Of all the birds that have either reduced in numbers, or disappeared all together on Sheppey in recent years, it is the demise of Sand and House Martins, Swifts and even Swallows that has dismayed me the most.
The first of these to go were the Sand Martins and they had gone by probably the mid 1960's. I had a few years after that where my bird watching dropped off and so they might of hung on a little later than that. The cliffs on Sheppey's north facing coast range between Minster beach and Warden Bay to the east and are pretty much the highest land on the whole of Sheppey. In the main they are made up of London clay and are continually eroding and collapsing to form treacherous boggy areas at lower levels. However there is one shortish stretch at the end of Oak Lane in Minster where the soil is of a much sandier type and certainly during my childhood in the 1950's, was home to a substantial Sand Martin colony each year. This short stretch of sandy cliff fell away in largish chunks just as regularly as the rest and still does today, but always seemed to do so to still leave a sheer face with a drop of 50-80yds that was ideal for the Sand Martins.
Why the colony was eventually abandoned all those years ago I don't really know. It was some miles from my home on foot for a 12-14 year old and I only visited it a few times before my major teenage years took over with other interests, but I suspect that it has a lot to do with the rapid colonisation over the last forty years of the cliffs lower and middle slopes by both willow and silver birch. The cliff face where the birds nested was an exposed, deep face with nothing in front of it except the open sea to restrict flight access but that has not been the case for many years now. The area in front of what used to be the nest colony is now full of silver bush and willow bushes that have grown to the height of the top of the cliff, masking the cliff face almost completely in places. Whatever the reason, they are a bird only ever seen passing over Sheppey in very low numbers these days.
House Martins are an enigma because the majority of their previous habitual nest sites on Sheppey are still there, clearly the reasons for their absence are due to factors away from Sheppey, a substantial drop in numbers perhaps, or a shortage of insect life. Throughout my youth and certainly as recent as the 1980's, House Martins were still a fairly common nesting bird on Sheppey and a large number of the older streets in Sheerness would normally have one or two pairs in attendance. Today those streets and houses continue to provide the same nest sites as they always did but in 99% of the places no House Martins have been seen for years. One small colony of 3-4 pairs hung on as recently as 3 years ago on some fairly new Old People's apartments in the town but now they have failed to return for the last couple of years. For countless years there were also two significant breeding colonies in Sheerness Docks totaling around 20 pairs, but by the time that I retired in 2006 this colony had dwindled down to 4-5 pairs at best and although lack of access has not enabled me to see if this colony is still active, it's unlikely that it is, although the buildings still remain in-situ. Whilst I haven't checked out every single potential site still remaining on Sheppey it's pretty clear that apart from 3-4 pairs nesting at Shellness Hamlet in recent years, that the House Martin has pretty much been lost as a breeding bird on Sheppey.
Swifts too, always a lovely sight and sound as they formed large flocks high overhead on warm summer's evenings, are becoming less and less common to see as a breeding bird on Sheppey. While once again, a reduction in flying insects must be partly to blame, the lack of nest sites is the greatest reason. In Minster where I live, the largest breeding colony since the year dot was always at the old Sheppey General Hospital in the center of the village. A large number of the hospital's buildings had formed the Minster Workhouse for over a hundred years, until it was closed in 1934 and re-opened as the hospital. The old condition of these buildings provided numerous nest sites for a large colony of Swifts right up until the site was demolished four years ago and replaced by a new housing estate since. A few pairs still hang on at some old houses nearby but the large gatherings overhead in the summer here in Minster are now sadly, a thing of the past. One particular small area of older streets in Sheerness still retain a number of pairs but apart from that the skies over Sheerness remain far, far quieter Swift wise, than they used to be.
To complete the quartet there are the Swallows and while they still remain as a breeding species in fairly good numbers on Sheppey, even their numbers appear to have reduced in recent years. In their case I believe that a reduction in suitable nest sites is the one of the biggest reasons. With a large rise in horse paddocks around Sheppey, often with associated stabling or store sheds, the Swallows should be doing a lot better but access for nesting via broken or open windows and doors is greatly denied these days for security reasons. Also, I know of two sites on Harty where Swallows are still allowed access to nest in good numbers, up to sixteen pairs in one case. But the owners increasingly find that the amount of droppings that the birds produce through a season in their sheds does become a slightly annoying problem, so perhaps this is another reason why some people deliberately deny the birds access.
On the Swale NNR we have had odd pairs of Swallows nest when sites became available. The last pair to nest were in a very small and old bird hide that had become so rotten and mouldy that we had nick-named it the "tumbledown hide". We put a sign on it telling the public not to use it and I deliberately left a viewing flap open for the swallows and they successfully nested the first year. They returned the second year and had a nest with eggs that was doing OK until I found two elderly lady birdwatchers in the hide having their lunch. The head of one was only a foot or so below the nest and the parent birds were flying round outside in some agitation. On entering, I politely remarked on the "no entry" sign on the door and pointed to the Swallow's nest which they were keeping the birds from, but apart from acknowledging both, they steadfastly refused to leave the hide and the next day the eggs had been deserted.
It's not until you spend a couple of summers deliberately monitoring the skies overhead that you realise just how quiet they have become in respect of the birds mentioned above, or at least, that's certainly the case here on Sheppey. I particularly miss the House Martins, they always brought busy bird life into quiet back streets that were normally devoid of bird life for many months of the year, it should always be a privilege to share your house with them.