Ancient introductions of mammals in Mediterranean islands and their implications for conservation

Gippoliti, S., & Amori, G. (2006). Ancient introductions of mammals in the Mediterranean Basin and their implications for conservation. Mammal Review,36(1), 37-48.

1 The importance of taxonomy to the determination of conservation priorities and actions is widely accepted. It should be not surprising therefore that the taxonomic treatment of mammal species that have been subject to human actions in antiquity may well influence the contemporary assessment of conservation priorities at various levels.
2 As a result of early extinctions caused by humans and protohistoric and historic introductions, we suggest that the Mediterranean Basin and its islands are particularly prone to misdirection of efforts towards biodiversity conservation.
3 The two main risks associated with the failure to use an evolutionary and palaeoecological approach to conservation efforts are (i) an underestimation of the conservation importance of distinctive continental taxa vs. the apparent endemicity of island taxa; and (ii) a serious risk for native and endemic island species when anthropochorous mammals, especially ungulates, misguidedly become the focus of conservation actions, particularly inside protected areas.
4 Urgent measures, including refinement of mammal taxonomy, the exclusion of known anthropochorous taxa from conservation lists and implementation of protective legislation, are necessary to maintain the uniqueness and richness of the Mediterranean biodiversity hotspot.

Mandatory spay ordinance as the solution to San Francisco dog problem

Lang, D. (2013). A Mandatory Spay/Neuter Ordinance in San Francisco: The Solution to San Francisco’s Other Homeless Problem. Master's Capstone Projects.Paper 6. University of San Francisco

The dog overpopulation in San Francisco has been straining San Francisco’s Department of Animal Care & Control’s already limited resources with the increase in dog impoundments and animal cruelty cases, particularly ones involving dogs. At least 33 local governments around the United States have implemented mandatory spay/neuter laws for all dogs as a way to curb the companion animal overpopulation. San Francisco should adopt a similar mandatory spay/neuter law, in which all dogs over the age of six months, with certain exceptions, must be spayed or neutered. This will relieve the strain on Animal Care & Control, will save the City money, and will decrease pain, suffering, and even death among San Francisco’s dog population.

Humans have a responsibility to care for companion animals because we domesticated them and allow them to breed in a world where there are not enough homes for them. So humans should take action to decease breeding, especially accidental breeding, so as to decrease the population of unwanted dogs. This human action should be in the form of implementing a mandatory spay/neuter law, so the majority of dogs will be unable to reproduce and so that breeders are restricted to one litter per year to minimize their contribution to the companion animal overpopulation. Not only is spaying and neutering crucial to reducing the population of unwanted dogs, but it also has many health, behavioral, and societal benefits. Spaying and neutering will increase the health of dogs by reducing their chances of developing certain cancers; it will increase their life span; and it will increase public safety and public health byreducing aggression, making them less likely to bite, and reducing the number of stray dogs wandering the streets.

Even though most veterinarians, most members of the animal shelter community, and most animal welfare/rights activists agree that spaying/neutering is vital to decreasing the companion animal overpopulation, they disagree on whether spaying/neutering should be mandatory or simply encouraged. Proponents of mandatory spay/neuter laws argue that they will save local governments money, produce more revenue, and improve public safety and public health. On the other hand, opponents argue that low-cost spay/neuter programs are more effective at decreasing the companion animal overpopulation, mandatory spay/neuter laws punish poor people and will result in more companion animals being abandoned in shelters, they discourage people from taking their animals to the vet or to the animal shelter for fear of being reported to authorities for having an unaltered animal, they punish responsible companion animal guardians and breeders, they waste public resources, and they are difficult to enforce.

An analysis of shelter data from two municipalities—Clark County, Nevada, and Los Angeles County, California—that have implemented mandatory spay/neuter laws reveals that recent dog intake and euthanasia rates are the lowest they have been in the past two decades, indicating that these laws are successful at reducing the unwanted dog population. In 2005, San Francisco’s Commission of Animal Control and Welfare considered implementing a mandatory spay/neuter ordinance for all dogs, but it never went past Commission meetings. However, in 2006, San Francisco implemented a mandatory spay/neuter law for Pit Bulls, which resulted in a decrease in Pit Bull euthanasia rates. The success of this law can be partly attributed to the free spay/neuter services for Pit Bulls offered by the San Francisco Society for the Prevention of Cruelty to Animals (SF SPCA). Other free spay/neuter services for any breed of dog are also offered in various locations in San Francisco, which would help ensure the success of a mandatory spay/neuter ordinance for all dogs.

San Francisco should implement a mandatory spay/neuter ordinance that requires that all dogs six months or older must be spayed or neutered, with exemptions for dogs who are too old or sick to undergo the spay/neuter surgery and dogs whose health would be threatened by the spay/neuter surgery. In addition, guardians who do not want to spay or neuter their dogs must obtain an intact dog license or a breeding license. Animal Care & Control can enforce the mandatory spay/neuter law by modifying its dog licensing system to assign different colored tags for different licenses—regular dog licenses, intake dog license, and breeding license.

Furthermore, breeders must show proof that they have a breeding license by putting the license number on their advertisements or sales receipts, and they must be restricted to one litter per year and the number of unaltered animals they are allowed to have should be limited, as well, so as to not further contribute to the companion animal overpopulation problem. And finally, penalties for violations of the mandatory spay/neuter law should be civil, rather than criminal.

Cats' threat to wildlife in San Diego County

(from http://www.utsandiego.com)

...In San Diego County, the potential threat feral cats pose to wildlife is particularly troublesome. Our county is within one of the world’s biodiversity hot spots. Our ocean, beaches, bays, mountains and desert landscapes, and unique coastal sage scrub and chaparral plant communities, support a wide diversity of plant and animal life, including more than 500 species of birds.

San Diego County is home to more endangered species than any other county in the nation.

Many of these species exist in small islands of habitat surrounded by urban development. At the edges of these small habitat patches, urban predators — animals that thrive in developed landscapes and prey on native species — pose a significant threat to their survival. Some of the urban predators that disturb or kill sensitive bird species in our county include crows, ravens, raccoons, opossums, rats — and feral cats.

One example of this situation can be found at the Kendall-Frost Marsh in Mission Bay. The marsh is home to a population of federal- and state-listed endangered light-footed clapper rails, a secretive bird that relies on coastal wetland habitats. Urban predators are trapped in the marsh as part of management efforts to protect clapper rails. Feral cats have been trapped at the marsh and brought to San Diego County’s animal shelter. This co-occurrence of feral cats and light-footed clapper rails creates the possibility of a predation problem. Biologists who monitor this species counted fewer than 600 breeding pairs in 2013. Predation of even a few of these birds may have a significant effect on the species’ ability to recover to stable population numbers in the marsh....

Evolutionary basis of feeding behaviour of dogs and cats

Bradshaw, J. W. (2006). The evolutionary basis for the feeding behavior of domestic dogs (Canis familiaris) and cats (Felis catus). The Journal of nutrition,136(7), 1927S-1931S.


The dentition, sense of taste and meal patterning of domestic dogs and cats can be interpreted in terms of their descent from members of the order Carnivora. The dog is typical of its genus, Canis, in its relatively unspecialized dentition, and a taste system that is rather insensitive to salt. The preference of many dogs for large infrequent meals reflects the competitive feeding behavior of its pack-hunting ancestor, the wolf Canis lupus. However, its long history of domestication, possibly 100,000 years, has resulted in great intraspecific diversity of conformation and behavior, including feeding. Morphologically and physiologically domestic cats are highly specialized carnivores, as indicated by their dentition, nutritional requirements, and sense of taste, which is insensitive to both salt and sugars. Their preference for several small meals each day reflects a daily pattern of multiple kills of small prey items in their ancestor, the solitary territorial predator Felis silvestris. Although in the wild much of their food selection behavior must focus on what to hunt, rather than what to eat, cats do modify their food preferences based on experience. For example, the “monotony effect” reduces the perceived palatability of foods that have recently formed a large proportion of the diet, in favor of foods with contrasting sensory characteristics, thereby tending to compensate for any incipient nutritional deficiencies. Food preferences in kittens during weaning are strongly influenced by those of their mother, but can change considerably during at least the first year of life.

Urban coyotes and cats

Webster, J.C. (2007). Missing cats, stray coyotes: one citizen’s perspective. Wildlife Damage Management Conferences -- Proceedings.Paper 78.

Comments

Originally published in Proceedings of the 12th Wildlife Damage Management Conference (D.L. Nolte, W.M. Arjo, D.H. Stalman, Eds). 2007. This is the revised version that appears in Urban Coyote Management: A collection of papers pre-sented at the Urban Coyote Symposium within the 12th Wildlife Damage Management Conference Corpus Christi, Texas, April 11, 2007, Robert M. Timm, Editor (Collierville, TN, 2008). ISBN 978-1-60458-362-5 Copyright © 2007 by the Wildlife Damage Management Working Group of The Wildlife Society. Used by permission.


Abstract

The author explores the issue of urban coyotes and coyote management from a cat owner’s perspective, with specific examples from Vancouver, B.C., Canada. Following a personal encounter with two coyotes in July 2005 that led to the death of a cat, the author has delved into the history of Vancouver’s “Co-existing with Coyotes”, a government-funded program run by a nonprofit ecological society. The policy’s roots in conservation biology, the environmental movement, and the human dimensions branch of wildlife management are documented. The author contends that “Co-existing with Coyotes” puts people and pets at greater risk of attack by its inadequate response to habituated coyotes, and by an educational component that misrepresents real dangers and offers unworkable advice. The environmental impact of domestic cats is addressed. The author makes the case that generalized opinions about the negative effects of cats on songbird populations and other wildlife, and assertions that urban coyotes are beneficial, are unsupported by objective experimental data. When environmentalists, who predominantly hold these views, also research, promote, and oversee urban wildlife policy, there is a consequent lack of interest in restricting coyote populations in cities, along with little concern for the fate of outdoor cats and even a desire for their depredation.

Exurban development and biodiversity

Hansen, A. J., Knight, R. L., Marzluff, J. M., Powell, S., Brown, K., Gude, P. H., & Jones, K. (2005). Effects of exurban development on biodiversity: patterns, mechanisms, and research needs. Ecological Applications, 15(6), 1893-1905.

Low-density rural home development is the fastest-growing form of land use in the United States since 1950. This “exurban” development (6–25 homes/km²) includes urban fringe development (UFD) on the periphery of cities and rural residential development (RRD) in rural areas attractive in natural amenities. This paper synthesizes current knowledge on the effects of UFD and RRD. We present two case studies and examine the patterns of biodiversity response and the ecological mechanisms that may underlie these responses. We found that many native species have reduced survival and reproduction near homes, and native species richness often drops with increased exurban densities. Exotic species, some human-adapted native species, and species from early successional stages often increase with exurban development. These relationships are sometimes nonlinear, with sharp thresholds in biodiversity response. These effects may be manifest for several decades following exurban development, so that biodiversity is likely still responding to the wave of exurban expansion that has occurred since 1950. The location of exurban development is often nonrandom relative to biodiversity because both are influenced by biophysical factors. Consequently, the effects on biodiversity may be disproportionately large relative to the area of exurban development. RRD is more likely than UFD to occur near public lands; hence it may have a larger influence on nature reserves and wilderness species. The ecological mechanisms that may underlie these responses involve alteration of habitat, ecological processes, biotic interactions, and increased human disturbance. Research on the patterns and mechanisms of biodiversity remains underdeveloped, and comparative and experimental studies are needed. Knowledge resulting from such studies will increase our ability to understand, manage, and mitigate negative impacts on biodiversity.

Spatial organisation of urban feral cats in Jerusalem

Mirmovitch, V. (1995). Spatial organisation of urban feral cats (Felis catus) in Jerusalem. Wildlife Research, 22(3), 299-310.

Feral cats were studied for 10 months in a residential area in Jerusalem and their spatial distribution compared during two 1-month periods, the first in the autumn prior to the mating season and the second during the mating season (winter). Cat locations were recorded by direct observations, and home-range sizes were calculated with the minimum convex polygon method. No significant change in home-range size of adult males or females was found between the 2 periods. Young males expanded their home ranges considerably during their first mating season. Home ranges of males were significantly larger than those of females in both periods (0.56 and 0.30 ha, respectively, in autumn; 0.75 and 0.27 ha in winter). The home ranges of both sexes overlapped considerably with individuals of the same sex. Overlap among home ranges of females indicated a group pattern. High overlap (80%) was found among females that fed from the same set of garbage bins with similar frequency. Lower overlap (20%) was found between individual females that shared only a subset of their food resources and used it with different frequency. It is suggested that the distribution of food patches (garbage bins), the amount of food available and the rate of food renewal determined the cats' spatial organisation.

Assessment of the effort to eradicate feral cats

Parkes, J., Fisher, P., Robinson, S., & Aguirre-Muñoz, A. (2014). Eradication of feral cats from large islands: an assessment of the effort required for success.New Zealand Journal of Ecology, 38(2), 0-0.

Feral cats (Felis catus) are predators and competitors of native species on many islands and are therefore the target of control efforts. Cat eradication has been achieved on 83 islands worldwide. Six of these successes have been from large islands (over 2000 ha) and have reported sufficient data to examine how the eradication was achieved through combinations of aerial and ground-based poison baiting, fumigation in rabbit burrows used by cats, cage and leghold trapping, day and night shooting, and hunting with dogs. No common sequence of tactics was deployed although leghold traps were used in the latter phases of most projects. It took a mean reported effort of 543 ± 341 person-days per 1000 ha of island over 5.2 ± 1.6 years to completely remove cats and validate success from the six islands. These precedents may assist in planning future proposals to eradicate cats from other large islands.

Sex bias on cat predation on Eastern bluebirds

Pitts, T. D., & Snow, R. W. (1996). Mortality of Banded Adult Eastern Bluebirds. Audubon Society of Omaha.

Domestic cats are, narrowly, the second most important cause of non-natural mortality, just after shooting. 

Of 51 Eastern Bluebirds killed by domestic cats, 19 were females and 5 were males; the sex of the other birds was not indicated. While this sample size is not much larger than that of bluebirds found dead in the nest (24 versus 16), the trend seen here shows a significant difference in the number of males and females killed (X² = 8.16, df = 1, P <0.005). Figure 5 shows that mortality due to domestic cats is highest during the nesting season. Considering that the female bluebirds, who construct each nest, lay eggs, and incubate the eggs, receive significant amounts of help from the male only when caring for nestlings, we are not surprised that more females are captured by domestic cats. 

(Domestic cats kill an unknown, but probably large, number of nestling bluebirds. However, since this paper deals only with adult mortality we have not explored the effects of cat predation on nestlings.)

Eurasian origin of American dogs

Leonard, J. A., Wayne, R. K., Wheeler, J., Valadez, R., Guillén, S., & Vila, C. (2002). Ancient DNA evidence for Old World origin of New World dogs. Science,298 (5598), 1613-1616.

Mitochondrial DNA sequences isolated from ancient dog remains from Latin America and Alaska showed that native American dogs originated from multiple Old World lineages of dogs that accompanied late Pleistocene humans across the Bering Strait. One clade of dog sequences was unique to the New World, which is consistent with a period of geographic isolation. This unique clade was absent from a large sample of modern dogs, which implies that European colonists systematically discouraged the breeding of native American dogs.

Fine scale resource selection by feral cats

Recio, M. R., Mathieu, R., Virgós, E., & Seddon, P. J. 2014. Quantifying fine-scale resource selection by introduced feral cats to complement management decision-making in ecologically sensitive areas. Biological Invasions, 1-13.

The feral domestic cat (Felis catus) is considered to be one of the most damaging introduced predators, responsible for the decline and extinction of numerous native species. Advanced satellite technologies enable the study of resource selection by small mammals at fine-scales through remote data. These tools can improve understanding of the spatial ecology of introduced predators in ecologically sensitive areas, such as where cats pose a threat to native species and where improvement of predator control methods is required. We studied fine-scale resource selection by feral cats in the ecologically important New Zealand braided-river ecosystem, where they pose a risk to endangered native ground-nesting birds. We collected 34 location datasets from 21 cats fitted with lightweight global positioning system-collars, and extracted landscape variables from a resource map created using very high spatial resolution satellite imagery (Quickbird) and object-base imagery analysis for image classification. We modelled second-order seasonal and annual resource selection functions and characterized landscape composition of highly-used areas using compositional analysis. At a population level, cats generally selected fine-scale landscapes that are important for their primary prey rabbits (Oryctolagus cuniculus), and for refugia. An external validation of the annual model using data from cats tracked in an independent study showed a positive correlation with model predictions. Individual cats also visited habitats used by native ground-nesting birds, and thus pose a threat to them through secondary predation or individual specialization. Cat control operations should therefore focus around areas of concentrated ground-nesting bird activity and in areas identified as high-use by cats.

Mammal eradication from NZ islands

Clout, M. N., & Russell, J. C. (2006). The eradication of mammals from New Zealand islands. 127-141 In Koike, F., Clout, M.N., Kawamichi, M., De Poorter, M. and Iwatsuki, K. (eds.), Assessment and Control of Biological Invasion Risks. Shoukadoh Book Sellers, Kyoto, Japan and the World Conservation Union (IUCN), Gland, Switzerland, 2006.

Data on eradication operations against alien mammals on New Zealand islands show that there was a substantial increase in the number of successful eradications in the 1980s and 1990s. The most significant change has been in the ability to eradicate rodents from increasingly large islands (to over 11,000ha), using aerial poisoning techniques. Based on the New Zealand experience, there are good prospects for further eradications of alien mammals from islands around the world, facilitating ecological restoration and the recovery of threatened species. However, instances of reinvasion of rats (Rattus spp.) and stoats (Mustela erminea) onto previously cleared islands illustrate the importance of prevention, effective monitoring and a fuller understanding of invasion risks.

Prevalence of T. gondii in house cats

De Craeye, S., Francart, A., Chabauty, J., De Vriendt, V., Van Gucht, S., Leroux, I., & Jongert, E. (2008). Prevalence of Toxoplasma gondii infection in Belgian house cats. Veterinary parasitology, 157(1), 128-132.


Five hundred and sixty seven sera of healthy house cats aged 3 months to 7 years, were examined for the presence of anti-toxoplasma antibodies by indirect immunofluorescence assay and compared to SAG1 and TLA enzyme linked immunosorbent assays as alternative test. Twenty-five percent of cats tested positive for IgG and/or IgM. Seroprevalence increased with age from 2% below 12 months of age up to 44% at age 7. Sensitivities of SAG1 and TLA ELISA were 84.1% and 88.6%, respectively. Peak levels in seroprevalence were correlated to increased IgG titers in TLA ELISA. Our results suggest that T. gondii infections are common in house cats and that there is a high chance for a negative cat to seroconvert in its second life-year.

Cats, Toxoplasma and public health

Dabritz, H. A., & Conrad, P. A. (2010). Cats and Toxoplasma: implications for public health. Zoonoses and Public Health, 57(1), 34-52.

Cats are popular as pets worldwide because they are easy to care for and provide companionship that enriches the lives of human beings. Little attention has been focused on their potential to contaminate the environment with zoonotic pathogens. One such pathogen, the protozoan parasite Toxoplasma gondii, rarely causes clinical manifestations in cats or immunocompetent humans; however, it can have serious adverse effects on human foetuses and immunocompromised patients. Many human infections are believed to be acquired from eating undercooked or raw meat, such as pork and lamb (Tenter et al., 2000; Dubey et al., 2005). However, the prevalence of T. gondii infection in human populations that do not consume meat or eat it well-cooked suggests that the acquisition of infection from the environment, via oocysts in soil, water or on uncooked vegetables, is also important (Rawal, 1959; Roghmann et al., 1999; Chacin-Bonilla et al., 2001). In the past 20 years, two changes occurred that significantly increased the size of the cat population in the USA. Pet cat ownership grew from 50 million to 90 million animals, and animal welfare activists created feeding stations for abandoned and free-roaming cats. As many cat owners allow their cats to deposit faeces outside and cats maintained in colonies always defecate outside, ample opportunity exists for T. gondii oocysts to enter the environment and be transmitted to humans. Prevention efforts should focus on educating cat owners about the importance of collecting cat faeces in litter boxes, spaying owned cats to reduce overpopulation, reducing the numbers of feral cats and promoting rigorous hand hygiene after gardening or soil contact.

Prevalence of T. gondii depends on household effect

Fromont, E. G., Riche, B., & Rabilloud, M. (2009). Toxoplasma seroprevalence in a rural population in France: detection of a household effect. BMC infectious diseases, 9(1), 76.

Background

Toxoplasma gondii, the agent of toxoplasmosis, has a complex life cycle. In humans, the parasite may be acquired either through ingestion of contaminated meat or through oocysts present in the environment. The importance of each source of contamination varies locally according to the environment characteristics and to differences concerning human eating habits and the presence of cats; thus, the risk factors may be determined through fine-scale studies. Here, we searched for factors associated with seropositivity in the population of two adjacent villages in Lorraine region, France.

Methods
All voluntary inhabitants filled out a questionnaire and gave a blood sample. The seroprevalence was estimated globally and according to the inhabitants' ages using a cubic spline regression. A mixed logistic regression model was used to quantify the effect of individual and household factors on the probability of seropositivity.

Results

Based on serological results from 273 persons, we estimated seroprevalence to be 47% (95% confidence interval: 41 to 53%). That seroprevalence increased with age: the slope was the steepest up to the age of 40 years (OR = 2.48 per 10-year increment, 95% credibility interval: [1.29 to 5.09]), but that increase was not significant afterwards. The probability of seropositivity tended to be higher in men than in women (OR = 2.01, 95% credibility interval: [0.92 to 4.72]) and in subjects eating raw vegetables at least once a week than in the others (OR = 8.4, 95% credibility interval: [0.93 to 72.1]). These effects were close to statistical significance. The multivariable analysis highlighted a significant seroprevalence heterogeneity among households. That seroprevalence varied between 6 and 91% (5th and 95th percentile of the household seropositivity distribution).

ConclusionThe major finding is the household effect, with a strong heterogeneity of seroprevalence among households. This effect may be explained by common exposures of household members to local risk factors. Future work will quantify the link between the presence of oocysts in the soil and the seroprevalence of exposed households using a spatial analysis.