The 24hr Home Range and Movements of male feral cats Felis catus

1
The 24hr Home Range and Movements of male feral
cats (Felis catus)
Luke Boucher, Department of Biological and
Physical Sciences, University of Southern
Queensland, Australia
Introduction The house cat Felis catus has become
established in many countries and in particular
is a feral pest across the Australian continent.
The dietary ecology of the species in Australia,
has recently become of great importance due to
their impact on native fauna. Methods of
monitoring populations and effective control
strategies are required for this feral pest. The
movement patterns of feral cats are useful for
management purposes. Information on short term
patterns is used to refine track-based methods of
monitoring populations of feral cats. Information
can be used to space out poisoned baits and
determine the total area of occupancy of the
cats. Information can assess the minimum number
of feral cats detected during track based
population surveys on the basis of 24 hour home
range size. Rabbits have been identified as the
key prey determining the behaviour and abundance
of feral cats 1. The present study was in mixed
mulga woodland where rabbits are scarce. The aim
of the study was to track feral cat movements and
home range over a 24hr period.
Results (cont.) Feral cats remained on average
within 0.8km of the centres of their 24hr home
ranges (Figure 2.). Other comparisons between
longterm home ranges and 24 hour home ranges
indicate the cats shift their 24hr home ranges
within the bounds of their long term home ranges.
The mean distance between the centres of
successive 24hr home ranges was 1.2km.


Figure 2. Characteristics of 24 hour home ranges
of feral cats. Shown are means when n17 (Bars
are standard deviations)
Discussion Low density of cats in study area
meant low number of cats providing home range
size data of high quality. Mortality, misfunction
of collars and disappearance of animals from
study site were major problems. The male feral
cats in this study had the largest home ranges
ever recorded for the species, possibly due to
low availability of prey. Estimates of prey
abundance may not reflect actual prey
availability. Generally the numbers of consumers
present in a habitat reflects the number of
resources available. Correlations between home
range size and density (0.1km2) were
significantly negatively correlated, thus prey
availability is a primary determinant of home
range size in feral cats. In resource poor
environments, population densities are low and
feral cats occupy large home ranges. Prey
availability was low due to low numbers of
rabbits at this site, the cats mainly consumed
small mammals. The cats shifted from 24hr home
ranges to long-term home ranges, due to
territorial nature. Data from long term home
ranges indicated that the home range size in
long-term is 10 times that of 24hr home range
using MCP and fixed kernel data.
http//www.nationalparks.nsw.gov.au/npws.nsf/Conte
nt/Feralcats
Methods Study conducted in Northern Territory,
110km north west of Alice Springs (Figure 1).
Study area is 550km2 and situated on Western Part
of Hamilton Downs station and adjacent stations
Milton Park and Narwietoomba. Mild temp. with
annual rainfall 256mm. Texture contrast soils
support open grassland and open mulga woodland.
Ephemeral creeks and artificial water points.
Cats initially trapped in soft catch traps or
bait hook traps, anaesthetised, measured,
weighed, sexed, given a body condition score of
1-5 and fitted with 115g radio collars. On four
separate occasions intensive tracking from two
fixed stations was conducted to assess 24 hour
movement of cats.
Conclusion The home ranges of the feral cats were
determined using the MCP and fixed kernel
methods. The home range size determined using
these methods was slightly different. Prey
availability has a strong relationship with home
range size, as animals travel to seek prey.
Figure 1. Map of the study area showing (?,?)
water-points, ( ) station roads, (?) areas
of relief and (----) ephemeral creeks. Inset map
of Northern Territory shows (?) the study site in
relation to (?) Alice Springs.
Home range size determined using fixed kernel
method, minimum
convex polygon method and distance from centre
index. T-tests and correlations of 24 hour
data performed by SYSTAT.

Results 24 hour home ranges measured for 3 adult
males. 17 sets of locations over 24hr were
obtained. MCP estimates of 24hr total home range
(249.7ha) were larger than fixed kernel estimates
(103.1ha) (Figure 2). Mean 24hr core home ranges
were 18.6ha. (Figure 2).
Completed as part of BIO3314 Terrestrial Ecology
assessment - October, 2003