Conservation Science in the RSPB 2006

46
Ouse Washes
Andy Hay (rspb-images.com)
Predator control and
lapwings on RSPB reserves
During the last few decades,
lapwings have severely declined
across a range of habitats
throughout the UK. However, on
wet grassland reserves appropriate
management of livestock and
water levels has generally been
successful in attracting increased
numbers to breed. Whilst this is
gratifying, concern has been
expressed that, although good
nesting habitat has been provided,
on some reserves lapwings have
been suffering high levels of
breeding failure resulting from
predation of nests and young.
In response, a large-scale long-term
experiment was initiated in 1996 to
examine the need for control of
some predators on reserves
managed for breeding lapwings.
Although waders are vulnerable to a
range of predator species, attention
focused on crows and foxes, since
these were believed to be the most
important predators on RSPB
reserves. On each of 11 sites, we
examined the differences in
predator densities and breeding
success of lapwings in four-year
periods with and without fox and
crow control. All operations were
carried out in strict accordance
with the law and animal
welfare considerations.
neighbouring land. Whilst control of
foxes and crows effectively reduced
their densities (by 40% and 56%
respectively overall), the actual
number of predators removed varied
from site to site, depending on their
local density. We found no consistent
improvement in lapwing breeding
performance during years of predator
control. However, poor nest survival
was associated with high fox and
crow numbers and the impact of
predator control was dependent on
the ‘background’ density of foxes and
crows (ie densities in years without
predator control). There were
significant improvements in nest
survival in years of predator control
for those sites where background
densities of foxes and/or crows
were high.
Results from the study indicate that
fox and/or crow control is necessary
on several of our wet grassland
reserves and, following its
implementation, we will monitor the
effect over the next five years.
Contact:
Mark.Bolton@rspb.org.uk
See also: 2001: 33 & 35; 2002: 10;
2004: 30
Even in years with fox and crow
control, there were very large
variations in the numbers of foxes
and crows across sites, probably
related to regional differences in
densities of these predators and the
extent of predator control on