata lineage have not been described yet. We present the first cases of such hybrids. Also, a first locality for such hybrids is described in Phu Yen province, Vietnam.
The Keeled Box Turtle, Cuora mouhotii (Family Geoemydidae), is a small (carapace
length up to ca. 250 mm), once poorly-known terrestrial species. Recent extensive research on the
species in its natural habitat in northern Vietnam and Hainan, China, has significantly increased
available knowledge of the species. Cuora mouhotii is a highly terrestria...
Many reptiles encounter roads when making seasonal movements, while other species are attracted to roads for foraging, nesting or temperature regulation.2Most reptiles are poor at evading oncoming vehicles, and many drivers are poor at detecting or avoiding reptiles.3Turtles, many snakes and some lizards have biological traits that cause their popu...
Herpetoduct Elspeetsche Heide: de nieuwe standaard voor herpetofauna? Het intensief gebruikte Nederlandse landschap is voor veel diersoorten versnipperd. De laatste jaren wordt deze versnippering aangepakt door aanleg van ecoducten en andere faunapassages. Dit artikel behandelt de resultaten van een nieuw type faunapassage: het herpetoduct, zoals d...
In 2001 werd het landelijk Beschermingsplan Knoflookpad opgesteld. Wat is er sindsdien gedaan om de stand van de Knoflookpad te verbeteren en tot welke resultaten heeft dat geleid? Wat betekent dit voor de toekomst? Waar liggen de kansen voor de Knoflookpad? In een drietal artikelen komen achtereenvolgens aan bod: de historie van de Knoflookpad in...
A loss of habitat connectivity is often caused by roads. In order to mitigate isolation effects crossing structures such as culverts are frequently used. Because herpetofauna in particular is vulnerable to the negative aspects of habitat fragmentation, functioning crossing structures are of utmost importance. However, little is known about their us...
Risk analysis of Rana dalmatina in The Netherlands. This species is introduced in the north of the country. The risk of this species is categorised as being low.
Introduction Within the European Studbook Foundation (ESF, www.studbooks.org) there are eight Cuora studbooks. All current Cuora species are represented except Cuora yunnanensis which was thought to be extinct for a long time. Recently though, new initiatives of expeditions to find the species in the wild are taken (PHILIPPEN, pers. comm.) as pictu...
