Agriculture Reference
In-Depth Information
may result in serious losses. It should be noted that
the plants themselves are not eaten by the mole.
Life cycle
. Throughout the year, in its dark
environment, this solitary animal moves, actively
searching for earthworms, slugs, millipedes and
insects. About five hours of activity are followed by
about three hours of rest. Only in spring do males
and females meet. In June, one litter of two to seven
young are born in a grass-lined underground nest,
often located underneath a dense thicket. Young
moles often move above ground to find a new
territory, reaching maturity at about four months.
Moles live for about four years.
Control
. Natural predators of the mole include tawny
owls, weasels and foxes. The main control method is
trapping, best carried out between October and April,
when tunnelling is closer to the surface. Gardeners
can use
pincer
or
half-barrel traps
placed in fresh
tunnels and inserted carefully so as not to greatly
change the tunnel diameter. The soil must be replaced
so that the mole sees no light from its position in
the tunnel. The animal enters the trap, is caught
and starves to death. On areas such as lawns, the
drenching of a soluble product containing
aluminium
ammonium sulphate
(that acts as an irritant to the
mole, when reaching the tunnel) is often used. Smoke
formulations can be inserted inside mole tunnels:
the resulting vapour deposits a chemical such as
castor oil
on the inside of the tunnel and this keeps
earthworms away from the tunnel, causing the mole
to move away from the area.
Sonar deterrent
devices
(including solar-powered models), when inserted into
soil, deliver a frequency of sound intolerable to the
mole that causes the animal to move away from the
disturbance.
Figure 18.5
Wood pigeon
attention; in autumn, tree fruits may be taken in large
quantities; while in winter, cereals and brassicas are
often seriously attacked, the latter when snowfall
prevents the consumption of other food. The wood
pigeon is attracted to high-protein foods such as seeds
when they are available.
Life cycle
. Wood pigeons lay several clutches of two
eggs per year from March to September. The chicks
from August/September clutches are the most likely to
survive. Eggs are laid on a nest of twigs situated deep
inside the tree, and hatch after about 18 days, the
young remaining in the nest for 20-30 days. Predators
such as jays and magpies eat many eggs, but the main
population-control factor is the lack of food in winter.
Numbers in Britain and Ireland are boosted a little by
migrating Scandinavian pigeons in April, but the large
majority of birds are resident in the Britain and Ireland
and do not migrate around the country.
Control
. The wood pigeon spends much of its time
feeding on wild plants and only a small proportion of
its time is spent eating crops. Control of the whole
population therefore seems ethically unsound and is
both costly and impracticable.
Physical
control involves
the protection of particular areas by means of disturbing
or scaring devices. In gardens, plastic or stainless steel
strips bearing spikes may be placed in pigeon vantage
points on buildings and walls and reduce their damage
to garden plants.
Ultrasonic scarers
are effective over
a small area.
Water-scare
equipment, switched on by
the pest's presence, is becoming more popular with
gardeners. Five-centimetre mesh
netting
placed over
an area prevents the pigeon's entry to such targets as
young plants and soft fruit. Gel or liquid formulations
of
aluminium ammonium sulphate
applied to plant
areas or brushed on to pigeon vantage places such as
roof ledges act as an irritant and deter the pest. Life-
Deer
Deer (notably roe deer and muntjac) are increasingly
become important pests as more woodland areas are
developed in Britain and Ireland.
Bird pests
The wood pigeon (
Columba
palumbus
)
Damage
. This attractive-looking, 40 cm long, blue-
grey pigeon with white under-wing bars is known
to horticulturists as a serious pest on most outdoor
edible crops (Figure 18.5). In spring, seeds and
seedlings of crops such as brassicas, beans and
germinating turf may be systematically eaten. In
summer, cereals, clover and soft fruit receive its
