UK gardening - Red squirrel CON. Even Europe refuses to class it as endangered, despoite the hype by the CONservat

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Red squirrel CON. Even Europe refuses to class it as endangered, despoite the hype by the CONservat

Geoff

2006-11-24, 3:25 am

Red Squirrel Facts
Population information
Red squirrels are timid, tree-dwelling mammals that live at low
densities in the UK so are seldom seen. It is therefore very difficult
to carry out an accurate census of the UK populations or assess
population trends.

The most recent estimates of red squirrel population size were
compiled by Harris et al. (1995). They produced an estimate of 161,000
red squirrels in Great Britain, with approximately 30,000 in England,
10,000 in Wales (although recent estimates are significantly lower),
and a main population of 121,000 in Scotland, representing 70-75% of
the GB population.

The population in England has a very fragmented distribution,
occurring in isolated populations on the islands in Poole Harbour, on
the Isle of Wight, in Thetford forest, East Anglia (although this
population may already have disappeared) and across the north of
England.

The Welsh population is mostly confined to discreet woodland patches,
predominantly in large coniferous forest blocks such as Clocaenog
forest and on the Isle of Anglesey.

Scotland is a stronghold for the red squirrel with a habitat that
favours them over the grey squirrel such as the native Caledonian pine
forests and the large sitka spruce dominated conifer plantations.

A recent survey in Northern Ireland gave a figure of 10 000 red
squirrels across the province(O'Teangana, 1999).

Historical changes
It is thought that red squirrels made their way to the British Isles
from mainland Europe by the end of the last ice age, approximately 10
000 years ago. Records indicate a large population as far back as the
15th and 16th Century but, evidence shows that before grey squirrel
introductions, there were historical population fluxes of reds and by
the 18th century, populations were declining principally because of
loss of woodland. Red squirrels were reported to have become extinct
in some parts of Scotland following large-scale deforestation, but the
widespread planting of conifers and introductions of red squirrels
from England and possibly Scandinavia in the late 18th and early 19th
centuries resulted in increasing populations between 1890 and 1910.

In 1903, the Highland Squirrel Club was established to control red
squirrels, which were causing severe bark stripping damage to trees,
and over 82,000 animals were killed in the 20 years up to 1933.
Populations throughout the British Isles declined again between 1910
and 1930 becoming scarce in many places in the1920's (Gurnell, 1991).

A similar pattern of population change occurred in Northern Ireland.

Grey squirrel arrival
The grey squirrel was introduced to approximately 30 different sites
in the UK between 1876 and 1929, and contributed to the decline in red
squirrel populations since 1920. Grey squirrels have now replaced red
squirrel populations throughout much of their former range.

It is thought that once grey squirrels arrive in a woodland populated
by red squirrels, the two species can co-exist for about 20 years
before red squirrels disappear from the site.

All data from the NBN Gateway. Map © Crown copyright. All rights
reserved 2005.

This map shows the range contraction of red squirrels in the UK. The
black and red dots highlight the recorded distribution up till 1985.
Sites with only red dots are the known distribution post 1985. Please
note that this is based on positive recording, many sites in Scotland
may still have red squirrels present but they have not been positively
recorded since 1985.

Throughout the whole of the UK, the red squirrel is still under threat
from long term habitat loss and change, and from competition and
potential grey squirrel incursion and disease transmission and it is
predicted that their numbers will continue to decline, at least in
mainland UK, without specific habitat management. See what the UKRSG
are doing about this.

Population Monitoring
The red squirrel is one of the most threatened of native UK mammals
and one of the important recommendations of the red squirrel SAP is to
carry out long-term monitoring to assess population trends in
different areas and the effects of interaction with the grey squirrel.
It is also important to monitor populations to assess the effects of
conservation management on local populations.

There are six existing methods for monitoring red squirrels, but all
the methods have problems and only two of the methods can
differentiate between red and grey presence (Gurnell et al., 2004).
Transect walks noting sightings of red squirrels, accompanied by
distance sampling if appropriate, is problematic because of very low
encounter rate in low density populations, giving sample sizes too
small to allow statistical analysis. An indirect method, using
hair-tubes to assess presence/absence could be adapted to assess
abundance but only one study has tested this possibility (Garson &
Lurz, 1998). There are additional problems associated with red
squirrels not entering hair-tubes when greys are present (Cartmel,
2000), and the possibility of encouraging interaction between the two
species and the spread of poxvirus, which is a fatal disease for red
squirrels.

A review of all the methods and relevant studies has been carried out
by Gurnell et al. (2004) and recommendations have been made for
further work to develop monitoring methods for this species.

A consortium of organisations is carrying out a two-year scoping study
to investigate all the potential options and develop a protocol for a
comprehensive surveillance and monitoring scheme for red squirrels
across the UK. The scheme should be able to detect population trends
and distribution changes and should be able to differentiate between
red and grey squirrels in areas where both occur or in the interface
between populations of the two species. The scheme will also be able
to monitor the rate of grey incursion into red squirrel areas. A
report on the work is expected in 2007.

In Northern Ireland the Environment and Heritage Service recently
commissioned a study into changes in red squirrel distribution,
following a previous study that estimated red squirrel population size
in Northern Ireland (O'Teangana,1999). The report (O'Teangana et al.,
2000) showed that grey squirrels are continuing to expand and long
term red squirrel survival is now only likely in large conifer
woodlands.

Legal status
As the red squirrel is still widespread and common throughout Europe,
with the exception of northern Italy, it is not protected by the
Habitats Directive and is listed as Lower - risk, not threatened in
the IUCN red data lists. However, the red squirrel is vulnerable in
England and Wales and is therefore fully protected under UK
legislation. This provides protection for both the animals themselves
and their dreys.

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