Vulture declines and increased dog scavenging

Ogada, D. L., Torchin, M. E., Kinnaird, M. F., & Ezenwa, V. O. (2012). Effects of vulture declines on facultative scavengers and potential implications for mammalian disease transmission. Conservation Biology, 26(3), 453-460.

Vultures (Accipitridae and Cathartidae) are the only known obligate scavengers. They feed on rotting carcasses and are the most threatened avian functional group in the world. Possible effects of vulture declines include longer persistence of carcasses and increasing abundance of and contact between facultative scavengers at these carcasses. These changes could increase rates of transmission of infectious diseases, with carcasses serving as hubs of infection. To evaluate these possibilities, we conducted a series of observations and experimental tests of the effects of vulture extirpation on decomposition rates of livestock carcasses and mammalian scavengers in Kenya. We examined whether the absence of vultures changed carcass decomposition time, number of mammalian scavengers visiting carcasses, time spent by mammals at carcasses, and potential for disease transmission at carcasses (measured by changes in intraspecific contact rates). In the absence of vultures, mean carcass decomposition rates nearly tripled. Furthermore, the mean number of mammals at carcasses increased 3-fold (from 1.5 to 4.4 individuals/carcass), and the average time spent by mammals at carcasses increased almost 3-fold (from 55 min to 143 min). There was a nearly 3-fold increase in the mean number of contacts between mammalian scavengers at carcasses without vultures. These results highlight the role of vultures in carcass decomposition and level of contact among mammalian scavengers. In combination, our findings lead us to hypothesize that changes in vulture abundance may affect patterns of disease transmission among mammalian carnivores.

________________

Los buitres (Accipitridae y Cathartidae) son los únicos carroñeros obligados que se conocen. Se alimentan de cadáveres en descomposición y son el grupo funcional de aves más amenazado del mundo. Los efectos posibles de las declinaciones de buitres incluyen una mayor persistencia de cadáveres y el incremento de la abundancia de y contacto entre carroñeros facultativos en esos cadáveres. Estos cambios podrían incrementar las tasas de transmisión de enfermedades infecciosas, con los cadáveres funcionando como focos de infección. Para evaluar estas posibilidades, realizamos una serie de observaciones y pruebas experimentales de los efectos de la extirpación de buitres sobre las tasas de descomposición de cadáveres de ganado y mamíferos carroñeros en Kenia. Examinamos sí la ausencia de buitres cambiaba el tiempo de descomposición de cadáveres, el número de mamíferos carroñeros visitando los cadáveres, el tiempo utilizado por mamíferos en los cadáveres y la potencial transmisión de enfermedades en los cadáveres (medida por cambios en las tasas de contacto interespecífico). En ausencia de buitres, las tasas medias de descomposición de cadáveres incrementaron 3 veces (de 1.5 a 4.4 individuos/cadáver), y el tiempo promedio invertido por mamíferos en los cadáveres incrementó casi 3 veces (de 55 min a 143 min). Hubo un aumento de casi tres veces en el número promedio de contactos entre mamíferos carroñeros en cadáveres sin buitres. Estos resultados resaltan el papel de los buitres en la descomposición de cadáveres y del nivel de contacto entre mamíferos carroñeros. En combinación, nuestros resultados nos llevaron a plantear la hipótesis de que cambios en la abundancia de buitre pueden afectar los patrones de transmisión de enfermedades entre mamíferos carnívoros.

Pathogens of wild maned wolves in Brazil

Curi, N. H. D. A., Coelho, C. M., Malta, M. D. C. C., Magni, E. M. V., Sábato, M. A. L., Araújo, A. S., ... & Souza, S. L. P. D. (2012). Pathogens of wild maned wolves (Chrysocyon brachyurus) in Brazil. Journal of wildlife diseases, 48(4), 1052-1056.

The maned wolf, Chrysocyon brachyurus, is an endangered Neotropical canid that survives at low population densities. Diseases are a potential threat for its conservation but to date have been poorly studied. We performed clinical evaluations and investigated the presence of infectious diseases through serology and coprologic tests on maned wolves from Galheiro Natural Private Reserve, Perdizes City, Minas Gerais State, southeastern Brazil. Fifteen wolves were captured between 2003 and 2008. We found high prevalences of antibody to canine distemper virus (CDV; 13/14), canine
parvovirus (CPV; 4/14), canine adenovirus type 2 (13/14), canine coronavirus (5/11), canine parainfluenza virus (5/5), and Toxoplasma gondii (6/8), along with Ancylostomidae eggs in all feces
samples. Antibodies against Leishmania sp. were found in one of 10 maned wolves, and all samples were negative for Neospora caninum. Evidence of high exposure to these viral agents was also observed in unvaccinated domestic dogs from neighboring farms. High prevalence of viral agents and parasites such as CDV, CPV, and Ancylostomidae indicates that this population faces considerable risk of outbreaks and chronic debilitating parasites. This is the first report of exposure to canine parainfluenza virus in Neotropical free-ranging wild canids. Our findings highlight that canine pathogens pose a serious hazard to the viability of maned wolves and other wild carnivore populations in the area and emphasize the need for monitoring and protecting wildlife health in remaining fragments of the Cerrado biome.

Modelling the population control of the domestic cat from an island

Lessa, I. C. M., & Bergallo, H. G. (2012). Modelling the population control of the domestic cat: an example from an island in Brazil. Brazilian Journal of Biology, 72(3), 445-452.

The domestic cat is an invasive species that often causes great impacts where introduced due to its high predatory and reproductive potential, especially on islands. In this study, carried out on Ilha Grande (RJ, Brazil), we aimed to: i) estimate the population density of domestic cats, ii) calculate the number of animals preyed upon annually by domestic cats, and iii) evaluate the efficiency of methods to control the cat population. We used the Vortex program to project the population growth of domestic cats in fifty years, and simulated different scenarios of population control (without control, castration, spay and harvest). Population density of owned cats was 662 cats/km². The annual predation rate was 1.97 prey animals/cat which is an average of 1497.96 prey/year. The population would only be reduced if 70% of females were spayed or removed annually. Measures to control the domestic cat population must be undertaken urgently, since uncontrolled growth of this predator has the potential to seriously impact the biodiversity of Ilha Grande.

______________________

O gato doméstico é uma espécie invasora que frequentemente causa grandes impactos onde é introduzido, em razão do seu alto potencial predatório e reprodutivo, especialmente em ilhas. Com este estudo realizado na Ilha Grande-RJ, Brasil, tivemos como objetivos: i) estimar a densidade populacional de gatos domésticos; ii) calcular o número de animais predados anualmente por gatos domésticos, e iii) estimar a eficiência de métodos para o controle da população de gatos. Nós utilizamos o programa Vortex para projetar o crescimento da população de gatos em 50 anos e simulamos diferentes cenários de controle populacional: sem controle, castração, esterilização de fêmeas e remoção de indivíduos. A densidade populacional de gatos que possuem donos foi de 662 gatos/km². A taxa anual de predação foi de 1,97 animais predados/gato, ou seja, uma média de 1497,96 presas/ano. A população de gatos pode ser reduzida apenas se no mínimo 70% das fêmeas forem esterilizadas ou removidas anualmente. Medidas para o controle populacional de gatos domésticos devem ser tomadas com urgência, uma vez que o crescimento descontrolado da população desse predador tem o potencial de causar graves impactos à biodiversidade da Ilha Grande.

Use of camera traps to examine the mesopredator release hypothesis in a fragmented landscape

Cove, M. V., Jones, B. M., Bossert, A. J., Clever Jr, D. R., Dunwoody, R. K., White, B. C., & Jackson, V. L. (2012). Use of camera traps to examine the mesopredator release hypothesis in a fragmented Midwestern landscape. The American Midland Naturalist, 168(2), 456-465.

The mesopredator release hypothesis (MRH) has been suggested as a reason why many mammalian generalist mesopredators flourish and become abundant. However, the MRH has only been examined in a limited number of field studies. Some studies have argued that coyotes (Canis latrans) act as top predators in fragmented forest systems and coyote presence has a positive effect on song bird diversity and abundance by controlling mesopredator abundance. We integrated camera trap data and occupancy modeling to determine the factors that affect coyote detection probability and habitat use in a fragmented suburban landscape in central Missouri. We then examined the influence of coyote presence and other habitat variables on mesopredator detection probability and habitat use in the same system. Coyote detection was negatively related to increasing forest cover, whereas red fox (Vulpes vulpes) detection was positively related to increasing urbanization. Coyote occurrence models suggested little habitat selection, while the mesopredator occurrence models suggested an affinity for urbanization. Although there was a slight negative effect of coyote presence on site use by other mesopredators, we suggest that the smaller species are better adapted to coexisting with humans and thus have increased in abundance.

In defense of TNR

Schmidt, R. H. Cat Fight! The TNR Wars. 2012. Proc. 25th Vertebr. Pest Conf. (R. M. Timm, Ed.) Published at Univ. of Calif., Davis. 2012. Pp. 89-94.

Although trap-neuter-return (TNR) programs for feral cats are in use or being proposed in many communities, a number of non-governmental organizations have gone on record as being opposed to them. For example, The Wildlife Society’s (TWS) policy statement on feral cats (2011) includes a comment that TWS “Oppose the passage of any local or state ordinances that legalize the maintenance of “managed” (trap/neuter/release) free-ranging cat colonies.” Similarly, the American Bird Conservancy’s (ABC) resolution on free-roaming cats (feral and tamed) states that ABC “strongly opposes managed free-roaming cat colonies.” Wildlife managers often lament the loss of tools and techniques (e.g., traps, pesticides, regulatory authority) for managing “nuisance” animals. The attack against TNR programs is indicative of an active program to eliminate a management tool. Is the negativity toward TNR justified? Stated another way, do the negative aspects of TNR programs outweight any possitive elements? I argue that the complete rejection of TNR is premature, erroneous, and without merit.

Videographic evidence of endangered species depredation by feral cat in Hawaii

Judge, S., Lippert, J. S., Misajon, K., Hu, D., & Hess, S. C. (2012). Videographic evidence of endangered species depredation by feral cat. Pacific Conservation Biology, 18(4), 293.

Feral cats (Felis catus) have long been implicated as nest predators of endangered 'Ua'u (Hawaiian Petrel; Pterodroma sandwichensis) on Hawai'i Island, but until recently, visual confirmation has been limited by available technology. 'Ua'u nest out of view, deep inside small cavities, on alpine lava flows. During the breeding seasons of 2007 and 2008, we monitored known burrows within Hawai'i Volcanoes National Park. Digital infrared video cameras assisted in determining the breeding behaviour and nesting success at the most isolated of burrows. With 7 cameras, we collected a total of 819 videos and 89 still photographs of adult and nestling 'Ua'u at 14 burrows. Videos also confirmed the presence of rats (Rattus spp.) at 2 burrows, 'Oma'o (Myadestes obscurus) at 8 burrows, and feral cats at 6 burrows. A sequence of videos showed a feral cat taking a downy 'Ua'u chick from its burrow, representing the first direct evidence of 'Ua'u depredation by feral cat in Hawai'i. This technique provides greater understanding of feral cat behaviour in 'Ua'u colonies, which may assist in the development of more targeted management strategies to reduce nest predation on endangered insular bird species.

Attitudes of residents and tourists towards stray dogs in Samoa

Farnworth, M., Blaszak, K., Hiby, E. F., & Waran, N. K. (2012). Incidence of dog bites and public attitudes towards dog care and management in Samoa. Animal welfare. 21 : 477-486.

In many developing nations, dogs (Canis familiaris) present a significant issue in terms of human health, safety and animal welfare. We assessed attitudes towards dogs and their management in Samoa, a developing South Pacific island nation, using a questionnaire. It demonstrated that Samoa has one of the world’s highest recorded levels of household dog ownership (88%) but a comparatively low rate of vaccination (12%) and sterilisation (19%). Those interviewed believe dogs were important and should be considered part of the family; however most households reported that their dogs were kept for protection (79%). There was a clear skew in the sex distribution. The dog population showed a strong male bias (71%) suggesting females are removed from the population. Of those surveyed only 16% had received any education about dogs and their management and overall the respondents showed a clear disparity between attitudes and behaviour (eg the majority believe dogs should be vaccinated [81%] yet most dogs in this sample [72%] had never been to a veterinarian). Overall, there was a willingness to manage the free-roaming dog population which was considered by many to be a nuisance, however there were few enforceable mechanisms by which this could occur and most dogs were not confined. Harm or killing of dogs was relatively commonplace with 30% of households reporting they knew someone who had harmed or killed a dog and 26% of respondents indicating they believed harming or killing dogs was good for Samoan society, presumably by reducing problems associated with the free-roaming population. Dog bites were relatively frequent in Samoa and reports from two hospitals indicated a frequency of 37 new bites per annum requiring hospitalisation per 10,000 head of population. Furthermore, this paper outlines strategies and further research that could be considered to improve dog welfare and reduce the need to harm or kill dogs, namely improvements in veterinary provision and dog-focused education. It also considers the need for legislative controls and more research and funding to be made available for small developing nations to explore their animal welfare obligations.

Beckman, M., Hill, K. E., Farnworth, M. J., Bolwell, C. F., Bridges, J., & Acke, E. (2014). Tourists’ Perceptions of the Free-Roaming Dog Population in Samoa.Animals, 4(4), 599-611.

Simple Summary: For travelers, the way in which people in other nations interact with animals may be different to that in their home nation. This research explores how the treatment of dogs impacted upon the holiday experiences of tourists visiting a developing island nation. In general, and where tourists encountered dogs, their treatment was perceived as less positive than in their home country and had a negative impact upon the holiday experience. Although it is important to recognize that the local population will have a different worldview, tourists felt that the dog population required more effective management and were most supportive of techniques that were non-lethal and humane.
Abstract: A study was undertaken to establish how visiting tourists to Samoa perceived free-roaming dogs (Canis familiaris) and their management, additionally some factors that influence their perceptions were assessed. Questionnaires were administered to 281 tourists across Samoa over 5 weeks. Free-roaming dogs were seen by 98.2% (n = 269/274) of respondents, with 64.9% (n = 137/211) reporting that their presence had a negative effect on overall holiday experience. Respondents staying in the Apia (capital city) area were more likely to consider dogs a problem (p < 0.0001), and there was a significant association between whether the respondent owned a dog and if they thought dogs were a nuisance in Samoa (p < 0.003). Forty-four percent (20/89) of non-dog owners agreed that dogs were a nuisance compared to 22% (80/182) of dog owners. The majority felt that dogs required better control and management in Samoa (81%, n = 222) and that there were too many “stray” dogs (67.9%, n = 188). More respondents were negatively affected by the dogs’ presence (64.9%, 137/211), and felt that the dogs made their holiday worse, than respondents that felt the dogs’ presence improved their holiday experience (35.1%, 74/211). Most respondents stated that the dogs had a low impact (one to three; 68%, 187/275) on their stay in Samoa, whilst 24% (65/275) and 8% (23/275) stated they had a medium or high impact, respectively, on their stay. Respondents showed strong support for humane population management. Free-roaming dogs present a complex problem for Samoa and for its tourism industry in particular. The findings of this study further support the need for more discussion and action about the provision of veterinary services and population management for dogs in Samoa. It also provides information complementing an earlier study of the attitudes of local Samoans.

Discovering geographic information for exploratory spatial analysis of stray cats

Aguilar, G. D., & Farnworth, M. J. (2012). Stray cats in Auckland, New Zealand: Discovering geographic information for exploratory spatial analysis. Applied Geography, 34, 230-238.

Stray cats are a common feature of urban landscapes and are associated with issues of animal welfare and negative environmental impacts. Management, planning and decision-making require readily accessible information on stray cats. However, much of the existing data is not immediately useful for a geographic information system (GIS) in terms of format, content and explicit location information. Spreadsheets we obtained from a single large shelter in the Auckland region. They contained records of stray cat pickups and admissions for an entire year (n = 8573) of which 56.4% (n = 4834) contained data that could be processed to derive relevant spatial information. The resulting data consisted of identified roads and areas of Auckland where the stray cats were found. Published census databases and shapefiles were matched with the data to build a GIS of stray cats. Global and local regression analysis was employed to discover spatial distribution characteristics including the identification of areas with relatively high and low concentrations of stray cats and to explore relationships between socioeconomic condition and stray cat density. Significant clustering is more evident in South Auckland than elsewhere in the region. Specific geographical information is valuable, not only for understanding population dynamics of stray cats, but also to allow spatial and temporal targeting of resources to minimise their impact and promote responsible ownership.

Highlights

► Spreadsheets containing records of stray cat observations for an entire year in the Auckland area were processed to derive relevant spatial information. ► Data were matched with existing official census databases and shapefiles of the Auckland region to build a GIS of stray cats. ► Spatial characterization results include identification of areas with relatively high and low concentrations of stray cats. ► Insights on the relationship between stray cat density and social factors was derived.

Effects of feral cats on the evolution of antipredator behavior in the Aegean wall lizard

Li, B. (2012). Effects of feral cats on the evolution of antipredator behaviors in the Aegean wall lizard Podarcis erhardii (Doctoral dissertation, University of Michigan).

Exotic predators such as feral cats (Felis catus), have been the driving force behind the extinction of many endemic species of island mammals, birds and reptiles. Island endemics appear to be exceptionally susceptible to invasive predators because of small population size and frequent lack of anti-predator defenses. The goal of this study was to determine the impacts of feral cats on the island populations of Aegean Wall lizards (Podarcis erhardii, Lacertidae) in relationship to the expression of anti-predator behaviors. I estimated lizard population densities in areas with low cat density sites (LCD) versus high cat density (HCD) sites by conducting 100-m transect along dry-stone walls, on the island of Naxos, as well as on surrounding islets (Cyclades, Greece). Degree of expression of antipredator behaviors was determined by measuring flight initiation distance (FID) and rates of tail autotomy both in the field and in the lab for six populations in HCD, LCD sites and four satellite islets without cat presence. I also staged controlled encounters with mounted cats decoys and quantified escaping responses from lizards from these populations. I found that feral cats had a strong negative effect on lizard population densities. Lizards adapted their antipredator behaviors in response to cat predation by extending their FIDs, increasing their capacity for tail autotomy, and by staying closer to refugia. In laboratory predation simulations, lizards from cat-free islets had significantly shorter FIDs than LCD site lizards and in particular than HCD site lizards. Furthermore, some unique islet behaviors, presumably evolved in response to lack of predators and to ameliorate chronic conditions of food shortage, appear to render islet lizards strongly susceptible to cat predation. These behaviors include rarely utilizing available refugia, and moving towards anything new, including cat decoys. Nonetheless, I found that repeated exposures over three trials led to significant increases in FIDs for all populations, indicating at least some behavioral plasticity. My results suggest that although lizards may adapt their antipredator behaviors to cope with introduced predators, this offers at best only partial protection, so that there remains strong concern about their survival in the face of expanding feral cat populations.


Read also this post

Two studies on Paleolithic dogs and a controversy

Germonpré, M., Sablin, M. V., Stevens, R. E., Hedges, R. E., Hofreiter, M., Stiller, M., & Després, V. R. (2009). Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes. Journal of Archaeological Science, 36(2), 473-490.

Using multivariate techniques, several skulls of fossil large canids from sites in Belgium, Ukraine and Russia were examined to look for possible evidence of the presence of Palaeolithic dogs. Reference groups constituted of prehistoric dogs, and recent wolves and dogs. The fossil large canid from Goyet (Belgium), dated at c. 31,700 BP is clearly different from the recent wolves, resembling most closely the prehistoric dogs. Thus it is identified as a Palaeolithic dog, suggesting that dog domestication had already started during the Aurignacian. The Epigravettian Mezin 5490 (Ukraine) and Mezhirich (Ukraine) skulls are also identified as being Palaeolithic dogs. Selected Belgian specimens were analyzed for mtDNA and stable isotopes. All fossil samples yielded unique DNA sequences, indicating that the ancient Belgian large canids carried a substantial amount of genetic diversity. Furthermore, there is little evidence for phylogeographic structure in the Pleistocene large canids, as they do not form a homogenous genetic group. Although considerable variation occurs in the fossil canid isotope signatures between sites, the Belgian fossil large canids preyed in general on horse and large bovids.

Dorsal view of the skulls from (a) Goyet (dog); (b) Trou Balleux (wolf); (c) Trou des Nutons (wolf),
showing the relative wide braincase of the Goyet dog 

Germonpré, M., Lázničková-Galetová, M., & Sablin, M. V. (2012). Palaeolithic dog skulls at the Gravettian Předmostí site, the Czech Republic. Journal of Archaeological Science, 39(1), 184-202.

Whether or not the wolf was domesticated during the early Upper Palaeolithic remains a controversial issue. We carried out detailed analyses of the skull material from the Gravettian Předmostí site, Czech Republic, to investigate the issue. Three complete skulls from Předmostí were identified as Palaeolithic dogs, characterized by short skull lengths, short snouts, and wide palates and braincases relative to wolves. One complete skull could be assigned to the group of Pleistocene wolves. Three other skulls could not be assigned to a reference group; these might be remains from hybrids or captive wolves. Modifications by humans of the skull and canine remains from the large canids of Předmostí indicate a specific relationship between humans and large canids.

Highlights

► Accepting an Aurignacian beginning of the domestication of the wolf is controversial. ►The Gravettian canid skulls from Předmostí were studied to check for the presence of dogs. ►Ancient dogs are characterized by short skulls and snouts, and wide palates and braincases. ►Using these criteria three Předmostí skulls were singled out as Gravettian dogs. ►Human modifications of the skulls hint at a specific human/large canid relationship.

Susan J. Crockford, S.J. & Y.V. KuzminComments on Germonpré et al., Journal of Archaeological Science 36, 2009 “Fossil dogs and wolves from Palaeolithic sites in Belgium, the Ukraine and Russia: osteometry, ancient DNA and stable isotopes”, and Germonpré, Lázkičková-Galetová, and Sablin, Journal of Archaeological Science 39, 2012 “Palaeolithic dog skulls at the Gravettian Předmostí site, the Czech Republic” Journal of Archaeological Science, 39(8):2797–2801. DOI: 10.1016/j.jas.2012.04.033

Issues related to the identification of Late Pleistocene dogs from different sites in Eurasia, triggered by recent publications (see Germonpré et al., 2009, 2012; Ovodov et al., 2011), are discussed. The main focus is the problem of how to distinguish wolves from early dogs on the basis of skull and teeth morphology. The studies by 18 and 19, reporting so-called ‘Palaeolithic dogs’ from Předmostí, Goyet, and other sites in Eastern and Central Europe, have some serious deficiencies. In our opinion, more work needs to be done to understand the biological mechanisms involved in wolf domestication and until then, it is premature to classify these Palaeolithic canids as fully domesticated dogs or even incipient dogs.

Highlights


► We discuss issues related to so-called ‘Palaeolithic dogs’ from sites in Eurasia. ► Our comments pertain to studies described in 18 and 19. ► We suggest it is premature to classify these Palaeolithic canids as fully domesticated dogs.

Germonpré, M., Sablin, M. V., Després, V., Hofreiter, M., Lázničková-Galetová, M., Stevens, R. E., & Stiller, M. (2013). Palaeolithic dogs and the early domestication of the wolf: a reply to the comments of Crockford and Kuzmin (2012). Journal of Archaeological Science, 40(1), 786-792.

This is a response to the comments of Crockford and Kuzmin (2012) on our identification of Palaeolithic dogs from different European Palaeolithic sites. In their comments Crockford and Kuzmin (2012) present some errors, misunderstandings and misrepresentations that we remedy here. In our opinion, the early wolf domestication must be regarded as an intimate relationship between humans and canids including the breeding of the latter by prehistoric people, resulting in the European Palaeolithic dogs.

Highlights

► Accepting an Aurignacian beginning of the domestication of the wolf is controversial. ► Crockford and Kuzmin (2012) conjecture such an early domestication. ► This is a response to the comments of Crockford and Kuzmin (2012) on our identification of European Palaeolithic dogs. ► Two large canid types occur in certain European Palaeolithic sites. ► This is explained by the presence of Palaeolithic dogs and Pleistocene wolves.

see also 

Perception of village dogs by villagers and tourists

Ruiz-Izaguirre, E., & Eilers, C. H. A. M. (2012). Perceptions of village dogs by villagers and tourists in the coastal region of rural Oaxaca, Mexico. Anthrozoos: A Multidisciplinary Journal of The Interactions of People & Animals, 25(1), 75-91.

The objective of this study was to gain an understanding of the village dog-keeping system, and of perceptions of dog-related problems by villagers and tourists, in the coastal region of Oaxaca, Mexico. We conducted a survey of the inhabitants of three villages (Mazunte, Puerto Angel, and Río Seco), whose main economic activities were tourism, fishing, and farming (n = 99), and a survey of tourists (n = 151). Dogs were the most commonly kept animals in all the villages. Cultural and economic aspects were reflected in dog-keeping practices. All dog owners allowed their dog(s) to roam free in the farming village (Río Seco), but not in the tourist villages (Mazunte and Puerto Angel). Significantly more dog owners in the tourist village of Mazunte mentioned companionship as a reason for keeping dogs than those in the farming village. All villagers perceived as a problem that there were too many dogs. The mean number of dogs per household was 1.8, and there were significantly more male dogs in the farming village than in the tourist villages. Efforts to control the dog population in the rural coastal region are aimed at rabies prevention or wildlife protection, whereas this study revealed that these issues were far less often mentioned by local people as other dog-related problems. Significantly more villagers in the tourist villages perceived there to be dog-welfare problems than those in the farming village. Significantly more North American and European tourists were concerned about dog welfare than Mexican tourists. Despite significant differences in dog-keeping between the tourist and farming villages, opinions of villagers in regard to dog breeding and methods of dog population control were similar. Villagers agreed on dog sterilization to control the dog population, but also considered that female dogs should breed at least once in their lifetime. Those living in tourist villages could benefit from improving dog welfare and implementing strategies to lessen the problems dogs cause tourists.

Space use and intraguild interactions among three opportunistic predators

Krauze-Gryz, D., Gryz, J. B., Goszczyński, J., Chylarecki, P., & Zmihorski, M. (2012). The good, the bad, and the ugly: space use and intraguild interactions among three opportunistic predators—cat (Felis catus), dog (Canis lupus familiaris), and red fox (Vulpes vulpes)—under human pressure. Canadian Journal of Zoology, 90(12), 1402-1413.

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

Modeling interventions in owned cat population

Lancaster, E. P. (2012). Modeling Interventions in the Owned Cat Population in Knox County, TN.

The rapid growth of cat populations in many communities across the United States has resulted in overpopulation and an increase in euthanasia procedures. To combat these challenges, communities have instituted spay/neuter programs as a preventative strategy. In particular, Knox County, Tennessee, has developed and implemented a program, called the Spay Shuttle, which offers free spays and neuters for owned cats throughout the county.

We develop a discrete time, age-structured model of owned female cats in Knox County to investigate the effects of implementing extra spaying intervention strategies to the population over the course of 5 years. We determine that a 50% increase in spay surgeries per two month time step for each age class capable of reproducing will result in a 33% decrease in the population. Also, the number of surgeries performed during those five years will also drop. Analysis of the cumulative number of surgeries performed reveals a sharp increase in surgeries during the first two years, followed by a decrease in surgeries in the following years. We also examine other scenarios, by which we target different age groups for extra spay interventions. We determine that the most impact is seen when extra spaying of cats ages 4-6 months is included in the intervention.

Apex predator control and mesopredator release in Australia

Brook, L. A., Johnson, C. N., & Ritchie, E. G. (2012). Effects of predator control on behaviour of an apex predator and indirect consequences for mesopredator suppression. Journal of applied ecology, 49(6), 1278-1286.

1. Apex predators can benefit ecosystems through top–down control of mesopredators and herbivores. However, apex predators are often subject to lethal control aimed at minimizing attacks on livestock. Lethal control can affect both the abundance and behaviour of apex predators. These changes could in turn influence the abundance and behaviour of mesopredators.
2. We used remote camera surveys at nine pairs of large Australian rangeland properties, comparing properties that controlled dingoes Canis lupus dingo with properties that did not, to test the effects of predator control on dingo activity and to evaluate the responses of a mesopredator, the feral cat Felis catus.
3. Indices of dingo abundance were generally reduced on properties that practiced dingo control, in comparison with paired properties that did not, although the effect size of control was variable. Dingoes in uncontrolled populations were crepuscular, similar to major prey. In populations subject to control, dingoes became less active around dusk, and activity was concentrated in the period shortly before dawn.
4. Shifts in feral cat abundance indices between properties with and without dingo control were inversely related to corresponding shifts in indices of dingo abundance. There was also a negative relationship between predator visitation rates at individual camera stations, suggesting cats avoided areas where dingoes were locally common. Reduced activity by dingoes at dusk was associated with higher activity of cats at dusk.
5. Our results suggest that effective dingo control not only leads to higher abundance of feral cats, but allows them to optimize hunting behaviour when dingoes are less active. This double effect could amplify the impacts of dingo control on prey species selected by cats. In areas managed for conservation, stable dingo populations may thus contribute to management objectives by restricting feral cat access to prey populations.
6. Synthesis and applications. Predator control not only reduces indices of apex predator abundance but can also modify their behaviour. Hence, indicators other than abundance, such as behavioural patterns, should be considered when estimating a predator's capacity to effectively interact with lower trophic guilds. Changes to apex predator behaviour may relax limitations on the behaviour of mesopredators, providing enhanced access to resources and prey.

Feral dogs as potential threat for pinnipeds

García-Aguilar, M.C. & J.P. Gallo-Reynoso 2012. Feral dogs at Isla de Cedros, Baja California, Mexico: a possible threat for pinnipeds. . Revista Mexicana de Biodiversidad, 83 (3): 785-789.

The presence of feral dogs (Canis lupus familiaris) in Isla de Cedros, Baja California, Mexico, has been documented for over 15 years. In the summer of 2009 and the winter of 2009/2010, 2 sampling surveys were conducted in the northeast coastal portion of the island to assess the diet of feral dogs in the vicinity of hauled out California sea lions (Zalophus californianus) and northern elephant seals (Mirounga angustirostris). Mammals were the most important prey group in the diet of dogs (85.4%). Our results show that in the northeast coast of Isla de Cedros, feral dogs feed on pinnipeds: the elephant seal was the most important prey in both seasons (43.3% in summer and 51.9% in winter), followed by the sea lion as the second most important prey during the summer (23.3%), while its importance decreased in the winter (5.8%). Besides the potential predatory activity, there is an important likelihood that pinnipeds could be infected by pathogens of dogs, with serious epizootic consequences.


García-Aguilar, M.C. & J.P. Gallo-Reynoso 2012. Perros ferales en la isla de Cedros, Baja California, México: una posible amenaza para los pinnípedos. Revista Mexicana de Biodiversidad, 83 (3): 785-789.

La presencia de perros ferales (Canis lupus familiaris) en la isla de Cedros, Baja California, México, fue documentada hace más de 15 años. En el verano de 2009 e invierno 2009/2010, se realizaron 2 campañas de muestreo en la costa noreste de la isla para evaluar los hábitos alimentarios de los perros en las cercanías de las zonas de reproducción y descanso del lobo marino de California (Zalophus californianus) y del elefante marino del norte (Mirounga angustirostris). Los mamíferos constituyeron el grupo consumido más importante en la alimentación de los perros (85.4%). Los resultados de este estudio muestran que en la costa noreste de la isla de Cedros los perros se alimentan de pinnípedos: el elefante marino fue la especie que más se consumió, con el mayor porcentaje en ambas temporadas (43.3% en verano y 51.9% en invierno); el lobo marino, fue la segunda durante el verano (23.3%), aunque su porcentaje disminuyó en el invierno (5.8%). Además del potencial impacto que el consumo por los perros pueda tener sobre las poblaciones de los pinnípedos, una amenaza adicional es la posible transmisión de los patógenos caninos, con serias consecuencias epizoóticas.

Monitoring feral dog’s population at Isla de Cedros

García-Aguilar, M.C. 2012. Monitoring feral dog’s population at Isla de Cedros, Baja California, and the associated threats over native mastofauna. Acta Zoológica Mexicana (n. s.), 28(1): 37-48.

Monitoring introduced species is an important management tool in order to preserve native species. The aim of this study was to monitor the feral dog’s population in Isla de Cedros and to identify actual and potential threats of their presence over the native mastofauna. Data were collected at two sampling areas of the island, the Northeast Coast (CNE) and the Central-South Region (RCS). Dog’s distribution pattern and density was assess using a non-invasive method based on scat counts along transect surveys and relative density (R) and faecal relative abundance index (fRAI) were estimated. Dog’s diet composition was evaluated by scat analysis. Both R and fRAI were significant greater (P < 0.05) in the CNE than in the RCS. The results showed that feral dogs are feeding from at least three endemic terrestrial mammal species (the mule deer, the brush rabbit, and the Anthony’s pocket mouse) and two pinnipeds species (the northern elephant seal and the California sea lion). With this study provide a useful baseline for future comparison and monitoring and control purposes. Nevertheless, it is necessary to conduct studies about the dog’s feeding behavior to measure their predatory activity and to assess the associated damage level. Also, due to the fact that interactions between dogs and pinnipeds appeared frequently and because they are phylogenetically related, the greatest threat of the dog’s presence is that it could be a disease vector, with serious health outcomes for the wildlife.


García-Aguilar, M. C. 2012. Monitoreo de la población de perros ferales en la Isla de Cedros, Baja California, y las amenazas a la mastofauna nativa. Acta Zoológica Mexicana (n. s.), 28(1): 37-48.

El monitoreo de especies introducidas es una herramienta importante para preservar las especies nativas. El objetivo de este estudio fue monitorear a la población de perros ferales en la Isla de Cedros e identificar las amenazas actuales y potenciales de su presencia sobre la mastofauna nativa. La colecta de datos se realizó en dos áreas de la isla, la costa noreste (CNE) y la región centro-sur (RCS). Los patrones de distribución y la densidad de los perros se determinaron con un método no invasivo basado en el conteo de excretas a lo largo de transectos y se estimó la densidad relativa (R) y el índice de abundancia relativa fecal (fRAI). La composición de la dieta se evaluó por medio del análisis de las excretas. Tanto los valores de R como de fRAI fueron significativamente mayores (P < 0.05) en CNE que en RCS. Los resultados mostraron que los perros se alimentan de al menos tres especies de mamíferos endémicos (el venado bura, el conejo matorralero y el ratón de abazones de Cedros) y de dos especies de pinnípedos (el elefante marino del norte y el lobo marino de California). A partir de este estudio se cuenta con una línea de base que podrá ser usada en los programas de control y monitoreo futuros. Sin embargo, es necesario desarrollar estudios sobre el comportamiento alimentario de los perros para evaluar su actividad predatoria y medir el nivel de daño asociado; además, dado que las interacciones entre pinnípedos y perros parecen ser frecuentes y están relacionados filogenéticamente, posiblemente la mayor amenaza de la presencia de los perros sea la propagación de enfermedades infeccionas, con graves resultados para la vida silvestre.

Semi-ownership and sterilisation of cats and dogs in Thailand

Toukhsati, S. R., Phillips, C. J., Podberscek, A. L., & Coleman, G. J. (2012). Semi-Ownership and Sterilisation of Cats and Dogs in Thailand. Animals, 2(4), 611-627.


The aim of this study was to identify the prevalence of cat and dog semi-ownership in Thailand and factors that predict sterilisation. Semi-ownership was defined as interacting/caring for a companion animal that the respondent does not own, such as a stray cat or dog. A randomised telephone survey recruited 494 Thai nationals residing in Thailand. The findings revealed that 14% of respondents (n = 71) engaged in dog semi-ownership and only 17% of these dogs had been sterilised. Similarly, 11% of respondents (n = 55) engaged in cat semi-ownership and only 7% were known to be sterilised. Using Hierarchical Multiple Regression, the findings showed that 62% and 75% of the variance in intentions to sterilise semi-owned dogs and cats, respectively, was predicted by religious beliefs, and psychosocial factors such as attitudes, perceived pressure from others, and perceived behavioural control. Community awareness campaigns that approach the issue of sterilisation in a way that is consistent with cultural and religious traditions using Thai role models, such as veterinarians, may go some way in reducing stray animal population growth.

Owners' attitude contribution to stray cat overpopulation

Finkler, H., & Terkel, J. (2012). The contribution of cat owners’ attitudes and behaviours to the free-roaming cat overpopulation in Tel Aviv, Israel. Preventive Veterinary Medicine, 104(1), 125-135.


The attitudes and behaviours of cat owners in regard to treatment of cats may have a cumulative effect on the food availability, reproduction, density and welfare of the free-roaming cat population and thus also on the extent of cat overpopulation. Understanding this is thus a vital step in the a priori planning of cat management programs on any scale, as well as in developing public education programs on this issue. Although recent years have seen an accumulation of knowledge in regard to cat owners’ attitudes and behaviours, the findings vary among countries and locations and in Israel this has never been investigated systematically. Using a questionnaire provided to cat owners in veterinary clinics, this study aimed at identifying those attitudes and behaviours that may be contributing to cat overpopulation in Tel Aviv, Israel, and at exploring the socio-economic factors that influence this problem. The findings show that the influential factors can be predicted from the cat owners’ socio-economic status, mainly education and income, as well as gender and age. A consistency in those cat owner behaviours that contribute to cat overpopulation was also uncovered, revealing a sub-population of individuals who persist in the undesirable behaviours. Finally, a strong relationship between attitude and consequent behaviour was demonstrated, indicating the importance of education and targeted publicity as a means to influence attitudes and thereby change behaviours in this respect. We propose several measures by which to reduce the current extent of cat owners’ contribution to the cat overpopulation: discouraging unwanted owner behaviours such as abandonment of their cats and allowing them to breed; promoting awareness of the neutering option among cat caretakers; and increasing pre-adoption neutering rates in shelters. Regional and national laws promoting responsible pet ownership need to be enacted. By improving the current level of knowledge and awareness among cat owners regarding cat overpopulation issues, and encouraging a more responsible attitude, cat owners’ bond with their cats could be strengthened, as well as their bond with and contribution to their environment

Incursion of domestic carnivores around urban areas: Three camera-trapping studies

Marks, B. K., & Duncan, R. S. (2009). Use of forest edges by free-ranging cats and dogs in an urban forest fragment. Southeastern Naturalist, 8(3), 427-436.

Free-ranging Felis catus (Domestic Cat) and Canis familiaris (Domestic Dog) can greatly impact native prey populations, but little is known about their occurrence in urban forest fragments. In this study, we used camera traps to photograph (capture) cats, dogs, and native wildlife in a 409-ha urban forest in Birmingham, AL from Jan–Apr 2007. Habitat treatments included forest interior and forest edges by industrial lands, neighborhoods with higher house values, and neighborhoods with lower house values. We employed both conservative (n = 31) and liberal (n = 64) methods of tallying the number of individual dogs, cats, and native mammals captured. Dogs and cats combined comprised 19% (conservative) and 26% (liberal) of all photographic captures. Procyon lotor (Raccoon) were the most abundant of the 7 native species at 32% (conservative) and 53% (liberal) of all captures. Dogs were more abundant in neighborhood edges, and cats were more abundant in the forest interior. Cats and dogs combined were 75% (conservative) and 86% (liberal) of captures from the forest interior. Captures of native species were far more frequent in neighborhood edges (conservative = 86.9%, and liberal = 92.3%) than in other treatments. These findings demonstrate that exotic predators can be an important ecological presence in certain portions of urban forest fragments, and more extensive studies of their impact are needed.

Ordeñana, M.A, K. R. Crooks, E.E. Boydston, R.N. Fisher, L.M. Lyren, S. Siudyla, C.D. Haas, S. Harris, S.A. Hathaway, G.M. Turschak, A. K. Miles, & D.H. Van Vuren (2010) Effects of urbanization on carnivore species distribution and richness. Journal of Mammalogy, 91 (6): 1322-1331.

Urban development can have multiple effects on mammalian carnivore communities. We conducted a meta-analysis of 7,929 photographs from 217 localities in 11 camera-trap studies across coastal southern California to describe habitat use and determine the effects of urban proximity (distance to urban edge) and intensity (percentage of area urbanized) on carnivore occurrence and species richness in natural habitats close to the urban boundary. Coyotes (Canis latrans) and bobcats (Lynx rufus) were distributed widely across the region. Domestic dogs (Canis lupus familiaris), striped skunks (Mephitis mephitis), raccoons (Procyon lotor), gray foxes (Urocyon cinereoargenteus), mountain lions (Puma concolor), and Virginia opossums (Didelphis virginiana) were detected less frequently, and long-tailed weasels (Mustela frenata), American badgers (Taxidea taxus), western spotted skunks (Spilogale gracilis), and domestic cats (Felis catus) were detected rarely. Habitat use generally reflected availability for most species. Coyote and raccoon occurrence increased with both proximity to and intensity of urbanization, whereas bobcat, gray fox, and mountain lion occurrence decreased with urban proximity and intensity. Domestic dogs and Virginia opossums exhibited positive and weak negative relationships, respectively, with urban intensity but were unaffected by urban proximity. Striped skunk occurrence increased with urban proximity but decreased with urban intensity. Native species richness was negatively associated with urban intensity but not urban proximity, probably because of the stronger negative response of individual species to urban intensity.

Fandos, G., Fernández-López, J., & Tellería, J. L. (2012). Incursion of domestic carnivores around urban areas: a test in central Spain. Mammalia, 76(2), 223-225.

Although domestic carnivores are frequently considered a threat to wildlife inside and around urban areas, little is known about the incursions of these animals from urban areas to the surrounding habitats. To explore this, we sampled carnivores in wooded areas surrounding four villages located in the mountains north of Madrid by using 40 camera-trapping stations. They were distributed at regular distances within a perpendicular transect distributed from 10 to 2000 m from the urban border. The results suggest that the incidence of domestic carnivores (cats and dogs) was constrained to <400 m from the urban border, and that the presence of domestic carnivores did not interfere with the distribution of wild carnivores (foxes, beech martens, badgers, genets, etc.), which show random distribution patterns around villages. This means that overpredation at the village edges could mainly be due to the effect of domestic animals and not to that of wild carnivores attracted to urban areas

Biology and impact of domestic cat in the Pacific

Duffy, D. C., & Capece, P. (2012). Biology and Impacts of Pacific Island Invasive Species. 7. The Domestic Cat (Felis catus) 1. Pacific Science, 66(2), 173-212.

This article reviews the biology, ecological effects, and management of the domestic cat (Felis catus) in the Pacific basin. The cat is one of the most controversial invasive species in the Pacific region because of its complex relations with humans. At one extreme, well-fed domestic house pets are allowed outdoors where they may hunt native animals; at the other, unsocialized feral cats have replaced native predators as apex predators or occupy a new niche on oceanic islands, where they have devastated native faunas. In the middle are stray cats that are still socialized around humans. Feral and stray cats can be reservoirs of diseases that infect free-roaming domestic cats, humans, and wildlife. Given these problems, the best response would be to keep domestic cats indoors, restrict cat breeding, and remove feral populations. However, most Pacific basin societies have failed to reach a consensus on the cat problem, so solutions are ad hoc, often lacking in any scientific basis, and reflect our conflicting views. Compromise management might best fall into three broad classes: (1) eradication of cats should be confined to islands and other areas of high native biodiversity where reintroduction can be prevented; (2) in a landscape of low or moderate biological value, efforts should be made to educate the public to reduce the impact of their cats on remaining wildlife, while excluding cats from “islands” of elevated biodiversity values or human sensitivity; (3) in drastically simplified urban ecosystems, management perhaps should occur only in response to local complaints.