The Dutch reptile populations are being monitored intensively within the scope of the Dutch Network Ecological Monitoring (NEM). Since 1994 volunteers, coordinated by RAVON (Reptile, Amphibian and Fish Conservation Netherlands), monitor reptiles on an annual base. All seven indigenous species are monitored on transects that are examined seven times a year. The data are used to monitor population trends and patterns and to support legal reporting obligations, scientific research and policy and conservation related issues. Locality data for GBIF are provided on a 5 x 5 km scale.
The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 5,625 records.
This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.
The table below shows only published versions of the resource that are publicly accessible.
How to cite
Researchers should cite this work as follows:
Janssen I (2021): RAVON (NL) - Network Ecological Monitoring Reptiles. v1.13. Reptile, Amphibian and Fish Conservation Netherlands (RAVON). Dataset/Occurrence. http://ipt.nlbif.nl/resource?r=ravon_nem_rep&v=1.13
Researchers should respect the following rights statement:
The publisher and rights holder of this work is Reptile, Amphibian and Fish Conservation Netherlands (RAVON). This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License.
This resource has been registered with GBIF, and assigned the following GBIF UUID: faf313a1-9ae4-43f4-bfc9-974281feac0e. Reptile, Amphibian and Fish Conservation Netherlands (RAVON) publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Netherlands Biodiversity Information Facility.
Occurrence; Observation; reptiles; The Netherlands; monitoring; trends; ecology; Occurrence
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|Bounding Coordinates||South West [50.63, 2.61], North East [53.64, 7.41]|
All indigenous reptile species in The Netherlands are included in the monitor network.
|Species||Anguis fragilis (Slow Worm), Lacerta agilis (Sand Lizard), Zootoca vivipara (Viviparous Lizard), Podarcis muralis (Common Wall Lizard), Coronella austriaca (Smooth Snake), Natrix natrix (Grass Snake), Vipera berus (Adder)|
|Start Date / End Date||1994-01-01 / 2015-12-31|
Transects are visited seven times a year under favourable weatherconditions. All encountered reptiles are counted.
|Study Extent||Transects are monitored within a two hour timespan. A transect typically consist of only one habitat type.|
|Quality Control||The raw data are validated by the coordinator. Statistics Netherlands (CBS) runs an extensive control of the monitor data before calculating trends and indices.|
Method step description:
- Trends and indices are calculated by Statistics Netherlands (CBS) using the TRIM-software package. This dataset summarizes the observations per km2 for each year in an occurrence value per species.