A mixed day weather wise, but a day with a fantastic result. We were due to survey the harbours important gull islands early this morning out in the Wareham Channel, but decided to delay for several hours due to the cooler air temperature at dawn. Anyway, having got under way by late morning/early afternoon we were thrilled when the combined totals of both nesting islands produced a Poole Harbour record total of 369 Mediterranean Gull nests. This is a fantastic result, but highlights perfectly the nomadic and often quite unpredictable behaviour and occurrence of breeding Mediterranean Gulls in southern England. We’ve heard anecdotally that other populations along the south coast and east cost have fluctuated massively this spring with a site in Kent having had c800 nests last year have only c150 this year. Below are our survey results and totals of Mediterranean Gull nests from the Poole Harbour islands, starting in 2008 indicating a similar, variable fluctuation in population. Todays result is great news as Med Gulls are a Poole Harbour SPA (Special Protection Area) feature species, meaning the harbour is specially protected because of their presence here.

Number of Med Gull nests

2008 – 87
2015 – 64
2016 – 38
2017 – 33
2018 – 155
2021 – 109
2023 – 278
2024 – 179
2025 – 43
2026 – 369

Sadly, hidden amongst the elation of the Med Gulls success, is the concern for the Black-headed Gulls demise. During the same survey today, we only logged 2823 Black-headed Gulls nests, which is a continued decline for this species. Below are our survey results and totals of Black-headed Gulls nests from the Poole Harbour islands, starting in 2008 highlighting the steady decline. There are probably several factors involved here, the main being habitat loss. In 2008 there were three main nesting islands, now there are only two, due to erosion. Predation levels have increased with regular visits from newly returned Marsh Harriers, Peregrines, Ravens, White-tailed Eagles and Goshawk. Also, Med Gulls tend to be more dominant and can take over areas of suitable habitat on the islands, restricting areas for Black-headed Gulls.

Number of Black-headed Gull nests

2008 – 8951
2015 – 6400
2016 – 2589 (year the colony was ‘egged’ / had eggs stolen)
2017 – 5736
2018 – 4115
2021 – 3706
2023 – 3568
2024 – 3174
2025 – 2901
2026 – 2823

Elsewhere today a great count of 4 Roseate Tern were on the Brownsea Lagoon mid-afternoon, with sightings of individuals around the harbour entrance this evening. On the gull islands during teh survey a good count of 130 Dunlin were counted, plus an Osprey was hunting in the Wareham Channel, a White-tailed Eagle flew over Shipstal,

Newly hatched Black-headed Gull chick – Gull Islands

Mediterranean Gull eggs and nest