Friday 23 April 2010

Signs of the times: Spring #10




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.


“The sun was warm but the wind was chill.
You know how it is with an April day.”
Robert Frost



(Copyright: Ladybird Books)


Back to the waterside for picture 11 from Spring – this time down on the canal bank. Here we see the canal environment with many plant species emerging from winter dormancy, with new Spring growth on an alder tree stump and the water’s edge plants, brook-lime, flag-iris and water plantain. The marsh marigold is already in flower with its beautiful golden yellow blooms. A water shrew is mooching about under the marsh marigold, a female mallard is nesting discreetly near the middle of the picture and a kingfisher is flying off to the left of centre. In the background, a canal narrowboat is heading towards a set of large lock gates.


The collection of plants down by the waterside, brook-lime (Veronica beccabunga), flag-iris (Iris pseudacorus), water plantain (Alisma plantago-aqutica) and marsh marigold (Caltha palustris) is typical of the lowland canal habitat, as well as many other wetland and waterside environments in Britain. The New Atlas of the Flora of Britain and Ireland reports that there has been no change in the distribution of any of these species since the original 1962 Atlas. At the time of writing, the marsh marigolds around my pond have been in flower for only two days, and the flag-iris plants are at much the same stage of growth as those in the picture.


The other plant species featured, the alder tree, is regenerating from a bankside stump. Alder (Alnus glutinosa) is a common tree of riverbanks, canal and loch-sides, wet woodland and fen habitats. It is native to most of mainland Britain and Ireland. It has some historical importance according to Richard Mabey in his magnificent book Flora Britannica, its resistance to rotting underwater leading to its use to shore up canal and river banks. But historically it is better known as a wood from which clogs were made, and as a source of charcoal for gunpowder manufacture. The New Atlas reports its distribution as stable since 1962, but highlights that a recently-evolved fungus, a Phytophthora species related to the potato blight fungus has killed 10% of the alder trees in southern England and Wales and is now also causing damage to alders on Scottish river systems, including on the Rivers Avon, Dee, Deveron, Duirinish and Spey. More information from the Forestry Commission and Forest Research here.


Other than the boatman on the narrow boat, there is only one mammal featured here, the tiny Water Shrew (Latin name: Neomys fodiens). This is the largest of the three native British shrew species. I have never seen one. I think my Dad, in over 20 years as a Ranger and a lifetime as a naturalist, only ever saw a dead one, in East Lothian, at a site well away from any water bodies. I could do worse here than reproduce information from the Mammal Society factsheet for water shrew:


The water shrew is found throughout mainland Britain but is probably rather local in northern Scotland. It is present on many of our larger islands, including ... Arran, Skye and Mull ... It is semi-aquatic and is most often found in habitats close to water, including the banks of streams, rivers, ponds and drainage ditches, as well as reed-beds and fens. It is particularly numerous at water-cress beds. Occasionally it is found far from water in rough grasslands, scrub, woodlands and hedgerows, usually as young ones are dispersing. ... Although water shrews are widespread in mainland Britain, they have a rather localised occurrence, probably because of their preference for clean, clear sources of freshwater for foraging. They have low populations densities compared with most small mammals, with a maximum of about 9 shrews per hectare in favoured sites such as water-cress beds. ...Water shrews inhabit burrows and come out to feed on invertebrates. Their main food source is freshwater shrimps, water slaters and caddis larvae which they obtain by diving and hunting underwater. Occasionally frogs, newts and small fish are eaten. They also feed on many terrestrial invertebrates such as earthworms, snails and beetles. The water shrew is most unusual amongst mammals in possessing venomous saliva. A mild toxin secreted into the saliva in the mouth helps to stun the prey. Even humans can feel the effects of this if bitten by a water shrew. Even though the shrew's bite rarely punctures the skin, a red rash appears at the site of the bite which is sore to touch.”


So far, so biologically interesting! But more bizarre is the text accompanying the picture. The author, zoologist E.L. Grant Watson noted: “In the springtime water shrews sometimes sit in twos and threes on a mudflat and sing – which they do very prettily.” Now, THAT I would love to see! For a better view of the water shrew than you will ever manage yourself (sadly not singing though), here is an excellent bit of film from the BBC which someone has put on Youtube. How well are they doing compared to 1959-61? It just isn’t clear - the species is probably too scarce to monitor easily or accurately. One estimate puts the British pre-breeding population at about 1900000: 1200000 in England, 400000 in Scotland and 300000 in Wales. The same source says: Historical changes: Unknown ... Population trends: Unknown.


Moving on to the birds in the picture, I have already written about the mallard in the 1st post in the series, so I won’t say more here except to note that the picture captures well why the female mallard isn’t as brightly coloured as the male bird – her colouration makes great camouflage when she is sitting on the nest. But few birds, especially in Britain, are as brightly coloured as the kingfisher (Latin name: Alcedo atthis), seen shooting off along the canal here. There are many kingfisher species in the world (including the kookaburras of Australia) but we only have the one species native to Britain. Luckily, it is one of the most beautiful kingfisher species (in my humble opinion), indeed one of the most stunningly attractive birds we have. I still remember the magic of my first kingfisher sighting – I must have been 10 or 11 and was walking up the River Garnock in Kilwinning with my Dad when we saw the iridescent turquoise flash of a kingfisher. Although he had fished the rivers of Ayrshire his whole life up to that point, I think that seeing a kingfisher in Ayrshire back in the early 1970s was still quite unusual, as the then-more frequent bad winters in Scotland would kill off a high percentage of the kingfisher population, reducing their ability to spread north.


The British Trust for Ornithology, with its Waterways Bird and Waterways Breeding Bird Surveys, makes the following observation about the kingfisher in Britain: “The Kingfisher declined along linear waterways (its principal habitat) until the mid 1980s, since when it seems to have made a complete recovery. The decline was associated with a contraction of range in England... Kingfishers suffer severe mortality during harsh winters but, with up to three broods in a season, and up to six chicks in a brood, their potential for rapid population growth is unusually high. Amber listing of this species in the UK results from its 'depleted' status in Europe as a whole, following declines between 1970 and 1990.” In Britain, the kingfisher’s population trends looks like this:



I’m guessing the extremely long and cold winter will have had a significant impact on kingfisher populations in Scotland, so there might be a dip in the graph for this year!


I don’t get to spend as much time on rivers as I would like to, so I think I can probably remember the few times I have seen kingfishers in Scotland. I think the most unexpected and unusual was to see a kingfisher in the middle of a very cold winter a few years ago fishing in the tidal freshwater part of the Forth Estuary (so far upstream that there is no salt water influence, just a tidal rise and fall of the river), by the Stirling County Rugby ground, where it was fishing in the river by diving in from a hovering position.


It is worth saying something here about the canal itself. Not everyone realises that there are 137 miles (220 km in new money) of canals in Scotland. In the 1960s, soon after these books were published, Scotland’s Lowland canals – the Forth & Clyde Canal and the Union Canal, which had already been declining in importance, were finally closed as operational canals, heralding a 30 year period of minimal maintenance and decline. When the M8 motorway was built, a monumentally short-term planning decision allowed it to be built across the Union Canal, effectively cutting the canal in two and preventing boat navigation along the length of the canal from Falkirk to Edinburgh.

It took the combination of decades of campaigning by canal enthusiasts, the advent of Heritage Lottery Millennium funding, ongoing regeneration of the English and Welsh canal systems, and a few British Waterways Scotland canal engineers with vision in Scotland to kick-start the regeneration of the Scottish lowland canals in the mid-late 1990s. This culminated in the construction of the Falkirk Wheel, the world’s first rotating boat lift, and the re-opening of the lowland canals to boat navigation following the completion of the Millennium Link project. This renaissance of the Scottish canal network continues today with the proposed Kelpies as part of the Helix project (see my earlier post and picture about this).

Throughout this regeneration, which also involved significant decontamination of several areas of historic industrial pollution, British Waterways Scotland aimed to conserve and enhance the habitat value of the canals. This was apparently successful as it is possible to see all the wildlife shown here on Scotland’s lowland canals (although I challenge you to spot a water shrew!), and much more. Indeed, British Waterways has just launched its annual wildlife survey. If you want to take part and submit records of wildlife from any of Scotland’s canals, you can find out more here, as well as finding out about their related canal wildlife photography competition.

2 comments:

  1. There was a water shrew on TV not that long ago. On the One Show I think, but it might have been Countryfile. Life is just one big blur for me.

    ReplyDelete
  2. Kate - I think it might have been the One Show, with that annoying balding naturalist bloke (yep, another one!). Re blur - have you considered an eye test?

    ReplyDelete

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