Evening at Shapwick Heath

I haven’t visited Shapwick Heath much this year, weather, tiredness and a couple of minor illnesses have all conspired to keep me away. I did visit the last two sundays though, as it is osprey season and most years produces one stopping over for a week or two on passage back to Africa. This year has not been an exception and I have had some fairly lengthy, if very distant views on both days, despite not being able to spend as long as I would have liked due to work committments. Today, I spent the late afternoon and evening there and had some productive (if distant) views of the osprey, along with a marsh harrier (possibly a juvenile bird) and a common buzzard. All were quickly mobbed by corvids, with the osprey clearly being mobbed by rooks.

Photography wasn’t that productive, although I did get some shots of a juvenil coot struggling with a large water snail or whelk. At one point it looked as if it was lodged in its bill, but eventually it managed to swallow it.

I had a bit of a treat walking back to the car though. As I reached the area leaving Decoy Lake, I noticed movement in the undergrowth, so stayed very still. I was rewarded with a view of a shrew, eventually coming less than a metre away from me. It was probably a small common shrew, but I couldn’t be sure that it wasn’t a pygmy shrew. Whatever it was though, I was able to watch it foraging for insects amongst the leaf litter for a few minutes, before it crossed the path and disappeared into the undergrowth next to the lake.

I had a further treat walking along the road though, as a blue flash flew past me, very close, revealing itself to be a kingfisher. All in all a pleasant evening, despite the unproductive photography.

Starling Roost 11/1/11

Last night, I decided to go and see the starling roost that occurs every evening during the winter months on the Somerset Levels. The roost in the Avalon Marshes area is one of the largest in the country, due to the large area of suitable natural habitat, with the extensive reed beds. Of course the downside is the number of people it attracts, which is the main reason I don’t watch the spectacle more often. Parking is at a premium in the area and some days there can be almost 200 vehicles parked in the small car park and along the verges.

Starling roost on the Somerset Levels, showing motion.

Some of the photographs are spectacular, but there is an element of luck involved (aside from patience and persistence), as no one evening is the same. In wet or windy conditions, the starlings don’t perform and dive straight into their chosen roosting sites. Also, conditions have to be just right to get the vivid colours as a backdrop. Even when conditions are seemingly perfect though, there are no guarantees of a good display and it is thought that the presence of raptors provokes a response; certainly a close examination of the best photos would seem to suggest this. Also, while some years they seem to have a preferred site, they are liable to move around and the past couple of years, they seem to have been much less decisive in where they will roost.

Black and white conversion and slow shutterspeed as roosting starlings fly south, showing a more abstract view.

Yesterday, despite the heavy cloud in the morning, things looked pretty good, the clouds thinned and the sun bathed both of the Shapwick Heath and Ham Wall reserves. However, as sunset appproached, more cloud started to roll in from the west, preventing the vivid colours that make the best photogaphs. It was also quite windy, which didn’t bode well for a good display. However, despite the conditions, it turned out not to be too bad a display, at least they didn’t dive straight into the reeds. In fact, they seemed to be quite indecisive and split into three large groups, coming in at different times. The first group seemed to fly over the reserve from the west to roost to the northeast of the first viewing platform. The second group however, flew more to the south, as did the third, which came in quite a bit later. Finally, the first group seemed to change their mind and flew back south, to roost directly east of the easterly facing screens, to the south of the main path.

The Fall and Rise of the Eurasian Otter

When I was growing up in the 1970’s and 80’s, the Eurasian otter was scarce. Decades of pollution in the rivers of the UK and much of Europe as a whole was having a serious detrimental effect on otter survival. Being an apex predator, any pollutants were concentrated, causing organ damage, ultimately leading to premature death. Even less severe cases of pollution were probably enough to reduce the fertility of otters, which for a species that perhaps lived 3-6 years in the wild and reproduced every 18 months or so, was a serious concern. In the early 1980’s, the situation had become so bad, that the otter had disappeared from many countries in central and southern Europe and much of England and Wales too. There was a real danger that the Eurasian otter would become extinct in most of Europe. Only in Scotland, where there were populations of coastal otters and Northern Europe, were they still widespread. The only other areas in the UK, where there were still healthy (albeit small) populations, were Southwest England (mainly Devon and Cornwall) and parts of Wales and inland Scotland, particularly higher ground, where the effects of pollution were lessened.

It was during this time, that I had an ambition, or perhaps given the situation, it was more like a dream. I wanted to see an otter in the wild. Of course, not only was the otter population plummeting, but they are also largely nocturnal in most habitats, which made the chances of seeing one, pretty remote.

Fast forward to 2008 and the otter population was much more healthy, at least in the UK. Many areas had been repopulated from the west and they were slowly spreading east. I visited Scotland and was finally able to fulfill my dream of 30 years earlier. I caught sight of my first wild otter, running along one of the supports of North Kessock bridge, near Inverness, before it dived into the surf. It was around 6.30 am and bitterly cold, with frequent snow flurries, but it was worth it. My ambition was achieved, but I wanted more. I then spent hundreds of hours in the summer, observing otters in the daylight, much closer to home at Shapwick Heath. Unlike most populations, the otters on the Somerset Levels show themselves at all times of the day. It is probably in part due to the local diet, where freshwater mussels make up a large part of what they eat. One of the reasons that otters are nocturnal, is because their favoured prey items are less active then, so they can expend less energy catching them.

Over the past ten years in particular, but really since the 1990’s, the otter population has become stable and even increased slowly. However, the past has shown how precarious that recovery may be. Pollution, while lessened, still occurs and a recent incident involving paint thinner almost certainly had some effect in parts of the Somerset Levels. There is also a new threat, this time from a fluke carried by oriental fish that have escaped into the Somerset river systems and have since spread further afield. This bile fluke (Pseudamphistomum truncatum) can contribute to death and certainly debilitates infected otters. Generally, parasites are adapted not to cause serious harm to their host, it’s in their interest for the host to survive. However, the otter isn’t the natural host and as is commonly the case with accidental hosts, it causes serious harm to the otter’s internal organs.

Human activity also remains a threat to the survival of the Eurasian otter as a species. While pollution is lessened, in the period when the otter all but disappeared, many fish farms have sprung up. This has now become a source of potential conflict, with calls from some quarters for an otter cull. This call, has largely come about due to ignorance. Many seem to think that otters have deliberately been reintroduced by scientists and conservationist on a large scale, which simply isn’t the case. Even some individual anglers have joined the call for a cull, with some heated debates on internet forums. The fact is, the greatest cause of depleted fish stocks in rivers is human activity. If a river is able to support otters, then it is a good sign that there is some sort of balance. Otters simply are not present in high enough densities to cause depletions in fish stocks and numbers would soon decrease, if there were insufficient prey items (i.e. fish and crustaceans) to support them. Only in fish farms, where they are allowed access, are they likely to cause a problem and that problem is one that is easily overcome. Fish farms are big business and many of the fish are prized oriental carp, worth thousands of pounds, so an otter let loose in a fish farm will cause alot of damage. However, it is the responsibility of any business to protect their assets. In the case of fish farming, it is very easy to keep otters out, by using fences. Otters won’t try to force their way through an electric fence, as it would cause them discomfort. Like many predators, they will go for the easiest prey, if the fish farm isn’t otter-proof, then it will be the fish farm, but if it has adequate protection, then the otter will go elsewhere, where they won’t get a jolt of electricity. Also, to put things in a bit more perspective, there are an estimated 3500-4000 otters in England and Wales, with a further 4000-4500 in Scotland (many of which are around the coasts). Their diet consists of around 90% fish and crustaceans. In comparison, the American mink has a diet of around 40% fish and crustaceans, with the rest being birds and small mammals. The mink is much smaller than the otter, so will eat less, but population estimates for the mink are around 35000 to 40000, perhaps five times as many as otters. It is therefore likely that mink account for more fish predation in total than otters, not to mention the other problems they cause to native breeding birds and small mammals, such as the water vole, which has seen an 80% drop in numbers in the period that the American mink has been at large in the British countryside.

Otter Swimming Through Reeds

Eurasian otter in lake

I now have several photographs of otters, but none that I am really happy with. Otters have provided me with hours of pleasure and I hope they will continue to do so for many years to come. While the otter is a protected species, it still faces numerous threats, mostly either directly (through pollution and altered habitat) or indirectly (through realease of non-native species, such as oriental fish) caused by human activity. If the otter and the whole of the habitat each one inhabits is to survive, we have a responsibility to protect our environment. We must preserve the otter for future generations to enjoy.