Evento de muestreo

Batumi Raptor Count (BRC) - Autumn migration data

Última versión Publicado por Batumi Raptor Count en 16 de junio de 2020 Batumi Raptor Count
Fecha de publicación:
16 de junio de 2020
Published by:
Batumi Raptor Count
CC0 1.0

Descargue la última versión de los datos como un Archivo Darwin Core (DwC-A) o los metadatos como EML o RTF:

Datos como un archivo DwC-A descargar 725 registros en Inglés (13 MB) - Frecuencia de actualización: annual
Metadatos como un archivo EML descargar en Inglés (17 KB)
Metadatos como un archivo RTF descargar en Inglés (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.


Los datos en este recurso de evento de muestreo han sido publicados como Archivo Darwin Core(DwC-A), el cual es un formato estándar para compartir datos de biodiversidad como un conjunto de una o más tablas de datos. La tabla de datos del core contiene 725 registros.

también existen 2 tablas de datos de extensiones. Un registro en una extensión provee información adicional sobre un registro en el core. El número de registros en cada tabla de datos de la extensión se ilustra a continuación.

Event (core)

Este IPT archiva los datos y, por lo tanto, sirve como repositorio de datos. Los datos y los metadatos del recurso están disponibles para su descarga en la sección descargas. La tabla versiones enumera otras versiones del recurso que se han puesto a disposición del público y permite seguir los cambios realizados en el recurso a lo largo del tiempo.


La siguiente tabla muestra sólo las versiones publicadas del recurso que son de acceso público.

¿Cómo referenciar?

Los usuarios deben citar este trabajo de la siguiente manera:

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. http://ipt.nlbif.nl/resource?r=brc-autumn_migration_counts&v=1.2


Los usuarios deben respetar los siguientes derechos de uso:

El publicador y propietario de los derechos de este trabajo es Batumi Raptor Count. En la medida de lo posible según la ley, el publicador ha renunciado a todos los derechos sobre estos datos y los ha dedicado al Dominio público (CC0 1.0). Los usuarios pueden copiar, modificar, distribuir y utilizar la obra, incluso con fines comerciales, sin restricciones.

Registro GBIF

Este recurso ha sido registrado en GBIF con el siguiente UUID: d19c0287-15ee-45fd-b810-d30e8026a785.  Batumi Raptor Count publica este recurso y está registrado en GBIF como un publicador de datos avalado por Netherlands Biodiversity Information Facility.

Palabras clave

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


¿Quién creó el recurso?:

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

¿Quién puede resolver dudas acerca del recurso?:

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

¿Quién documentó los metadatos?:

BRC Foundation
BRC Foundation
Dijkgraaf 35
6721 NJ Bennekom

¿Quién más está asociado con el recurso?:

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

Cobertura geográfica

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.

Coordenadas límite Latitud Mínima Longitud Mínima [41,684, 41,699], Latitud Máxima Longitud Máxima [41,688, 41,802]

Cobertura taxonómica

Soaring birds and few others such as Roller

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

Cobertura temporal

Periodo de formación mid Aug to mid Oct annually from 2008 till present.

Datos del proyecto

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.

Título Batumi Raptor Counts - Autumn migration data
Fuentes de Financiación NLBIF partly funded publication and processing of the BRC dataset to GBIF
Descripción del área de estudio 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.
Descripción del diseño Migration counts are performed simultaneously from two count stations to cover the approximately 12km long transect line.

Personas asociadas al proyecto:

Jasper Wehrman
Punto de Contacto

Métodos de muestreo

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.

Área de Estudio The villages Sakhalvasho and Shuamta, North of Batumi, in the Republic of Georgia.
Control de Calidad 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.

Descripción de la metodología paso a paso:

  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.

Referencias bibliográficas

  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. https://doi.org/10.3897/zookeys.836.29252
  2. 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

Metadatos adicionales

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".

Propósito 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.
Descripción de mantenimiento Dataset is annually maintained.
Identificadores alternativos d19c0287-15ee-45fd-b810-d30e8026a785