YELLOW-LEGGED GULL Larus cachinnans Increasingly common and regular passage migrant.Seen each year since 1992 when it was split from Larus argentatus.
2015 -
It was a very similar picture to 2014, with 18 birds seen at seven locations; all except one bird were reported by the same observer. Seven of the gulls appeared at Redcar Tarn between May and November, these all being non-breeding birds in various stages of development - two juveniles, three 1st-winter, a 1st-summer and a 2nd-summer bird.
At Leeshaw Reservoir, what was thought to be the returning bird of 2014 (now in 2nd-summer plumage) was seen intermittently from spring to early autumn, and briefly also visited nearby Lower Laithe Reservoir. A 1st-winter bird appeared during the last week in August, and a different 2nd-summer was here in early October, also being seen at Thornton Moor Reservoir. The latter site also hosted one of the year’s few adults, in April, and a 3rd-summer bird in late June. In Bradford, a 1st-winter, was at Girlington for three days in October, and a juvenile at nearby Brown Royd on 11th August. Finally, four different adults were in the flocks at Cullingworth Fields during late August and early September.
2016
- Following its being given full specific status, rather than a sub-species of Herring Gull, records started to appear in 1992, and have increased ever since, to the point where, with this year’s tally, the gull can almost be regarded as common in the area. That said, all the reports came from south of the River Aire, and are attributable to just five observers. Almost all the sightings relate to the period between late June and early September when birds accompany the many Lesser Black-backed Gulls passing through the area, and there were only three records outside this, a 1st-winter bird at Redcar Tarn on 31st January, and adults at Cullingworth on 6th March and 31st December.
Thornton Moor Reservoir remains the main and most intensively watched site, and nearly 60% of the records came from there. Given the transient nature of all the gulls in the main period, it is impossible to say with any accuracy how many different birds were involved, but it is probable there were at least 43. In July, all the birds were adults, but by August (when most birds seen were recorded) there were also sightings of at least four juveniles, a 1st-winter, a 2nd-winter, and 10 3rd-summer birds. The largest single count was of six birds on 11th August. Redcar Tarn had two 2nd-winters in July, and two juveniles in August, Brown Royd a 1st-summer in June and three different 1st-winters in August and September, and a sub-adult, possibly one of the Thornton Moor contingent, was seen at Ogden in September.
At Leeshaw Reservoir, the bird first seen in 2014, and now in 3rd-summer plumage, returned for its third successive year. It paid a brief visit to nearby Lower Laithe Reservoir, but was otherwise faithful to the site between 9th July and 21st August.
2017
- The exponential increase continues, probably largely due to increased observer awareness and regular coverage of the transient Lesser Black-backed parties, which are often the carrier species. About 74 birds were recorded, all from the south, and from five main areas:
Cullingworth Fields 8 adults 18 sub-adults
Redcar Tarn - 13 sub adults
Thornton Moor Reservoir 4 adults 6 sub-adults
Leeshaw/Lower Laithe/Leeming 3 adults 13 sub-adults
Brown Royd, Bradford - 9 sub-adults
At Leeshaw Reservoir, the returning bird, now in 4th-summer plumage, was present for its fourth year.
2018
- Though numbers are well down on last year, 45 different birds is still a significant total. The main sites are the same as 2017:
Cullingworth Fields 1 adult 2 sub-adults
Redcar Tarn - 2 adults 10 sub adults
Thornton Moor Reservoir 1 adult 6 sub-adults
Leeshaw/Lower Laithe/Leeming 3 adults 6 sub-adults
Brown Royd, Bradford - 1 adult 8 sub-adults
Single adults were also seen near Barden, and at Queensbury, and Ogden Reservoir, and two sub-adults were at Scargill.