The Irish hare (Lepus timidus hibernicus) is an endemic
sub-species of mountain hare and is the focus of an All-Ireland
Species Action Plan. The Irish Government is required to report the
status of Irish hares under the EC Habitats Directive. Quercus
undertook a survey for the National Parks and Wildlife Service in
order to report on the current and historical status of hares and
to formulate recommendations for monitoring.
Historical game bag data suggest that the
Irish hare population is likely to have been considerably larger
during the mid-19th to early 20th century than at present. Since
then, there has been a substantial decline in the number of hares
shot per year. Similar hunting data from Britain and Europe are
accepted as evidence of the historical decline of hare populations.
Game bags show marked fluctuations and multiannual periodicity in
Irish hare populations. Intrinsic density dependence and extrinsic
climatic effects influence the scale and period of fluctuations.
Coursing records mainly reflect changes in practice, but with
information on capture effort, they may be suitable for monitoring
changes in hare numbers.
Quercus staff and >80 NPWS personnel
surveyed 691 1km2 squares across Ireland during 2006 and 2007. To
estimate hare densities, novel distance sampling approaches were
developed to account for non-uniform distribution of animals with
respect to distance from roads. Here, we demonstrate the importance
of accounting for this bias when designing and analysing hare
Assuming that the survey areas were
representative and stratifying data analysis by region, the spring
density of Irish hares in the Republic of Ireland was estimated to
be 3.33 hares/km2 in 2006 and 7.66 hares/km2 in 2007. Multiplying
density estimates by land area, the population of Irish hares in
the Republic of Ireland was approximately 233,000 hares in early
2006 and 535,000 in early 2007. The scale of this marked and
significant change between consecutive years is consistent with
historical data and with recent surveys of Northern Ireland.
Approximately 50% and 70% of the Irish hare population were found
on pastoral farmland in 2006 and 2007 respectively. The bulk of
change in population estimates between years was ascribed to an
increase in density on pastoral farmland.
No records of brown hares were confirmed
during the survey, suggesting that this non native and potentially
invasive species is mostly, if not entirely, restricted to Northern
We make several recommendations:
1. The aim of future monitoring
should be clarified prior to the adoption of a particular survey
strategy as there are major implications for cost and analytical
a. If the main aim is to produce
accurate estimates of density, a custom Distance sampling approach
similar to that developed here is essential.
b. If the main aim is to establish
temporal trends in population change, repeated counts of relative
abundance with standardised effort will provide an index of change
in numbers over time.
c. Annual counts supplemented with
the intermittent collection of distance data could be analysed to
establish temporal trends punctuated with reference points of
2. A pilot investigation of the
use of coursing records supplemented with capture effort data for
monitoring hares would contribute to a low cost monitoring
3. Better understanding of the
drivers of population change, particularly on pastoral farmland, is
Please cite as: Reid, N., Dingerkus, K., Montgomery, W.I., Marnell, F., Jeffrey, R., Lynn, D., Kingston, N. & McDonald, R.A., (2007), Status of hares in Ireland: Hare Survey of Ireland 2006/07