Wednesday 18 August 2010

Signs of the times: Summer #13

More comparisons between the British countryside of today and that from 1959-1961 in the paintings of Charles Tunnicliffe in the Ladybird "What to look for..." series of books.



"As he sat on the grass and looked across the river, a dark hole in the bank opposite, just above the water's edge, caught his eye, and dreamily he fell to considering what a nice snug dwelling-place it would make for an animal with few wants and fond of a bijoux riverside residence, above flood level and remote from noise and dust. As he gazed, something bright and small seemed to twinkle down in the heart of it, vanished, then twinkled once more like a tiny star. But it could hardly be a star in such an unlikely situation; and it was too glittering and small for a glow-worm. Then, as he looked, it winked at him, and so declared itself to be an eye; and a small face began gradually to grow up round it, like a frame round a picture.
A brown little face, with whiskers.
A grave round face, with the same twinkle in its eye that had first attracted his notice.
Small neat ears and thick silky hair.
It was the Water Rat!"

Kenneth Grahame, from "The Wind in the Willows"





(Copyright: Ladybird Books)



Summer Picture 13
We are back on the canal again for this picture, having already looked at canal wildlife in Spring, here. Back then, we also, as here, saw a kingfisher. There is also a water vole feeding in the right foreground, among a collection of waterside plants: arrowheads, great water-plantain, flowering rush, on and around which are flying damsel-flies, while in the background, across the canal, some anglers are fishing (in one case, successfully, as he lands a fish).

As I discussed the kingfisher in some detail in an earlier post in Spring, I won’t say any more about it here. The other (non-human) warm-blooded vertebrate in the picture, the water vole (Latin name: Arvicola terrestris) is a rodent, found throughout mainland Britain, principally on lowland rivers and, as here, canals, although I have also seen the tunnels and signs of relatively recently discovered colonies now known to be widespread fairly high up in the Cairngorm mountains. So, we are still discovering new information about this widespread species. The water vole might be described as a member of Britain’s most threatened mammal species and, perhaps, its unluckiest mammal species. How can this be, given the public popularity of the water vole, one of the stars of the much-loved “tales of the riverbank in Kenneth Grahame’s “The Wind in the Willows”, where “Ratty", friend of Mr Toad was indeed a water vole? I still remember the first time I saw a water vole, when I was perhaps eight or nine, on “patrol” with my Dad, and heard the “plop” sound as the vole dropped from the bank into a little coastal stream at Longniddry in East Lothian, and watched it swim underwater, all silvery from the layer of air bubbles trapped in its fur.

As the Joint Nature Conservation Committee’s Review of UK mammals reports, at the start of the 20th century, “water voles were abundant in all suitable localities in England, were found in all low-lying districts of Scotland except Argyll, and were common in the streams of Anglesey and North Wales, but were comparatively scarce in south Wales ...Subsequently there has been a long-term decline.”

The JNCC report continues, starkly, that a field survey in the 1990s showed that there has been a steady long-term decline this century, with two periods of accelerated site loss, the first in the 1940s and 1950s, and the second between the 1970s and 1990s. The first decline: “was most marked in northern and western Britain and may correlate with increased afforestation and subsequent acidification of waterways”. The second period of loss, most marked in the 1980s: “is correlated with the spread of the American mink”. On top of this, before and as well as the escape of mink from fur farms, “habitat destruction by riparian engineering works causing fragmentation and isolation of colonies, coupled with water pollution, acted as cumulative factors which also contributed to this decline.” The extent of the decline is quite breathtaking: since 1900, 68% of occupied water vole sites have been lost, and this could be as high as 77%. Also, as the number of voles at each site is believed to decline with the percentage of occupied sites, the reduction in water vole numbers has been even greater.

Mink, particularly a female feeding young, can demolish a water vole colony in a few days of hunting activity. Valuable research at Aberdeen University has shown that water voles can tolerate predation by American mink where there are wide vegetated corridors on the banks alongside the river as mink do not forage far from the river. But the poor way that we manage the banks of so many of our rivers flowing through agricultural and urban areas, with perhaps only a metre or two’s width of uncultivated or ungrazed vegetated river bank between the river and the landuse inland simply leaves too little habitat space for water voles to survive the pressure of mink in those areas.

But all is not doom and gloom for the water vole. The species is listed as a priority under the UK’s Biodiversity Action Plan (UKBAP) and this has galvanized a considerable programme of activity geared at turning around this calamitous decline. The plan has been led since 1996 by a very dynamic Environment Agency Conservation Officer, Alastair Driver – if you’ve heard radio interviews (e.g. Radio 4’s “Today” programme) or seen countryside programmes on TV which have discussed water vole conservation projects, then Alastair was either speaking or was likely to have been behind the media opportunity. I was privileged to represent my agency for 12 years on the UKBAP water vole action plan group led by Alastair and so I’m aware of a wide range of actions being taken to try to protect remaining stronghold populations of water vole across Britain, as well as reintroduction programmes, improvements in the way that the water vole’s habitats are being managed, and a water vole habitat management handbook (to which we managed to contribute some funding). There are also mink control programmes across Britain, and my own agency has found water vole populations establishing in some of the urban drainage pond schemes that we have been encouraging for many years as a part of developments, and which are now a legal requirement for all major developments. The group was also involved in helping to secure increased legal protection for water voles under British law, from killing, disturbance and destruction of their burrow systems. The campaign isn’t yet won but there are some significant strides being made now, by partnerships of many organizations at national, county and local level, to turn around the significant decline in this popular and characteristic species of British rivers, canals and wetlands.

Incidentally, my life-long interest in water vole populations in coastal burns in East Lothian has also led to my observation of water voles feeding, and forming tunnels, in saltmarsh vegetation at the foot of these little streams, where they have short sections that flood tidally. I am not aware of any other reports of coastal populations of water voles using saltmarsh vegetation in this way.

There are three beautiful waterside plants in flower in this picture. The big, butch, pink flowering plant on the right is the Flowering Rush (Butomus umbellatus). It grows both as a submerged and an emergent species, at the edges of rivers, lakes, canals, ditches and in swamps. The New Atlas reports that it has maintained its distribution since the 1962 Atlas and, indeed, has spread in the Tweed, where it was first recorded in 1956, 3-4 years before these Ladybird books were first published. Other than the Tweed, it seems that this species is not native in Scotland, although it has been introduced in a few dispersed locations across Scotland.

The small three-petalled white and purple flower above the water vole belongs to the arrowhead (Sagittaria sagittifolia) – you can also see the arrowhead-shaped leaves below. The New Atlas states that the arrowhead is a: “perennial herb of shallow, still or slowly flowing, calcareous and eutrophic water. In major rivers it may be present only as submerged leaves, but in ditches, lakes, ponds and canals it often produces emergent leaves and flowers”. It also reveals that is a distinctly southern species in Britain and is absent from northern Britain almost entirely, other than largely the Forth & Clyde and Union Canals in central Scotland, where it is an introduced species. The New Atlas reports no significant changes in distribution since 1962, other than some losses from ditches in some areas, where it remains as a riverine species.

Finally, the tall, wispy flower stalk on the left, with the tiny three-petalled white flowers, is from the Common Water Plantain (Alisma plantago-aquatica), a perennial plant growing on exposed mud at the shallow edge of still or slow-flowing waters, or in marshes and swamps. It is confined to moderately or very enriched freshwater habitats. Its range extends as a native species well up into Scotland, as far as the Moray Firth, and the New Atlas says that this well-recorded species is still found largely where it was in 1962. We have this in our garden pond (and it is quite lovely in person!).

I'm afraid the image of damselflies in the picture doesn't really give me enough to go on as far as species. Maybe I will do a special post on damsels and dragonflies in future, once I've finished this series of posts.

4 comments:

  1. I do love these old ladybird book pictures, they bring back such memories

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  2. I've read these posts with great interest and enjoyed them immensely. It's been a prodigous amount of work to be sure.

    Thanks for doing them. What's next to look forward to?

    cheers....Al.

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  3. Thanks Al, it's good to know they are being enjoyed - as for prodigious, well it passed some time in the evenings in Wales last week! I have another 2-3 stockpiled (I'm catching up again witht he timetable a bit) - 11 more pictures of Summer to go, then 24 each of Autumn (some lovely images coming up) and for Winter too. Aiming to finish this series of Ladybird posts in Jan or Feb. What on earth will I write about then? Spitfires maybe!

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