Public perception of the problem of free roaming dogs and cats in Central Italy

Slater, M. R., Di Nardo, A., Pediconi, O., Villa, P. D., Candeloro, L., Alessandrini, B., & Del Papa, S. (2008). Free-roaming dogs and cats in central Italy: Public perceptions of the problem. Preventive veterinary medicine, 84(1), 27-47.

A cross-sectional telephone survey of randomly selected households examined the extent and types of problems associated with free-roaming dogs and cats in the Teramo province of Italy. The households were sampled randomly within each municipality; municipalities were combined into coastal, central hills and mountain regions for analysis. The survey was conducted in May and June of 2004 with a response rate of 74% (397/536). Ninety percent of respondents (N = 356) believed that free-roaming dogs and cats were a problem. They were most commonly concerned about personal safety, followed by animal welfare, public health and environmental sanitation. Sixty-nine percent of respondents (274) actually saw free-roaming dogs or cats where they live. While dogs were most commonly seen, cats were seen in greater numbers. Overall, 10% (39/297) and 5% (21/397) of respondents cared for free-roaming cats and dogs, respectively. Two-thirds of the respondents (251/397) believed that animals were abandoned because the owners lost interest. About 2/3 of respondents (251/397) reported that the community government should have the responsibility for dealing with free-roaming dogs and cats. The respondents supported the idea of building more shelters and controlling the birth rate as control measures rather than euthanizing dogs and cats. The results suggest that free-roaming dogs and cats are a very common sight in this part of Italy with substantial concerns by the residents. However, concerns about the animals’ welfare were clearly raised, supporting the laws that make it illegal to euthanize a healthy dog or cat in Italy. Using the information from this study, research on the underlying causes of abandonment of dogs and cats or failing to sterilize them should be undertaken to begin to address this problem. Further, national and regional funding must be provided to support existing laws which should help protect and eventually decrease the numbers of free-roaming and homeless dogs and cats.

Cats, mice and climate change impact on Marion island's birds

Huyser, O., Ryan, P. G., & Cooper, J. (2000). Changes in population size, habitat use and breeding biology of lesser sheathbills (Chionis minor) at Marion Island: impacts of cats, mice and climate change?. Biological Conservation, 92(3), 299-310.


Impacts on the native avifauna of sub-Antarctic islands by introduced vertebrates are well documented for species such as burrowing petrels (Procellariidae), but less is known about impacts on surface-nesting species. The sub-Antarctic Prince Edward Islands, comprising Marion and Prince Edward Islands, support an endemic form of lesser sheathbill (Chionis minor). Marked differences have developed over the last 20 years in winter habitat use and population trends of sheathbills between the two islands. Currently birds at Marion forage almost exclusively along the coastline and in penguin colonies during winter, but at Prince Edward they occur at higher densities and forage throughout the coastal plain. Compared to the 1970s, sheathbills at Marion are now less abundant around most of the island, forage proportionally less in the vegetation of the coastal plain, commence breeding with a lower body mass and lay smaller clutches. These changes are likely a result of a decrease in terrestrial macro-invertebrate prey, formerly an important winter food resource for sheathbills at Marion Island. The main biological difference between the two islands is the presence of many more introduced species at Marion, including house mice (Mus musculus) and feral cats (Felis catus) (now eradicated). We suggest that house mice are impacting the sheathbill population by consuming terrestrial macro-invertebrates, and that this impact has been exacerbated by the removal of feral cats, by the massive reduction in burrowing petrels (which promote invertebrate populations through manuring), and by climatic warming (which may be promoting higher densities of mice). This proposed web of interactions between sheathbills, introduced species, invertebrates and burrowing petrels needs to be further investigated, given the likelihood of further climatic change.

Feeding ecology and population dynamics of the feral cat in Australia

Molsher, R., Newsome, A., & Dickman, C. (1999). Feeding ecology and population dynamics of the feral cat (Felis catus) in relation to the availability of prey in central-eastern New South Wales. Wildlife Research, 26(5), 593-607.

The diet of feral cats (Felis catus) was studied at Lake Burrendong, central-eastern New South Wales, from July 1994 to June 1997. Mammals were the major prey in 499 scats that were analysed. Rabbits (Oryctolagus cuniculus) were the staple prey, while carrion was an important secondary food. Invertebrates, other mammalian prey, vegetation, birds and reptiles were generally minor components of the diet. Few significant seasonal differences in diet were found; however, invertebrates contributed less and possums more to the diet in winter and summer respectively. A significant dietary response was found to changes in rabbit abundance, but not for the other prey types. Cats continued to prey heavily on rabbits even after a 90% decline in rabbit abundance occurred, which coincided with the advent of Rabbit Calicivirus Disease (RCD). House mice (Mus domesticus) increased in importance in the diet ten months post-RCD. Although the abundance of cats was correlated with the abundance of some prey species, other factors may have influenced the observed patterns; these are discussed.

Home range of male feral cats in Central Australia

Edwards, G. P., De Preu, N., Shakeshaft, B. J., Crealy, I. V., & Paltridge, R. M. (2001). Home range and movements of male feral cats (Felis catus) in a semiarid woodland environment in central Australia. Austral Ecology, 26(1), 93-101.

There is a paucity of data on the movement patterns of feral cats in Australia. Such data can be used to refine control strategies and improve track-based methods of monitoring populations of feral cats. In this study the home ranges and movements of male feral cats were examined over 3.5 years in a semiarid woodland environment in central Australia. Two home range estimators were used in the examination: (i) minimum convex polygon (MCP); and (ii) fixed kernel. The most widely used method of estimating home range in feral cats is MCP, while the fixed kernel method can be used to identify core areas within a home range. On the basis of the MCP method, the long-term home ranges of feral cats in central Australia were much larger than those recorded elsewhere (mean, 2210.5 ha). Twenty-four hour home ranges were much smaller (mean, 249.7 ha) and feral cats periodically shifted their 24 h ranges within the bounds of their long-term home ranges. Core area analysis indicated marked heterogeneity of space use by male feral cats. Several instances where feral cats moved large distances (up to 34 km) were recorded. These long distance movements may have been caused by nutritional stress. Using data from the literature, it is shown that prey availability is a primary determinant of long-term home range size in feral cats. The relevance of the results to the design of management strategies for feral cats in central Australia is also discussed.

Diet of fox, dog and cat in south-eastern Victoria

Triggs, B., Brunner, H., & Cullen, J. M. (1984). The food of fox, dog and cat in Croajingalong National Park, south-eastern Victoria. Wildlife Research, 11(3), 491-499.

The diet of foxes, dogs and cats living in Croajingalong National Park in extreme south-easten Victoria was studied during 1979 and 1980. From 1397 scats collected over 20 months, remains of 22 indigenous and 7 introduced mammal species were identified. Remains of ringtail possums Pseudocheirus peregrinus predominated in the scats from all three predators (fox 58%, cat 56% and dog 38%). Other main prey species for the fox and cat were Antechinus spp.(24% and 15% respectively) and Rattus spp. (15% and 19%) and for the dog two species of wallabies, Macropus rufogriseus and Wallabia bicolor (34%), wombat Vombatus ursinus (11%), Antechinus spp.(l5%) and Rattus spp.(10%). Nonmammalian items for the three predators were birds, reptiles, fish, insects, crustaceans, molluscs and plant material.

Comparison between feral cat and fox diets in Australia

Catling, P. C. (1988). Similarities and contrasts in the diets of foxes, Vulpes vulpes, and cats, Felis catus, relative to fluctuating prey populations and drought. Wildlife Research, 15(3), 307-317.

The diets of the fox, Vulpes vulpes, and feral cat, Felis catus, were studied at Yathong Nature Reserve in semi-arid western New South Wales. The overall occurrence of rabbit was 45.1% in stomachs of foxes and 54.0% in cats, representing 51.3 and 82.6% respectively of the weight of stomach contents. Both predators exhibited a functional response to rabbits, Oryctolagus cuniculus, (their staple prey) during the rabbit breeding season. Predation on rabbits was greatest on an increasing prey population during good pasture conditions and a decreasing population during drought. After the rabbit breeding season, diet changed to other prey and resulted in an annual prey cycle which was similar for foxes and cats. Both predators successfully co-exist in the semi-arid environment by primarily utilising different age groups of the same staple prey and to some extent different supplementary prey. Foxes mainly ate adult rabbits and cats young rabbits. During the drought foxes preyed heavily on adult rabbits; cats ate some rabbits but relied heavily on other food sources. The supplementary prey of foxes were invertebrates, birds, reptiles and carrion; small mammals and fruits opportunely eaten. Invertebrates, birds, reptiles and small mammals were supplementary prey for cats with carrion opportunely eaten.

Home range and population ecology of feral cats in Australia

Jones, E., & Coman, B. J. (1982). Ecology of the Feral Cat, Felis catus (L.), in Souht-Eastern Australia III.* Home Ranges and Population Ecology in Semiarid North-West Victoria. Wildlife Research, 9(3), 409-420.

This paper reports home range sizes and population ecology of feral cats in a 19000-ha study area situated in the Victorian Mallee. Movements of six cats were monitored by radio-tracking for 8-21 months. Adults maintained discrete home ranges; areas varied from 3.3 to 9.9 (mean 6.2) km² for males and from 0.7 to 2.7 (mean 1 ,7) km² for females. Rabbit warrens, hollow logs and dense thickets were favoured daytime refuges. Mean daily straight-line distances moved bet-veen daytime refuges varied from 0.06 km for a female with juveniles to 1.67 km for an adult male. Relative abundance of cats over four years showed seasonal fluctuations, with summer maxima and winter or spring minima; the calculated mean summer and winter densities were 2.4 and 0.74 cats per km² respectively. Summer maxima were composed of adults, adolescents and juveniles; winter minima were usually composed only of adults. Mortality, presumably caused by a nutritional stress acting particularly on subadults, maintained the adult population at a relatively stable level.

Spacing patterns in a urban cat population in Italy

Natoli, E. (1985). Spacing pattern in a colony of urban stray cats (Felis catus L.) in the historic centre of Rome. Applied Animal Behaviour Science,14(3), 289-304.

Factors controlling the spatial organization of a colony of stray cats (Felis catus Linnaeus, 1758) in an urban environment were investigated. Neighbouring colonies of stray cats were also observed, but in less detail. The findings were that:

(1) the animals of the colony selected for intensive study showed an active spacing pattern, i.e. they were not randomly distributed within the boundaries of the study area;

(2) the existence of an active spacing pattern was related to the resources offered by the environment where the animals lived;

(3) these resources (food and shelter) were concentrated in some parts of the study area. Consequently, the animals used these parts more intensively than others. The observations carried out on neighbouring colonies of cats confirmed the results reported for the colony examined in detail.

Some workers consider domestic cats to be a unique resource for evolutionary studies of social behaviour because it has been shown that this species has a high degree of intra-specific variation of behaviour in contrasting habitats. The object of this study was to examine the spacing behaviour and the evolution of the domestic cat social system as a response to a particular urban environment.

Spacing patterns in a rural cat population in Sweden

Liberg, O. (1980). Spacing patterns in a population of rural free roaming domestic cats. Oikos, 336-349.

Spacing patterns in a population of domestic and feral cats in a rural area in southern Sweden were investigated by visual observations, trapping and radio tracking. Females lived alone or in groups around human households. Within each female group the home ranges almost completely overlapped, but between different female groups there was little or no overlap. Most females remained in the same place all their lives, but a few individuals moved and became established at new households, invariably one where there were no other female cats. There were always six to eight feral, well established males in the area, with moderately overlapping home ranges. These ranges were considerably larger than those of females, and one male might include several female groups within his home range. Young males, born in the area, stayed with the female group, where they were born until they were 1.5-3 yr old. They then left and tried to settle somewhere else. Spacing patterns in this cat population can be explained by the influence of proximate and ultimate factors, among which intraspecific aggression and adaptation to living in human households are the most important. Parallel evolution of lion and house cat social organizations is discussed.

Myths and facts about “managed” cat colonies

Winter, L. (undated). Myths and facts about “managed” cat colonies. ABC

1. Cat colonies don't just die out in one or two years: Although promoters of Trap/Neuter/Release (TNR) often claim that the colonies die out through attrition in just a few years, there is very little evidence to support this claim. Even the Adams Morgan cat colony of only 30 original cats in the District of Columbia, which was "managed" by the founders of Alley Cat Allies, took 10 years to die out. It is often difficult to trap all of the cats, the cat food that is left out attracts more cats, and cat colonies often become dumping grounds for unwanted pets (Donald, R.L. 1992. Should Feral Cats Be Euthanized? Shelter Sense: 3-7). Volunteers can become overwhelmed and may not have all of the financial resources or the manpower needed to trap and alter every cat in a colony (Passamsi, w.c., D.W. Macdonald. 1990. The Fate of Controlled Feral Cat Colonies. Universities Federation for Animal Welfare, Hertfordshire, England. 48).
Please note the following: "It's just so overwhelming. I'm in over my head. I can't even afford to eat or buy clothes or do anything. I wake up in the morning hoping I can make it through the day." (Puzzanghera, J. 1995. So Many Cats, So Little Time, San Jose Mercury News, July 19, 1995.)

2. TNR is not meant to eliminate colonies of cats: The purpose of TNR is NOT to eliminate cat colonies, but to perpetuate them because cat feeders believe that if a neutered colony is removed, an intact colony will move in and take it's place.
Please see the following: "You will never get rid of the cats in that area, and it is not advisable to do that. Because if you're doing a neutering to eradicate the cats by neutering, and remove them completely from the area, you are just being the same as somebody who wishes to go and trap them out and kin them. All you're doing is delaying the day Of death." (From a presentation by Roger Tabor, Alley Cat Allies Seminar, "Focus on Ferals," July 8, 1994, Washington, DC.)
More cats may move into an area ONLY if the food source remains. If cats are trapped out and the food source is removed, a cat colony will not reform in that location. This is exactly what occurred at Riverside National Park where over 25 cats were being fed daily. Over the strong objections of the cat feeders and Alley Cat Allies, and in the face of a negative media campaign, the National Park Service removed the cats, the feeding was stopped, and no additional cats have congregated in the area. The Cats were not euthanized, but taken to a local Shelter (Sealy, D. 1996. Removal of a Colony of Free-Ranging Cats From an Area Administered by the National Park Service: A Case History, in: Proceedings of the 1995 International Wildlife Rehabilitation Council Conference, Virginia Beach, VA. Pp 75-77).

3. Cat colonies attract other predators: The cat food left out attracts raccoon, skunk, opossum, fox, coyote, and rats, all predators of birds and carriers of diseases that can be transmitted to other cats, wildlife, or humans, such as rabies. No one is neutering and giving rabies vaccinations to these animals to control their populations and the spread of disease. I have personally witnessed a huge rat hole right under a cat feeding station, and studies have shown that cats do not do a very good job of Controlling rat populations (Childs, J. E. 1991. And the Cat Shall Lie Down With the Rat, Natural History: 16 - 19).
I also have slides of raccoons at cat feeding stations, and e-mail messages from cat feeders discussing the problem of raccoon and opposum at their stations.

4. The cats are not always tested or vaccinated for fatal feline diseases: Some groups, such as the Feral Cat Coalition (http://www.feralcat.com/tpolicy.html), do not follow the American Veterinary Medical Association's guidelines which state that cats in a "managed" cat colony should be tested and vaccinated for infectious diseases and adopted or euthanized if positive. Thus, diseased cats in "managed" cat colonies could come in contact with and infect free-roaming pet cats. Cats with fatal feline diseases will suffer and die a miserable death, calling into question the very humaneness of this practice.

5. Domestic cats are not strictly territorial: Cat feeders will often say that altered cats defend their territory, and do not let other cats join the colony. There is scant scientific evidence to support this claim either. It is well-known that the home ranges of domestic cats overlap. In fact, Dr. Carol Haspel, who conducted a number of studies of cat colonies in Brooklyn, NY, says that cats occupying a certain area "absolutely do not" keep others out, "particularly if there is a feeder." (Donald, R.L. 1992. Should Feral Cats Be Euthanized? Shelter Sense: 3-7).

6. Well-fed, altered cats still kill birds and can impact wildlife populations: It has been extensively documented that domestic cats can severely impact seabird populations on islands (Moors, P.J. and I.A.E. Atkinson. 1984. Predation on seabirds by introduced animals, and factors affecting its severity. ICBP Technical Publication 2:667-690), and well-fed Cats still kill wildlife (Adamec, R.E. 1976. The interaction of hunger and preying in the domestic cat (Felis catus): an adaptive hierarchy? Behavioral Biology 18: 263-272.)
Cats and other predators can also have an impact on songbird populations in fragmented and isolated habitat (Wilcove, D.S. 1985. Nest predation in forest tracts and the decline of migratory songbirds. Ecology 66: 1211- 1214.)

Please see the following quote regarding a scientific study conducted in two California parks-one with over 20 cats that were fed daily, and one without cats:
Cats at artificially high densities, sustained by supplemental feeding, reduced the abundance of native rodent and bird populations, changed the rodent species composition, and may have facilitated the expansion of the house mouse into new areas. Thus we recommend that the feeding of cats in parks Should be Strictly prohibited. (Hawkins, C.C., W.E. Grant, М.Т. Longnecker. 1999. Effect of Subsidized House Cats on California Birds and Rodents. 1999 Transactions of the Western Section of The Wildlife Society 35: 29-33.)

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.

Eradication of cats and other aliens as conservation tool in isla Cabritos, Dominican Republic

Ortiz, R., Rijo, C., Ramnanan, N., Brocca, J., Jolley, W., Hall, T., Herrera-Giraldo, J.L., Swinnerton, K. 2014. The eradication of invasive species as conservation tool for protection and increase of populations critically threatened species in isla Cabritos, Dominican Republic.  VIII Congreso Biodiversidad Caribeña, Universidad Autónoma de Santo Domingo

The eradication of invasive alien species is one of the most valuable tools for effective conservation and protection of native wildlife on islands. The presentation disclosed efforts in 2012 and 2013 to eradicate feral cats (Felis catus) and donkeys (Equus asinus) on Cabritos Island, Lake Enriquillo, Dominican Republic. There, the invaders have negatively impacted many species, including one of the four subpopulations globally fragmented Ricord's iguana (Cyclura ricordi), endemic to Hispaniola and Critically Endangered. Local partners working with eradication experts assembled and trained a local field team to eradicate invasive species on this island, development and application of methods and strategies for removal. After six weeks, the team continued to work independently, with technical support and remote assistance. The cats were removed by cage-trapping and elevated leg-holder traps, the donkeys with the use of snares, most of them delivered to local community organizations. The primary objective of the project is the restoration of Cabritos, to ensure the survival of endangered species, maintain ecotourism initiatives and develop local capacity and support from the local government for future restoration projects islands. These activities take place in the framework of the project "Mitigating the Threats of Invasive Alien Species in the Insular Caribbean" implemented in the Dominican Republic by the Ministry of Environment and Natural Resources, with funding from GEF / UNEP.


La erradicación de especies invasoras como herramienta de conservación para proteger e incrementar poblaciones de especies críticamente amenazadas en las isla Cabritos, República Dominicana.

La erradicación de especies exóticas invasoras es una de las herramientas más valiosas y eficaces deconservación para proteger la vida silvestre nativa en islas.Se presentarán los esfuerzos realizados en 2012 y 2013 para erradicar gatos (Felis catus) y burros (Equus asinus) asilvestrados en la isla Cabritos, Lago Enriquillo, República Dominicana. Allí, las invasoras han impactado negativamente numerosas especies, incluyendo una de las cuatro subpoblaciones globalmente fragmentadas de la iguana de Ricord (Cyclura ricordi), endémica de la Hispaniola y en Peligro Crítico. Los socios locales, trabajando con expertos en erradicación, ensamblaron y entrenaron un equipo de campo local para erradicar las especies invasoras en esta isla, desarrollo y aplicación de métodos y estrategias de remoción. Después de seis semanas, el equipo local continuó trabajando de forma independiente, con apoyo técnico y asistencia remota. Los gatos fueron removidos por captura con trampas-jaula y trampas sujeta-patas elevadas; los burros con el uso de lazos, la mayoría de éstos entregados a organizaciones comunitarias locales. El objetivo primario del proyecto es la restauración de la Isla Cabritos, para garantizar la supervivencia de especies amenazadas, mantener las iniciativas de ecoturismo y desarrollar la capacidad local y el apoyo del gobierno para futuros proyectos locales de restauración de islas. Estas actividades se desarrollan en el marco del proyecto “Mitigando las Amenazas de las Especies Exóticas Invasoras en el Caribe Insular”, implementado en la República Dominicana por el Ministerio de Medio Ambiente y Recursos Naturales, con el financiamiento de GEF/UNEP.

Removing invasive mammals from Alto Velo Island, Dominican Republic

Herrera-Giraldo, J. L. , León, Y., Rijo, C. & Swinnerton, K. 2014. Restoring Alto Velo Island, Dominican Republic: Protecting important colonies of marine birds and habitats for endemic reptiles by removing exotic invasive spscies. VIII Congreso Biodiversidad Caribeña, Universidad Autónoma de Santo Domingo

Caribbean islands host numerous endemic species, unique ecosystems, and globally irreplaceable biodiversity. In the Caribbean Biodiversity Hotspot, invasive species have been identified as the greatest threat to biodiversity. Globally, about 80% of species extinctions have occurred on islands, with invasive species implicated as a primary cause. Worldwide, invasive species eradication is increasingly being used as a valuable conservation tool with which to successfully restore island biodiversity. In the Dominican Republic, a partnership between Grupo Jaragua, the Ministry of Environment and Natural Resources, and Island Conservation, has provided an opportunity to restore Isla Alto Velo through invasive species eradication. Alto Velo is part of the Jaragua National Park which is itself an Important Bird Area and a Key Biodiversity Area. The island is home to one of the largest breeding colony of sooty terns in the insular Caribbean and supports three species of reptiles unique to the island. A feasibility study indicated that the complete and permanent removal of invasive rats, cats, and goats from Isla Alto Velo is technically achievable. During the next months, the project partners will develop a systematic and science-based strategy to remove these invasive species from the island. The overall project goal is to create a wildlife sanctuary in the Dominican Republic where endemic and native species are free from invasive species impacts. In addition, this conservation action would promote the recovery of historically important seabird colonies and could provide future breeding habitat for the endangered black-capped petrel (Pterodroma hasitata), a species threatened by invasive vertebrates.




Restauración de la Isla Alto Velo, República dominicana: Protegiendo importantes colonias de aves marinas y hábitat para reptiles endémicos mediante la remoción de Especies exóticas invasoras

Las Islas del Caribe son refugio de numerosas especies endémicas, ecosistemas únicos y de una irremplazable biodiversidad a nivel mundial. Dentro de los Focos de Biodiversidad en el Caribe, las especies invasoras han sido identificadas como la mayor amenaza para la biodiversidad. Globalmente, cerca del 80% de las extinciones de especies han ocurrido en islas, siendo las especies invasoras uno de los principales causantes. Actualmente, la erradicación de especies invasoras se está utilizando cada vez más como un útil y eficaz instrumento de conservación para restaurar exitosamente la flora y fauna en islas. En la República Dominicana, una alianza entre el Grupo Jaragua, el Ministerio del Medio Ambiente y Recursos Naturales y Island Conservation, ha creado una oportunidad de restaurar la Isla Alto Velo mediante la erradicación de especies invasoras. Alto Velo es parte del Parque Nacional Jaragua, el cual es un Área Importante para las Aves y un Área Clave para la Biodiversidad. La isla provee refugio para una de las mayores colonias de la gaviota oscura en el Caribe Insular y para tres reptiles endémicos. Un estudio de viabilidad indicó que la remoción completa y permanente de ratas, gatos y chivos asilvestrados de Isla Alto Velo es técnicamente viable. Durante los próximos meses, los aliados del proyecto desarrollarán una estrategia sistemática y fundamentada en ciencia para eliminar estas especies invasoras de la isla. El objetivo general del proyecto es crear un santuario de vida silvestre en la República Dominicana, donde las especies endémicas y nativas estén libres de los impactos de especies invasoras. Además, esta acción de conservación promoverá la recuperación de las colonias de aves marinas y podría proporcionar hábitat para la reproducción del diablotín, una especie en amenaza por la presencia de vertebrados invasores.

Genetics of a dockyard cat population

Dards, J. L., & Robinson, R. (1983). Gene frequencies in a population of feral cats in Portsmouth naval Dockyard. Theoretical and Applied Genetics, 64(3), 197-204.

The free-living or feral cats of Portsmouth Dockyard were examined for the frequency of six mutant colour and coat genes. With the exception of one mutant, they were found to differ from the values to be expected for Southern England cat populations. The differences observed may have resulted from selection in the isolated environment (to produce a unique gene profile in terms of frequencies) or from a founder effect. If the latter, the observed frequencies could represent a relict population reflecting the frequencies of the town of Portsmouth before the dockyard was totally enclosed by a high wall. Some evidence of selection related to coat colour was found.

The behaviour of dockyard cats

Dards, J. L. (1983). The behaviour of dockyard cats: Interactions of adult males.Applied Animal Ethology, 10(1), 133-153.

A study was conducted on the feral cats living in Portsmouth Naval dockyard, an enclosed site with an area of less than 100 ha, supporting a population of about 200 adult cats. Data were collected by direct observation, and individuals were recognized primarily by coat pattern. The behaviour of mature tom-cats was observed with respect to females and to other mature males. Most toms visited several groups of females, but the frequency with which a particular group was visited varied between toms. Some toms spent most of their time with one group, adopting a role similar to that of a “pride lion”. The courtship and mating behaviour observed in the dockyard conformed with that recorded for laboratory cats. However, females in oestrus were not heard to call, but toms which were apparently seeking oestrus females emitted a characteristic cry. Up to 6 toms were observed in attendance on unreceptive oestrus females. Sexual behaviour was observed in most months, with peaks in the spring and autumn. Most of the aggressive interactions observed between toms and females were initiated by unreceptive females during courtship. Male aggression towards females was rare. Amicable behaviour was shown, and was more frequently initiated by females than by toms. Females appeared to interact amicably more frequently with toms with which they were familiar. No amicable behaviour between mature toms was observed. Interactions were characterised by aggression, tolerance or avoidance. Agonistic encounters were mainly ritualised, and few fights were observed. It is possible that a dominance hierarchy existed between toms, formed by fights when young toms first became sexually mature.