Lesser Black-backed Gull (graellsii & intermedius)

(last update: June 25, 2012)


LBBG rings

lbbg 1cy May
lbbg 1cy June
lbbg 1cy July
lbbg 1cy August
lbbg 1cy September
lbbg 1cy October
lbbg 1cy November
lbbg 1cy December

lbbg 2cy January
lbbg 2cy February
lbbg 2cy Mar-April
lbbg 2cy May
lbbg 2cy June
lbbg 2cy July
lbbg 2cy August
lbbg 2cy September
lbbg 2cy October
lbbg 2cy Nov - Dec

lbbg 3cy Jan-April
lbbg 3cy May
lbbg 3cy June
lbbg 3cy July
lbbg 3cy August
lbbg 3cy September
lbbg 3cy October
lbbg 3cy Nov - Dec

lbbg sub-ad Jan-April
lbbg sub-ad May
lbbg sub-ad June
lbbg sub-ad July
lbbg sub-ad Aug
lbbg sub-ad Sept
lbbg sub-ad Oct
lbbg sub-ad Nov
lbbg sub-ad Dec

lbbg ad January
lbbg adult February
lbbg adult Mar-April
lbbg adult May
lbbg adult June
lbbg adult July
lbbg ad August
lbbg ad September
lbbg ad October
lbbg ad Nov - Dec

Lesser Black-backed Gull graellsii Y.BWP 2CY, July 20 2016, Utrecht, the Netherlands.

Continental graellsii from this population are also referred to as 'Dutch intergrade', upperparts between medium grey British graellsii and dark grey Scandinavian intermedius
Ringed as pullus on June 29 2015, at forteiland, IJmuiden, the Netherlands. On structure, YBWP is a female (F0 coded).

Green YBWP, together with sister YBWN is an offspring of two ringed adults: Lesser Black-backed Gull graellsii YASC and (presumed) hybrid graellsii x michahellis YAHH. This make YBWP an F2 hybrid (second generation hybrid from michahellis), as is the sister (also F0 code) YBWN. If examined into the smallest details, one may find traits that may indicate this michahellis influences (e.g. inherited may be pale on innerwebs of inner primaries and limited proximal barring or flecking in outer rectrices), but probably this may also be found in pure graellsii populations: phenotypically YBWP is a graellsii in all respects, as was its sister PWN. Both are/were gentle birds, probably females (F0). It will be interesting to measure upperpart grey tone once this bird is in adult plumage. Unfortunately, bird YBWN was found death while migarting south on October 05 2015 along the Atlantic coast of Algarve, Portugal (halfway Quarteira and Portimao). Cause of death unknown.

Two papers have been published on the occurrence of michahellis and its hybrids in this colony:
Dutch Birding 2004-1 "Yellow-legged Gulls and hybrids breeding at IJmuiden", by Fred Cottaar.
Dutch Birding 1994-6 "Geelpootmeeuw gepaard met Kleine Mantelmeeuw broedend te IJmuiden", by Fred Cottaar & Kees Verbeek.

Complete moult: P1-P5 new fully grown, P6 growing, P7 missing, P8-P10 old juvenile. Tail: R1-R4 missing/growing, R5-R6 old juvenile. Secondaries: at least S1 missing, other juvenile.