Part III: Conservation and Management334
Hunting from the ground may be most useful as a follow-
up measure after other control tools have been used (Caley &
Ottley 1995). Aerial shooting from helicopters, however, can
be very useful and cost-effective for achieving rapid popula-
tion reductions over large areas where the vegetation is suit-
ably open (e.g. Saunders 1993; McIlroy 1995; Choquenot et al.
1999). Aerial shooting was originally opposed by animal welfare
groups because it was thought to pose a high risk of wounding.
However, this risk has been reduced through the development
of robust codes of practice (e.g. Sharp & Saunders 2014), and
aerial shooting is now widely used by government agencies and
private contractors.Shortcomings in Contemporary Practice
One of the greatest impediments to effective pig management
at local scales has been the scarcity of detailed information on
pig damage and relationships between pig density and damage.
Without this knowledge, it is difficult to develop rational man-
agement strategies based on reducing damage to assets that are
affected by pigs, rather than just reducing the numbers of pigs.
This ecological/economic rational approach is fundamental to
the prevailing strategic pest animal management paradigm in
Australia (Braysher 1993; Braysher et al. 2012). Intensive stud-
ies have demonstrated positive relationships between feral
pig density and lamb predation in a rangeland environment
(Choquenot et al. 1997) and ground rooting in a subalpine envi-
ronment (Hone 2002, 2012). Modelling has provided further
insights to help inform strategic decision-making for feral pig
management to improve lamb survival (Choquenot & Hone
2002) and pasture productivity (Hone 2006). A New Zealand
study has linked the rate of ground rooting to feral pig density
in a temperate forest environment during a ground-hunting
control programme. Their models demonstrate that the rate at
which ground rooting can be reduced by pig control regimes
diminishes rapidly as more intense and expensive regimes are
implemented (Krull et al. 2016). However, these studies rep-
resent a fraction of the types of damage that pig management
programmes across Australia and New Zealand aim to reduce,
and managers often lack the capacity to conduct similar work
in their own areas. Emerging technologies and methods for
monitoring feral pig impacts and abundance may help over-
come some of these limitations (e.g. Edwards et al. 2004; Gentle
et al. 2010; Bengsen et al. 2011a). Greater integration of research
objectives and expertise into routine management programmes
could provide much-needed information on the relationships
between investment in management activity and the effects on
feral pig populations and the damage that they cause. As well
as facilitating cost-effective strategic management and continu-
ous improvement, this information should support continued
public investment in feral pig management programmes in an
environment of increasing public concern over animal welfare
and public spending (Bengsen et al. 2014b).
Another enduring impediment to effective feral pig man-
agement has been conflict between different sections of the
community that view feral pigs variously as a pest, a benign
presence, or a valuable resource. Even individual landholders
often change their view on feral pigs over time, depending ontheir abundance and impacts. For example, some landholders
like to keep a small number of pigs available for hunting or to
clean up carcasses or fallen fruit that can host insect pests. This
conflict can cause inconsistency in management among neigh-
bouring landholders, particularly those with different land
uses, which reduces the effectiveness of cross-property manage-
ment programmes. Perhaps more importantly, people who find
the prevailing pig management paradigm unacceptable, most
notably hunters, sometimes act in opposition to management
objectives. This has involved illegally translocating feral pigs
(e.g. Spencer & Hampton 2005) and acting in open hostility to
specific management programmes by sabotaging infrastructure
such as traps (Meurk 2011) or temporarily dispersing pigs away
from management areas (A.J. Bengsen, personal observation).
This resistance and hostility likely stems from being excluded
from the management of what they view as a communal
resource rather than a pest. Some commentators have argued
for more inclusive feral pig management, for example through
spatial segregation of management plans that treat pigs as pests
and resources (Izac & O’Brien 1991) or by incorporating con-
sideration of beneficiary–benefactor relationships into existing
ecological/economic rationalist approaches to management
(Meurk 2014). There has been some movement in this direc-
tion with the opening up of public lands such as state forests and
national parks in some states to different forms of recreational
hunting (Bengsen & Sparkes 2016). However, it may be some
time before the prevailing paradigm shifts further towards more
inclusive management, particularly while the commercial har-
vesting industry remains small and volatile.Conclusion
Feral or free-roaming pigs have been regarded as a pest since the
earliest days of European settlement in Australia. However, the
full breadth of their impacts has only begun to be appreciated
in recent decades and is yet to be fully realized in New Zealand.
Most types of damage that feral pigs cause to agricultural, envi-
ronmental, and social values remain poorly understood. Indeed,
examination of what is known with certainty reaches the unde-
niable conclusion that many assumptions and seemingly self-
evident impacts of feral pigs are far from clear. Moreover, the
current failure to resolve competing values of feral pigs in many
parts of both countries can make it difficult to establish an agreed
rational suite of impacts to manage. Thus, while a great deal of
research, extension, and management effort has been expended
in the pursuit of improved feral pig control, a means of achieving
strategic management of actual impacts often remains elusive.
It is also difficult to evaluate and demonstrate the benefit of the
many feral pig control programmes conducted across Australia
and New Zealand each year. There are many practical and ethi-
cal imperatives for improving this situation, including: enhanc-
ing our ability to identify and protect important assets that are
threatened by pigs; securing and enhancing public support for
pig management programmes and objectives; freeing resources
for other environmental and agricultural management opera-
tions; and minimizing the number of individual pigs that need
to be killed over time to achieve desired outcomes..03212:55:46