By mid June the results of the breeding season start to come in, although how successful it proves to have been in terms of chick production will have to wait for next month.
Starting with the good news Common Terns continue to strengthen there foothold on the island with the colony increasing from 29 pairs in 2010 to 35 pairs this year. For those not familiar with the story of the terns on Havergate they reached a nadir in 2009 when only 2 pairs nested across the island. This situation was only ameliorated by a stroke of luck last year when inexplicably 29 birds arrived extremely late (early July) and proceeded to breed with a degree of success. These successful birds have made up the bulk of our returning colony this year.
Common Tern chick
Common gulls continue to breed in good numbers and help Havergate maintain its position as the largest common gull colony in the south east of England. This species was up by 1 on last year from 18 to 19. The largest the colony has been since 2008 and nudging us ever closer to our management plan total.
It doesn’t really feel like good news when one considers the history of the island but avocets continue to have a foothold on the island with 3 pairs nesting in and around the tern colony this year. In all reality these birds are likely to be failed breeders from other sites who are having one last throw of the dice this season. Whilst this is down on last year and continues the trend of avocets becoming an ever scarcer breeding bird on the island. For a long time it looked like we would have no avocets for the first time in a long time, so lets celebrate what we do have.
Now the bad news, though much depends on your attitudes towards large gulls but both lesser black backed gulls and herring gulls have declined this year.
Indeed lesser black backed gulls have dipped below a thousand breeding pairs (991) for the first time since 2007.
After their huge increase from 330 to 550 pairs in one year herring gulls have settled down to 492 pairs across the island. This means that the complete large gull population (both lesser and herring gulls) has declined overall for the first time since 2009.
Jane and Geoffrey surveying the gulls
The decline in both species specially the lesser’s is likely to reflect national trends, herring gulls the picture is not quite so clear as it bouncing around all over the place and has been for the last three years. What does seem likely, though perhaps I shall be proven wrong next year is that the era of the exponential growth in the large gull population is over.
Oystercatchers have declined to an all time low of 16 pairs nesting. Years of gull predation is likely to be driving the population down and Mallards, Shovelers and Tufted Ducks maintain little more than a toehold on the island. What is perhaps more surprising though is that Canada geese have declined by 8 pairs and are down to 44. Though we have had the bonus of prospecting swallows and singing whitethroats this year, along with red legged partridges, pheasents and a pair of moorhens
This wraps up the breeding season surveys. Most species are feeding chicks of various sizes some of the large gull chicks are big to small tern chicks which are just starting to hatch. The wet weather is a concern as this is not ideal weather for young chicks, a lot will now depend on the attentiveness of the parents and predation is always an issue.