Tim Davis
Nature Notes series and more from Berrynarbor's resident ornithophile.
WHERE HAVE OUR GREENFINCHES GONE?
Greenfinch © Mike Langman
I sometimes get asked why
Greenfinches have disappeared from many of our gardens. Certainly in the 12
years that Tim Jones and I have lived at Harpers Mill we have noticed fewer
Greenfinches in and around the village, as well as at Smythen Farm. For some reason
Greenfinches are only infrequent visitors to our garden, despite lots of
apparently suitable habitat. Among several diseases which affect birds, one in
particular, trichomonosis, has been the principal cause of the decline in
Greenfinches, and to a lesser extent Chaffinches.
Trichomonosis typically causes disease at the
back of the throat and in the gullet. Affected birds show signs of general
illness, such as lethargy and fluffed-up plumage, and may show difficulty in
swallowing or laboured breathing. Some individuals may have wet plumage around
the bill and drool saliva or regurgitate food that they cannot swallow. In some
cases, swelling of the neck may be evident. The disease may progress over
several days or even weeks. It does not affect humans or
other mammals.
An item on the British Trust
for Ornithology's website in mid-September reported new research that brings
our understanding of the disease outbreak up to date.
The widespread emergence of
trichomonosis in 2006 has resulted in a substantial decline in the Greenfinch
breeding population. The new research demonstrates
that mass mortality in Greenfinches continued in 2007-2009 at a rate of more
than 7 per cent of the population each year, but with a shifting geographical
distribution across the UK. In this time the population of Greenfinches in
Great Britain fell from some 4.3
million to about 2.8 million birds. It appears that the disease jumped from pigeons or doves to finches, but
quite why Greenfinches suffered more than other small birds remains unknown.
For more information on
trichomonosis and other bird diseases, visit the BTO website at www.bto.org and
follow these links: home > volunteer-surveys >
garden birdwatch > gardens & wildlife > birds > disease. This will
take you to a page on 'Disease and garden birds'. Here you will find advice on
what you can do to look after your garden birds, especially the need to keep
feeders clean. If you would like to report finding dead garden birds or signs
of disease in garden birds, there is also an online reporting form.
Tim Davis
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SAVING
SWIFTS
Most Berrynarbor residents will be familiar with Swifts,
which arrive in the
In addition, their
habit of [literally] screaming at high speed low over rooftops, often in small
parties, especially towards dusk, makes them unmissable to anyone out and about
the village.
Swifts are the most aerial of birds. They feed on flying
insects and never perch on wires like Swallows. In fact, once a young Swift has fledged, it
is unlikely to land anywhere until it reaches maturity and looks for a nest
site of its own three or four years later.
But finding that desirable location in which to nest is becoming
increasingly hard for Swifts. Their
nesting places, in the eaves of rooftops and older buildings with cavities,
such as the Manor Hall, are
disappearing as buildings are modernised and access to roof spaces blocked up.
Ten years ago, when Tim Jones and I came to live in the
Now, we have a chance to help them. As
some of you may have seen in a recent issue of the North Devon Journal, a
conservation project has been launched within the North Devon Area of Outstanding Natural Beauty [AONB] to help Swifts. With funding from the North Devon AONB,
researcher Greg Ebdon has been visiting villages within the AONB to record the
numbers of Swifts and the location of nest sites, as well as looking for
appropriate sites where specially constructed Swift nestboxes can be put up. Four nestboxes have already been installed
at St Helen's Church in Abbotsham, for example.
If you would like to encourage Swifts to nest within the
eaves of your house or on the wall under the eaves, you can obtain a nestbox
from Greg by contacting him on greg_ebdon@hotmail.com. Note that because Swifts need height to take
off, single-storey buildings are not suitable; nest sites are usually located
at least six metres from the ground. Once
a nestbox has been installed, to stop other birds using it, the opening can be
blocked until the Swifts return. If you
are unsure whether your house is suitable, I should be happy to give advice. You can contact me on 882965 [daytime] or
883807 [evenings/weekends] or at tim.davis@djenvironmental.com.
Tim
Davis
For
more information on Swifts, including a short video and a sound recording of
their calls, visit www.rspb.org.uk/wildlife/birdguide/name/s/swift.
Artwork
by Mike Langman [www.mikelangman.co.uk]
32
THE
BIRDS OF LUNDY
Lying
some ten miles off the nearest point on the
We
- that is the Tims of Harpers Mill - have been visiting Lundy for more than 50
years between us. The idea to write a
new book on the island's birds first struck in 1999. Initially we contacted former Lundy Warden
Nick Dymond to ask if he had any plans to update his own book on Lundy's birds,
published by Devon Bird Watching & Preservation Society in 1980. At that stage Nick was part way through
revising the text but, as he put it, 'running out of steam' and with many other
things on his plate. Nick kindly forwarded his notes, giving us a
great starting point. In the intervening
years, as well as scouring every Lundy Field Society (LFS) Annual Report, Devon Bird Report and the surviving LFS logbooks
from the island, we have researched every scrap of information we could find.
This included a fascinating visit to the Alexander Ornithological Library in
Most
of the work has been done in our spare time, but, conscious of the years
passing by, we began to step on the accelerator in 2005 until finally, in
February this year, we completed the manuscript. Since
then we've been polishing it and adding bird records for 2007. We took the book to the printer, Short Run
Press Limited of
The
Birds of Lundy itself fledged on 29th September at a launch at RM
Young (Bookseller) in
The
goals we set ourselves in preparing the book were:
- To produce an up-to-date account of the ornithology of Lundy, with
a review of historical records and an account of all bird species that
have occurred on the island since the founding of the LFS in 1946 and the
commencement of daily records in 1947.
- To raise awareness of the Devon Bird Watching & Preservation
Society and the Lundy Field Society and promote their roles in the
research and conservation of birds and the natural environment, both in
Devon and on Lundy.
- To invest any proceeds made from sales of the book in bird-related
conservation work on Lundy.
- To promote awareness and appreciation of Lundy's conservation value
and its importance as a prime 'ecotourism' destination and birdwatching
venue.
- To stimulate enhanced recording of birds and other wildlife on
Lundy.
Manx Shearwaters by: Mike Langman
Whether
we succeed in all of these objectives only time will tell. The immediate result is a detailed account of
the 317 species that currently make up the Lundy bird list, plus a further 36
species which for various reasons do not qualify for the full list. Internationally renowned biologist Hugh Boyd,
who began his ornithological career as LFS Warden in 1948/49, has penned the
book's foreword. [Health permitting,
Hugh will be staying with us on the island this October.]
As
well as writing the book, we also published it on behalf of Devon Birds and the
LFS. Both organisations contributed
grants to cover the printing costs, and we are grateful also to several other
individuals and organisations that have supported the book financially. All are acknowledged within the books 319
pages, which are enlivened by 20 colour photographs and more than 100 line
drawings by
For
more information visit www.birdsoflundy.org.uk or contact us on 882965 [daytime]
or 883807 [evenings and weekends].
If
you have thought about going to Lundy but have yet to do so, we hope that The Birds of Lundy might inspire you to
step onto the island boat, MS Oldenburg, and off at the other end onto the
Tim
Davis & Tim Jones
Manx Shearwaters are breeding on Lundy in increasing numbers following eradication of the rat population.
17
A RARE BUTTERFLY IN THE STERRIDGE VALLEY
Large Tortoiseshell Butterfly at Harpers Mill, 17th April 2003
We have been recording all kinds of wildlife in our garden at Harpers Mill over the past two years. On Maundy Thursday [17th April] this year, as we stood at the top of our drive waving off some visitors, a butterfly flew past that we immediately recognized as something different. Fortunately, it settled and basked in the sun on our rockery, allowing a careful approach to within 1-2 metres but always flying off fast and strongly if approached too closely, before returning to a sunlit area. We identified the butterfly as a Large Tortoiseshell, a distant relative of the familiar Small Tortoiseshell, that we recognised from time abroad, but knew to be very rare in this country. Fortunately, we were able to take three photographs at pretty close range, which have proved good enough to confirm the sighting. After basking for some minutes, the butterfly flew off down the valley.
The Millennium Atlas of Butterflies in Britain and Ireland, published in 2001, shows how Large Tortoiseshells used to be quite widespread but declined in the 20th century to become officially extinct as a breeding species. The Atlas says: "The few genuine sightings in recent years are thought to be mainly of individuals that have been reared in captivity from larvae obtained abroad and that have either escaped or been released into the wild". It also shows that the last record of Large Tortoiseshell in the Berrynarbor area was more than thirty years ago. We sent details of our sighting, along with the photographs, to the Devon branch of Butterfly Conservation, which featured the butterfly on the front cover of their county newsletter. The record is also being submitted, through the Devon Butterfly Recorder, to the Devon Biological Records Centre.
This was the first sighting of a Large Tortoiseshell in Devon for many years. We'll never know if it was a truly wild migrant from the continent, one which hibernated over the winter, or a butterfly that was bred and released in the UK. Interestingly, as everyone will recall, the week before Easter was unusually sunny, which may have played a part. Whatever, its appearance in our garden was very exciting and goes to show just what can turn up when you garden with wildlife in mind. In the last six months alone, we have recorded more than 150 different kinds of moth - many of them very striking and colourful. More about them in a future issue!
Tim Davis and Tim Jones - Harpers Mill
29