Exposure to predators reduce immune response in birds

Navarro, C., De Lope, F., Marzal, A., & Møller, A. P. (2004). Predation risk, host immune response, and parasitism. Behavioral Ecology, 15(4), 629-635.

Predation risk may affect the allocation priorities of limiting resources by potential prey. Investment in immune function should receive reduced priority, when hosts are exposed to predators because of the costs of immune function. We tested this hypothesis by randomly exposing adult house sparrows, Passer domesticus, to either a cat, Felis catus, or a rabbit, Oryctolagus cuniculus, for 6 h while assessing their ability to raise a T-cell–mediated immune response to a challenge with phytohemagglutinin. Sparrows exposed to a cat had a significant reduction of, on average, 18% and 36% in T-cell response in two different experiments compared with sparrows that were exposed to a rabbit. In a field experiment with a barn owl, Tyto alba, or a rock dove, Columba livia, placed next to a nest-box during laying, we found a mean reduction in T-cell–mediated immune response of 20%. In males, the reduction in cell-mediated immune response owing to cat exposure increased with increasing size of the badge, which is a secondary sexual character, but only during the breeding season. In a third experiment, house sparrows were either exposed to a barn own, T. alba, or a rock dove, C. livia, and development of malarial infections was recorded during the following 6 weeks. Individual sparrows exposed to a predator had a higher prevalence and intensity of Haemoproteus malarial infection than did control individuals. Therefore, exposure to predators reduced their ability of hosts to cope with parasitism mediated through effects on immune function.

Pathogens of domestic carnivores around a National Park

Fiorello, C. V., Deem, S. L., Gompper, M. E., & Dubovi, E. J. (2004). Seroprevalence of pathogens in domestic carnivores on the border of Madidi National Park, Bolivia. Animal Conservation, 7(1), 45-54.

The importance of diseases of domestic animals in the conservation of wildlife is increasingly being recognised. Wild carnivores are susceptible to many of the pathogens carried by domestic dogs and cats and some of these pathogens have caused disease outbreaks and severe population declines in threatened species. The risk of disease spillover from domestic to wild carnivores in South America has not been extensively investigated. This study examined the disease exposure of domestic carnivores living near a protected area in Bolivia. Forty dogs and 14 cats living in three towns on the eastern border of Madidi National Park were sampled. High levels of exposure to canine distemper virus, canine parvovirus, Sarcoptes scabiei and Toxoplasma gondii were found among domestic dogs, with similarly high levels of exposure to feline parvovirus, feline calicivirus and T. gondii being found among domestic cats. If contact occurs between domestic and wild carnivores, disease spillover may represent an important risk for the persistence of wild carnivores in the region. Additional research is therefore necessary to determine if wild carnivores living in proximity to these domestic carnivore populations are being exposed to these pathogens.

Feral cat predation on seabirds on Japanese islands

KAWAKAMI, K., & FUJITA, M. (2004). Feral cat predation on seabirds on Hahajima, the Bonin Islands, southern Japan. Ornithological Science, 3(2), 155-158.



The feral cats in the Bonin Islands are the cause ofgreat concern in relation to the conservation of native birds. Among the species found dead during this study, Tristram’s Storm-Petrel is listed as‘Vulnerable’ in the Japanese Red Data Book, so it isespecially urgent to take measures to conserve them. Many other threatened seabirds such as Matsudaira’s Storm-Petrel O. matsudairae and Audubon’s Shearwater P.lherminieri bannermani also breed in the Bonin Islands and they sometimes accidentally land on the ground in bad weather making them vulnerable to cat attacks. Thus, it is necessary to clarify the extent of feral cat predation in the islands and to control the cat population.

Are birds winners or loosers in cities?

Shochat, E. 2004. Credit or debit? Resource input changes population dynamics of city-slicker birds. Oikos 106:622-626.

The underlying evolutionary mechanisms of urban bird populations have hardly been studied. High food density and low predation risk serve to explain the global pattern of extremely high urban bird population densities. Both these bottom-up and top-down effects are paradoxical since the per capita amount of food is small due to competition, and domestic predator density is high in cities. The bottom-up paradox can be resolved by taking into account the high food resource-predictability in cities. Concerning the top-down effect, recent studies suggest that at least when it comes to nest predation the effect of cats is minor. I suggest that the combination of high food predictability and low predation risk in cities alter bird foraging behaviour, which in turn affects population dynamics. In terms of density, the result is that bird populations exceed the carrying capacity of the urban environment, costing heavily on body condition and/or life span. Under such conditions the population should consist of a few winners and many losers. Only the winners have sufficient access to food resources and the opportunity to reproduce. The highly predictable continuous input of food in the urban environment allows them to “live on their credit”. They may trade off between offspring body condition and clutch size. In the lack of predation, the losers among the fledglings may survive for a relatively long period, getting just enough energy to survive. Though they may never become healthy enough to reproduce, they will have a major contribution to the observed population density. Results of several case studies seem to support the credit card hypothesis and suggest that it can serve as a general rule for the evolution of animal populations and communities in highly predictable human managed environments.

The welfare of feral cats and wildlife

Jessup, D. A. (2004). The welfare of feral cats and wildlife. Journal of the American Veterinary Medical Association, 225(9), 1377-1383.

There are an estimated 60 to 100 million feral and abandoned cats in the United States. By any measure, this is an important welfare issue, and the many bodies of free-roaming cats visible along roadsides across the country are mute testimony to the tragedy of their unhappy lives ...

	No. of animals accessioned	No. Cat related accessions	%
All birds	4,409	1,050	24
All mammals	1,187	143	12
All reptiles	73	11	15

Table 1—Data used to calculate the percentage of cat-related accessions to the Lindsay Museum of Walnut Creek, Calif, for all species and for susceptible birds (ie, nonraptors and pelagic birds).

Origin of dingoes and Polynesian dogs

Oskarsson, M. C., Klütsch, C. F., Boonyaprakob, U., Wilton, A., Tanabe, Y., & Savolainen, P. (2011). Mitochondrial DNA data indicate an introduction through Mainland Southeast Asia for Australian dingoes and Polynesian domestic dogs. Proceedings of the Royal Society B: Biological Sciences, rspb20111395.

In the late stages of the global dispersal of dogs, dingoes appear in the Australian archaeological record 3500 years BP, and dogs were one of three domesticates brought with the colonization of Polynesia, but the introduction routes to this region remain unknown. This also relates to questions about human history, such as to what extent the Polynesian culture was introduced with the Austronesian expansion from Taiwan or adopted en route, and whether pre-Neolithic Australia was culturally influenced by the surrounding Neolithic world. We investigate these questions by mapping the distribution of the mtDNA founder haplotypes for dingoes (A29) and ancient Polynesian dogs (Arc1 and Arc2) in samples across Southern East Asia (n = 424) and Island Southeast Asia (n = 219). All three haplotypes were found in South China, Mainland Southeast Asia and Indonesia but absent in Taiwan and the Philippines, and the mtDNA diversity among dingoes indicates an introduction to Australia 4600–18 300 years BP. These results suggest that Australian dingoes and Polynesian dogs originate from dogs introduced to Indonesia via Mainland Southeast Asia before the Neolithic, and not from Taiwan together with the Austronesian expansion. This underscores the complex origins of Polynesian culture and the isolation from Neolithic influence of the pre-Neolithic Australian culture.

Frequency of the Polynesian haplotypes Arc1 and Arc2, and the dingo founder haplotype A29 in geographical regions. The number of individuals carrying each haplotype, total number of samples for the region and frequency (per cent) are shown. Arrows indicate suggested introduction routes. For Australia, A29 denotes both haplotypes A29 and A29′

Savolainen, P., Leitner, T., Wilton, A. N., Matisoo-Smith, E., & Lundeberg, J. (2004). A detailed picture of the origin of the Australian dingo, obtained from the study of mitochondrial DNA. Proceedings of the National Academy of Sciences of the United States of America, 101(33), 12387-12390.

To determine the origin and time of arrival to Australia of the dingo, 582 bp of the mtDNA control region were analyzed in 211 Australian dingoes sampled in all states of Australia, 676 dogs from all continents, and 38 Eurasian wolves, and 263 bp were analyzed in 19 pre-European archaeological dog samples from Polynesia. We found that all mtDNA sequences among dingoes were either identical to or differing by a single substitution from a single mtDNA type, A29. This mtDNA type, which was present in >50% of the dingoes, was found also among domestic dogs, but only in dogs from East Asia and Arctic America, whereas 18 of the 19 other types were unique to dingoes. The mean genetic distance to A29 among the dingo mtDNA sequences indicates an origin ≈5,000 years ago. From these results a detailed scenario of the origin and history of the dingo can be derived: dingoes have an origin from domesticated dogs coming from East Asia, possibly in connection with the Austronesian expansion into Island Southeast Asia. They were introduced from a small population of dogs, possibly at a single occasion, and have since lived isolated from other dog populations.

Determining the antiquity of dog origin

Raisor, M. J. (2004). Determining the antiquity of dog origins: canine domestication as a model for the consilience between molecular genetics and archaeology (Doctoral dissertation, Texas A&M University).

Archaeologists have favored a date of 14,000-15,000 years before present (BP) for canine domestication. However, recent studies of mutations in the mitochondrial DNA sequence by molecular geneticists have implied that dogs were domesticated over 100,000 years ago, which has challenged traditional theory. Geneticists have further hypothesized that dogs originated from wolf ancestors based upon the number of substitutions observed in dog and wolf haplotypes. Although both disciplines provide substantial evidence for their theories, the origin of dog domestication remains controversial. Several areas continue to be debatable. First, both geneticists and archaeologists incorrectly use the term domestication to describe events that clearly can not be proven to under human control. Second, the evolutionary development of canines is viewed by molecular biologists as well as archaeologist to be indicators of domestication without any further exploration of other probable causes. Third, the studies in canine genetics are so complex that most archaeologists have difficulty in providing evidence that would be contradictory to molecular theory. Fourth, both fields of study continually ignore innate behavioral characteristics of wolves that would make domestication highly improbable. Fifth, geneticists rely heavily on data gathered from sequencing of mitochondrial DNA, which has been assumed to maternally inherited. However recent human studies have shown that this assumption has now been proven to be incorrect. And finally, not only are morphological traits of fossilized dogs and wolves so similar that making a taxonomic identification improbable, but also the amount of archaeological remains available are too sparse and fragmented for accurate affiliation. An alternate theory of canine domestication will be proposed utilizing data gathered from the archaeological record and molecular research. I hypothesize that dogs diverged naturally from wolves 100,000 years ago as a result of the natural course of evolution, not human intervention, and had already evolved into a dog prior to being domesticated by humans 14,000-15,000 years ago. Evidence will be presented to clearly show that this hypothesis is a more accurate scenario of canine domestication.

Black wolves in Italy

Apollonio, M., Mattioli, L., & Scandura, M. (2004). Occurrence of black wolves in the Northern Apennines, Italy. Acta theriologica, 49(2), 281-285.

The occurrence of black-coated individuals in wolf Canis lupus Linnaeus, 1758 populations is not surprising itself, but their presence in populations recovering from a severe numerical decline has been considered a possible sign of crossbreeding with the domestic dog. In the northern Apennines (Italy), black wolves occur at a non-negligible frequency. In a 3300 km² area, 22% of wolves observed and 23% of all dead wolves found were represented by animals with a completely black coat. One ‘black’ wolf belonging to the studied population was analysed by a set of microsatellite loci, and no trace of hybridization was found in its ancestry. This result induced us to consider the occurrence of a black phenotype in this area possibly derived from a natural combination of wolf alleles in coat colour determining genes, and not necessarily as the result of crossbreeding with the domestic form.


Read more about canine hybidisation and gene introgression

Demography of free roaming cats

Nutter, F. B., Levine, J. F., & Stoskopf, M. K. (2004). Reproductive capacity of free-roaming domestic cats and kitten survival rate. Journal of the American Veterinary Medical Association, 225(9), 1399-1402.

Objective—To determine reproductive capacity of naturally breeding free-roaming domestic cats and kitten survival rate.

Design—Prospective cohort and retrospective crosssectional study.

Animals—2,332 female cats brought to a trap-neuterreturn clinic for neutering and 71 female cats and 171 kittens comprising 50 litters from a cohort study of feral cats in managed colonies.

Procedure—Data collected for all cats included pregnancy, lactation, and estrus status and number of fetuses for pregnant cats. Additional data collected for feral cats in managed colonies included numbers of litters per year and kittens per litter, date of birth, kitten survival rate, and causes of death.

Results—Pregnant cats were observed in all months of the year, but the percentage of cats found to be pregnant was highest in March, April, and May. Cats produced a mean of 1.4 litters/y, with a median of 3 kittens/litter (range, 1 to 6). Overall, 127 of 169 (75%) kittens died or disappeared before 6 months of age. Trauma was the most common cause of death.

Conclusions and Clinical Relevance—Results illustrate the high reproductive capacity of free-roaming domestic cats. Realistic estimates of the reproductive capacity of female cats may be useful in assessing the effectiveness of population control strategies. 

Sanitary conditions of a colony of urban feral cats in a zoological garden of Rio de Janeiro

Mendes-de-Almeida, F., Faria, M. C. F., Branco, A. S., Serrão, M. L., Souza, A. M., Almosny, N., Charme, M. & Labarthe, N. (2004). Sanitary conditions of a colony of urban feral cats (Felis catus Linnaeus, 1758) in a zoological garden of Rio de Janeiro, Brazil. Revista do Instituto de Medicina Tropical de São Paulo, 46(5), 269-274.

The colony of urban stray cats living in the Rio de Janeiro zoological garden was studied in order to develop a population and health control program. As many cats as possible were captured during two months (47 animals) and were classified according to gender, age, weight and coat markings. They were submitted to a general health evaluation, examined for the presence of ectoparasites and sent to a surgical neutering program. All animals had a blood sample drawn for CBC, platelet count, heartworm and retroviruses detection. Capillary blood smears were made for hemoparasites detection. Coat marking and colors were tabby (59.7%), followed by solid black (17%); torbie (10.6%); bicolor (10.6%) and harlequin (2.1%). The only ectoparasites found were fleas, which infested 28% of the animals. The hemoparasites found were Haemobartonella felis (38%) and piroplasmas that could not be differentiated between Cytauxzoon spp. and Babesia spp. (47%). No cat was found infected by Dirofilaria immitis or FeLV (Feline Leukemia Virus), although FIV (Feline Immunodeficiency Virus) antibodies could be detected (21%). There was no correlation between hemoparasites and FIV infections. The estimated total cat population (mark-recapture method) was 59; 68% female and 32% male, suggesting that a neutering program is in fact needed.

Prevalence of pathogens in feral cats in Florida

Luria, B. J., Levy, J. K., Lappin, M. R., Breitschwerdt, E. B., Legendre, A. M., Hernandez, J. A., Gorman, S.P. & Lee, I. T. (2004). Prevalence of infectious diseases in feral cats in Northern Florida. Journal of Feline Medicine and Surgery, 6(5), 287-296.

Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.

Interactions between feral cats, foxes, native carnivores, and rabbits in Australia

Robley, A., Reddiex, B., Arthur T., Pech R. & Forsyth, D. (2004). Interactions between feral cats, foxes, native carnivores, and rabbits in Australia. Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Melbourne.

Through the Natural Heritage Trust, the Department of the Environment and Heritage (DEH) is working to develop and implement coordinated actions to reduce damage to the natural environment and primary production caused by feral animals.

Predation by foxes (Vulpes vulpes) and feral cats (Felis catus) have been identified as known or perceived threats to 34 and 38 native species, respectively, in threat abatement plans provided for under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). Land degradation and competition with native species by European rabbits (Oryctolagus cuniculus) is also listed as a key threatening process under the EPBC Act. The aim of this report is to review the evidence of the interactions between these three pest species, their control and the impact they have on Australian native species. The objectives of this report are:

1. To determine the nature of interactions between feral cats and foxes (competition and/or predation), especially in relation to control of either or both species, and the associated impacts on native species and ecological communities (especially those

listed as threatened under the EPBC Act), and feral rabbit populations within Australian habitats/regions.

2. To determine the implications of feral rabbit control to feral cat, fox and native prey populations, and the importance of rabbits for maintaining high feral cat and fox numbers within Australian habitats/regions.

3. To determine the interactions between feral cats, foxes and native carnivores and relative significance of competition and predation by feral cats and foxes to these native species.

Based on the degree of overlap in distribution and diet of feral cats and foxes, there is a potential for competitive interactions. There is circumstantial evidence of foxes excluding feral cats from food resources, and of foxes killing feral cats. No studies have experimentally demonstrated an increase in the rate of predation by feral cats on native species following a reduction in fox abundance in Australia. Several studies have described increases in cat abundance following reductions in fox numbers resulting from control operations. However, the evidence for an increase in abundance in cat abundance following fox control is inconsistent between studies and may be confounded by inadequate monitoring techniques and behavioural changes.

A potential cost of predator control is an increase in rabbit abundance, which may cause increased competition for food and other resources with native herbivores. Several studies suggest that predators can exert prolonged regulating pressure on rabbits at low densities and can impede recovery of rabbit populations. Particularly when populations have already been significantly reduced through external factors such as disease, drought, high or low rainfall, floods or warren ripping. However, predator manipulation studies over a wide range of habitats have provided inconsistent evidence of predator regulation of rabbits. Predation appears to play an important role in regulating rabbit populations in arid and semi-arid systems under certain conditions (e.g. after drought has reduced rabbit populations), but has weaker effects in more temperate environments or when environmental conditions improve and rabbits escape regulation. It is important to note that many of the studies that have shaped our understanding of population regulation of rabbits in Australia were undertaken prior to the escape of Rabbit Haemorrhagic disease (RHD) in Australia. The potential regulatory effect of RHD on rabbit populations and the effect this could have on rabbit–predator interactions is largely unknown. The impact of rabbits on flora and soils is well documented, but the impact on native mammal species is poorly understood.

The impact of changes in predators and their primary prey on native mammal species has been the focus of few experimental studies. Studies that have discussed the role of foxes and feral cats in regulating rabbit populations have largely not investigated the benefits or costs of predator control to native species. Other studies that have investigated the impact of fox and cat control on native mammal species have reported benefits from pest control; however, there are many acknowledged limitations of these studies. While several studies have reported that fox removal has benefited a range of native species, many have not assessed pre-control population parameters, do not have control sites, are not replicated, and have not attempted to test alternative hypotheses to predation, such as competition by herbivores. Also there are several notable exceptions to a general response to fox control (e.g. mixed responses of small mammal abundance from Operation FoxGlove WA, Project Eden, WA and Project Deliverance, Vic). While

the limitations cited above might have resulted from limited budgets and logistical constraints associated with large-scale operations, the inferences that can be drawn are limited nevertheless.

From the studies reviewed it is unclear what the impact of a decline in rabbits is on native species. In the studies reviewed in this report, both feral cats and foxes shift consumption to the next most abundant prey item (e.g. invertebrates, reptiles, or birds) in the absence or decline of rabbits. There is no evidence that as a result of a decrease in rabbits there is an increase in predation rates on populations of rare or endangered species. The interactions between rabbits and predators in arid and semi-arid environments have been relatively well studied in comparison to more temperate parts of Australia. Our level of understanding of these interactions and the impact on native species in arid and semi-arid and temperate environments is less well understood. In temperate environments the relationship between changes in rabbit abundance and declines in either feral cats or foxes has not been clearly demonstrated. Also, no studies showed that a decline in rabbit abundance leads to an increased rate of predation on native species. It appears that in systems where rabbits are not the staple prey item, changes in rabbit abundance have little impact on populations of feral cats or foxes.

Little quantitative information is available on the interactions between introduced predators and native carnivores. Available data suggests that dingoes (Canis lupus dingo), may be capable of suppressing fox populations, but that this is likely to be mediated by specific environmental conditions such as drought. There is some evidence to suggest that foxes spatially and temporally avoid wild dogs and that only during times of limited resources do the two come into direct conflict. Similarly, there is a lack of knowledge on the impacts of feral cats and foxes on native predators.

We used simulation models to explore the potential interactions between rabbits, foxes and feral cats. The sensitivity of the model to small changes in rainfall suggests a more detailed understanding of the relationships is required. More specifically, there is a need to quantify the relationship between rabbits and foxes and feral cats. Numerical responses for the two predators should be determined in relation to both the abundance of rabbits (or juvenile rabbits) and simultaneously the abundance of alternative food sources. To properly quantify and model the impact of foxes and feral cats on both rabbits and native prey requires kill rates of these prey to be assessed in relation to the availability of all prey types. This is particularly important for native prey. It is also important to understand the population dynamics of native Australian prey and the population dynamics of rabbits following the arrival of RHD, in the absence of predation from introduced predators. The limited data available for temperate systems suggest fox population dynamics may not be linked as strongly to rabbit dynamics as they appear to be in semi-arid systems. Alternative models are thus required for temperate systems. These models will almost certainly require data on the interactions of predators and a wide variety of foods. Feral cats are rarely seen in spotlight counts in temperate systems and no quantitative numerical relationships can be established from

the available data. Several studies have reported that integrated control (ripping, RHD or both poison baiting and RHD) has enhanced the decline of predator species, but to our knowledge no studies have investigated the costs and benefits of integrated feral animal control. A risk-averse approach would be to undertake integrated control wherever feral cats, foxes and rabbits co-occur. However, this may not be practical or possible due to limitations on resources. At present we have no clear understanding of the costs and benefits associated with integrated control programs. Despite a number of studies that have provided valuable insights into the impacts that changes in prey abundance can have on populations of introduced predators, and how predators can influence the abundance of prey species, there are many gaps in our understanding of predator prey interactions.

The four main areas where further information would improve our understanding of the interactions between feral cats, foxes, rabbits, their control and the impacts on native species are:

1. How to effectively monitor changes in abundance of introduced predators, particularly feral cats. At this point in time we are limited in our ability to control feral cats over large areas, although this is an area of current research.

2. The impact of predator control operations on the population dynamics and social organisation of sympatric predators and the impacts on native species and communities.

3. The role of rabbits in temperate systems in supporting elevated numbers of foxes and feral cats.

4. The effects of disease (RHD and myxomatosis), particularly in temperate environments, on the interactions between predators and their prey A combination of focused research programs on the more tractable parameters of the above identified gaps, and larger scale experiments conducted over appropriate temporal and spatial scales is likely to produce important advances in our understanding of the interactions between feral cats, foxes, rabbits, their control and native species. It is recommended that at the completion of such studies the information gained is used to update the models of the systems as presented in this review, that the results be peer reviewed and made widely available, and the outcomes from the models should be used to direct management strategies for these pest species.

Introduction of dogs in Australia and the Pacific

Savolainen, P., Leitner, T., Wilton, A. N., Matisoo-Smith, E., & Lundeberg, J. (2004). A detailed picture of the origin of the Australian dingo, obtained from the study of mitochondrial DNA. Proceedings of the National Academy of Sciences of the United States of America, 101(33), 12387-12390.

To determine the origin and time of arrival to Australia of the dingo, 582 bp of the mtDNA control region were analyzed in 211 Australian dingoes sampled in all states of Australia, 676 dogs from all continents, and 38 Eurasian wolves, and 263 bp were analyzed in 19 pre-European archaeological dog samples from Polynesia. We found that all mtDNA sequences among dingoes were either identical to or differing by a single substitution from a single mtDNA type, A29. This mtDNA type, which was present in >50% of the dingoes, was found also among domestic dogs, but only in dogs from East Asia and Arctic America, whereas 18 of the 19 other types were unique to dingoes. The mean genetic distance to A29 among the dingo mtDNA sequences indicates an origin ≈5,000 years ago. From these results a detailed scenario of the origin and history of the dingo can be derived: dingoes have an origin from domesticated dogs coming from East Asia, possibly in connection with the Austronesian expansion into Island Southeast Asia. They were introduced from a small population of dogs, possibly at a single occasion, and have since lived isolated from other dog populations.

Oskarsson, M. C., Klütsch, C. F., Boonyaprakob, U., Wilton, A., Tanabe, Y., & Savolainen, P. (2012). Mitochondrial DNA data indicate an introduction through Mainland Southeast Asia for Australian dingoes and Polynesian domestic dogs.Proceedings of the Royal Society B: Biological Sciences, 279(1730), 967-974.

In the late stages of the global dispersal of dogs, dingoes appear in the Australian archaeological record 3500 years BP, and dogs were one of three domesticates brought with the colonization of Polynesia, but the introduction routes to this region remain unknown.

This also relates to questions about human history, such as to what extent the Polynesian culture was introduced with the Austronesian expansion from Taiwan or adopted en route, and whether pre-Neolithic Australia was culturally influenced by the surrounding Neolithic world. We investigate these questions by mapping the distribution of the mtDNA founder haplotypes for dingoes (A29) and ancient Polynesian dogs (Arc1 and Arc2) in samples across Southern East Asia (n = 424) and Island Southeast Asia (n = 219). All three haplotypes were found in South China, Mainland Southeast Asia and Indonesia but absent in Taiwan and the Philippines, and the mtDNA diversity among dingoes indicates an introduction to Australia 4600–18 300 years BP. These results suggest that Australian dingoes and Polynesian dogs originate from dogs introduced to Indonesia via Mainland Southeast Asia before the Neolithic, and not from Taiwan together with the Austronesian expansion. This underscores the complex origins of Polynesian culture and the isolation from Neolithic influence of the pre-Neolithic Australian culture.

Regulation of cat ownership based on precautionary principle

Grayson, J. and Calver, M.C. (2004) Regulation of domestic cat ownership to protect urban wildlife: a justification based on the precautionary principle. In: Lunney, D. and Burgin, S., (eds.) Urban wildlife: more than meets the eye. Royal Zoological Society of New South Wales, Mosman, pp. 169-178.

While it is undeniable that both feral cats and owned domestic cats prey on native wildlife, evidence that this is a threat to the viability of wildlife populations is contentious, particularly in the suburbs. Where uncertainty is great or the risks are high, the precautionary principle is a guide as to whether or not action should be taken to regulate domestic cats This involves an evaluation of the available evidence and the extent of uncertainty, as well as consideration of the viewpoints of major stakeholders. Applying this approach leads to the conclusion that wildlife can be protected while improving cat welfare, Containing cats at night not only separates cats and nocturnal wildlife, but minimises trauma from both cat fights and road accidents while reducing nuisance to neighbours from caterwauling and fighting. Desexed cats no longer contribute toward unwanted stray and feral cat populations that depredate native wildlife populations and are often less of a nuisance to neighbours and themselves as spraying and fighting are reduced. Cats with identification can be returned to their owners should they be found lost or injured, while problem cats can be identified. Therefore, the cat welfare issue is the key to a successful precautionary approach because it achieves wildlife protection while respecting the interests of cat owners.

Habitat structure mediates the non-lethal effects of mesopredation

Arthur, A. D., Pech, R. P., & Dickman, C. R. (2004). Habitat structure mediates the non‐lethal effects of predation on enclosed populations of house mice. Journal of Animal Ecology, 73(5), 867-877.

1 Prey behavioural changes in response to predation risk can result in significant effects on prey body growth rates and reduced reproductive output, with resultant impacts on prey population dynamics. This paper examines the influence of habitat structure on these non-lethal impacts of predation using a model, field-based experimental system, with house mice as prey.
2 Three treatments were employed in eight 50 × 50 m pens that contained mice, but allowed access to a suite of free-living vertebrate predators, which included feral foxes, feral cats and native raptors: a treatment where the natural grassland vegetation in the pens was maintained at a height < 10 cm; a treatment where small, felled cypress pine trees covered with wire netting were added to low grassland vegetation to create refuge areas covering 10–15% of the area in a pen; and a treatment where predators were excluded from a 25 × 25 m section of some pens with an underlying grassland structure. A 5 × 5 grid of felled trees was added to grassland and predator-exclusion pens to allow assessment of mouse behaviour.
3 Mice in grassland pens avoided open areas, had lower body growth rates, and began breeding later in spring than mice in both predator-exclusion areas, where they foraged more readily in the open, and in refuge pens, where mice avoided open areas but had safe access to supplementary food located within the refuge. These results occurred despite mouse population densities being much lower in grassland pens, and presumably competition for food being much less, compared with under the other treatments.
4 The results indicate predators can have significant non-lethal impacts on prey, and these effects can be mediated by habitat structure.

Impact of dogs on gazelle kids

Manor, R., & Saltz, D. (2004). The impact of free-roaming dogs on gazelle kid/female ratio in a fragmented area. Biological Conservation, 119(2), 231-236.

One of the consequences of fragmentation is a combination of increased proximity to human dominated areas and an influx of free-roaming dogs. In fragmented habitats those dogs are expected to have a considerable impact on ungulate populations since conditions are, in effect, similar to alien species on islands.

 We studied the impact of free-roaming dogs (Canis familiaris) on the kid/mother ratio of mountain gazelle (Gazella gazella gazella) in an isolated area heavily disturbed by human activity. We used the kid/female ratio as an index of recruitment in the gazelle populations and evaluated the impacts of dog presence, intensity of human disturbance, and forage and cover availability on this ratio over space and time. Data were collected from direct observations. Overall, kid/female ratio in the area is too low for population growth; a finding that is in agreement with drive counts indicating a consistent decline over the past four years (1998–2001). Our results show that free-roaming dogs were the overwhelming factor affecting kid/female ratio in this area. Gazelles responded positively and quickly to dog culling. Thus, free-roaming dogs appear to be a considerable threat to the gazelle population in the study area. Removal of those dogs on a regular basis is an adequate short-term management protocol for increasing gazelle recruitment rate. However, a permanent solution would require reducing the number of dogs by limiting human waste disposal. These results suggest that, in addition to the loss of habitat and connectivity, free-roaming dogs can be a major threat to native ungulates in human dominated fragmented landscapes.

Dogs in rural Zimbabwe: disease transmission and competition with scavengers

Butler, J. R. A., & Toit, J. T. (2002). Diet of free‐ranging domestic dogs (Canis familiaris) in rural Zimbabwe: implications for wild scavengers on the periphery of wildlife reserves. Animal Conservation, 5(1), 29-37.

Numbers of free-ranging dogs (Canis familiaris) have reached unprecedented levels in Zimbabwean communal lands (agropastoralist rural areas). This study examined the potential competitive interactions between dogs and wild scavengers on the boundary of Gokwe Communal Land (GCL) and the Sengwa Wildlife Research Area (SWRA) in 1995–96. Dietary studies showed that dogs were primarily scavengers of human waste and animal carcasses. Twelve experimental carcasses indicated that dogs were the most successful species in the vertebrate scavenger guild, consuming 60% of available biomass and finding 66.7% of carcasses. Dogs monopolized the supply of domestic animal carrion within GCL, but also consumed wild carrion up to 1 km within the SWRA, and were seen 3 km inside the reserve. Their principal competitors for carcasses were vultures, and to a lesser degree lions (Panthera leo), leopards (P. pardus) and spotted hyaenas (Crocuta crocuta). Dogs outcompete vultures on wildlife reserve boundaries owing to their high densities, nocturnal and diurnal activity, physical dominance and greater tolerance of human disturbance. With a population growth rate of 6.5% per annum the influence of dogs will intensify on the peripheries of reserves, exacerbating their existing threat to wild scavengers. This scenario is probably occurring in many other African countries.

Butler, J. R. A., Du Toit, J. T., & Bingham, J. (2004). Free-ranging domestic dogs (Canis familiaris) as predators and prey in rural Zimbabwe: threats of competition and disease to large wild carnivores. Biological Conservation, 115(3), 369-378.

Domestic dogs (Canis familiaris) arrived in Zimbabwe ca. 1000 years ago. Numbers of free-ranging dogs have reached unprecedented levels in communal lands (agro-pastoralist rural areas), and interact with large wild carnivores along boundaries with wildlife reserves as predators and prey. This study examined a population of 236 dogs in a 33-km² section of Gokwe Communal Land (GCL) bordering the Sengwa Wildlife Research Area (SWRA) in north-western Zimbabwe in 1995–1996. Dogs were found up to 6 km within the SWRA, and were the most common carnivore on the GCL–SWRA boundary. Observations of 16 radio-collared dogs showed that they were inefficient predators. Only 20 kills were recorded amongst the remaining dog population, of which three were wild ungulates. Dogs were unsuccessful predators due to their small group size (mean 1.7) and body mass (mean 14.7 kg), and the abundance of alternative food. It is therefore unlikely that they compete with large carnivores for wild prey. However, leopards (Panthera pardus), lions (P. leo) and spotted hyaenas (Crocuta crocuta) preyed on dogs in GCL, removing ⩾6% of the dog population in 1993. Such predation provides ideal circumstances for disease transmission. Canid disease was prevalent in the study area; including rabies and probably distemper. The risk of infection is greatest during the dry season (May–October), when peaks in rates of disease, carnivore incursions into GCL, and predation on dogs coincided. The role of jackals (Canis adustus and Canis mesomelas) and spotted hyaena predation of dogs is discussed in relation to disease epidemics within wildlife reserves. With a dog population growth rate of 6.5% per annum, and the prevalence of canid diseases, the conservation threat posed by dogs is escalating on communal land–wildlife reserve boundaries in Zimbabwe. Measures to control dog numbers and improve vaccination coverage of dogs are discussed.

Inside/outside cats' impact on a suburban nature reserve

Roland K, DeWan A (2004) Ecological impacts of inside/outside cats around a suburban nature preserve. Animal Conservation 7: 1–11.

While subsidised populations of feral cats are known to impact their prey populations, little is known about the ecological impact of inside/outside hunting cats (IOHC). We studied IOHC around a suburban nature preserve. Mail surveys indicated an average of 0.275 IOHC/house, leading to a regional density estimate of 0.32 IOHC/ha. A geographical model of cat density was created based on local house density and distance from forest/neighbourhood edge. IOHC hunted mostly small mammals, averaging 1.67 prey brought home/cat/month and a kill rate of 13%. Predation rates based on kills brought home was lower than the estimate from observing hunting cats (5.54 kills/cat/month). IOHC spent most outside time in their or their immediate neighbours’ garden/yard, or in the nearby forest edge; 80% of observed hunts occurred in a garden/yard or in the first 10 m of forest. Radio-tracked IOHC averaged 0.24 ha in home range size (95% minimum convex polygon (MCP)) and rarely entered forest. Confirming this, scent stations detected cats more often near the edge and more cats were detected in smaller forest fragments. There was no relationship between the number of cats detected in an area and the local small mammal abundance or rodent seed predation rates. Cold weather and healthy cat predator populations are speculated to minimise the ecological impact of IOHC on this area.

Professional, ethical, and legal dilemmas of TNR

Barrows, P. L. 2004. Professional, ethical, and legal dilemmas of trap-neuter-release. Journal of the American Veterinary Medical Association 225:1365–1369.

Although some have portrayed the current feral and abandoned cat trap-neuter-release (TNR) controversy as pitting cat haters against cat lovers, this is not the case. Those opposing TNR and the proliferation of free-roaming cats consider domestic cats to be important and valuable companion animals to the pet-owning public and their families. What opponents of TNR object to are cats in the wrong places doing destructive and undesirable things ...

(Continue reading)

Cat ownership regulation

Grayson, J. and Calver, M.C. (2004) Regulation of domestic cat ownership to protect urban wildlife: a justification based on the precautionary principle. In: Lunney, D. and Burgin, S., (eds.) Urban wildlife: more than meets the eye. Royal Zoological Society of New South Wales, Mosman, pp. 169-178.

While it is undeniable that both feral cats and owned domestic cats prey on native wildlife, evidence that this is a threat to the viability of wildlife populations is contentious, particularly in the suburbs. Where uncertainty is great or the risks are high, the precautionary principle is a guide as to whether or not action should be taken to regulate domestic cats This involves an evaluation of the available evidence and the extent of uncertainty, as well as consideration of the viewpoints of major stakeholders. Applying this approach leads to the conclusion that wildlife can be protected while improving cat welfare, Containing cats at night not only separates cats and nocturnal wildlife, but minimises trauma from both cat fights and road accidents while reducing nuisance to neighbours from caterwauling and fighting. Desexed cats no longer contribute toward unwanted stray and feral cat populations that depredate native wildlife populations and are often less of a nuisance to neighbours and themselves as spraying and fighting are reduced. Cats with identification can be returned to their owners should they be found lost or injured, while problem cats can be identified. Therefore, the cat welfare issue is the key to a successful precautionary approach because it achieves wildlife protection while respecting the interests of cat owners.