Seroprevalence and risk factors for Toxoplasma gondii exposure in Australian feral and stray cats using an in-house modified agglutination test

Toxoplasma gondii is a globally distributed zoonotic protist, capable of infecting all warm-blooded animals. In Australia, cats (Felis catus) are the only definitive host capable of spreading T. gondii infection via oocysts. Free-roaming cats are widespread in Australia and can play a central role in the ecology of T. gondii. Therefore, understanding the epidemiology of this parasite in stray and feral cats is essential to understanding the potential risk of infection in animals and humans. Due to a lack of easily accessible commercial kits, an in-house modified agglutination test (MAT) was established to test for IgG antibodies against T. gondii, using cell culture-derived T. gondii tachyzoites, and compared with a commercial MAT. A total of 552 serum samples collected during 2018 - 2021 from stray (n = 456) and feral cats (n = 90) (samples with missing data n = 6) from four Australian states, representing different age groups of both sexes, were screened for antibodies against T. gondii. Risk factors for T. gondii infection were assessed using multivariable logistic regression analysis. The in-house MAT had excellent agreement with the commercial MAT and provided a reliable and economical serological tool for T. gondii screening in animals. The overall observed seroprevalence for T. gondii in cats was 40.4 % (223/552). Bodyweight (as a proxy for age), geographical location, season and whether cats were feral or stray, were factors associated with T. gondii seropositivity in cats. Sex was not found to be a risk factor for T. gondii infection in feral and stray cats. This study shows that Australian stray and feral cats have a high T. gondii seroprevalence, which may translate to significant health impacts for wildlife species, livestock and the public.

Comparison of Locomotor and Feeding Rhythms between Indoor and Outdoor Cats Living in Captivity

The plastic nature of cat behaviour allows this “friendly symbiont” of humans to adapt to various housing conditions. Beyond daylight, one could wonder if other environmental factors affect its patterns. Yet, how its activity and feeding rhythms are impacted by its environment is rarely studied in standardised conditions between populations. We compared the behaviour of cats living in a 29 m2 indoor room and cats living in a 1145 m2 outdoor enclosure, tracking them simultaneously in summer for 21 days, with advanced technologies. Both populations received daylight but weather fluctuations only occurred outdoors. Bimodality was detected in the activity and feeding rhythms of both groups, while twilight triggered crepuscular peaks. Daily, the outdoor population covered more distance (4.29 ± 0.27 km; p < 0.001) and consumed more food (67.44 ± 2.65 g; p < 0.05) than the indoor population (2.33 ± 0.17 km, 57.75 ± 2.85 g, respectively), but displayed less rhythmic behaviours, assumedly because of rhythm disruptors met only in outdoor conditions. Finally, outdoor housing seemed to promote the exploratory behaviour of the cats at night, while indoor housing increased both meal frequency (p = 0.063) and the impact of human interactions on the feeding rhythms of the cats.

Home Range and Activity Patterns of Free-Ranging Cats: A Case Study from a Chinese University Campus

Simple Summary

In this study, we used collar-mounted sensors to determine the home range size of free-ranging cats on a Chinese university campus. Twenty-nine adult cats (fifteen males and fourteen females) were tracked via attached GPS units from October 2018 to June 2020. Throughout the study, home range sizes ranged from 0.56 to 19.83 ha at 95% KDE for all cats. The home range of free-ranging cats is affected by the breeding status and sex; for example, male cats tend to have a larger home range size in the breeding season than in the non-breeding season, and in the breeding season, male cats generally have a larger home range than females. In the study of activity patterns, we provided the activity steps of free-ranging cats at different times of the day, and the mean (±SE) number of steps a cat takes per day was 19,863.96 ± 1627.21. The results show that free-ranging cats have more intense activities at twilight and relatively lower activity intensity in the afternoon. Our study provided a case study of the home range and activity patterns of free-ranging cats living on a Chinese university campus, and provided theoretical support for the management and conservation implications of free-ranging cats in cities.

Abstract

Human activities and the available resources influence the home range and activity patterns of free-ranging cats. Our objective in this study was to determine sex and breeding season vs. non-breeding season home range size, as well as activity patterns for unowned free-ranging cats at a university campus in China. Twenty-nine adult cats (fifteen males and fourteen females) were tracked with attached GPS units from October 2018 to June 2020. We considered the effects of sex and breeding status on the home range size of free-ranging cats. Male cats had larger home ranges (95% KDE: 12.60 ± 2.61 ha) than female cats (95% KDE: 5.02 ± 1.34 ha) in the breeding season. There was a seasonal effect on the home range size of male cats; for example, during the non-breeding season, the home range (95% KDE: 6.68 ± 1.22 ha) was smaller than that during the breeding season (95% KDE: 12.60 ± 2.61 ha), while female cats tended to have larger home ranges in the non-breeding season (95% KDE: 7.73 ± 2.77 ha) than in the breeding season (95% KDE: 5.02 ± 1.34 ha). We used the number of activity steps to measure the activity intensity of cats to explore their activity patterns. The mean (±SE) number of steps a cat takes per day was 19,863.96 ± 1627.21. There were two peak periods of activity in a day, 6:00–10:00 and 17:00–21:00. Our study provided a case study of the home range and activity patterns of free-ranging cats living on a Chinese university campus, and the results show that the home range of free-ranging cats is affected by the breeding status and sex, and free-ranging cats have more intense activities at twilight and relatively lower activity intensity in the afternoon. The results provided theoretical support for the management and conservation implications of free-ranging cats in cities.

Evaluating the efficacy of a landscape scale feral cat control program using camera traps and occupancy models

The impact of introduced predators is a major factor limiting survivorship and recruitment of many native Australian species. In particular, the feral cat and red fox have been implicated in range reductions and population declines of many conservation dependent species across Australia, including ground-nesting birds and small to medium-sized mammals. The impact of predation by feral cats since their introduction some 200 years ago has altered the structure of native fauna communities and led to the development of landscape-scale threat abatement via baiting programs with the feral cat bait, Eradicat. Demonstrating the effectiveness of broad-scale programs is essential for managers to fine tune delivery and timing of baiting. Efficacy of feral cat baiting at the Fortescue Marsh in the Pilbara, Western Australia was tested using camera traps and occupancy models. There was a significant decrease in probability of site occupancy in baited sites in each of the five years of this study, demonstrating both the effectiveness of aerial baiting for landscape-scale removal of feral cats, and the validity of camera trap monitoring techniques for detecting changes in feral cat occupancy during a five-year baiting program.

Success criteria not met, but valuable information gained: monitoring a reintroduction of the tammar wallaby

Context Fauna translocations are a tool for improving the conservation status of threatened species. Reviews of translocations undertaken in Australia and globally have reported that many fail because of predation by exotic predators. The outcome of ~40% of translocations was unknown, often owing to inadequate post-release monitoring. Monitoring methods such as global positioning system data-loggers can provide valuable information on survival, habitat use and sociality, and can be particularly useful for cryptic species. Aims The present study used global positioning system (GPS) data-loggers and VHF radio-transmitters to evaluate the success of a reintroduction of the tammar wallaby and measured survival, short-term home-range, habitat use and proximity between reintroduced individuals (as a proxy for association). Methods Sixty-nine tammar wallabies of captive and wild stock were reintroduced to Kalbarri National Park (KNP) following long-term and broad-scale fox control, with nine receiving GPS data-loggers, and 16 receiving VHF radio-transmitters. Wallabies were intensively monitored for up to 11 months post-release. Mortalities were investigated using DNA identification and field necropsies. Key results In total, 16 of the 25 collared wallabies died within 11–319 days of release. Ten of the sixteen deaths were from predation. Home-range areas were larger than those reported elsewhere. Wallabies utilised long-undisturbed vegetation with a dense canopy cover during crepuscular periods. These areas were likely sought as refuge from predation and thermal extremes. During the main feeding period, a mosaic of recently burnt (i.e. ~1 year) and >10 years since last disturbance was important. Conclusions The reintroduction was not considered successful because two-thirds of the collared wallabies died within 1 year of release and, therefore, the success criteria were not met. Implications Despite long-term fox control in KNP, the majority of collared wallaby deaths were a result of fox predation. This highlights the inherent difficulty of establishing populations of some species in the presence of introduced predators. Additional research could assist in determining appropriate control levels for introduced predators, to help ensure the success of future translocations of this species. Consideration should be given to the prey naivety of source animals, prey-switching by introduced predators, and short-term supplementary feeding to assist population establishment.

The 'Feline Five': An exploration of personality in pet cats (Felis catus)

The idea of animals possessing personalities was once dismissed by the scientific community, but has since gained traction with evidence for potential application to improve captive animal management and welfare. Although domestic cats are popular companion animals, research has tended to overlook the value of personality assessment for management and care of pet cats. The aim of this study was to investigate personality in a large sample of pet cats with a view to understanding practical implications for pet cats in the home. Personality of 2,802 pet cats, from South Australia and New Zealand, was rated by their owners utilising a survey measuring 52 personality traits. Five reliable personality factors were found using principal axis factor analysis: Neuroticism, Extraversion, Dominance, Impulsiveness and Agreeableness. Implications for the 'Feline Five' are discussed in relation to their potential application to improving the management and welfare of pet cats. Highly Impulsive cats for example, may be reacting to something stressful in their environment, whereas cats with low Agreeableness scores, showing irritability may indicate underlying pain or illness. Thus, the need for a systematic and holistic approach to personality that includes both the individual pet cat and its environment is recommended, and opens the door to future interdisciplinary intervention.

Research challenges and conservation implications for urban cat management in New Zealand

Over the past 20 years, conservation efforts in New Zealand have moved from being concentrated in rural and isolated island locations, where exotic mammalian predators are often controlled, to begin to bring native fauna back to major cities. However, human–wildlife conflicts arise when conservation occurs in close proximity to cities. These are particularly intense when companion animals are involved either as potential predators or prey of high-value conservation animals. Within New Zealand, this conflict is particularly fraught around domestic cats (Felis catus) in the urban environment. Cats in New Zealand are recognised as major introduced predators of native fauna, but they also prey on small introduced predatory mammals. This dynamic causes much conflict between people with different attitudes towards animals; however, as yet, few studies have explored the role(s), either negative or positive, of urban cats in New Zealand. Here, we review current knowledge on domestic cats in urban New Zealand, identify gaps in knowledge and make suggestions for future research, which includes further social science research, citizen science-based research programs, market research, investigation into cat-management legislation, and more in-depth studies of cat diseases and zoonoses. These data are vital for informing the public and improving the management of urban cat populations, including mitigating conservation impacts. Urban ecologists will need to be versatile in the way they design and conduct experiments, exploiting multiple disciplines to both ensure scientific robustness, but also community and government support for uptake of results into management and legislation.

Ranging behaviour and movements of the red fox in remnant forest habitats

Context The Eurasian red fox (Vulpes vulpes) is a widespread pest in mixed agricultural and remnant forest habitats in southern Australia, and is controlled most commonly with baits containing poison (1080) to protect both agricultural and ecological assets. An understanding of fox movements in such habitats should assist in the strategic placement of baits and increase bait encounters by foxes across the landscape, thus improving the success of control efforts. Aims We seek to understand the ranges, movements and habitat use of foxes to aid the development of effective management plans. The fate of tracked animals was examined during a control program. Methods We radio-tracked 10 foxes using VHF transmitters and three foxes using GPS receivers during control operations in a remnant forest area near Dubbo, New South Wales. We used VHF location fixes to estimate fox range areas and GPS fixes to describe temporal and spatial aspects of fox movements and range use, focal points of activity and potential bait encounters. Selection of forest versus cleared areas was assessed, as was the impact of control operations on collared foxes. Key results Range areas (mean ± s.e.; 95% minimum convex polygon) for VHF- and GPS-tracked foxes were 420 ha ± 74 and 4462 ha ± 1799 respectively. Only small parts of range areas were visited on a daily basis, with little overlap. Animals were often within 200 m of roads and crossed or travelled on roads more than expected. At least 75% of collared foxes were probably poisoned in the control program. Conclusions Foxes occupy large ranges and move long distances in the study region, with little daily overlap, so successful defence of range areas is unlikely. Control efforts successfully poisoned foxes but also limited data collection because of reduced tracking periods. Implications The large and variable areas occupied by foxes suggested that control efforts need to be on-going, coordinated across the landscape, and use a minimum bait density of 0.5 baits per 100 ha in remnant forest habitat to ensure that gaps are minimised. Control operations should target roads and forest edges for bait placement, and increase the time that baits are available, to increase fox encounters and maximise the success of control efforts.

Regional seroprevalence of Toxoplasma gondii antibodies in feral and stray cats (Felis catus) from Tasmania

Toxoplasma gondii is a cosmopolitan protozoan parasite of felids that also has significant implications for the health of wildlife, livestock and humans worldwide. In Australia, feral, stray and domestic cats (Felis catus) are the most important definitive host of T. gondii as they are the only species that can excrete the environmentally resistant oocysts that provide a major source of infection for mammals and birds. In Tasmania, the rapid decline of the Tasmanian devil (Sarcophilus harrisii) may allow an increase in feral cat abundance, thereby increasing the risk of T. gondii infection to a range of susceptible wildlife species. At present, there is scant information on the prevalence of T. gondii infection in feral cat populations across Tasmania. We tested feral cats from 13 regions across Tasmania for the presence of T. gondii–specific IgG antibodies using a modified agglutination test. Results were combined with serosurveys from three previous studies to enable a comparison of seroprevalence among 14 regions across Tasmania. We found that 84.2% (224 of 266) of cats tested positive for T. gondii IgG antibodies. This is among the highest rates of prevalence recorded from Australia, and significantly higher than for most other countries. Adult cats had higher seroprevalence than kittens but there was no difference between sexes. In Tasmania, seroprevalence was high in 12 of 14 regions (range: 79.3–100.0%), with only two regions (Tasman Island and Southern Tasmania) recording significantly lower seroprevalence (≤50%). This suggests a high risk of infection across Tasmania, and has significant implications for wildlife conservation should feral cat abundance increase with the ongoing declines in Tasmanian devils.

The good, the bad, and the ugly: space use and intraguild interactions among three opportunistic predators—cat (Felis catus), dog (Canis lupus familiaris), and red fox (Vulpes vulpes)—under human pressure

Examples of interspecific interactions have been described for mammalian predators, but less is known regarding disturbances of native predator guilds by domestic predators. We investigated intraguild interactions among three opportunistic predators (dog ( Canis lupus familiaris L., 1758), cat ( Felis catus L., 1758), and red fox ( Vulpes vulpes (L., 1758)) co-occurring in the extensive farmlands of central Poland. Their space use was monitored using tracking stations distributed in field and forest plots along a distance gradient from buildings and analyzed using the occupancy-modeling framework. For all three species occupancy decreased with increased distance from buildings, although for the fox the pattern was relatively weak. The occurrence of cats at the stations was higher in the forest than in the field; for fox and dog, there was a strong variation between study plots. For all three predators, the probability of detection was higher during the night than during the day and varied between the seasons; however, the exact patterns were species-specific. The presence of one predator was also linked to the presence of the other two species—generally, a given species was detected more frequently in the absence of the other two species. We recorded spatiotemporal niche segregation among the three species. We conclude that interspecific antagonistic interactions and differences in foraging ecology are the main drivers shaping co-occurrence of the three species in the agriculture landscape.

Applying home-range and landscape-use data to design effective feral-cat control programs

Context Effective feral-cat (Felis silvestris catus) management requires a sound understanding of the ways cats use their environment. Key characteristics of landscape use by cats vary widely among different regions and different conditions. Aims The present study aimed to describe the most important characteristics of landscape use by feral cats on a large, human-populated island, and to use this information to guide the development of feral-cat management programs. Methods We used GPS tracking collars to record the movements of 13 feral cats at two sites on Kangaroo Island, South Australia, for between 20 and 106 days. We described home-range extents by using local convex hulls, and derived management suggestions from examination of home-range and movement data. Key results Median feral-cat home range was 5.11 km2, and this did not differ between sexes or sites. Cats at a fragmented pastoral site tended to favour woody vegetation over open paddocks, but habitat preferences were less clear at a bushland site. Cats that preferentially used treelines at the pastoral site were almost twice as likely to be recorded close to a tree-line junction as expected. Conclusions Control programs for feral cats on Kangaroo Island should deploy control devices at a density no less than 1.7 devices km–2. Spatial coverage should be as large as practicable or repeated frequently. Infrequent programs covering small areas can be expected only to provide short-term reductions in cat abundance. Implications The information gained from the present study will contribute to the development of strategic sustained management plans for feral cats on Kangaroo Island. The principles from which we inferred management guidelines are applicable to other regions and species.

Is water the key? Dingo management, intraguild interactions and predator distribution around water points in arid Australia

Context Predators are major beneficiaries of artificial water points in arid environments, yet little is known of the effects of water on the distribution of many sympatric species. Intraguild interactions around water points in arid Australia may play a significant role in structuring mammalian predator assemblages and influence spatial predation on some native prey species. Aims We examined how management of an apex predator, the dingo (Canis lupus dingo), influenced the distribution of two introduced mesopredators, foxes (Vulpes vulpes) and feral cats (Felis catus), around water points in arid Australia. Methods The spatial activity of dingoes, foxes and feral cats was assessed at five study sites with varying dingo management regimes. Sampling of predator activity was monitored using track counts at measured proximity to water points. Key results At sites where dingoes were uncontrolled, foxes were less likely to be found within 5 km of water points; conversely, where dingoes were controlled using exclusion fencing, fox activity was highest near water. Where dingo activity was reduced using 1080 baiting, feral cats were found closer to water. Conclusions These patterns suggest that the presence of dingoes instigates avoidance behaviour by foxes and feral cats, and through doing so may limit the use of artificial waters by these mesopredators. Through limiting access to such an essential resource in arid environments, dingoes may reduce mesopredator populations and minimise their impact on native prey. Implications For the conservation of native biodiversity, it may prove beneficial to maintain intact dingo populations due to their suppressive effect on mesopredators.

Movement patterns of feral predators in an arid environment – implications for control through poison baiting

Control of introduced predators is critical to both protection and successful reintroduction of threatened prey species. Efficiency of control is improved if it takes into account habitat use, home range and the activity patterns of the predator. These characteristics were studied in feral cats (Felis catus) and red foxes (Vulpes vulpes) in arid South Australia, and results are used to suggest improvements in control methods. In addition, mortality and movement patterns of cats before and after a poison-baiting event were compared. Thirteen cats and four foxes were successfully fitted with GPS data-logger radio-collars and tracked 4-hourly for several months. High intra-specific variation in cat home-range size was recorded, with 95% minimum convex polygon (MCP) home ranges varying from 0.5 km2 to 132 km2. Cat home-range size was not significantly different from that of foxes, nor was there a significant difference related to sex or age. Cats preferred habitat types that support thicker vegetation cover, including creeklines and sand dunes, whereas foxes preferred sand dunes. Cats used temporary focal points (areas used intensively over short time periods and then vacated) for periods of up to 2 weeks and continually moved throughout their home range. Aerial baiting at a density of 10 baits per km2 was ineffective for cats because similar high mortality rates were recorded for cats in both baited and unbaited areas. Mortality was highest in young male cats. Long-range movements of up to 45 km in 2 days were recorded in male feral cats and movement into the baited zone occurred within 2 days of baiting. Movement patterns of radio-collared animals and inferred bait detection distances were used to suggest optimum baiting densities of ~30 baits per km2 for feral cats and 5 per km2 for foxes. Feral cats exhibited much higher intra-specific variation in activity patterns and home-range size than did foxes, rendering them a potentially difficult species to control by a single method. Control of cats and foxes in arid Australia should target habitats with thick vegetation cover and aerial baiting should ideally occur over areas of several thousand square kilometres because of large home ranges and long-range movements increasing the chance of fast reinvasion. The use of temporary focal points suggested that it may take several days or even weeks for a cat to encounter a fixed trap site within their home range, whereas foxes should encounter them more quickly as they move further each day although they have a similar home-range size. Because of high intra-specific variability in activity patterns and home-range size, control of feral cats in inland Australia may be best achieved through a combination of control techniques.