Occurrence of Caspian Gulls Larus cachinnans along the Dutch coastline
Klaas van Dijk
Sula (in press)
Black-headed Gull of 33 years and re-appeal to stop using aluminium rings to mark gulls
Klaas van Dijk, Date Lutterop, Rob Voesten & Frank Majoor
Are European Herring Gull Larus argentatus movement patterns changing in relation to anthropogenic activities?
Caroline Elizabeth Coleman University of Birmingham MSc dissertation
This project investigated whether there were changes in Herring Gull (Larus argentatus) movement patterns and possible links with anthropogenic change.
Observational data from BirdTrack and ringing data from EURING schemes, the Severn Estuary Gull Group and North Thames Gull Group were used. Mapping, statistical analysis and visual examination of plotted data were employed to determine whether there were changes in the distributions of observations and ring recoveries; population-level movements within distance bands; or individual movements. Seasonal and age-related influences were also investigated.
A range of sedentary and migratory behaviours were found amongst Herring Gulls ringed in Britain, with those from the Severn Estuary being the most likely to remain sedentary.
There was a decrease in percentage recovery rates at Herring Gulls’ original ringing locations and significant changes over medium distances (particularly those up to 60 km from the ringing location). Evidence of human activities in and around ringing locations indicated that they could be associated with the observed changes in Herring Gull movements. Limited evidence was found for seasonal and age-related differences in responses.
Herring Gulls are of conservation concern in Britain and declining in some other European countries, but they also frequently cause conflict when they occur within the human environment. Further research approaches, including tracking techniques, are recommended to enhance the evidence underpinning conservation and management of the species.
New longevity records of Black-headed Gull, with comments on wear and loss of aluminium rings
Klaas van Dijk, René Oosterhuis, Benny Middendorp & Frank Majoor
Differential Age-Related Phenology in Lesser Black-Backed Gull Larus fuscus Wintering in the Malaga Area
S. García-BarcelonaArdeola 57(Especial), 2010, 127-132.
We aimed to identify the existence of age-classes groups that shared similar seasonal
patterns in migration movements for the lesser black-backed gull Larus fuscus. The gull age-classes
groups were defined as sets of age-classes that were present in the harbour of Malaga (South of Spain)
simultaneously during the wintering season.We distinguished ten groups of age-classes, which can be
subsequently lumped into four big age-class groups: (i) immature stage-class, (ii) young breeders, (iii)
age-classes from 6 to 11 years old, and (iv) age-classes older than 11 years old. Our present results
supported the ‘dominance and arrival time model’.
The influence of colour-rings on recovery rates of Herring and Lesser Black-backed Gulls
C. B. Shedden, P. Monaghan, K. Ensor and N. B. Metcalfe
Ringing and Migration. (1985) 6: 52-54.
Comparison of recovery rates of Herring and Lesser Black-backed Gulls with and without colour-rings in addition to a metal ring shows that colour- ringed birds are twice as likely to be recovered and reported to the British Trust for Ornithology. Implications for studies of mortality rates are discussed.
Migration of Pontic Gulls Larus cachinnans form ‘ponticus’ ringed in the south of Ukraine: a review of recoveries from 1929 to 2003.
A. G. Rudenko in Boere, G.C., Galbraith, C.A. & Stroud, D.A. (eds). 2006.
Waterbirds around the world. The Stationery Office, Edinburgh, UK.
The Morlan Method - Dichotomous Keys for Western North American Gull Identification
J. Morlan
Yellow-legged Gull and Caspian Gull (in German)
Martin Gottschling Der Falke 51, 148-155
Yellow-legged Gull Larus michahelllis and Caspian Gull Larus cachinnans are not found in many standard field guides.
Only in recent times have these been recognized as separate species, which decades ago were still counted as Herring Gull.
Hints and tips for the determination of the two very similar species are important for birdwatchers.
Scandinavian Herring Gulls wintering in Britain
Coulson, J. C., Monaghan, P., Butterfield, J. E. L., Duncan, N., Ensor, K., Shedden, C. and Thomas, C. Ornis Scand. 15: 79-88.
Biometric information was obtained from 13000 Herring Gulls Larus argentatus caught and ringed
in northern England and southern Scotland outside the breeding season between 1978 and 1983. Morphological differences
between males and females and between British and Scandinavian Herring Gulls have been used to identify both the sex
and race of the birds. We describe the wintering distribution of the Scandinavian birds in Britain, their age and sex
ratios and their time of arrival in and departure from Britain. Scandinavian Herring Gulls start to arrive in Britain
in small numbers in September. The proportion of Scandinavian birds increases to a peak in December- January and the
birds depart abruptly in late January or early February. Very few Scandinavian Gulls penetrate to the west side of
Britain, while on the east side there is considerable regional variation in the proportion of Scandinavian birds.
Between 70% and 80% of the adult Scandinavian birds examined were female. The proportion of adults amongst
Scandinavian birds was much higher than amongst British birds.