Spatial and Temporal Movements of Free-Roaming Cats and Wildlife in Two Local Government Areas in Greater Sydney, Australia

Abstract

Free-roaming cats pose a risk to their own health and welfare, as well as to the health and welfare of wildlife and humans. This study aimed to monitor and quantify area-specific free-roaming cat movement. Two local government areas (LGAs) in Greater Sydney were included, Campbelltown (CT) and the Blue Mountains (BM). Motion-capture cameras were installed on 100 volunteer properties (50 per LGA) to indirectly capture animal movements over two months. Transect drives were completed eight times (four per LGA) to directly observe roaming cats in residential areas. The cameras and transects both identified higher free-roaming cat numbers in CT (density of 0.31 cats per ha, resulting in an estimated abundance of 361 cats in the 1604 ha of residential area) than the BM (density of 0.21 cats per ha, resulting in an estimated abundance of 3365 cats in the 10,000 ha of residential area). More wildlife events were captured in the BM (total = 5580) than CT (total = 2697). However, there was no significant difference between CT and the BM for cat events (p = 0.11) or wildlife events (p = 0.32) observed via the cameras. Temporally, cats were observed via the cameras throughout the entire day with peaks at 9:30 am and 8:00 pm in the BM, and 7:00 am and 12:00 pm in CT. Overlaps in activity times were recorded for free-roaming cats with bandicoots (BM), possums (BM), and small mammals (BM and CT). This study demonstrates that camera monitoring on private property and transect drives are useful methods to quantify free-roaming cat abundance to inform cat management interventions.

Keywords: Felis catus; One Health; behaviour; cat; free-roaming; monitoring; outdoor; veterinary science; wildlife.

Figure 1

The Blue Mountains weather trends adapted from the Bureau of Meteorology (BOM). Data collected at Farnells Rd, Katoomba weather station: (a) Mean monthly temperatures (minimum and maximum), data collected 1907–2022 [39,41]; (b) Mean monthly rainfall, data collected 1885–2022 [40].

Figure 2

Campbelltown weather trends adapted from the BOM. Data collected at Mount Annan, Campbelltown weather station: (a) Mean monthly temperatures (minimum and maximum), data collected 2006–2022 [42,43]; (b) Mean monthly rainfall, data collected 2006–2022 [44].

Figure 3

Camera locations and transect drive routes in: (a) The Blue Mountains (BM); (b) Campbelltown (CT). Maps were created using ESRI 2022. ArcGIS Pro: Release 2.9. Redlands, CA: Environmental Systems Research Institute.

Figure 3

Camera locations and transect drive routes in: (a) The Blue Mountains (BM); (b) Campbelltown (CT). Maps were created using ESRI 2022. ArcGIS Pro: Release 2.9. Redlands, CA: Environmental Systems Research Institute.

Figure 4

Cameras set up in the field on volunteer properties at approximately 90 cm above ground level: (a) Camera on a tree in the BM LGA on private property encroaching on wildlife habitat; (b) Camera on a car port in the CT LGA; (c) Camera on a tree looking out at potential cat trails in the BM. BM = Blue Mountains, CT = Campbelltown, LGA = local government area.

Figure 5

Roaming cats (F. catus) on the motion-capture cameras: (a) Cat with a collar during the day on a BM camera; (b) Cat at night on a CT camera. BM = Blue Mountains, CT = Campbelltown.

Figure 6

Indirect (camera) events: (a) Cat (F. catus) events with 1 true outlier removed in CT for better visualisation—median cat events observed 20.0 (BM) and 27.5 (CT). There was no significant difference between these local government areas (p = 0.11); (b) Wildlife events with 1 true outlier removed in the BM—median events observed 63.0 (BM) and 24.0 (CT). No significant difference between the local government areas was found (p = 0.32). BM = Blue Mountains, CT = Campbelltown.

Figure 7

Activity overlaps graphed from motion-capture camera data: (a) Cats and bandicoots (BAN) in the BM; (b) Cats and possums (POS) in the BM; (c) Cats and small mammals (SMLMAM) in the BM; (d) Cats and small mammals (SMLMAM) in CT. BM = Blue Mountains, CT = Campbelltown.

Figure 8

Wildlife captured on the motion-capture cameras in the Blue Mountains (BM): (a) Foxes (Vulpes vulpes) at night; (b) Swamp wallaby (Wallabia bicolor) in daylight.

Figure 9

Direct (transect drive) cat observations for the two LGAs, the Blue Mountains (BM) and Campbelltown (CT): (a) Number of cats observed across four study days in each LGA; mean cats observed in the BM (18.8) and CT (25.8) was not significantly different (p = 0.38); (b) Densities of cats per hectare (cats/ha); (c) Overall estimated abundance of free-roaming cats (total number of cats).