Little evidence of top-predators biocontrol on invasive mesopredators

Allen, B. L., Allen, L. R., & Leung, L. K. P. 2014. Interactions between two naturalised invasive predators in Australia: are feral cats suppressed by dingoes?.Biological Invasions, 1-16.

Top-predators can play important roles in terrestrial food webs, fuelling speculation that top-predators might be used as biocontrol tools against invasive mesopredators. Feral cats are believed to be largely responsible for the current declines of native fauna across tropical northern Australia, where substantial beef cattle production occurs. Dingoes are known to impact cattle production there and are predicted to impact native fauna also. However, dingoes are forecasted to curtail the impacts of cats and reverse native fauna declines. We review (1) empirical studies investigating the relationships between dingoes and cats, and dingo control and cats, (2) records of cat remains in dingo diets, and (3) historical records of lethal dingo control using 1080-poisoned baits across Australia between 1999 and 2008 to show how two naturalised invasive species can interact in dynamic agro-ecological landscapes. From the 35 studies assessed, most reported no detectable relationship between dingoes and cats; negative or positive relationships were seldom detected. Dingoes do not appear to exclude cats beyond fine scales, but may alter cat activity periods under certain conditions. Cat remains were found in only 0.63 % of over 31,000 dingo diet records. Lethal dingo control occurs (in varying degrees) across about two-thirds of Australia and does not appear to substantially influence dingo-cat relationships. We conclude that the presently available data provides little evidence that bolstering dingo populations will reduce the impacts of cats. Much more work is needed to identify situations where top-predators might be used as effective biocontrol tools against invasive mesopredators in agro-ecological systems.

Low density feral cats cause local extirpation of small mammals in Australia

Frank, A.S.K, C.N. Johnson, J. M. Potts, A. Fisher, M. J. Lawes, J.C. Z. Woinarski, K. Tuft, I. J. Radford, I.J. Gordon, M.-A. Collis & S. Legge. 2014. Experimental evidence that feral cats cause local extirpation of small mammals in Australia's tropical savannas. Journal of Applied Ecology. doi: 10.1111/1365-2664.12323

Small mammal species are declining across northern Australia. Predation by feral cats Felis sylvestris catus is one hypothesised cause. Most evidence of cat impacts on native prey comes from islands, where cat densities are often high, but cats typically occur at low densities on mainland Australia.

We conducted a field experiment to measure the effect of predation by low-density cat populations on the demography of a native small mammal. We established two 12.5-ha enclosures in tropical savanna in the Northern Territory. Each enclosure was divided in half, with cats allowed access to one half but not the other. We introduced about 20 individuals of a native rodent, Rattus villosissimus, into each of the four compartments (two enclosures x two predator-access treatments). We monitored rat demography by mark-recapture analysis and radio-tracking, and predator incursions by camera surveillance and track and scat searches.

Rat populations persisted over the duration of the study (18 months) in the predator-proof treatment, where we detected no predator incursions, but declined to extinction in both predator-accessible compartments. In one case, cat incursions were frequently detected and the rat population was rapidly extirpated (< 3 months); in the other, cat incursions were infrequent, and the population declined more gradually (c. 16 month) due to low recruitment. We detected no incursions by dingoes Canis dingo, the other mammalian predator in the area.

Synthesis and applications. This is the first study to provide direct evidence that cats are capable of extirpating small mammals in a continental setting, in spite of their low population densities. This finding supports the hypothesis that predation by feral cats is contributing to declines of small mammals in northern Australia. The conservation management of native small mammals in northern Australia may require intensive control of cat populations, including large cat-free enclosures.

Cat eradication on Hermite island

Algar, D. A., Burbidge, A. A., & Angus, G. J. (2002). Cat eradication on Hermite Island, Montebello Islands, Western Australia. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN: 14-18.

Feral cats (Felis catus) and black rats (Rattus rattus) became established on the Montebello Islands, an archipelago of about 100 islands, islets and rocks off the Pilbara coast of Western Australia, during the late 19th century. They were probably introduced from pearling vessels. The largest island in the group is Hermite at 1020 ha. Three species of native mammals and two of birds became extinct well before the British used the islands for testing nuclear weapons in the 1950s. Montebello Renewal (part of the ‘Western Shield’ fauna recovery programme) aims to eradicate feral animals from, and reintroduce and introduce threatened animals to, the Montebellos. Rats occurred on almost every island and islet when eradication was attempted in 1996. In 1999 small numbers of rats were detected on Hermite and two adjacent islands and work is under way to eliminate them. Feral cats occurred on several islands at various times, but by 1995 were naturally restricted to Hermite. Feral cat eradication took place in 1999 and comprised two stages – aerial baiting and trapping. Aerial baiting utilised recently developed kangaroo meat sausage baits with flavour enhancers and the toxin 1080. About 1100 baits were dropped by hand from a helicopter. Hermite Island has two main soil types – sand and limestone. Aerial baiting primarily targeted sandy soils. Four cats, all females, remained after baiting. These were trapped using Victor ‘softcatch’^® traps set either in association with phonic and odour lures or set in narrow runways. Eradication was achieved over a six-week period. Searches for evidence of cat activity in 2000 confirmed that cats had been eradicated.

The eradication of alien mammals from five offshore islands, Mauritius

Bell, B. D. (2002). The eradication of alien mammals from five offshore islands, Mauritius, Indian Ocean. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN 40-45.

Following the removal of rabbits from Round Island in 1979 and the publication of a management plan in 1989, the Mauritius Government contracted Wildlife Management International Limited in 1993 to fulfil one of the plan’s recommendations to survey the offshore islands of Mauritius and Rodrigues and to prepare an offshore islands management plan. This plan made a number of recommendations and priorities in relation to the removal of alien species. In 1995 work on the priorities began with the removal of Norway rats (Rattus norvegicus) and hares (Lepus nigricollis) from Gunner’s Quoin, ship rats (R. rattus) from Gabriel Island and mice (Mus musculus) from Ile Cocos and Ile aux Sables. In 1998 cats (Felis catus), ship rats and mice were removed from Flat Island and rabbits (Oryctolagus sp.), which had been illegally released following the earlier eradications, from Gunner’s Quoin. These programmes were hand-laid operations. In all cases the main bait was grain-based pellets containing 0.02gm/kg brodifacoum. The bait was set out on at least half of the maximum grid recommended for the rodent species targeted. The exception was cats, which were trapped in leg-hold traps. Plans are being considered for the re-introduction of reptiles and birds. Some planting of native trees has begun. This paper covers the eradication sector of the management plan

Introduced mammal eradications for nature conservation on Western Australian islands: a review

Burbidge, A. A., & Morris, K. D. (2002). Introduced mammal eradications for nature conservation on Western Australian islands: a review. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN, 64-70.

There are about 3400 islands off the Western Australian coast, many of which have high nature conservation
values. Eleven species of introduced mammals occur or occurred on 124 islands, including three domestic animals (horse, camel and sheep) that have not become feral. In addition, Aborigines introduced dingoes to at least four islands before European settlement. Six exotic mammals (red fox, feral cat, goat, rabbit, black rat and house mouse) have now been eradicated from more than 45 islands in a series of projects since the 1960s. Most effort has been directed at black rats with more than 31 islands now clear of this species. Pindone, vacuum-impregnated into oats, was used until the 1990s, when bran pellets with brodifacoum were used in the Montebello Islands. Rabbits have been eradicated using carrots soaked in sodium monofluoroacetate (1080), red foxes with dried meat baits impregnated with 1080 and cats with a combination of baiting and trapping. After a period of 20 years of ground shooting, goats were finally eradicated from Bernier Island using an experienced shooter operating from a helicopter. The house mouse has been eradicated from Barrow Island four times after introductions in food and equipment, and from Varanus and adjacent islands after introduction in food containers. Both islands are utilised by the petroleum industry. Difficulties and how they were overcome, and future eradication priorities, are discussed.

Alien mammal eradication and quarantine on inhabited islands in the Seychelles

Mertori, D., Climo, G., Laboudallon, V., Robert, S., & Mander, C. (2002). Alien mammal eradication and quarantine on inhabited islands in the Seychelles. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN, 182-198.

During the period 1996-2000, eradication of five introduced mammal species (feral cat (Felis catus), rabbit (Oryctolagus cuniculus), ship rat (Rattus rattus), Norway rat (R. norvegicus) and house mouse (Mus domesticus)), was attempted on four inhabited islands, including three resort islands, ranging in size from 101–286 ha in the Seychelles group, Indian Ocean. Objectives were to avert extinctions of, and restore urgently-needed habitat for, localised threatened endemic animals and to facilitate ecological restoration in line with a national biodiversity strategy. Local political, economic and biological constraints meant that adaptations were necessary to traditional poisoning and trapping methods and regimes. Furthermore, since no rat-free island was available to which native animals at risk from primary and/or secondary poisoning might be transferred, it was necessary to maintain approx. 590 individuals of three threatened animal species in captivity for the three months of the eradication programme. Strategies and techniques developed, and some of the many challenges encountered in conducting eradication and quarantine programmes on inhabited, tropical islands are outlined, together with progress to date. One island (Bird) has been maintained free of rats and rabbits since their eradication in 1996. Two others (Denis and Curieuse) are now free of feral cats but have been recolonised by Rattus rattus since eradication attempts in 2000. The fourth (Frégate), was successfully cleared of R. norvegicus and mice in 2000, in time to avert extinctions of localised threatened endemic animals. These positive results will, we hope, inspire similar effort on other inhabited islands with high biological values or potential.

Cat eradication and the restoration of endangered iguanas on Long Cay

Mitchell, N., Haeffner, R., Veer, V., Fulford-Gardner, M., Clerveaux, W., Veitch, C. R., & Mitchell, G. (2002). Cat eradication and the restoration of endangered iguanas (Cyclura carinata) on Long Cay, Caicos bank, Turks and Caicos Islands, British West Indies. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN, 206-212.

Endangered Turks and Caicos rock iguanas (Cyclura carinata) are being displaced on Big Ambergris Cay
by an expansive development project. We chose Long Cay, Caicos Bank, as a relocation site for some iguanas because it: (1) is a large (111 ha), uninhabited, protected reserve, (2) previously supported iguanas but did not have a current population, (3) could support thousands of iguanas, and (4) had no native mammals, few scavenging birds, and no nesting colonies of scavengers. There was a small population of feral cats, well-known iguana predators. To restore the island, we conducted an intensive cat poisoning campaign using sodium monofluoroacetate (1080), in July 1999. In November 1999, a test-group of 25 iguanas was taken from Big Ambergris Cay to Long Cay. Since their successful establishment we have relocated more than 400. The first hatchlings were confirmed in January 2001. Occasional trapping may be necessary to maintain Long Cay free of cats. We have begun patrols and courtesy visits to vessels cruising the area, installed informative and cautionary signs, and produced public service announcements for TV to reinforce the importance of keeping domestic animals away from uninhabited islands.

Removing cats from islands in NW Mexico

Wood, B., Tershy, B. R., Hermosillo, M. A., Donlan, C. J., Sanchez, J. A., Keitt, B. S., Croll, D.A. Howald, G.R. & Biavaschi, N. (2002). Removing cats from islands in north-west Mexico. In Veitch, C. R., & Clout, M. N. (2002). Turning the Tide: The Eradication of Invasive Species: Proceedings of the International Conference on Eradication of Island Invasives,[University of Auckland, 19 to 23 February 2001] (No. 27). IUCN, 374-380.


Feral cats have been associated with extinctions of endemic island species throughout the world. Removing cats from islands is an effective way to protect biodiversity, but compared to other invasive alien mammals, cats are difficult to eradicate. Here we describe the techniques we used to eradicate cats from 15 islands in north-west Mexico between <1 and 43 km²  These eradication techniques were developed and refined on small islands (<1 km²) and then adopted successfully on larger islands (1– 43 km² . Experienced hunters and trappers, and high quality hunting dogs were critical for successful cat eradication. The most effective technique was trapping and the most critical components of trapping were trap design and placement.

Human infrastructures and feral pets explain the distribution of native carnivores

Zapata G, Branch L, 2014. Evaluación de los factores determinantes de presencia – ausencia de los carnívoros en los Andes ecuatorianos. En: Cuesta F, Sevink J, Llambí LD, De Bièvre B, Posner J, Editores. Avances en investigación para la conservación de los páramos andinos, CONDESAN.

Carnivore surveys using scent stations, camera traps and reconnaissance surveys were carried out in five study areas in the northern Ecuadorian Andes. Nine species of carnivores are known to occur in the Ecuadorian Andes (puma, pampas cat, Andean fox, long-tailed weasel, Colombian weasel, striped hog-nosed skunk, mountain coati, neotropical river otter, and Andean bear).
A total of six species were recorded. The pampas cat, the Colombian weasel, and the Neotropical river otter were the three species that were not recorded. Data analysis suggests that the “distance to the nearest
house”, the “distance to roads”, and the “presence of exotic carnivore species” (feral cats and dogs) are the
most important variables that explain the presence of native carnivore species in the paramo ecosystem of northern Ecuador.

Welfare and behaviour of communal dogs and community perception

Rüncos, L. H. E. (2014). Bem-estar e comportamento de cães comunitários e percepção da comunidade. Dissertação apresentada ao Programa de Pós-Graduação em Ciências Veterinárias, Universidade Federal do Paraná como requisito parcial à obtenção do grau de Mestre em Ciências Veterinárias.

The maintenance of community dogs rises as an alternative of compassionate management that contributes to population control and for improving dogs lives, contributing to diminishing risks for human health. Therefore it is important to study relevant questions of community dogs management. This work’s objectives were to evaluate the life conditions of dogs kept as community ones, performing a welfare diagnosis, studying their behavior, and the attitude and opinion of caretakers and other neighbors about related questions. Such knowledge is essential to understand the local community´s culture and help improving compassionate population control strategies. The present study is divided in five chapters: (I) Presentation; (II) Welfare, (III) Behavior of community dogs in two cities in Southern Brazil, (IV) Attitude and opinion of community dogs caretakers and local neighbors in Southern Brazil, and (V) Final Considerations. Chapter´s 2 results indicate that dogs welfare was regular or high for most dogs. However, there are welfare restrictions that should be minimized. Welfare indicators of behavior presented the best results. Community dogs behavior, studied in chapter 3, was docile and based on positive interactions in general. However there were punctual cases of agonistic behavior, which deserve attention. Caretakers and neighbors attitude was of concern and care towards dogs.

However, responsible guardianship was not well known and practiced by all oh them. The opinion of the studied population was in accordance with a no-kill culture for dogs. The results all together may be used as a base for the community dogs strategy improvement, as for improving dogs welfare. With this work, we expect to contribute for enhance and consolidate a compassionate dog population management strategy.

Roaming behaviour and home range estimation of domestic dogs in northern Australia

Dürr, S., & Ward, M. P. (2014). Roaming behaviour and home range estimation of domestic dogs in Aboriginal and Torres Strait Islander communities in northern Australia using four different methods. Preventive Veterinary Medicine.

Disease transmission parameters are the core of epidemic models, but are difficult to estimate, especially in the absence of outbreak data. Investigation of the roaming behaviour, home range (HR) and utilization distribution (UD) can provide the foundation for such parameter estimation in free-ranging animals. The objectives of this study were to estimate HR and UD of 69 domestic dogs in six Aboriginal and Torres Strait Islander communities in northern Australia and to compare four different methods (the minimum convex polygon, MCP; the location-based kernel density estimation, LKDE; the biased random bridge, BRB; and Time Local Convex Hull, T-LoCoH) for investigation of UD and estimating HR sizes. Global positioning system (GPS) collars were attached to community dogs for a period of 1–3 days and positions (fixes) were recorded every minute. Median core HRs (50% isopleth) of the 69 dogs were estimated to range from 0.2 to 0.4 ha and the more extended HR (95% isopleth) to range from 2.5 to 5.3 ha, depending on the method used. The HR and UD shapes were found to be generally circular around the dog owner's house. However, some individuals were found to roam much more with a HR size of 40–104 ha and cover large areas of their community or occasionally beyond. These far roaming dogs are of particular interest for infectious disease transmission. Occasionally, dogs were taken between communities and out of communities for hunting, which enables the contact of dogs between communities and with wildlife (such as dingoes). The BRB and T-LoCoH are the only two methods applied here which integrate the consecutiveness of GPS locations into the analysis, a substantial advantage. The recently developed BRB method produced significantly larger HR estimates than the other two methods; however, the variability of HR sizes was lower compared to the other methods. Advantages of the BRB method include a more realistic analytical approach (kernel density estimation based on movements rather than on locations), possibilities to deal with irregular time periods between consecutive GPS fixes and parameter specification which respects the characteristics of the GPS unit used to collect the data. The BRB method was therefore the most suitable method for UD estimation in this dataset. The results of this study can further be used to contact rates between the dogs within and between communities, a foundation for estimating transmission parameters for canine infectious disease models, such as a rabies spread model in Australia.

Has the management of stray dog populations and rabies control improved since 2008?

Miranda, E. (2014). Has the management of stray dog populations and rabies control improved since 2008?. In Proceedings of the Third OIE Global Conference on Animal Welfare, Implementing the OIE standards-addressing regional expectations. Kuala Lumpur, Malaysia, 6-8 November 2012. (pp. 41-43). OIE (World Organisation for Animal Health).

Stray and feral dogs are serious threats to public health, safety and welfare. The prevention of zoonotic diseases, notably rabies, depends, inter alia, on effective control of stray dog populations, which should be considered as a priority. There are several approaches to stray dog control, including capture and impounding, and culling. However, to eliminate rabies, stray dog control alone has never had a significant impact on dog population densities and has never been effective as a single method in controlling or eliminating canine rabies. It is, therefore, not recommended as a rabies control strategy on its own. This paper sets out key considerations for humane dog population control as a support to an effective programme for rabies prevention and control.

Prevalence and distribution of gastrointestinal parasites of stray and refuge dogs in India

Traub, R. J., Pednekar, R. P., Cuttell, L., Porter, R. B., Rani, P. A. A. M., & Gatne, M. L. (2014). The prevalence and distribution of gastrointestinal parasites of stray and refuge dogs in four locations in India. Veterinary Parasitology.

A gastrointestinal parasite survey of 411 stray and refuge dogs sampled from four geographical and climactically distinct locations in India revealed these animals to represent a significant source of environmental contamination for parasites that pose a zoonotic risk to the public. Hookworms were the most commonly identified parasite in dogs in Sikkim (71.3%), Mumbai (48.8%) and Delhi (39.1%). In Ladakh, which experiences harsh extremes in climate, a competitive advantage was observed for parasites such as Sarcocystis spp. (44.2%), Taenia hydatigena (30.3%) and Echinococcus granulosus (2.3%) that utilise intermediate hosts for the completion of their life cycle. PCR identified Ancylostoma ceylanicum and A. caninum to occur sympatrically, either as single or mixed infections in Sikkim (Northeast) and Mumbai (West). In Delhi, A. caninum was the only species identified in dogs, probably owing to its ability to evade unfavourable climatic conditions by undergoing arrested development in host tissue. The expansion of the known distribution of A. ceylanicum to the west, as far as Mumbai, justifies the renewed interest in this emerging zoonosis and advocates for its surveillance in future human parasite surveys. Of interest was the absence of Trichuris vulpis in dogs, in support of previous canine surveys in India. This study advocates the continuation of birth control programs in stray dogs that will undoubtedly have spill-over effects on reducing the levels of environmental contamination with parasite stages. In particular, owners of pet animals exposed to these environments must be extra vigilant in ensuring their animals are regularly dewormed and maintaining strict standards of household and personal hygiene.

Toxoplasmosis prevalence in Tasmania's cats

Fancourt, B., & Jackson, R. (2014). Regional seroprevalence of Toxoplasma gondii antibodies in feral and stray cats (Felis catus) from Tasmania. Australian Journal of Zoology.

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 84.2% (224/266) of cats tested positive for T. gondii IgG antibodies. This is among the highest rates of prevalence recorded from Australia, and significantly higher than 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 devils.

Introduced predators selectively culls medium-sized species from island mammal faunas

Hanna, E., & Cardillo, M. (2014). Predation selectively culls medium-sized species from island mammal faunas. Biology letters, 10(4), 20131066.

Globally, elevated extinction risk in mammals is strongly associated with large body size. However, in regions where introduced predators exert strong top-down pressure on mammal populations, the selectivity of extinctions may be skewed towards species of intermediate body size, leading to a hump-shaped relationship between size and extinction risk. The existence of this kind of extinction pattern, and its link to predation, has been contentious and difficult to demonstrate. Here, we test the hypothesis of a hump-shaped body size–extinction relationship, using a database of 927 island mammal populations. We show that the size-selectivity of extinctions on many islands has exceeded that expected under null models. On islands with introduced predators, extinctions are biased towards intermediate body sizes, but this bias does not occur on islands without predators. Hence, on islands with a large-bodied mammal fauna, predators are selectively culling species from the lower end of the size distribution, and on islands with a small-bodied fauna they are culling species from the upper end. These findings suggest that it will be difficult to use predictable generalizations about extinction patterns, such as a positive body size–extinction risk association, to anticipate future species declines and plan conservation strategies accordingly.

The role of cats in the eco-epidemiology of Spotted Fever Group diseases

Segura, F., Pons, I., Miret, J., Pla, J., Ortuño, A., & Nogueras, M. M. (2014). The role of cats in the eco-epidemiology of Spotted Fever Group diseases. Parasites & Vectors, 7(1), 353.

Background

Mediterranean Spotted Fever (MSF), whose etiological agent is R. conorii, is one of the oldest described vector-borne infectious diseases. Although it is endemic in the Mediterranean area, clinical cases have also been reported in other regions. R. massiliae-Bar29 is related to MSF cases. This strain is distributed worldwide. R. conorii and R.massiliae-Bar29 are transmitted by ticks. Dogs are considered the sentinel of R. conorii infection. Cats could also be involved in their transmission. Rickettsia felis, etiological agent of Flea-borne spotted fever, is mainly transmitted by the cat flea, Ctenocephalides felis. Up to now, the role of cats in its transmission is not entirely elucidated. The aim of the study is to analyze the infection in cats by these microorganisms.

Methods

The study was undertaken in Northeastern Spain. Twenty municipalities of seven regions participated in the study. 212 cats (pets and stray cats) were analyzed. Variables surveyed were: date of collection, age, sex, municipality, source, living place, outdoor activities, health status, type of disease, contact with other animals, and ectoparasite infestation. Sera were evaluated by indirect immunofluorescence antibody assay (IFA). Molecular detection (realtime PCR and sequencing) and cultures were performed on blood samples.

Results

There were 59 (27.8%) cats seroreactive to one or more microorganisms. Considering crossreactions, the seroprevalences were 15.6%-19.5% (R. massiliae-Bar29), 1.9%-6.2% (R. conorii), and 5.2%-7.5% (R. felis). A weak association was observed between SFG seropositivity and tick infestation. Ticks found on seropositive cats were Rhipicephalus pusillus, R. sanguineus and R. turanicus. DNA of Rickettsia was detected in 23 cats. 21 of them could be sequenced. Sequences obtained were identical to those sequences of SFG rickettsiae similar to R. conorii and R. massiliae. No amplification of R. felis was obtained.

Conclusions

Cats can be infected by SFG rickettsiae and produce antibodies against them. Cats may play a role in the transmission cycle of R. conorii and R. massiliae-Bar29, although the role in the R. felis cycle needs further analysis.

Rabies antivirus in dogs in SW Nigeria

Oluwayelu, D. O., Adebiyi, A. I., & Ohore, O. G. (2015). A survey of rabies virus antibodies in confined, hunting and roaming dogs in Ogun and Oyo States, Southwestern Nigeria. Asian Pacific Journal of Tropical Disease, 5(1), 17-21.

Objective

To screen for rabies virus (RABV) antibodies in apparently healthy confined, hunting and roaming dogs by a community-based approach.

Methods

Sera from 230 (80 confined, 92 hunting and 58 roaming) dogs in some urban and peri-urban communities in Ogun and Oyo states, Southwestern Nigeria were screened for RABV antibodies using the indirect ELISA method.

Results

Analysis of administered questionnaires showed that of 80 confined dog owners, 37 were aware of anti-rabies vaccination (i.e. they were informed) while 17 were negligent and 26 uninformed. Of the 230 sera tested, only 13 (5.7%) from vaccinated confined dogs in Oyo state were positive (i.e. had optimal RABV antibody titres) (mean 0.54, 95% CI: 0.42–0.67) while all confined dog sera in Ogun state were negative. Eleven (12.0%) and 14 (24.1%) of the hunting and roaming dogs respectively had sub-optimal RABV antibody titres while the rest were negative.

Conclusions

Evidently, these groups of dogs are a totally unprotected and susceptible dog population that can serve as potential reservoirs of RABV in the study area. Responsible pet ownership, vaccination of hunting and roaming dogs, and community-based active rabies surveillance are therefore advocated in Nigeria.

Light birds are more under risk of predation during migratory stopover

Dierschke, V. 2003. Predation hazard during migratory stopover: are light or heavy birds under risk? - J. Avian Biol. 34: 24-29.

On the offshore island Helgoland, passerine birds killed by predators (feral cats Felis catus and raptors, mainly sparrowhawks Accipiter nisus) during stopover were measured and weighed when found freshly killed and still intact. Supplemented by data of migrating birds ringed on Helgoland and predated on the island later on, age and body mass of victims were compared to live birds trapped on Helgoland during ringing operations. In the eleven species considered, most predator kills fell within the lightest 20% of birds measured during ringing, regardless of which type of predator was involved. It seems that the risk of being heavy due to fuel loads with respect to reduced escape performance is overestimated. The higher exposure of light birds due to more intense foraging and displacement to suboptimal habitats is probably of higher biological significance by offering conspicuous prey for predators. The lower risk of heavy birds when prey of different body condition is available for predators has implications for modelling optimal migration behaviour, and predation risk is perhaps not an important factor for migrants when deciding on site use.

Chapter 4. Feral globetrotters

Koch, K., Algar, D., & Schwenk, K. (2014). Feral Cat Globetrotters: genetic traces of historic human-mediated dispersal and recent gene flow. Genetic diversity and phylogeography of Australian feral cats, 78.

Endemic species on islands are highly susceptible to local extinction if they are exposed to invasive species. In particular invasive predators, such as feral cats have been introduced to islands around the world, causing major losses in local biodiversity. However, control and management of invasive species depends on information about the source populations and the level of current gene flow. Here we investigate the origin of feral cats of Hawaiian and Australian islands to verify their European ancestry and a potential pattern of isolation by distance. We analysed the genetic structure and diversity of feral cats from eleven islands as well as samples from Malaysia and Europe using mitochondrial DNA (ND5 and ND6 region) and microsatellite data. Our results suggest that Hawaiian cats originate from Europe and overall no pattern of isolation by distance was detected. Instead we found low levels of genetic differentiation between samples from Tasman Island, Lana’i, Kaho’olawe, Cocos (Keeling) Island and Asia. Since these populations are separated by up to 10,000 kilometres, we assume that this pattern is explained by extensive passive dispersal on global maritime trade routes in the beginning of the 19th century, connecting Australian, Asian and Hawaiian Islands. Thus, islands populations which are characterized by low levels of current gene flow represent valuable sources of information on historical, human-mediated global dispersal patterns of feral cats

Capter 3: A voyage to Terra Australis

Koch, K., Algar, D., Searle, J., Pfenninger, M., & Schwenk, K. (2014). A voyage to Terra Australis: human-mediated dispersal of cats. Genetic diversity and phylogeography of Australian feral cats, 56.

Domestic and ship cats have been transported as human commensals around the world, especially in the last 200 years. They have given rise to populations of feral cats in many places. The feral population in Australia is believed to have led to the decline and extinction of native mammal species, but until now the time and origin of the cat introduction into Australia is unclear. Here we investigate the history of arrival of cats to Australia, considering the possibility that this was pre- or post-European settlement, and the potential for admixture. We analyse the genetic structure and diversity of feral cats from six locations on mainland Australia and seven offshore islands as well as samples from Malaysia and Europe using microsatellite and mitochondrial DNA data. Our data suggest that cats in Australia originated from Europe with possible isolated cases of invasions from Asian locations. We find low genetic differentiation between samples from Dirk Hartog Island, Flinders Island, Tasman Island and Cocos (Keeling) Island (Australian Indian Ocean Territory). Historical records suggest that introduction of cats to these islands occurred at the time of exploration and in connection with the pearling, whaling and sealing trades at the beginning of the 19th century. On-going influx of domestic cats into the feral cat population is causing the Australian mainland populations to be genetically differentiated from those on Dirk Hartog, Tasman and Flinders Islands, which exhibit remnants of the historically introduced cat genotypes.

Chapter 2: Population structure and management

Koch, K., Algar, D., & Schwenk, K. (2014). Population structure and management of invasive cats on an Australian Island. Genetic diversity and phylogeography of Australian feral cats: 42.

Invasive predators have a major impact on endemic island species; therefore, information about invasion dynamics are essential for implementing successful control measures. The introduction of feral cats onto Dirk Hartog Island, Western Australia, has had devastating effects, with presumably 10 of 13 native terrestrial mammal species being lost because of predation. Since detailed records of historical introduction events were lacking, we analysed genetic variation of the current population to gain information about past invasion dynamics and current gene-flow patterns. We analyzed the genetic structure and diversity of feral cats on the island and 2 adjacent mainland populations (Peron Peninsula and Steep Point). Analysis of mitochondrial DNA (ND5 and ND6) showed 2 primary haplotypes that we attribute to 2 main introduction events. Pairwise G’’ST values indicated high connectivity on the island but some isolation to the mainland populations. Mitochondrial and nuclear data showed no evidence for genetic differentiation of island and mainland populations; however, kinship analyses rejected evidence for on-going immigration of members of the current cat populations. Overall, our data suggested that gene flow following the main introduction events ceased some years ago. Because current island populations appear to be reproductivelyisolated from mainland populations, a sufficiently large-scale eradication measure might successfully diminish feral cat populations long-term.

Chapter 1: Impact on local biodiversity

Koch, K., Algar, D., Onus, M., Hamilton, N., Streit, B., & Schwenk, K. (2014). Impact of invasive feral cats and foxes on local biodiversity in the southern rangelands of Western Australia. Genetic diversity and phylogeography of Australian feral cats, 24.

One of the main threats to the survival of native vertebrate species in Australia is predation by introduced carnivores such as feral cats and foxes. Long-term invasive predator control projects aim to decrease their density in strategic areas on the mainland and thereby reduce pressure on local fauna. We examined fauna survey data in comparison to the diet of cats and foxes in order to determine the impact on native vertebrate species. Altered environmental conditions in 2007 (drought, shifted rainfall period) had a major effect on native species abundance, yet total number of species did not change between years and still showed differences between the study sites. Significant differences in abundance of native species groups between study sites as well as differences in the total number of species indicated a major predatory impact by invasive predators on local fauna. Feral cats and foxes had a distinctive diet and showed a prey selection as well as prey switch toward native vertebrate species thereby underutilizing the introduced and most abundant alternate species (house mouse). Feral cats especially specialised on native bird species which comprised up to 31% of their diet. Overall, our data confirm a higher predation risk for native species compared to non-native mammal species by introduced predators and the tendency of threat reduction by predator control over the short period of two years.

Genetic diversity and phylogeography of Australian feral cats

Koch, K. 2014. Genetic diversity and phylogeography of Australian feral cats. Accepted Dissertation thesis for the partial fulfilment of the requirements for a Doctoral of Natural Sciences. Universität Koblenz-Landau

Biodiversity is not only threatened by habitat loss, climate change and pollution, but also by invasive species. The impact of introduced species is immense and causes substantial ecological and economical costs worldwide. With the start of domestications of the African wildcat (Felis lybica) in the Near East, the transport of house cats (Felis catus) around the world as a commensal and domesticate began. The general aim of my thesis was to investigate the impact of invasive feral cats on native species as well as underlying population genetic structures, diversity and phylogeography. This was studied in the context of the demographic history in Australia and Hawai’i. My studies confirmed that the main introductions of cats to Australia began in the 19th century via ships of European settlers, traders and workers. Similarly, I was able to confirm cat introductions to Hawai’i by European traders and explorers; which has to the present a devastating effect on Hawaiian endemic species. Likewise, cats are widespread across Australia, can be found on most islands and are recognized as one of the major threats to Australian native species. A selective feeding behaviour by invasive predators was found in one of my studies. This study additionally gives an indication for possible population recovery of small Western Australian vertebrate species after predator removal. Advancement and the combination of various management techniques allow, if adequately funded, a more efficient planning and implementation of eradication campaigns. Population genetic approaches are able to give insights into population genetic structure, diversity and kinship, thereby enabling management campaigns to be more cost effective and successful. No pattern of isolation by distance between populations of Hawai’i and Australia indicated that trade routes, such as the ‘Golden Round’ of the maritime fur trade, facilitated a link between far off global cat populations. Multiple introductions to Australia and intermixing with domestic breed cats resulted in feral cat populations which show no signs of reduced genetic variability. My studies also revealed the advantages of bioproxies in combination with phylogeography, which enable the inference and reconstruction of introduction routes, history and origin of invasive species. Genetic signals of historically introduced genotypes are still discernible on islands with low number of introductions over time and thereby low intermixing with domestic fancy breeds. Feral cats’ adaptability as an invader was reconfirmed and possible underlying genetic mechanisms enabling their success as a global invader (‘global supercat’) are discussed. Research into the feralisation process of cats will provide new information regarding the domestication of cats, the genetic basis of feralisation and allow additional insights into cats’ adaptive potential.

Domestic cat predation in an insular Atlantic Forest remnant

Ferreira, G. A., Nakano-Oliveira, E., & Genaro, G. (2014). Domestic cat predation on Neotropical species in an insular Atlantic Forest remnant in southeastern Brazil. Wildlife Biology, 20(3), 167-175.

The domestic cat Felis silvestris catus is considered a potential threat to the native fauna of regions it populates, particularly when it has free access to these areas. Although this problem is known in Brazil, little is known regarding the effects of this species on natural areas. This study aimed to obtain information concerning the diet of domestic cats by identifying the main items found in fecal samples from domestic cats. In addition, the effects of seasonality on the diet were examined, as it has been hypothesized that seasonal variation of food items has little influence of the diet of the domestic cat. These semi-domiciled cats are thought to face a constant and continuous supply food offered by their owners throughout the year. Feces were collected in a remnant fragment of an Atlantic Forest located south of the municipality of Ilha Comprida — SP, Brazil. These samples provided important information regarding the dietary ecology and predation behavior of this species in endangered forest areas. The results of the scat content analyses demonstrated that domestic cats inserted in this biome presented a generalist and opportunist diet with little seasonal variation, even when receiving food from their owners. The most frequently consumed groups of prey were insects (20.8%) followed by mammals (13.9%) and birds (4.0%). Although the cat is not the only factor that impacts the species of the region, management programs need to be established in conjunction with the local community with the aim of minimizing the pressure exerted by these animals on the native fauna.

Dog management for the control of echinococcosis

Kachani, M., & Heath, D. (2014). Dog Population Management for the Control of Human Echinococcosis. Acta Tropica.

Cystic and alveolar hydatid disease of humans caused by infection with Echinococcus granulosus or E.multilocularis are significant zoonoses in developing countries. For human infections, the main definitive host is the dog, and reduction in the population of unwanted dogs, together with anthelmintic treatment of wanted dogs, are recommended control procedures for these zoonoses. Both owned and unowned dogs have been shown to be a major source of Echinococcus spp infection in developing countries.

Unowned dogs are the most challenging category in dog population management for the control of major zoonotic diseases. Unowned dogs are those dogs that do not have an owner, and those dogs whose owner cannot readily be identified. Control of numbers of unowned dogs can be done in various ways if funds are available. Fertility control and humane euthanasia and are likely to be the most effective procedures in developing countries. Fertility control requires significant funding, and where resources are scarce humane euthanasia may be the most effective option. Both procedures are ongoing events, with no predictable end point. This paper examines the sociology and technology for the population management of owned and unowned dogs, specifically for the reduction of human hydatid disease. Examples are given for developing and developed countries. Although a “One Health” approach is desirable, the technology for hydatid control is different from that for rabies, and FAO Animal Welfare recommendations for dog population management should be adjusted accordingly.

Cat impact in Madagascar forests

Farris, Z. J., Karpanty, S. M., Ratelolahy, F., & Kelly, M. J. (2014). Predator–Primate Distribution, Activity, and Co-occurrence in Relation to Habitat and Human Activity Across Fragmented and Contiguous Forests in Northeastern Madagascar. International Journal of Primatology, 1-22.

Predator–primate interactions are understudied, yet predators have been shown to influence primate behavior, population dynamics, and spatial distribution. An understanding of these interactions is important for the successful management and conservation of these species. Novel approaches are needed to understand better the spatial relationships between predators and primates across changing landscapes. We combined photographic surveys of predators and humans with line-transect sampling of lemurs across contiguous and fragmented forests in Madagascar to 1) compare relative activity; 2) estimate probability of occupancy and detection; 3) estimate predator–primate and local people–primate co-occurrence; and 4) assess variables influencing these parameters across contiguous and fragmented forests. In fragmented (compared to contiguous) forest sites endemic predator and lemur activity were lower whereas introduced predator and local people activity were higher. Our two-species interaction occupancy models revealed a higher number of interactions among species across contiguous forest where predator and lemur occupancy were highest. Mouse lemurs show evidence of “avoidance” (SIF < 1.0) with all predator species (endemic and introduced) in contiguous forest whereas white-fronted brown lemurs show “attraction” (SIF > 1.0) with feral cats and local people in contiguous forest. Feral cats demonstrated the highest number of interactions with lemurs, despite their distribution being limited to only contiguous forest. Distance to forest edge and distance to nearby villages were important in predicting predator occupancy and detection. These results highlight the growing threat to endemic predators and lemurs as habitat loss and fragmentation increase throughout Madagascar. We demonstrate the effectiveness of a novel combination of techniques to investigate how predator species impact primate species across a gradient of forest fragmentation.

Movement patterns of feral predators in an arid environment

Moseby, K. E., Stott, J.,& Crisp, H. (2009). Movement patterns of feral predators in an arid environment – implications for control through poison baiting. Wildlife Research 36, 422–435.

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.

The potential for target-specific poisoning of feral cats through oral grooming

Read, J. L. (2010). Can fastidiousness kill the cat? The potential for target-specific poisoning of feral cats through oral grooming. Ecological Management & Restoration 11, 230–233.

The feral or unmanaged domestic cats (Felis catus) represents a serious threat to several endangered species and is one of the most significant predators of wildlife worldwide... 

Small vertebrate abundance in alien-proof exclosures

Moseby, K. E., Hill, B. M., & Read, J. L. (2009). Arid recovery – a comparison of reptile and small mammal populations inside and outside a large rabbit, cat and fox-proof exclosure in arid South Australia. Austral Ecology 34, 156–169.

Australian arid zone mammal species within the Critical Weight Range (CWR) of 35 g–5.5 kg have suffered disproportionately in the global epidemic of contemporary faunal extinctions. CWR extinctions have been attributed largely to the effects of introduced or invasive mammals; however, the impact of these threatening processes on smaller mammals and reptiles is less clear. The change in small mammal and reptile assemblages after the removal of rabbits, cats and foxes was studied over a 6-year period in a landscape-scale exclosure in the Australian arid zone. Rodents, particularly Notomys alexis and Pseudomys bolami, increased to 15 times higher inside the feral-proof Arid Recovery Reserve compared with outside sites, where rabbits, cats and foxes were still present. Predation by cats was thought to exert the greatest influence on rodent numbers owing to the maintenance of the disparity in rodent responses through dry years and the differences in dietary preferences between rabbits and P. bolami. The presence of introduced Mus domesticus or medium-sized re-introduced mammal species did not significantly affect resident small mammal or reptile abundance. Abundance of most dasyurids and small lizards did not change significantly after the removal of feral animals although reductions in gecko populations inside the reserve may be attributable to second order trophic interactions or subtle changes in vegetation structure and cover. This study suggests that populations of rodent species in northern South Australia below the CWR may also be significantly affected by introduced cats, foxes and/or rabbits and that a taxa specific model of Australian mammal decline may be more accurate than one based on body weight.