hybrids from mixed colonies in central and western Europe

(last update: May 21, 2021)

Coordinators:
Jeroen Nagtegaal

The Netherlands

Colonization of the interior by the Lesser Black-backed Gull and Herring Gull

- an overview up to and including 2015 -

by: Jeroen Nagtegaal & Joost van Bruggen (IN: Limosa 91 (2018): 168-180)

Both Lesser Black-backed Gull (Larus fuscus) and Herring Gull (L. argentatus) have had a positive trend for a long time, but numbers were kept low by extensive control and egg collection until the late 1960s. Then, annual numbers for both species increased sharply by 30% and 14% respectively (Teixeira 1979), nowadays (2016) up to 100,000 breeding pairs for Lesser Black-backed Gull in the Netherlands. Since the turn of the century numbers seem to be levelling, partly by declining breeding success on the Wadden Islands and in the Delta (www.sovon.nl).

For Herring Gull the peak years were in the late 1980s and early 1990s with more than 90,000 breeding pairs, but since numbers have decreased dramatically to just over 40,000 pairs in 2013 (Boele et al. 2015). Although national trends of the Lesser Black-backed and Herring Gull differ greatly, they share resemblance in ecology, e.g. traditionally, both species occupy mixed colonies on the Wadden Islands and in the dunes.

Herring Gull was already described as a breeding bird by Nozeman (1797) on Texel, while Lesser Black-backed Gull is a relatively newcomer in the Netherlands, with first breeding described in 1926 on Boschplaat, Terschelling (Tanis 1963). More recently, both species also colonised the interior (figure 1). The purpose of this study is to provide an overview of the distribution, and in addition, to draw attention to report new breeding attempts to Sovon Bird Research Netherlands.

The study area and locations of colonies of Lesser Black-backed Gulls and Herring Gulls in the Netherlands between 2000 and 2015.

2cy michahellis in August, ringed in Switzerland.The study area and locations of colonies of Lesser Black-backed and Herring Gulls in the Netherlands between 2000 and 2015.
2cy michahellis in August, ringed in Switzerland.The study area and locations of colonies of Lesser Black-backed and Herring Gulls in the Netherlands between 2000 and 2015.
2cy michahellis in August, ringed in Switzerland.Herring Gull argentatus -- / HK adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
2cy michahellis in August, ringed in Switzerland.Yellow-legged Gull michahellis 9.4 adult, June 2017 & May 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
2cy michahellis in August, ringed in Switzerland.Yellow-legged Gull michahellis -- / HF adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-HM michahellis
2cy michahellis in August, ringed in Switzerland.Yellow-legged Gull michahellis -- / HH adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-CY F1 hybrid michahellis x argentatus
2cy michahellis in August, ringed in Switzerland.Yellow-legged Gull michahellis -- / HM adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-HF michahellis
2cy michahellis in August, ringed in Switzerland.F1 hybrid michahellis x argentatus -- / AL 4CY, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
2cy michahellis in August, ringed in Switzerland.F1 hybrid michahellis x argentatus -- / CY adult, May 2019 & May 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-HH michahellis
2cy michahellis in August, ringed in Switzerland.F1 hybrid michahellis x argentatus L||9 5CY, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
2cy michahellis in August, ringed in Switzerland.probably F2 hybrid michahellis x argentatus X argentatus -- / HJ adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-HL probably F2 hybrid michahellis x argentatus X michahellis
2cy michahellis in August, ringed in Switzerland.probably F2 hybrid michahellis x argentatus X michahellis -- / HL adult, May 11 2021, Stevol eiland, the Netherlands. Picture: Jeroen Nagtegaal ringing team.
Partner is B/Y-HJ probably F2 hybrid michahellis x argentatus X argentatus