Batumi Raptor Count (BRC) - Autumn migration data
Citation
Wehrmann J, de Boer F, Vansteelant W, Creuwels J (2020). Batumi Raptor Count (BRC) - Autumn migration data. Version 1.6. Batumi Raptor Count. Sampling event dataset https://doi.org/10.15468/ur0vnh accessed via GBIF.org on 2024-01-26.Description
One of the most important geographical bottlenecks for migrating raptors in the east African-Palearctic migration system is situated between the easternmost tip of the Black Sea and the Lesser Caucasus, just north of Batumi, in the Republic of Georgia (Verhelst et al. 2011). Since 2008 citizen scientists of the Batumi Raptor Count(BRC) monitor the autumn raptor passage daily from mid August till mid October, collecting also detailed information about the age and sex of focal species. These data are included in the BRC dataset. This dataset offers a unique baseline for monitoring the state of migrant raptor populations in the east African-Palearctic flyway in the 21st century. Each season a large number of raptors are counted during the autumn migration count. The numbers fluctuate around the million individuals in each season. This dataset represent the data during the 2008-2019 seasons. A detailed description of the BRC migration count protocol, data management strategy, and the open access BRC dataset in GBIF are provided by Wehrmann et al. (2019). This dataset has been used to analyse changes in the abundance and demography of eight abundant raptor species at BRC between 2011-2017. The resulting research paper is currently in 2nd review and will be shared through this webpage immediately upon publication.Purpose
Monitoring the abundance, demography and timing of migrant raptors and selected threatened species in the East African-Palearctic flyway. In addition the data collected may be useful for studying the influence of weather on diel and seasonal migration dynamics of soaring birds.Sampling Description
Study Extent
The villages Sakhalvasho and Shuamta, North of Batumi, in the Republic of Georgia.Sampling
Daily counts from 17st August till 16st October. The daily count period starts at one hour after sunrise and ends two hours before sunset. Counts consisted of continuous monitoring during the count period and recording all occurrences.Quality Control
Counts are conducted by experienced and less experienced bird-watchers that volunteer to count at least two weeks. Count-coordinators screen, select and schedule volunteers such that each station can be staffed by a team consisting of one coordinator and 6 to 12 counters, depending on migration intensity, diversity and also counter availability. We try to enter records always immediately to enable the double count detection in later phase. Digital photography has become an important tool to aid identification of easily confused species.Method steps
- At the end of each day count-coordinators go through the records to check for major errors (using simple criteria such as large flocks of rare birds, or specific age and sex combinations), and where possible correct them by discussing these observations with their daily count team. Observations that are suspect due to insufficient information (for example, a large eagle cannot be identified without being aged) are degraded to a less specific level (large eagle spec.).
- At the end of each season the data is verified with an automated script in the open source R software (R Core Team 2017) that validates each single record, ensures count protocol integrity and changes the identification of the species-level of those records with insufficient information.
- An important final step in the production of the NLBIF data product is to detect all double counts in the overlapping count zones between the two stations. An automated procedure written in R detects potential double counts in different spatial and temporal windows for different species.
Additional info
Information about killed and injured birds during the Autumn raptor monitoring is given in the extension ExtendedMeasurementOrFact. Due to a technical error (which is under review at GBIF) this extension does not automatically link data in this extension with the occurrence dataset. Therefore these data will not be shown at the GBIF portal. However, these data can be retrieved from DwCA in the file "extendedmeasurementorfact.txt".Taxonomic Coverages
Soaring birds and few others such as Roller
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Accipitriformescommon name: Raptors rank: order
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Coracias garruluscommon name: European Roller rank: species
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Streptopelia turturcommon name: European turtle dove rank: species
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Ciconia ciconiacommon name: White Stork rank: species
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Ciconia nigracommon name: Black Stork rank: species
Geographic Coverages
The bottleneck is situated at the narrowest point between the eastern coast of the Black Sea and the foothills of the Lesser Caucasus, just to the north of the city of Batumi, in the Republic of Georgia.
Bibliographic Citations
- Wehrmann J, de Boer F, Benjumea R, Cavaillès S, Engelen D, Jansen J, Verhelst B, Vansteelant WMG (2019) Batumi Raptor Count: autumn raptor migration count data from the Batumi bottleneck, Republic of Georgia. ZooKeys 836: 135-157. - https://doi.org/10.3897/zookeys.836.29252
- Verhelst B, Jansen J, Vansteelant WMG (2011) South West Georgia: an important bottleneck for raptor migration during autumn. Ardea 99: 137–146. - https://doi.org/10.5253/078.099.0203
Contacts
Jasper Wehrmannoriginator
BRC Foundation
Hannah Arendtweg 84
Almere
1349CM
NL
email: jasper.wehrmann@batumiraptorcount.org
homepage: http://www.batumiraptorcount.org
Folkert de Boer
originator
BRC Foundation
Hannah Arendtweg 84
Almere
1349CM
NL
email: folkert.deboer@batumiraptorcount.org
Wouter Vansteelant
originator
BRC Foundation
Hannah Arendtweg 84
Almere
1349CM
NL
email: wouter.vansteelant@batumiraptorcount.org
Jeroen Creuwels
originator
position: Data manager NLBIF
Naturalis
PO Box 9517
Leiden
NL-2300 RA
NL
Telephone: +31.71.7519632
email: nlbif@naturalis.nl
homepage: https://www.nlbif.nl
userId: http://orcid.org/0000-0001-6131-7026
metadata author
BRC Foundation
Dijkgraaf 35
Bennekom
6721 NJ
NL
email: monitoring@batumiraptorcount.org
homepage: http://www.batumiraptorcount.org
Niels Raes
processor
position: Node manager NLBIF
NLBIF
PO Box 9517
Leiden
NL-2300 RA
NL
Telephone: +31 71 7519362
email: nlbif@naturalis.nl
homepage: https://www.nlbif.nl/
userId: http://orcid.org/0000-0002-4329-4892
Frank de Miranda
administrative point of contact
position: Voorzitter
Stichting DuGof
IJskelderlaan 3
DOORN
3941 HS
NL
email: frank.demiranda@outlook.com
homepage: http://dugof.nl/
Jasper Wehrmann
administrative point of contact
BRC
Hannah Arendtweg 84
Almere
1349 CM
NL
email: jasper.wehrmann@batumiraptorcount.org
homepage: http://www.batumiraptorcount.org
Folkert de Boer
administrative point of contact
BRC Foundation
Hannah Arendtweg 84
Almere
1349CM
NL
email: folkert.deboer@batumiraptorcount.org