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Items from Recent Newsletters |
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For the complete version of the latest Newsletter please click here |
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| March 2010 Monitoring the Internationally Important Wintering Wetland Bird Populations in the Forth Estuary |
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| Viewers of BBC's Spring and Autumn Watch programmes will be familiar with the enormous flocks of geese, swans, ducks and waders that migrate to over-winter in the UK before returning to their breeding areas in Greenland, Iceland, Scandinavia, Western Russia etc. Some of these birds just stop off to rest and refuel on their way further south but the majority stay on our estuaries, lakes and flooded countryside. |  |
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Goldeneye (Neil Calbrade/BTO) |
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| In winter the UK hosts internationally important numbers of many types of wetland birds (ie more than 1% of all the individuals of that species). This is because we have nearly a third of Europe's estuaries and compared with Northern and Eastern Europe our winters are relatively mild leaving the feeding sites unfrozen. The concentration of all these water birds into relatively few sites provides the opportunity to monitor their populations and once a month throughout the winter just over 3000 volunteers go out to allocated sites and count the different species. In our Members Centre area 44 volunteers are involved monitoring the Forth, Teith and Devon. This scheme has been running for 60 years and is currently known as the Wetland Bird Survey (WeBS) which is coordinated by a team of professionals based at the British Trust for Ornithology's (BTO) HQ in Thetford. |
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In the UK 218 "principal sites" have been identified as supporting 10,000 waterbirds or internationally important numbers of at least one species . Of these the Forth Estuary ranks 12th with a five year average of 85,000 birds compared with 368,000 in the Wash and 120,000 in the Solway. We have internationally important numbers of Pink-footed and Icelandic Greylag Geese, Shelduck, Slavonian Grebe, Knot, Bar-tailed Godwit, Turnstone and Redshank. In addition, seventeen other species are defined as nationally important and of these we have the biggest GB populations of Goldeneye, Red-breasted Merganser, Red-necked Grebe and Shag.
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| a whole series of Forth species have triggered this alert including Scaup, Great Crested Grebe, Common Scoter, Goldeneye, Red-breasted Merganser, Golden and Grey Plover, Knot and Bar-tailed Godwit. Fortunately there are also a few species which are increasing like the Curlew and Velvet Scoter.
If a decline is common to all the birds' UK sites then a generic cause is implicated such as adverse conditions in the breeding grounds. However if the Forth population is declining while the UK population is static then a local cause is more likely. Along the Forth pressure from developments like the new bridges and disturbance due to easier access are given as reasons for the decline. Ironically improving the water quality has also probably been detrimental to some species. For example the discharge of spent grain from breweries and distilleries used to provide a great source of food for some ducks. Under treaty obligations specified in the EC Birds Directive (1979) and the International Ramsar Convention (Ramsar, Iran, 1971) the bird populations in the Firth of Forth require automatic designation as both a Ramsar Site and an SPA (EC Special Protection Areas). This gives them the highest level of protection with the possibility of EC fines if we are in default. The Scottish Wildlife Trust plays its part in this conservation activity having three wetland bird reserves in the upper Forth estuary at Alloa Inch, Tullibody Inch and Cambus Pools.
More Volunteers Wanted to Monitor Garden Birds |
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November 2009 Here Come the Girls - Influx of Painted LadiesElegant painted lady butterflies with their black, white and tawny wing markings are usually seen on sunny late summer days, nectaring on Buddleia or knapweeds with red admirals, small tortoiseshells and peacocks. This year however, after a population explosion in their North African breeding grounds we saw one of the greatest immigration events of the last 50 years. |
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| Millions headed north in a butterfly tidal wave which spread across an 850 mile wide front from Ireland to Poland. Moving at a rate of about 100 miles per day thousands per hour were arriving in south coast gardens in late May and a few days later they could be counted by the hundred as far north as Durness. The good weather during this period encouraged these adventurous pioneers and sightings were recorded in St Kilda, the Faroes and even Iceland during the beginning of June. By August the initial migrants, now rather tattered and faded, had bred, giving us a second batch of fresh young adults. If you spotted painted ladies this year please record them at www.butterfly-conservation.org
The Powan is a distinctive Scottish variety of the freshwater whitefish which was confined to Loch Lomond and Loch Eck. Growing up to 46cm long it has a dark bluish back, pale silvery underside and striking dark fins. Currently numbers are in serious decline because of predation by ruffe, a small member of the perch family. This invasive alien is thought to have been introduced by pike fishermen as live bait. It eats powan eggs and competes with the adults for food. Thanks to the foresight of a few dedicated conservationists, protected populations of powan have now been established in Carron Valley Reservoir and Loch Sloy. Loch Lomond also contains a unique population of River Lampreys members of which, instead of spending part of their life at sea, live entirely in fresh water. |
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| The Arctic Charr which is related to both salmon and trout takes its name from the Gaelic for the breeding male's red belly. Our native fish are non-migratory, populations having survived in lochs with cold, well-oxygenated water since the end of the last Ice Age. Locally Charr are still found in Lochs Doine, Voil and Lubnaig, but sadly the Loch Katrine population is probably extinct. The fish is given little protection in law and there has been a steady loss of populations probably as a result of water engineering works, pollution, afforestation, trout stocking and climate change. |  |
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Arctic Charr painted by Robin Ade - © P S Maitland |
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Sparling or smelt is a small silvery fish 10-20cm long which inhabits clean estuaries and comes upstream to spawn in freshwater. Originally there were 16 Scottish estuarine locations though currently the fish is confined to the Forth, Tay and Cree. Sparling seem to occur throughout the Forth estuary but assemble in the upper estuary near Alloa in late February migrating into fresh water to spawn in March. It is not know where the current spawning beds are. As a result of pollution local numbers plummeted in the 60s and 70s but glad to say they are increasing again as the river quality improves. |
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August 2009 Breeding Nuthatches In last autumn's newsletter we reported that residents of Bridge of Allan and the University had seen nuthatches on their bird feeders. During Jan - March they were rarely seen but after hearing their distinctive call in April breeding pairs were found in both Mine and Hermitage Woods. Nuthatches use old holes in trees as nests and plaster up the entrance with mud until they can scarcely squeeze inside. |
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Picture kindly supplied by Lewis Thomson |
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The range of nuthatches has gradually been moving north. The limit of breeding pairs at the end of the 19th century was Harrogate in Yorkshire and by the early years of the 20th century they had spread to Durham. There was suitable woodland habitat in Scotland - indeed the Duke of Argyll tried to introduce them at Inverary. They finally crossed into the Borders in 1989 and rapidly colonized the woodlands so five years later 220 pairs were recorded. We now find ourselfes at the leading edge of this march north and if local breeding is successful we can look forward to more of these lovely birds in our gardens this autumn. We would be very interested to hear from anyone who has seen nuthatches locally - are there any in Clacks or Western Villages? If you are near well-established deciduous woodland particularly with beech (beechmast is a favourite food) you may see them. Did you hear any Cuckoos this year? Cuckoos can still be heard on Flanders Moss and in the Trossachs but they seem to have become very rare around Stirling and in the Hillfoots. Is this a symptom of another species in decline? Mandy Cook of the British Trust for Ornithology whose Scottish office is based at Stirling University confirmed that the Breeding Bird Survey (BBS) shows UK cuckoo abundance has been falling since the early 1980s. As a result the species has recently been moved from amber to red status on the list of the Birds of Conservation Concern. Although the BBS shows a continuing strong reduction in England and Wales there is an apparent increase in Scotland particularly in the north. The general decline has been attributed to a corresponding fall in Dunnock and Meadow Pipit populations which incubate cuckoo eggs. There has also been a decrease of the moths whose big hairy caterpillars provide vital food supplies for returning adult birds.
March 2009 Waxwing Invasion There can be few sights more guaranteed to cheer up a dull winter's day than a flock of waxwings gorging on rowan or hawthorn berries. During November and December these beautiful birds have been seen in flocks of up to 200 in the centre of Stirling and Dunblane. They are pinkish brown, about the size of starlings but with a prominent crest and yellow, black and red markings. Waxwings do not appear every winter, only during "invasion" years when birds migrate here from Scandinavia. Our sporadic influxes are caused initially by warm weather in their breeding grounds in Scandinavia, Finland and Western Siberia. This results in high chick survival rates together with a good rowan berry set which sustains the birds through the winter. When these birds breed the next summer the population increases still further. Unfortunately the rowans suffer from biennial bearing i.e. they get "tired out" by their previous exertions and produce a poor crop of berries in the second year. This shortage of winter food induces a mass migration into eastern Scotland from where the birds eat their way south and west. Waxwings ringed in Aberdeen in November were spotted in Yorks, Lancs and Suffolk a few weeks later. In both Stirling and Dunblane the flocks have been seen on the berried trees planted around Tesco's but a national survey has shown a preference for Morrisons car parks! A look back through the annual Forth Area Bird Reports indicate that there have been 11 invasions in the last 34 years of which several occurred in consecutive winters, so if you missed them this time keep an eye out next autumn.
Mike started the project back in 1990 whilst working with the Forestry Commission (FCS) when he was involved in erecting 100+ boxes on their land. Initially there were only 4 known breeding pairs of barn owls in the Stirling area but by 2006 this had increased to 39 of which 23 pairs were in the FCS boxes. In 2005 the programme was expanded to provide new nest sites throughout the Stirling, Clackmannan and Loch Lomond & Trossachs National Park (LLTNP) areas. In part this was necessary to accommodate all the offspring from FCS sites that were searching for new territories. Stirling Landfill Tax Trust funded 20 nest boxes in 2006 and Barn Owls of Lowland Scotland (BOOLS) provided a further 27 boxes in Stirling and Clacks areas. This year 20 more boxes have been provided by both Clackmannanshire and Stirling Environment Trust and the LL&TNP for the southern part of the National Park. The breeding success of barn owls follows very closely the highs and lows of the field vole population, their chief prey species. These peak every 3 years (approx) and with this abundance of food a pair of barn owls will on average fledge 3 young. However the following year the vole population crashes resulting in a reduction in the number of barn owls attempting to breed and young owls surviving. 2007 was the most successful year since local records began with 66 known breeding pairs and 179 young owls ringed. Despite a crash in vole numbers in 2008, 65 breeding pairs were recorded and 56 young owls were ringed. The current loss of set-aside land - a rich source of small mammal prey - may well have a negative effect so next years numbers will be important. Should anyone know of any natural barn owl breeding sites in the above areas please email Mike Steward with details at mike.stew@tiscali.co.uk
Hand over of our Flanders Moss Reserve to Scottish Natural Heritage
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