| Coordinators:Albert de Jong
 Leon Kelder
 Roland-Jan Buijs
 Thijs Horst
 Merijn Loeve
 Mars Muusse
 Home Project InfoInternational trend
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 Fecundity
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 | Caspian Gull cachinnans  C:M 1CY, July 18 2025, De Kreupel colony, the Netherlands.  Picture:  Thijs Horst & Mars Muusse.
        
          | You can participate in this project too! 
            Please send in your observations of colour ringed birds to: ring@buijsecoconsult.nl |  Tibia  Y-C:M and metal Arnhem NLA 5.633.759, ringed as  pullus Larus cachinnans on May 16 2025 at IJsselmeer (De Kreupel), Holland (5247.00 N 513.00 E), by ringer Leon Kelder. Recoveries:18-07-2025 IJsselmeer (De Kreupel), Noord-Holland, NL 5.247,00 N 513,00 E colourring read T. Horst & M. Muusse
 Data for nest H2 - 2025. 
        
        
        
        
        
        
        
        
        
        
        
        
          | Metal    ring | Colour ring | Date | Species | Age | Clutch size | Location | Nest code | Ringer | Head+Bill | Mass | Wing | Parents |  
          | NLA 5633758 | y-C:L | 16-5-2025 | Caspian Gull | pullus | 1 egg | the Netherlands, De Kreupel - eiland H. | H2 | Leon Kelder | 60,0 | 106,0 |  |  |  
          | NLA 5633759 | y-C:M | 16-5-2025 | Caspian Gull | pullus | 1 egg | the Netherlands, De Kreupel - eiland H. | H2 | Leon Kelder | 68,0 | 176,0 |  |  |  below: Caspian Gull cachinnans  C:M 1CY, July 18 2025, De Kreupel colony, the Netherlands.  Picture:   Thijs Horst & Mars Muusse.
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