Ring reading statistics after sand suppletion activities at Katwijk aan Zee 2013-2014

From October 2013 until March 2014, the coastline at Katwijk aan Zee was reinforced with a dyke in new and wider dunes in an effort to protect that part of the Dutch coast from the North Sea.

1 December 2013

1 December 2013

During this period, sand from the bottom of the North Sea was deposited on the beach on a 24-hours-a-day, 7-days-a-week schedule (only interrupted by a few days of heavy winds). The vessels kept a routine which involved one hour of depositing the sand on the beach, one hour of traveling to a position off the Dutch coast, one hour of collecting the sand and one hour of traveling back to the beach.

As expected, this attracted a huge number of gulls who quickly adapted to this rhythm of being fed with nutritious sea food once every 4 hours.

For the local gull watchers (me included), this was a great opportunity to check for any (color-)ringed individuals.

Conditions were initially great with huge numbers of gulls and good views.

As the months progressed and the new dunes started to take shape, the gulls were more and more hidden from view and could for most of the time only be observed from a large distance. This obviously had a negative impact on the number of rings that could be read. Only during the last few weeks did conditions improve again when constructions were finalized close to the boulevard.

Below are my personal totals of my ring reading efforts during this period. (Note: I have not yet received all ringing details so all data is subject to change.)

Summary

Observations……………………………………….263
Visits…………………………………………………….25 (on separate days)
Individuals……………………………………………183
Countries……………………………………………..11
Gull species………………………………………….7

Ring reading on 26 January 2014.

Ring reading on 26 January 2014.

Observations per species

European Herring Gull…………….…………..164 (62%)
Lesser Black-backed Gull……………………..40 (15%) *
Black-headed Gull…………….………………....29 (11%)
Great Black-backed Gull…………….………..15 (5%)
Caspian Gull…………….…………..……………....11 (4%)
Yellow-legged Gull…………….………………...2 (0%)
Yellow-legged Gull x Caspian Gull…....2 (0%)

* Lesser Black-backed Gull is a migratory species and was absent in the months of December and January. Ringed individuals were only observed in the months of October and November, while a few un-ringed individuals were seen in February and March.

26 January 2014. Herring Gulls were in the majority at Katwijk aan Zee.

26 January 2014. Herring Gulls were in the majority at Katwijk aan Zee.

Observations per age

First-winter…………….……..………….…………..106 (40%)
Second-winter………………………..…………….19 (7%)
Sub-adult……………………..….………………...…61 (23%)
Adult……………………..….………………...………..77 (29%)

Observations per country

The Netherlands…………….…………………...158 (60.8%)
Germany…………….………………...……………..45 (17.3%)
Norway…………….………………...……………….24 (9.2%)
United Kingdom…………….…………………...11 (4.2%)
Denmark…………….……………….…..………….11 (4.2%)
Poland…………….………………...………………..9 (3.5%)
Finland…………….………………...………………..2 (0.8%)
Lithuania…………….……………….……………….1 (0.4%)
Belarus…………….………………...………………..1 (0.4%)
Russia…………….………………...………………….1 (0.4%)

26 January 2014. One of the most interesting gulls that was seen was this 2nd-calendar year Caspian Gull ringed in the Belarus.

26 January 2014. One of the most interesting gulls that was seen was this 2nd-calendar year Caspian Gull ringed in the Belarus.

Observations per month

October…………….……….…………….………....114 (45%)
November …………….…………..………………..4 (2%)
December…………….…………..…………….…..42 (17%)
January…………….…………..…………….……....79 (31%)
February…………….…………..………..…………..7 (3%)
March…………….…………..…………….………....7 (3%)

Individuals per country

The Netherlands…………….…………………...105 (58.0%)
Germany…………….………………...……………..32 (7.7%)
Norway…………….………………...……………….20 (11.0%)
Denmark…………….……………….…..………….8 (4.4%)
Poland…………….………………...………………..8 (4.4%)
United Kingdom…………….…………………...6 (3.3%)
Finland…………….………………...………………..2 (1.1%)
Lithuania…………….……………….……………….1 (0.6%)
Belarus…………….………………...………………..1 (0.6%)
Russia…………….………………...………………….1 (0.6%)

Individuals per Dutch ringer

Roland-Jan Buijs…………...……………………..58 (55.2%)
Frank Majoor…………...……………………………18 (17.1%)
Kees Camphuysen (IJmuden colony)….13 (12.4%)
Kees Camphuysen (Texel colony)………..11 (10.5%)
Norman van Swelm…………....………………..3 (2.9%)
A. Spaans……...………..…………...………………..2 (1.9%)

Longest distance traveled

Black J2648,  adult Herring Gull. Ringing location: Hornøya, Vardø, Finnmark, Norway (70.23 N 31.09 E).
Distance traveled: 2432km.

Yellow KW37, 3rd-calendar year Herring Gull, Ringing location: Kandalakshskiy Nature Reserve, Severnoe lesnichestvo, isl.Farvaternaya, Russia, Murmansk O. (67.05 N  32.29 E)
Distance traveled: 2251km.

Red C.JH86, 2nd-calendar year Herring Gull. Ringing location: Kemi, Kallio (65 39’N 24 33’E).
Distance traveled: 1800km.

longest-distance

Conclusion

Obviously, we were quite fortunate to have this spectacle of gulls at our doorstep for such a long period of time and it has certainly resulted in many interesting observations. As a bonus, the activities also attracted a first-winter Glaucous Gull Larus hyperboreus and a first-winter Iceland Gull Larus glaucoides who both stayed at the location for many weeks.

Second-calendar year Iceland Gull with Sanderlings. Katwijk aan Zee, The Netherlands, 18 January 2014.

Second-calendar year Iceland Gull with Sanderlings. Katwijk aan Zee, The Netherlands, 18 January 2014.

Although I made every effort to make as many visits as I could, I was very limited in the time that I could invest (mainly weekends and the odd weekday).

It so happened that during the whole period, the activities could be followed by a web cam and on many days I could see a large number of gulls sitting on the beach in perfect view with no-one checking them for rings. Unfortunately, only a few birders (can) actively participate in ring reading and I can’t help but wonder how many observations we have missed and what the outcome could have been had the effort been higher than it was.

Interestingly, the activities started while winter migration was still ongoing and we also experienced a very mild winter. I therefore hope that our observations will one day show what the effect (if any) of these circumstances has been: have individuals stayed longer in the Netherlands than usual and have they arrived later at their wintering grounds?

Published blog posts

October 2013

Sand suppletion activities at Katwijk aan Zee off to a good start

Caspian Gulls at Katwijk aan Zee – 20131019

Yellow-legged Gulls and gulls with yellow legs at Katwijk

January 2014

2cy Iceland Gull – 20140118

Re-sighting of ‘my’ 29cy Herring Gull

Leucistic Black-headed Gull – 20140119

Kleptoparasitic behavior in Black-headed Gulls towards Sanderlings – 20140119

March 2014

Adult Herring Gulls regurgitating food for 1st-winter gulls – 20140308

Pale 2cy Herring Gulls – 20140308

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2 thoughts on “Ring reading statistics after sand suppletion activities at Katwijk aan Zee 2013-2014

  1. You could have asked the guys working there if they would write down any band numbers they saw for you (if they got the chance). If it’s one thing that gulls do well, it’s hanging around closely when humans are eating their lunches. Heh, or did they think that you were some crazy guy hanging around? 🙂

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