Données d'échantillonnage

Batumi Raptor Count (BRC) - Autumn migration data

Dernière version Publié par Batumi Raptor Count le 16 juin 2020 Batumi Raptor Count
Date de publication:
16 juin 2020
Publié par:
Batumi Raptor Count
CC0 1.0

Téléchargez la dernière version de la ressource en tant qu'Archive Darwin Core (DwC-A), ou les métadonnées de la ressource au format EML ou RTF :

Données sous forme de fichier DwC-A (zip) télécharger 725 enregistrements dans Anglais (13 MB) - Fréquence de mise à jour: annuel
Métadonnées sous forme de fichier EML télécharger dans Anglais (17 KB)
Métadonnées sous forme de fichier RTF télécharger dans Anglais (16 KB)


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 2008-2017 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.

Enregistrements de données

Les données de cette ressource données d'échantillonnage ont été publiées sous forme d'une Archive Darwin Core (Darwin Core Archive ou DwC-A), le format standard pour partager des données de biodiversité en tant qu'ensemble d'un ou plusieurs tableurs de données. Le tableur de données du cœur de standard (core) contient 725 enregistrements.

2 tableurs de données d'extension existent également. Un enregistrement d'extension fournit des informations supplémentaires sur un enregistrement du cœur de standard (core). Le nombre d'enregistrements dans chaque tableur de données d'extension est illustré ci-dessous.

Event (noyau)

Cet IPT archive les données et sert donc de dépôt de données. Les données et métadonnées de la ressource sont disponibles pour téléchargement dans la section téléchargements. Le tableau des versions liste les autres versions de chaque ressource rendues disponibles de façon publique et permet de tracer les modifications apportées à la ressource au fil du temps.


Le tableau ci-dessous n'affiche que les versions publiées de la ressource accessibles publiquement.

Comment citer

Les chercheurs doivent citer cette ressource comme suit:

Wehrmann J, de Boer F, Benjumea R, Cavaillès S, Engelen D, Jansen J, Verhelst B, Creuwels JCS, Vansteelant WMG (2018): Batumi Raptor Count (BRC) - Autumn migration data. v1.2. Batumi Raptor Count. Dataset/Samplingevent.


Les chercheurs doivent respecter la déclaration de droits suivante:

L’éditeur et détenteur des droits de cette ressource est Batumi Raptor Count. En vertu de la loi, l'éditeur a abandonné ses droits par rapport à ces données et les a dédié au Domaine Public (CC0 1.0). Les utilisateurs peuvent copier, modifier, distribuer et utiliser ces travaux, incluant des utilisations commerciales, sans aucune restriction.

Enregistrement GBIF

Cette ressource a été enregistrée sur le portail GBIF, et possède l'UUID GBIF suivante : d19c0287-15ee-45fd-b810-d30e8026a785.  Batumi Raptor Count publie cette ressource, et est enregistré dans le GBIF comme éditeur de données avec l'approbation du Netherlands Biodiversity Information Facility.


Occurrence; Autumn migration; raptor; African-Palearctic flyway; monitoring


Personne ayant créé cette ressource:

Jasper Wehrmann
BRC Foundation
Hannah Arendtweg 84
1349CM Almere
Folkert de Boer
BRC Foundation
Hannah Arendtweg 84
1349CM Almere
Wouter Vansteelant
BRC Foundation
Hannah Arendtweg 84
1349CM Almere
Jeroen Creuwels
Data manager NLBIF
PO Box 9517
NL-2300 RA Leiden

Personne pouvant répondre aux questions sur la ressource:

Jasper Wehrmann
Folkert de Boer
BRC Foundation
Hannah Arendtweg 84
1349CM Almere

Personne ayant renseigné les métadonnées:

BRC Foundation
BRC Foundation
Dijkgraaf 35
6721 NJ Bennekom

Autres personnes associées à la ressource:

Niels Raes
Node manager NLBIF
PO Box 9517
NL-2300 RA Leiden
+31 71 7519362
Frank de Miranda
Stichting DuGof
IJskelderlaan 3

Couverture géographique

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.

Enveloppe géographique Sud Ouest [41,684, 41,699], Nord Est [41,688, 41,802]

Couverture taxonomique

Soaring birds and few others such as Roller

Order Accipitriformes (Raptors)
Species Coracias garrulus (European Roller), Streptopelia turtur (European turtle dove), Ciconia ciconia (White Stork), Ciconia nigra (Black Stork)

Couverture temporelle

Epoque de formation mid Aug to mid Oct annually from 2008 till present.

Données sur le projet

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. Counts are focused on high-quality data for monitoring of target species, and for which species we can provide high-quality data useful for trend analyses.

Titre Batumi Raptor Counts - Autumn migration data
Financement NLBIF partly funded publication and processing of the BRC dataset to GBIF
Description du domaine d'étude / de recherche The two count stations are located on hilltops with unobstructed view facing north into the landscape, and within visible range from each other. Locations are the villages Sakhalvasho and Shuamta, North of Batumi, in the Republic of Georgia, between the easternmost tip of the Black Sea and the Lesser Caucasus.
Description du design Migration counts are performed simultaneously from two count stations to cover the approximately 12km long transect line.

Les personnes impliquées dans le projet:

Jasper Wehrman
Personne de Contact

Méthodes d'échantillonnage

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.

Etendue de l'étude The villages Sakhalvasho and Shuamta, North of Batumi, in the Republic of Georgia.
Contrôle qualité 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.

Description des étapes de la méthode:

  1. 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.).
  2. 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.
  3. 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.

Citations bibliographiques

  1. 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.
  2. Verhelst B, Jansen J, Vansteelant WMG (2011) South West Georgia: an important bottleneck for raptor migration during autumn. Ardea 99: 137–146.

Métadonnées additionnelles

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".

Objet 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.
Description de la fréquence de mise à jour Dataset is annually maintained.
Identifiants alternatifs d19c0287-15ee-45fd-b810-d30e8026a785