Gestión de perros y gatos en zonas rurales

De Iván Parrillo (Fundación Gypaetus)
Una vez más y siguiendo en nuestra tarea de poder minimizar a la mínima expresión los casos de envenenamiento, hemos montado esta jornada de trabajo: Gestión de perros y gatos en zonas rurales, una herramienta contra el VENENO.

Para ello se ha contado con la Estrategia Andaluza para la erradicación de cebos envenandos de la Consejería de Agricultura, Pesca y Medio Ambiente de la Junta de Andalucía, Consejo Andaluz de Veterinarios de Andalucía, la Diputación de Córdoba, el Ayuntamiento de Alcaracejos, la empresa ABECOR-Aplicaciones Medioambientales y la Mancomunidad de Municipios de Los Pedroches.

En algunas ocasiones una de las motivaciones del uso ilegal de cebos envenenados que se ha detectado está relacionado con el objetivo de la eliminación de las molestias derivadas como consecuencia de perros y gatos domésticos y asilvestrados. Este hecho, lejos de ser residual, se presenta de forma relativamente habitual en zonas rurales y urbanas. Desde el proyecto Life+ y en el marco la Red Europea de Municipios contra el veneno, pretendemos poner nuestro granito de arena para poder atajar este problema y por ello hemos desarrollado esta jornada.

La asistencia es libre, hasta completar aforo y la cita será el día 9 de abril en el Salón de Convivencia del Ayuntamiento de Alcaracejos

Humane strategies for controlling feral cat populations

Levy, J. K., & Crawford, P. C. (2004). Humane strategies for controlling feral cat populations. Journal of the American Veterinary Medical Association, 225(9), 1354-1360.

There are several options available for integrated nonlethal feral cat control, and no single solution is likely to be appropriate for all situations. Adoption is an ideal outcome for socialized cats and should be employed whenever feasible. Placement in sanctuaries or relocation of colonies may be required for unadoptable cats that must be removed from their colony sites because of welfare or environmental concerns. Sterilization and return to the colony is a third alternative and represents the most cost-effective and scalable strategy. Those who care for feral cats often have a strong human-animal bond and will not cooperate with programs that threaten these cats. Engaging cat feeders in solutions for feral cats will undoubtedly be more productive and economical than warring against them.

Impact of alien predators on seabirds on Corvo island (Azores)

Henriques, A. C. M. (2010). Impacto dos predadores introduzidos na ilha do Corvo no sucesso reprodutor das populações de cagarro (Calonectris diomedea borealis) (Doctoral dissertation, Universidade Técnica de Lisboa) (in Portuguese with English abstracts).

In the Corvo island, Azores, there are important species of seabirds classified as prioritary by the Annex I of the Bird Directive, for example Cory’s Shearwater Calonectris diomedea borealis, is one of the species that represents in terms of number and density the biggest expression in this archipelago in an European level. One of the major threats for the birds that reproduce in islands is the presence of predators, like rats, so, in this context, we analysed the variables that could explain the distribution of rodents, identified the accessible places of nesting of Cory’s, monitored the reproductive season and tried to understand the causes of fail in the egg and chick phase. The results point out a positive relation between rat abundance and reproductive success of Cory’s. The characteristics of the reproductive season are similar to those described for Berlengas and Selvagens, but they differ in the hatching success and chick success. We verified that in the first days of life of the chicks the predation is very significant and other variables should be taken into account, for example the predation by cats.

The Corvo Island has unique features, in terms of endemic fauna and flora, numbers of human population, introduced predators, size of the island, among others, that gave to this island the status of Biosphere Reserve. Additionally, there are important species of seabirds that only reproduce in restricted areas of Europe, and are classified as prioritary by Annex I of the Birds Directive. Nevertheless, the populations of some species are still to confirm (e.g Pterodroma feae, Oceanodroma castro) and others need more research in terms of numbers and localization of the colonies (e.g Puffinus puffinus, Puffinus assimilis). 

The more conspicuous of the seabirds here present is Cory’s Shearwater, Calonectris diomedea borealis and has the biggest expression in terms of numbers and densities in the Azores archipelago which represents 60-70% of the world population. The Corvo population is one of the major ones but the nidification areas and the actual size of the population is still not well known. One of the major causes of the decline of the seabirds, besides the fisheries, specially those ones who reproduce in cavities on the soil, are the introduced predators in islands, places that originally yield millions of seabirds. The biggest problem is that they evolved in environments that were predator free and lack defense mechanisms to face the predation of eggs and chicks by rats and cats. This causes the reproductive collapse in some species and could force the nesting places to sub-optimal conditions, that can compromise the viability of the populations. Last year, SPEA started a LIFE+ project “Safe islands for seabirds” to assess the impacts of the predators on seabirds and prepare the restoration of habitat, by ways of predator and invasive plants control and reforestation with endemic species. This project has an important ecological relevance as it can represent a important step in the developing of protocols for exotic species eradication in islands with human population, with both cats and rats as the major predators. 

The objectives of this thesis were to quantify the influence of rodents in the reproductive success of Cory’s Shearwater. We analyse the distribution of three species of rodents (Rattus rattus, R. norvegicus and Mus musculus) in different habitats and their dependence with some environmental variables. The method chosen was by means of tracking tunnels in two different seasons, one in April-May and the other in September-October, that wanted to express different food availability and different stages of the reproductive period of Cory’s in Corvo. For this analysis we decide do use an algorithmic model Random Forest for the software R 2.9.2. Our results point out the dependence of the presence of rodents with introduced anthropogenic characteristics as roads, exotic vegetation and distance to village. Also we noticed some differences between the house mice and the rats in terms of abundance and selection of habitat. 

We were able to identify different accessible colonies of Cory’s Shearwater in the island, and monitor almost 200 nests, once a week, in eight different places of Corvo. We analysed and compared times of hatching, fledging, incubation period and breeding success, with other islands (Berlenga, Selvagem Grande and others from Azores, such as Graciosa) where Cory’s shearwater reproduces, and finally we tried to understand which are the main causes of failure using the model Nest Survival for the program MARK. This program is an important ecological tool for testing different factors and the correlation between them that could influence the weekly nest survival. Also give us the weight of the model for explaining the data. 

Our results point out the synchronization of times of hatching and fledging among the different places in the Atlantic, but there’s a major difference in the hatching and fledging successes. Surprisingly the causes of failure don’t seem to be related with rat abundance, as the majority of the studies point out, ant the time with less survival probability seems to coincide with the first days after hatching when the chick is more vulnerable. Our assumption is that there is a third variable that wasn’t account for, that is influencing the abundance of rats and the reproductive success of Cory’s. This variable is the presence of cats. 

The analyse of the Life Table demonstrate the big resilience in fluctuations of the population of Cory’s Shearwater in Corvo Island, a characteristic of long lived species. 

We recommend that for the planning of the eradication protocol both cats and rats should be target of control at the same time, incorporate prioritary areas of control for rodents and to study more accurately the causes of fail that influences the seabirds success. 

Dogs digging turtle's nest

Although dogs aren't the biggest predators of turtles, they take their share:

From http://biodiversitycatrice.wikispaces.com/Biodiversity

Dog-mediated rabies in China

Tang, X., Luo, M., Zhang, S., Fooks, A. R., Hu, R., & Tu, C. (2005). Pivotal role of dogs in rabies transmission, China. Emerging infectious diseases, 11(12), 1970.

The number of dog-mediated rabies cases in China has increased exponentially; the number of human deaths has been high, primarily in poor, rural communities. We review the incidence of rabies in China based on data from 1950 and 2004, obtained mainly from epidemiologic bulletins published by the Chinese Ministry of Health.

Rabies in Southern China

Song, M., Tang, Q., Wang, D. M., Mo, Z. J., Guo, S. H., Li, H., Tao, X.Y, Rupprecht, C.E., Feng, Z.J. & Liang, G. D. (2009). Epidemiological investigations of human rabies in China. BMC infectious diseases, 9(1), 210.
Background

The epidemic of rabies showed a rising trend in China in recent years. To identify the potential factors involved in the emergence, we investigated and analyzed the status and characteristics of human rabies between 1996 and 2008. Moreover, the status of rabies infection and vaccination in dogs, and prophylaxis of humans after rabies exposure were analyzed.

Methods

Human rabies data in China between 1996 and 2008 collected from the annual reports of Chinese Center for Disease Control and Prevention (China CDC) were analyzed. To investigate the status of dogs and postexposure prophylaxis (PEP) of humans, brain specimens of domestic dogs were collected and detected, and the demographic details, exposure status and PEP of rabies patients were obtained in 2005 and 2006 in Guangxi, Hunan and Guizhou provinces.

Results

The results showed 19,806 human rabies cases were reported in China from 1996 to 2008, with an average of 1,524 cases each year, and the incidence almost was rising rapidly, with the peak in 2007 (3,300 cases). It was notable that nearly 50% of the total rabies cases nationwide were reported in Guangxi, Hunan and Guizhou provinces. In these three provinces, the rabies infection rate in dogs was 2.3%, and 60% investigated cities had a dog vaccination rate of below 70%; among the 315 recorded human cases, 66.3% did not receive any PEP at all, 27.6% received inadequate PEP, and only 6.0% received a full regime of PEP.

Conclusions

In recent years, rabies is reemerging and becoming a major public-health problem in China. Our analysis showed that unsuccessful control of dog rabies and inadequate PEP of patients were the main factors leading to the high incidence of human rabies in China, then there are following suggestions: (1) Strict control of free-ranging dogs and mandatory rabies vaccination should be enforced. (2)Establishing national animal rabies surveillance network is imperative. (3) PEP should be decided to initiate or withhold according to postmortem diagnosis of the biting animal. (4) The cost of PEP should be decreased or free, especially in rural areas. (5)Education of the public and health care staff should be enhanced.

When does an alien become a native?

Carthey A.J.R. & P.B. Banks. 2012. When Does an Alien Become a Native Species? A Vulnerable Native Mammal Recognizes and Responds to Its Long-Term Alien Predator. PLoS ONE 7(2): e31804. doi:10.1371/journal.pone.0031804

The impact of alien predators on native prey populations is often attributed to prey naiveté towards a novel threat. Yet evolutionary theory predicts that alien predators cannot remain eternally novel; prey species must either become extinct or learn and adapt to the new threat. As local enemies lose their naiveté and coexistence becomes possible, an introduced species must eventually become ‘native’. But when exactly does an alien become a native species? The dingo (Canis lupus dingo) was introduced to Australia about 4000 years ago, yet its native status remains disputed. To determine whether a vulnerable native mammal (Perameles nasuta) recognizes the close relative of the dingo, the domestic dog (Canis lupus familiaris), we surveyed local residents to determine levels of bandicoot visitation to yards with and without resident dogs. Bandicoots in this area regularly emerge from bushland to forage in residential yards at night, leaving behind tell-tale deep, conical diggings in lawns and garden beds. These diggings were less likely to appear at all, and appeared less frequently and in smaller quantities in yards with dogs than in yards with either resident cats (Felis catus) or no pets. Most dogs were kept indoors at night, meaning that bandicoots were not simply chased out of the yards or killed before they could leave diggings, but rather they recognized the threat posed by dogs and avoided those yards. Native Australian mammals have had thousands of years experience with wild dingoes, which are very closely related to domestic dogs. Our study suggests that these bandicoots may no longer be naïve towards dogs. We argue that the logical criterion for determining native status of a long-term alien species must be once its native enemies are no longer naïve.

Dogs as scavengers in India

http://www.indiawilds.com/diary/indiawilds-newsletter-vol-5-issue-ii/

A lot of people as well as animal welfare activists feed street dogs in various parts of our country. Whereas, animal welfare is good, one ought to understand the consequences of each of our actions.

Apart from the food given by people, due to our wasteful nature and the improper garbage disposal, a lot of street dogs find food. They outcompete our traditional scavengers like vultures and jackals. In the earlier days any dead animal used to be cleaned up by vultures, jackals and hyenas. Today with vultures impacted by diclofenac, during the day time it is the dogs who clean up the carcass. In the night, large wildboars get the first share, then the wildboar piglets followed by feral dogs and only after that the jackals get any chance to have food.

To stop the feral dog population from growing:

1) don't waste food

2) don't dump garbage

3) don't feed street dogs/feral dogs

Toxoplasmosis in NW China

Wu, S. M., Huang, S. Y., Fu, B. Q., Liu, G. Y., Chen, J. X., Chen, M. X., Yuan, Z.G., Zhou, D.H., Weng, I.B., Zhu, X.Q. & Ye, D. H. (2011). Seroprevalence of Toxoplasma gondii infection in pet dogs in Lanzhou, Northwest China. Parasit Vectors, 4, 64.

Background: In recent years, surveys of Toxoplasma gondii infection in dogs have been reported worldwide, including China. However, little is known about the prevalence of T. gondii in pet dogs in Northwest China. In the present study, the prevalence of T. gondii in pet dogs in Lanzhou, China was investigated using the modified agglutination test (MAT).

Results: In this survey, antibodies to T. gondii were found in 28 of 259 (10.81%) pet dogs, with MAT titers of 1:20 in 14 dogs, 1:40 in nine, 1:80 in four, and 1:160 or higher in one dog. The prevalence ranged from 6.67% to 16.67% among dogs of different ages, with low rates in young pet dogs, and high rates in older pet dogs. The seroprevalence in dogs >3 years old was higher than that in dogs ≤1 years old, but the difference was not statistically significant (P >0.05). The seroprevalence in male dogs was 12.50% (17 of 136), and in female dogs it was 8.94% (11 of 123), but the difference was not statistically significant (P >0.05).

Conclusions: A high prevalence of T. gondii infection was found in pet dogs in Lanzhou, Northwest China, which has implications for public health in this region. In order to reduce the risk of exposure to T. gondii, further measures and essential control strategies should be carried out rationally in this region.

Toxoplasmosis in SE China

Zhang,H. D.H. Zhou, Y.Z. Chen, R.Q. Lin, Z.G. Yuan, H.Q. Song, S.J. Li & X.Q. Zhu (2010) Antibodies to Toxoplasma gondii in Stray and Household Dogs in Guangzhou, China. Journal of Parasitology, 96 (3): 671-672.

The frequency of Toxoplasma gondii antibodies in stray and household dogs in Guangzhou, China was examined by ELISA on serum samples from 150 animals (36 strays and 114 from households) and the overall prevalence was 21.3%. The extent of infection in stray dogs (33.3%) was significantly higher (P < 0.05) than in household dogs (17.5%). Infection in male and female dogs of both groups was not significantly different (P ≥ 0.05), i.e., 31.8% versus 35.7% for male and female in stray dogs, and 14.5% versus 22.2% in household dogs. The results of the present investigation indicate that the seroprevalence of T. gondii infection in dogs was high in Guangzhou, especially in strays. Therefore, it is essential to implement integrated strategies to prevent and control T. gondii infection in both stray and household dogs.

Factors affecting rabies in China

Kureishi, A., Xu, L. Z., Wu, H., & Stiver, H. G. (1992). Rabies in China: recommendations for control. Bulletin of the World Health Organization, 70(4), 443.

Reviewed are the results of 15 years' experience with rabies at You-An Infectious Disease Hospital, Beijing, China. The purpose of the study was to determine whether there are any epidemiological or clinical features of rabies that are unique to China and which might be important in developing a strategy to control it. During the period under study, 64 patients with rabies were admitted to You-An Hospital. Exposure to dogs was associated with 61 cases, two involving the handling of dog carcasses that were being prepared for meals. All of the exposures occurred in rural areas, and none of the patients received adequate prophylaxis. Patients with proximal sites of exposure and with severe injuries developed rabies after short incubation periods (P less than 0.05, and P less than 0.02, respectively). Failed vaccination was also associated with a short incubation period (P less than 0.05). Haematemesis occurred in 20 patients and was associated with shorter incubation periods (P less than 0.02), facial exposure sites (P = 0.021), and severe injuries (P = 0.047). A strategy to control rabies in China should include efforts to educate the public about handling the carcasses of stray dogs, in addition to the currently recommended strategy of controlling the dog population and of vaccinating domesticated animals.

Introduced mammals on California Channel and Baja California islands

McChesney, G. J., & Tershy, B. R. (1998). History and status of introduced mammals and impacts to breeding seabirds on the California Channel and northwestern Baja California Islands. Colonial Waterbirds, 21 (3) 335-347.

The California Channel Islands, U.S.A., and Northwestern Baja California Islands, Mexico, host important breeding populations of several seabird species, including the endemic Black-vented Shearwater (Puffinus opisthomelas) and Xantus' Murrelet (Synthliboramphus hypoleucus). Mammals introduced to nearly all of the islands beginning in the late 1800s to early 1900s include: cats (Felis catus), dogs (Canis familiaris), Black Rats (Rattus rattus), rabbits and hares (Leporidae), goats (Capra hirca), sheep (Ovis aries), and other grazers. Cats, dogs and rats are seabird predators, grazers such as goats and sheep cause habitat degredation, and rabbits destroy habitat and compete with hole-nesting seabirds. Cats, which were introduced to at least 19 islands and currently occur on ten islands, have had the greatest impacts on seabirds, including the extinction of the endemic Guadalupe Storm-Petrel (Oceanodroma macrodactyla). Cats are known to have eliminated or severely reduced colonies of Black-vented Shearwaters, Cassin's Auklets (Ptychoramphus aleuticus) and Xantus' Murrelets. Black Rats have occurred on a minimum of seven islands and have reduced numbers of small, hole-nesting alcids on at least one island. At many islands, defoliation and erosion caused by rabbits and large grazing mammals has been severe. Their effects on seabirds are not well documented but potentially are serious. Impacts from introduced mammals have been most severe on islands with no native mammalian predators. On the Northwestern Baja California Islands, temporary and permanent human settlements have led to a greater diversity and source of introductions. Programs to remove introduced mammals and to reduce the possibility of future introductions are needed to restore seabird populations and to preserve the biodiversity of the region. Surveys are needed particularly on the Northwestern Baja California Islands to update the status and distribution of seabirds and to further assess impacts from introduced mammals.

Kiwi casualties by dogs ...

Pierce, R.J. & Sporle, W., 1997. Causes of kiwi mortality in Northland. Conservation Advisory Science Notes No. 169. Department of Conservation, Wellington.

194 kiwi deaths reported in Northland between 1990 and June 1995 were caused primarily by dogs, indicating that the "Waitangi dog incident" of 1987 was not an isolated instance. Over the five and a half year period, dogs accounted for 135 (70%) of all reported kiwi deaths and 78% of all deaths for which the precise cause was established. The second greatest cause of death was vehicles (12; 6% of deaths). Although the data were biased against more cryptic predators, e.g. cats and mustelids, the figures nevertheless represent an alarming impact by dogs. Several categories of dog figured prominently, particularly stray/feral dogs and pet dogs, but farm dogs and hunters' dogs also killed many birds.

More about hybridisation in wolf

Randi, E. & V. Lucchini. 2002. Detecting rare introgression of domestic dog genes into wild wolf (Canis lupus) populations by Bayesian admixture analyses of microsatellite variation. Conservation Genetics, 3 (1): 29-43


Hybridization with free-ranging dogs is thought to threat the genetic integrity of wolves in Europe, although available mtDNA data evidenced only sporadic cases of crossbreeding.Here we report results of population assignment and genetic admixture analyses in 107wild-living Italian wolves, 95 dogs including 30 different breeds and feral dogs, and captive-reared wolves of unknown or hybrid origins, which were genotyped at 18 microsatellites. Two Italian wolves showed unusually dark coats ("black wolves''), and one showed a spur in both hindlegs ("fifth finger wolf''), suggesting hybridization. Italian wolves showed significant deficit of heterozygotes, positive FIS values and deviations from Hardy-Weinberg equilibrium. Genetic variability was significantly partitioned between groups, suggesting that wolves and dogs represent distinct gene pools.Multivariate ordination of individual genotypes and clustering of inter-individual genetic distances split wolves and dogs into two different clusters congruent with the prior phenotypic classification, but hybrids and wolves of unknown origin were not identified from genetic information alone. By contrast, a Bayesian admixture analysis assigned all the Italian wolves and dogs to two different clusters, independent of any prior phenotypic information, and simultaneously detected the admixed gene composition of the hybrids, which were assigned to more than one cluster.Captive-reared wolves of unknown origin were prevalently assigned to the Italian wolf population. Admixture analyses showed that one "black wolf" had mixed ancestry in the dog genepool and could be a hybrid, while the other two wolves with unusual phenotypes were assigned to the Italian wolf population.

See more about wild canid hybridisation with dogs

Multiple predators on Corvo island

Hervías, S., A. Henriques, N. Oliveira, T. Pipa, H. Cowen, J. A. Ramos, M. Nogales, P. Geraldes, C. Silva, R. Ruiz de Ybáñez & S. Oppel. 2012. Studying the effects of multiple invasive mammals on Cory’s shearwater nest survival. Biological Invasions, DOI 10.1007/s10530-012-0274-1

The most common invasive mammals—mice, rats, and cats—have been introduced to islands around the world, where they continue to negatively affect native biodiversity. The eradication of those invasive mammals has had positive effects on many species of seabirds. However, the removal of one invasive mammal species may result in abundance changes of other species due to trophic and competitive interactions among species. Understanding the overall impact of several invasive species is a key challenge when evaluating the possible effects of eradication programmes. Here we assess the influence of the three most common invasive mammals on nest survival of Cory’s shearwater (Calonectris diomedea). We monitored six breeding colonies over 3 years and measured the activity of mice, rats and cats to examine the influence of invasive mammals on nest survival. We found that nest survival showed a similar temporal trend in all years, with lowest weekly survival probabilities shortly after chicks hatched.Cats were identified as major predators of chicks, but no measure of colony-specific cat activity was able to adequately explain variation in shearwater nest survival. Nest survival was on average 0.38 (95 % confidence interval 0.20–0.53) and varied among colonies as well as over time. We found a small positive influence of rats on nest survival, which may indicate that the presence of small rodents as alternative prey may reduce cat predation of chicks. Our findings suggest that the eradication of rodents alone may exacerbate the adverse effects of cats on shearwater nest survival.