Arctic Skua? kittiwake? little tern?
All good guesses but since the year 2000 the two fastest declining seabirds are the much less heralded herring gull and lesser black backed gulls.
This is according to the SMP (seabird monitoring programme) data recently released by the JNCC. This is a ongoing annual monitoring programme of all 26 breeding seabirds in the UK that allows broad trends to be established and monitoring programmes to be implemented at a nationwide level.
Since the year 2000 the herring gull population in the United Kingdom has declined by 38% and lesser black backs have declined by some 36% since the year 2000. So, don't let the massive 943% increase in herring gulls nesting in cities in towns fool you, this is a bird in decline. What does this mean in real numbers? Well, both species had approximately 110,000 pairs in the year 2000 this is now reduced to just over 70,000 pairs.
Just in case you where wondering Arctic Skua's have declined by 34%, Kittiwakes have declined by 30% and Little terns have actually increased by 7%.
Obviously whilst the decline of both large species of gulls is a concern they do have one advantage both still have robust populations numbering well over 70,000 pairs in the British isles, unlike some other seabirds which are declining from a much smaller population base. A classic example is arctic skua's which only have around 1,500 apparently occupied territories after the recent decline.
I think I may have discussed this before but several theories exist as to the reasons for the nationwide decline. Ranging from mammalian predation to disturbance on the breeding colonies, no doubts these are having an impact. Likely it is these factors that are pushing herring gulls into urban areas, that and food is abundant.
The other theory is that both the species are returning to a natural level, previously both species have have had access to plentiful indeed virtually limitless food in the winter by utilising uncovered rubbish tips, specially when one considers the changing ecology of lesser black backed gulls which now no longer migrate to southern europe and northern africa in the winter. These days are coming to an end as governmental policy is to cover up rubbish tips, this may be increasing winter mortality rates of both species of gulls and also reducing the ability of adults to gain proper breeding body conditions. Other species are know to have much less productive breeding year if there body condition is lower.
To a certain extent only time will tell for both these species, sadly neither species have been particularity well monitored in the past which makes drawing conclusions subjective and at worst borderline guesswork.
Island wise, the summer is on us now. The first large gull chicks hatched on May the 17th, the exact same date as last year. Common gull nests are now in double figures, common terns are still showing an interest in Cottage flood. Sadly, it looks like for the first time in half a century avocets will not breed on Havergate island but both pairs of greater black backs (Suffolks only pairs) are both back and on eggs.