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Evolution of populations of coastal breeders at the inner port of Zeebrugge: breeding success [Evolutie van populaties van kustbroedvogels in de voorhaven van Zeebrugge: broedsucces]
Data Institute for Nature Conservation
Contact: Stienen, Eric

Availability: Unrestricted after moratorium period
Data are initially restricted, but the access condition relaxes to academic or unrestricted once a specified period of time after an event (such as collection, publication, completion of QC procedures or project cessation) has elapsed

Dataset as a result of determining breeding success and biometrics of eggs and chicks within 30 to 40 enclosed (chicken wire 50 cm height) nests in the outer harbour of Zeebruges. more

From the moment onwards that the birds are landing on the breeding sites on a regular basis and the digging of nest holes is observed, the breeding sites in Zeebruges are regularly checked for the presence of eggs. The date of the first encounter of eggs in the nest is noted. The nests are marked with a (bamboo) stick and a label containing the nest number. The eggs are marked using permeable inkt by writing the egg and nest number on the top of each egg. This makes it possible to determine afterwards wheter an egg has hatched or has been predated. The marked nests are checked at regular time intervals. All possible information on the fate of the eggs is noted. This way it is possible to keep track of the eggs and nests and to determine things like hatching and breeding succes of the marked nests. Chick weight is measured with an electronic balance to a precision of 1 g. Egg size, total head length and stretched wing chord is measured using a calliper with precision of 0,1 mm. At certain locations enclosures are placed around concentrations of marked nests. This method is applied to keep the chicks of semi-nest leavers on a fixed location so they can be easily observed and retrieved until the moment of flying out. An enclosure is a fence of chicken wire (+/-50 cm height) that is attached to wooden bars surrounding a number of nests. At the bottom of the fence at the inside of the enclosure a folio (20cm height) is attached to prevent the chicks from damaging theirselfs. The chicken wire has to be doug into the ground for a few centimeters to prevent the chicks to escape. Maximum once in the 2 or 3 days and minimum once a week, the chicks in the enclosures are checked. Chicks that are over 20 days old at the moment of checking and that have dissapeared from the enclosure, are considered to have flown out. If they are already missing at an earlier age, they are noted as ‘disappeared’. In most cases this means they have been predated. The enclosure method is applied in several European colonies and this makes the data immediately comparable.

Biology, Biology > Birds, Coastal studies (e.g. shores, estuaries)
Marine/Coastal, Terrestrial, Birds, Birds (marine), Breeding birds, Breeding success, Clutch size, Stock assessment, ANE, Belgium, Belgian Coast, ANE, Belgium, Brugge, Zeebrugge, Larus ridibundus Linnaeus, 1766, Sterna hirundo Linnaeus, 1758, Sterna sandvicensis Latham, 1787

Geographical coverage
ANE, Belgium, Belgian Coast [Marine Regions]
ANE, Belgium, Brugge, Zeebrugge [Marine Regions]

Temporal coverage
May 2002 - 21 July 2002
May 2003 - 21 July 2003

Taxonomic coverage
Larus ridibundus Linnaeus, 1766 [WoRMS]
Sterna hirundo Linnaeus, 1758 [WoRMS]
Sterna sandvicensis Latham, 1787 [WoRMS]

Biometrics of chicks Methodology , Breeding success Methodology , Clutch size Methodology , Egg size Methodology , Fledging success Methodology , Hatching success Methodology
Biometrics of chicks: Measuring of weight and total head length
Chick weight is measured with an electronic balance to a precision of 1 g. Total head length is measured using a calliper with precision of 0,1 mm.
Breeding success: Calculation of breeding succes
Product of: clutch size * haching success * fledging succes.
Clutch size: Count of eggs per nests
Number of eggs per nest are counted in 30 to 40 individual enclosed nests in a representative area of the colony. Counted nests are marked and counted eggs are marked.
Egg size: Measuring of maximum length and width
measurements are carried out using a calliper at a precision 0,1mm.
Fledging success: Count of % of hatched eggs that actually fledged
Cause of loss is noted: predation, found death (starvation or dehydratation). Rule for success of fledging is that winglength exceeds 160 mm for Common tern and 180 mm for Sandwich tern and Black headed gull.
Hatching success: Count of percentage of hatched eggs
Cause of loss are noted: predation, trampling, flooding. Hachlings are ringed individually within 3 days from hatching.

Belgian Science Policy (BELSPO), moredata owner
Vlaamse overheid; Beleidsdomein Leefmilieu, Natuur en Energie; Instituut voor Natuur- en Bosonderzoek; Afdeling Biodiversiteit en Natuurlijk Milieu; Onderzoeksgroep Ecosysteemdiversiteit, moredata creatordata managertaxonomic identifier
Vlaamse overheid; Beleidsdomein Omgeving; Instituut voor Natuur- en Bosonderzoek (INBO), moredata owner

Related datasets
Parent dataset:
Evolution of populations of coastal breeders at the inner port of Zeebrugge, more
Child datasets:
Evolution of populations of coastal breeders at the inner port of Zeebrugge: breeding success: biometry of chicks, more
Evolution of populations of coastal breeders at the inner port of Zeebrugge: breeding success: eggsize, more
(Partly) included in:
PROJECT DATA: Integrated data from projects PODOI and Trophos (1997-2006), more

TROPHOS: Higher trophic levels in the Southern North Sea, more

Based on this dataset
Provoost, S.; Stienen, E.; De Bruyn, L.; Herrier, J.-L. (2003). Kust, in: Dumortier, M. et al. Natuurrapport 2003: toestand van de natuur in Vlaanderen: cijfers voor het beleid. Mededelingen van het Instituut voor Natuur- en Bosonderzoek, 21: pp. 117-121, more
Van Waeyenberge, J.; Stienen, E.W.M. (2002). Broedsucces van sternen in de Zeebrugse voorhaven: overzicht van enkele resultaten van de Visdief. Vogelnieuws 1(3): 16-20, more
Van Waeyenberge, J.; Stienen, E.W.M.; Kuijken, E. (2002). Toekomstperspectieven voor kustbroedvogels in de voorhaven van Zeebrugge: adviesnota in het kader van de instandhouding van de populaties van kustbroedvogels. Advies van het Instituut voor Natuurbehoud, A.2002.231. Instituut voor Natuurbehoud: Brussel. 34 pp., more

Dataset status: Completed
Data type: Data
Data origin: Research
Metadatarecord created: 2004-05-10
Information last updated: 2010-11-05
All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy