When to Watch Wildlife
NEWSFLASH: Mixed results for seabirds
in Scotland - report from NTS (04/09/2006)
Copyright National Trust of Scotland 2006
Guillemots suffer as seabird breeding season delivers mixed results
IT HAS been a year of mixed fortunes for the breeding success of Scotland’s internationally important seabird colonies, according to monitoring by two of the country’s leading conservation organisations.
Experts on coastal reserves run by RSPB and The National Trust for Scotland have reported that guillemots appear to have suffered worst, with parents unable to find enough of the right fish to feed their young. As a result, hundreds of chicks died on nest ledges and in the sea beneath the colonies.
Breeding failures for guillemots were noted in particular at Fowlsheugh and the Isle of May off the east coast, and for most species off the west coast at widely spaced sites including Handa, St Kilda, Tiree and Ailsa Craig.
Kittiwakes have fared little better. On St Kilda only 1,516 kittiwake nests were found overall – a decline of 61% since 1999. The species also suffered on Mingulay with a 23% reduction in numbers since 2003 and a 30% reduction in guillemots over the same period. Even on Canna, where the removal of nest marauding, non-native rats has caused an overall improvement in the seabirds’ fortunes, productivity was only 0.5 chicks per kittiwake nest, significantly less than the long term average.
Both guillemots and kittiwakes rear their young to fledging almost exclusively on a diet of energy-rich sandeels. However, this year they were observed bringing in pipefish instead, a stiff, bony fish that lacks the nutritious value of the sandeel and often becomes lodged in the throats of young birds.
The failures are thought to be the result of many factors combining to have a greater influence than they would individually. The late start to the breeding season was caused by prolonged, inclement weather throughout most of May. Sandeel stocks in the North Sea may also have been given insufficient time to recover properly as the fishery was reopened this year following only a 9 month ban in 2005. The large Danish fishery is believed to have closed prematurely this year due to a scarcity of fish. Field reports have indicated that the size of the individual sandeels was very small this year.
Norman Ratcliffe, a senior research biologist at RSPB, who specialises in seabirds, said: “The season started off well for most species, but then deteriorated late in the year at a time when the chicks were well grown and in a typical year would have survived. It is plausible that the failures are explained by a timing mismatch: sandeels tend to burrow into the substrate after mid July and so become unavailable to most seabirds. Usually this does not matter since most seabirds will have fledged their chicks by then and can disperse to find alternative prey, but with the delay to the breeding season this year, seabirds still had chicks in July and so the loss of key prey locally resulted in starvation.”
He added: “Guillemots may have suffered in particular because they are only able to transport fish back to their young one at a time. Other species can catch and transport a load of small fish at one go in their beak or crop, and so prey size is less of an issue for them. With guillemots, it’s like taking chips back to your kids at home one at a time rather than buying them in a bag.”
The Centre for Ecology and Hydrology, along with RSPB, conducted detailed diet studies of guillemots at a large number of colonies around the UK this summer, and will be analysing the data to investigate whether fish size or quality was a contributor to the observed failures. Unfortunately, the future work of the CEH seabird team, who carried out this work, is in doubt owing to the closure of the Banchory research station. This type of research is vital if we are to understand better what is going on in the North Sea.
Other species, including puffins, Arctic terns and Arctic Skuas fared rather better. Success was patchy on Orkney, but productivity of most species in Shetland was similar to or slightly improved on 2005. Colonies along the Irish Sea coast again remained high, indicating that this region seems to be consistently avoiding the problems evident further north on the west coast and in the North Sea.
Richard Luxmoore, Head of nature conservation with the National Trust for Scotland, said: “Here in Scotland we have a global responsibility, with over 40 per cent of the seabirds breeding in the European Union, and yet we know little of what impacts their populations. While some studies have been carried out in the North Sea, on the west coast, where the vast colonies of St Kilda, Mingulay, Rum and the Shiants are located, we know virtually nothing of the relationships between seabirds and the factors at sea driving their vital food supplies. Until we devote more resources to this crucial research we will simply be documenting their inexorable demise.”
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The National Trust for Scotland is a charity (No. SC 007410) and depends for its support on the subscriptions of its members, donations and legacies.
NEWSFLASH: Seventeen bird species
having problems raising families (17/11/05)
The British Trust for
Ornithology/JNCC Nest Record Scheme has identified seventeen species whose
increasingly poor breeding performance in recent years is giving cause for
concern. Information collected by hundreds of volunteers, who visit nests to
keep an eye on bird productivity, is being used to alert decision-makers to
environmental problems faced by Britain’s birds.
Writing in the November edition of BTO News, Dr
Dave Leech and Dr Humphrey Crick report the latest findings from analyses of
the thousands of records that are submitted by volunteers to the Nest Record
Scheme (NRS) each year (Notes 1 & 2). The number of species on the NRS Concern
List has risen from fifteen to seventeen since last year. Four species have
been added to the list in 2005: Skylark, Spotted Flycatcher, Starling and
Mistle Thrush, and two (Lapwing and Bullfinch) have been removed.
A full list of the species on the list is given in the Notes
for Editors (Note 3).
Dave Leech, who heads
the BTO’s Nest Record Unit said:
“The NRS Concern List is designed to raise awareness of
declines in breeding success for species whose numbers have fallen
significantly in the UK. While the initial population declines were not
necessarily due to reduced productivity, we are concerned that hard times may
still lie ahead for these species.”
Skylark: Already on
the red section of the Conservation Concern list, following a decline of 59%
between 1978 and 2003. The losses of nests at the egg stage have risen
significantly over the last fifteen years. Nests may fail due to factors such
as predation, farming activity and poor weather. This is particularly worrying
as other BTO research has shown that the number of broods that are raised each
year has declined due to the increase in winter-sown cereals which provide
poor nesting habitat for the species later in the season.
Also on the red section of the Conservation Concern list, numbers have fallen
by 81% over a 25-year period. There has been a steady increase in the losses
of nests at the chick stage since the 1960s and it is now becoming obvious
that fewer chicks are being produced from each successful nest. Flycatchers
find insects, such as flies, hoverflies and butterflies, to feed to their
species on the red section of the Conservation Concern list, its numbers have
fallen by 78% over a 25-year period. Until recently, Starlings have been
raising more youngsters than they did in the 1960s and 1970s, a trend which
indicated that summer conditions were relatively good. However, in the last
ten years brood sizes have been falling rapidly. Starlings find much of the
food they need for their youngsters by probing in lawns and other grassland to
find larvae, such as leather-jackets.
Mistle Thrush: This
amber-listed species has fallen in numbers by 32%. There has been a severe
fall in brood sizes over the last ten years. Youngsters are fed on insects and
Notes for Editors
1. Over the last 60 years, details of more than 1.3 million
records of nesting attempts have been submitted to the BTO/JNCC Nest Record
Scheme, each one detailing the location of the nest and the number of eggs and
chicks it contained at each time that it was visited during the season. These
data enable staff at the BTO’s Thetford headquarters to investigate changes in
the nesting success of Britain’s birds over time.
2. The BTO/JNCC Nest Record Scheme is
funded by a partnership of the British Trust for Ornithology and the Joint
Nature Conservation Committee (on behalf of English Nature, Scottish Natural
Heritage and the Countryside Council for Wales, and also on behalf of the
Environment and Heritage Service in Northern Ireland).
3. Species on the Nest Record Scheme Concern List
are: Moorhen, Ringed Plover, Barn Owl, Skylark, Yellow Wagtail, Grey
Wagtail, Pied Wagtail, Dunnock, Wheatear, Mistle Thrush, Willow Warbler,
Spotted Flycatcher, Starling, House Sparrow, Linnet, Yellowhammer, Reed
4. Nests records for the following species
are particularly needed: Blackcap, Bullfinch, Carrion Crow, Chiffchaff,
Collared Dove, Corn Bunting, Garden Warbler, Goldfinch, Grey Wagtail, Jay,
Lesser Whitethroat, Little Owl, Long-tailed Tit, Magpie, Marsh Tit, Mistle
Thrush, Redstart, Reed Bunting, Ring Ouzel, Rook, Sedge Warbler, Skylark,
Sparrowhawk, Stonechat, Tree Pipit, Treecreeper, Turtle Dove, Wheatear,
Whinchat, Whitethroat, Willow Tit, Willow Warbler, Wood Warbler, Yellow
5. Details about the BTO/JNCC Nest Record Scheme
can be obtained by sending a stamped addressed envelope to the Nest Record
Unit (Dept NNBW), BTO, The Nunnery, Thetford, Norfolk, IP24 2PU.
NEWSFLASH: Fears of poor seabird breeding season confirmed
|RSPB article copied from www.rspb.org.uk/birds/seabirdfailure.asp - due to its serious nature this has been copied in full.|
"Scotland's seabirds have suffered yet another poor breeding season across much of the country with 2005 seeing the problem moving from the east coast and the Northern Isles over to the west, according to three of Scotland's leading conservation organisations.
Experts on reserves run by RSPB Scotland, the National Trust for Scotland (NTS) and the Scottish Wildlife Trust, have reported major failures of certain species, particularly in the west coast reserves, such as Tiree, St Kilda and Canna.
According to the RSPB warden on Tiree, guillemots, razorbills and Arctic terns have had a disastrous year. The most recent survey there showed just four guillemot chicks present at Ceann a' Mhara from a total of 2,173 birds. In a normal year, there would be 1,500 chicks in this area.
On St Kilda, owned and managed by the NTS, there was a spectacular breeding failure for puffins, with only 26% of burrows producing chicks, which compares to a normal figure of 71%. Canna's kittiwake colony of around a thousand pairs saw its worst recorded year with barely five chicks fledged. A dearth of guillemots and razorbills was also reported on the NTS islands of Mingulay and Berneray. Other west coast colonies, such as the Treshnish Isles and Handa have been reporting very poor breeding seasons.
Similarly, Orkney has suffered another very poor season with many species - particularly kittiwakes and great skuas - breeding unusually late. This is probably because they were waiting around in vain for sandeels - the small fish that provide their staple diet - to appear in any number.
On Papa Westray at RSPB Scotland's North Hill reserve, there were 1,050 adult Arctic terns in four colonies and only a single fledged chick was seen. On Fair Isle, also owned by the NTS, there have been complete failures for Arctic terns and great skuas as well as very poor breeding seasons for guillemots and kittiwakes, which are steadily declining in overall number.
Elsewhere across Scotland the picture was mixed. South-east Shetland experienced some breeding success although it was still a poor season generally for the area. Parts of the eastern mainland coast had a better year than expected.
In broad terms, it seems that the species that nested earliest, such as certain types of gull, fared best and those that bred later - kittiwake, Arctic tern, guillemot and razor bill - did worst. Interestingly this year, the shortage of sandeels has forced some species to find alternative food sources in the form of white fish such as pollock, which are less nutritious for chicks.
'This has been yet another disappointing season for Scottish seabirds, although it hasn't been the complete disaster that we saw last year,'said Stuart Housden, director of RSPB Scotland.
'We believe last year's breeding failures were due to lack of food for seabirds as a result of warming seas along the east coast which are a result of climate change. This year the picture is more complex, with the problem moving over to the west. It is of great concern that some birds are having to find an alternative diet just to survive.
We need to monitor closely their feeding habits to see what effect this has on their breeding success in the future. At this stage, we can only speculate about why the west has not been so badly affected before but climate change must be considered as a factor. The situation remains very worrying. Seabirds are excellent barometers of the state of the marine environment and we must do all we can to conserve these iconic species which are so emblematic of Scotland's coast.'
'It is very worrying that places like St Kilda and Fair Isle appear to be suffering breeding failures in their seabird colonies,' said Richard Luxmoore, Head of Nature Conservation at the NTS.
While it is normal for seabirds to suffer periodic failures, the frequency seems to have been increasing in recent years. Scotland has around 45% of all the seabirds in the European Union nesting on its coasts and we have an international responsibility to care for them. The recent breeding failures pose a significant threat to the future of Scotland's seabirds and it is important to remember that the country's seabirds attract significant amounts of tourism to certain areas, boosting the economy and making our coasts unique.'
The Scottish Wildlife Trust (SWT) has also reported a very poor breeding season on its reserves. On Eigg, where kittiwakes would normally be expected to number 5000, the highest number to be been seen this summer is 15.
Stuart Brooks, Head of Conservation at SWT said: 'We are not certain of the causes but we fear that climate change is the trigger for this rapid decline. These changes are obvious but there is likely to be similar devastating changes beneath the waves where we know relatively little. There is no doubt that our marine biodiversity, a jewel in the crown of our natural heritage is under serious threat. The implications for wildlife and people are far reaching.'