Analysis of six Latin American cat populations through coat genes and molecular microsatellite markers

Ruiz-García, M., & Alvarez, D. (2003). Análisis de seis poblaciones latinoamericanas de gatos mediante genes del pelaje y marcadores microsatélites. Acta zoológica mexicana, (89), 261-286. (Analysis of six Latin American cat populations through coat genes and molecular microsatellite markers)

Six Latin American cat populations (La Havana, San Jose, Bogotá, Asunción, Buenos Aires and Santiago) have been studied from a population genetics standpoint by using different morphological coat and molecular microsatellite markers (FCA43, FCA45, FCA96 and FCA126). The main aims of the current work are as follows: (1) To determine whether the type and intensity of the genetic differences found for diverse morphological loci among the current British cat populations and those from the British oversea colonies (USA, Canada and Australia) agree with the differences among the current Spanish cat populations and those from Latin America and (2) to determine if the genetic relationships among some of these Latin American cat populations are in agreement by using independently morphological and molecular microsatellite markers. The different results obtained were as follows: (A) All populations analyzed were in Hardy-Weinberg equilibrium at the O, S and at the four microsatellite loci studied with the exception of La Havana at the S locus. (B) The trees obtained showed that the relationships of the six cat populations studied regard to the Spanish populations, in particular, and with the European populations, in general, were extremely heterogeneous. Therefore, for instance, Asuncion was genetically identical to some Catalonian populations meanwhile Santiago (Chile) revealed more resemblance with the cat populations of presumed British origin in the Eastern Coast of the United States by means of the coat color genes. The striking genetic heterogeneity among some of these Latin American cat populations could be explained by the existence of different geographic, or temporal, migrations from Spain and/or that diverse gene drift degrees were present in the foundation of the diverse populations studied. Finally, the molecular results were similar to those obtained with the gross morphological genes. Therefore, the overall evolution of these morphological markers is controlled more probably by neutral stochastic forces than by selective ones.

Resumen
Seis poblaciones latinoamericanas de gatos (La Habana, San José, Bogotá, Asunción, Buenos Aires y Santiago) han sido estudiadas desde una perspectiva genético poblacional con marcadores que codifican características morfológicas del pelaje y marcadores moleculares nucleares microsatélites (FCA43, FCA45, FCA96, FCA126). A partir de las frecuencias alélicas de ambos tipos de marcadores genéticos se investigó: (1) si el tipo y la intensidad de las diferencias genéticas encontradas para diversos loci morfológicos entre las poblaciones de gatos en Gran Bretaña y en sus ex-colonias transmarítimas (EU, Canadá, Australia) se dio también entre las poblaciones de gatos actuales en España y en Latinoamérica y (2) si las relaciones genéticas de esos caracteres morfológicos entre algunas de esas poblaciones latinoamericanas de gatos fue paralela a las relaciones encontradas con marcadores moleculares microsatélites. Los resultados obtenidos fueron: (A) Todas las poblaciones analizadas estuvieron en equilibrio Hardy-Weinberg para los loci O, S y para los cuatro loci microsatélites estudiados, con la excepción de la población de La Habana para el locus S. (B) Los fenogramas obtenidos mostraron que las relaciones de las seis poblaciones latinoamericanas de gatos respecto a las poblaciones españolas y europeas fueron muy heterogéneas. Por ejemplo, la población de Asunción (Paraguay) fue genéticamente indistinguible de algunas poblaciones de gatos analizadas en Cataluña, tanto con los genes morfológicos como con los microsatélites, mientras que Santiago presentó más semejanzas con las poblaciones de gatos de presunto origen británico en la costa Este de los Estados Unidos cuando se utilizaron los genes del pelaje. La fuerte heterogeneidad genética entre algunas de las poblaciones latinoamericanas estudiadas hace pensar en que diversas migraciones geográficas, o temporales, se dieron desde España, o que diversos grados de deriva genética se dieron en la fundación de las diferentes poblaciones latinoamericanas estudiadas. Finalmente, los resultados moleculares son similares a los obtenidos con los genes de codificación morfológica por lo que la evolución global de éstos parece más modulada por fuerzas neutrales que selectivas.

A review of four successful recovery programmes for threatened sub-tropical petrels

Carlile, N., Priddel, D., Zino, F., Natividad, C., & Wingate, D. B. (2003). A review of four successful recovery programmes for threatened sub-tropical petrels. Mar. Ornithol, 31, 185-192.

Recovery programmes have significantly increased the population sizes of four threatened sub-tropical petrels: Zino’s Petrel Pterodroma madeira, Bermuda Petrel P. cahow, Gould’s Petrel P. leucoptera leucoptera and Hawaiian Petrel P. sandwichensis. These recovery programmes were reviewed to examine i) past and present nesting habitat; ii) the nature and commonality of threats; iii) the recovery actions undertaken; iv) the conservation gains; and v) the factors most responsible for these gains. The most significant causes of past population decline were exploitation by humans for food, loss of nesting habitat and the introduction of alien mammals. Primary contemporary threats are predation and disturbance at the breeding grounds by both alien and indigenous species. Current relict populations have restricted distributions and are often confined to nesting habitats that are severely degraded or sub-optimal and dissimilar from those known historically. The crucial attribute of these habitats is the absence or low density of alien predators. The most beneficial recovery actions involved the control or eradication of predators at breeding grounds and the provision of safe artificial nest sites. Recovery actions were more difficult to implement for species on large islands. The success of each recovery programme was due largely to concerted action spanning several decades.

Nest predation on endangered Hawaiian honeycreeper

Laut, M. E., Banko, P. C., & Gray, E. M. (2003). Nesting behavior of Palila, as assessed from video recordings. Pacific science, 57(4), 385-392.

We quantified nesting behavior of Palila (Loxioides bailleui), an endangered Hawaiian honeycreeper, by recording at nests during three breeding seasons using a black-and-white video camera connected to a videocassette recorder. A total of seven nests was observed. We measured the following factors for daylight hours: percentage of time the female was on the nest (attendance), length of attendance bouts by the female, length of nest recesses, and adult provisioning rates. Comparisons were made between three stages of the 40-day nesting cycle: incubation (day 1–day 16), early nestling stage (day 17–day 30 [i.e., nestlings ≤14 days old]), and late nestling stage (day 31–day 40 [i.e., nestlings > 14 days old]). Of seven nests observed, four fledged at least one nestling and three failed. One of these failed nests was filmed being depredated by a feral cat (Felis catus). Female nest attendance was near 82% during the incubation stage and decreased to 21% as nestlings aged. We did not detect a difference in attendance bout length between stages of the nesting cycle. Mean length of nest recesses increased from 4.5 min during the incubation stage to over 45 min during the late nestling stage. Mean number of nest recesses per hour ranged from 1.6 to 2.0. Food was delivered to nestlings by adults an average of 1.8 times per hour for the early nestling stage and 1.5 times per hour during the late nestling stage and did not change over time. Characterization of parental behavior by video had similarities to but also key differences from findings taken from blind observations. Results from this study will facilitate greater understanding of Palila reproductive strategies.

Reproductive behaviour of free-ranging rural dogs in West Bengal

Pal, S. K. (2003). Reproductive behaviour of free-ranging rural dogs in West Bengal, India. Acta theriologica, 48(2), 271-281.

Reproductive behaviour of free-ranging dogs Canis familiaris Linnaeus, 1758 was studied in a village in the state of West Bengal, India. Increased synchronized breeding was the most striking feature of this study. October (late monsoon) represented the peak period of mating for the feral dogs. Of all courting males, only 41% were observed to mount and copulate. On average, each male mounted 5.47 ± 2.49 (mean ± SD) times per hour. Of all mountings, only 10% were successful matings, ie copulatory ties. There was a negative correlation between the number of courting males and the number of successful copulations. The average duration of copulatory tie was 15.73 ± 7.75 min. Several factors interrupting the duration of copulatory ties were identified. December was the peak period of pup rearing. Mean litter size was 5.70 ± 2.03 with a male-biased sex ratio 1.41:1. Only a single annual breeding cycle recorded here differed from the previous studies on European and American dogs. Mothers spent most of the time with their pups at the dens during the early stage of rearing. The duration of time spent at dens by mothers was minimum when the pups were highly mobile at the age of 10 weeks. The lactating mothers were observed to be more aggressive immediately following litter production. Typically, an old adult male remained near the den as a ‘guard’.

Evaluation of outdoor access of owned cats

Clancy, E.A., Moore, A.S., and Bertone, E.R. 2003. Evaluation of cat and owner characteristics and their relationships to outdoor access of owned cats. Journal of the American Veterinary Medical Association. 222(11): 1541–1545.


Objective—To examine characteristics of cats and their owners with regard to outdoor access of owned cats.

Design—Cross-sectional study.

Animals—184 owned cats admitted to a veterinary referral center for nonemergency health concerns.

Results—Cats acquired recently were less likely to be allowed outdoors than those acquired during previous years. Outdoor access was often limited during the day; few owners allowed their cats to remain outdoors at night. Cats acquired from shelters were more likely to be kept exclusively as indoor pets than those cats acquired as strays. The presence of dogs but not other cats in the household was associated with increased outdoor access. Age, health status, and onychectomy status were not significantly associated with outdoor access. Cats allowed outdoor access were more likely to have been bitten by other cats.

Conclusions and Clinical Relevance—The basis for an owner's decision to allow outdoor access appears to be multifactorial, and there may be regional differences in outdoor access of owned cats. Acquisition source is associated with outdoor access of owned cats. Availability of information regarding outdoor access of cats may influence decision making. Educational efforts targeted at specific groups of cat owners, as well as programs that acknowledge owner beliefs regarding quality of life for their cats, may help to address the health, safety, and population concerns associated with outdoor access of owned cats. (J Am Vet Med Assoc2003;222:15417–1545)

Light birds are more under risk of predation during migratory stopover

Dierschke, V. 2003. Predation hazard during migratory stopover: are light or heavy birds under risk? - J. Avian Biol. 34: 24-29.

On the offshore island Helgoland, passerine birds killed by predators (feral cats Felis catus and raptors, mainly sparrowhawks Accipiter nisus) during stopover were measured and weighed when found freshly killed and still intact. Supplemented by data of migrating birds ringed on Helgoland and predated on the island later on, age and body mass of victims were compared to live birds trapped on Helgoland during ringing operations. In the eleven species considered, most predator kills fell within the lightest 20% of birds measured during ringing, regardless of which type of predator was involved. It seems that the risk of being heavy due to fuel loads with respect to reduced escape performance is overestimated. The higher exposure of light birds due to more intense foraging and displacement to suboptimal habitats is probably of higher biological significance by offering conspicuous prey for predators. The lower risk of heavy birds when prey of different body condition is available for predators has implications for modelling optimal migration behaviour, and predation risk is perhaps not an important factor for migrants when deciding on site use.

Domestic cats outcompete endemic endangered Iriomote cat

Watanabe, S., Nakanishi, N., & Izawa, M. (2003). Habitat and prey resource overlap between the Iriomote cat Prionailurus iriomotensis and introduced feral cat Felis catus based on assessment of scat content and distribution. Mammal Study, 28(1), 47-56.

The Iriomote cat Prionailurus iriomotensis occurs only on Iriomote Island in the Ryukyu Archipelago of southern Japan. The population is estimated at 100 individuals and is on the decline. We examined resource overlap for prey and habitat between this species and introduced cats Felis catus by scat census and analysis of scat contents. The distribution of scats was completely different between the two species. The distribution of scats from Iriomote cats was associated with environmental factors such as vegetation types and terrain conditions, while the distribution of scats from feral cats mainly depended on locations of garbage dumps. Although the feral cat heavily utilized human rubbish, it also preyed upon thirteen species of native animals, ten of which were also used by Iriomote cats. From 1997 to 2001, the number of observed scats from Iriomote cats declined significantly, while feral cat scat became more common. Feral cats on Iriomote Island still depend on humans, but the expansion of their distribution into habitats of Iriomote cats may increase the competition for prey and habitat resources in the future.

Control of feral cats for nature conservation (parts I to IV)

Risbey, D. A., Calver, M., & Short, J. (1997). Control of feral cats for nature conservation. I. Field tests of four baiting methods. Wildlife Research, 24(3), 319-326.

Four methods of baiting were evaluated on a radio-collared population of feral cats on Heirisson Prong, Shark Bay, Western Australia. Dried-meat baits, baiting rabbits to kill cats through secondary poisoning, a fishmeal-based bait and a bait coated in the flavour enhancer Digest were tested. All proved to be ineffective for controlling feral cats. Future research should explore baits more ‘natural’ in appearance and the effect of visual lures, and possibly bait over a larger area to increase the number of cats exposed to baits.

Short, J., Turner, B., Risbey, D. A., & Carnamah, R. (1997). Control of feral cats for nature conservation. II. Population reduction by poisoning. Wildlife Research, 24(6), 703-714.

A feral cat population was substantially reduced by poisoning at a semi-arid site in Western Australia. The control programme was designed to protect two species of endangered native mammals that had recently been reintroduced to the site. Feral cats were poisoned with carcasses of laboratory mice, each impregnated with 4.5 mg of sodium monofluoroacetate (1080). Baits were placed at 100-m intervals along the track system each night for four consecutive nights. Kill rates were assessed by monitoring survival of radio- collared cats and by spotlight counts of cats before and after baiting. All radio-collared cats were killed and there was a 74% reduction in spotlight counts of cats after baiting. Bait removal varied with the abundance of rabbits, the primary prey item for cats in this area. Effectiveness of control operations against feral cats is maximised by baiting at times of low prey abundance. Monitoring the changing abundance of the primary prey species provides important information for timing control operations against feral cats.

Short, J., Turner, B., & Risbey, D. (2003). Control of feral cats for nature conservation. III. Trapping. Wildlife Research, 29(5), 475-487.

We present comparative success of various trapping methods trialed during control of feral cats at a site for the reintroduction of threatened mammals at Shark Bay, Western Australia. Our results come from 31 703 trap-nights that caught 263 cats (an average of 0.83 per 100 trap-nights). Cats differed markedly in their vulnerability to trapping depending on whether they primarily scavenged at rubbish tips or around human settlement or whether they hunted for their food in the bush. Cage traps were an effective means of controlling the former, with 9.4 cats captured per 100 trap-nights. Scavenging cats included a higher proportion of sub-adults and kittens and lower proportion of adult males than hunting cats. Variation between years in capture success for hunting cats was largely explained by the abundance of rabbits relative to that of cats and whether the rabbit population was increasing or decreasing. These factors accounted for a nine-fold difference in trap success. The number of cats caught in any particular trapping session could be explained by location (rubbish tip or town versus bush), trapping effort (typically greater effort yielded higher captures), abundance of cats at the site (captures were highest when cats were abundant), and season (captures were highest in the first half of the year when the young of the year were becoming independent). Concealed foot-hold traps, in a range of possible sets, provided effective methods for capturing cats that hunt, except where capture of non-target species was a critical limiting factor. Cage traps caught cats at a comparable rate to foot-hold traps for standard sets, but caught a significantly different cohort. Concealed foot-hold traps caught a higher percentage of adult cats, particularly males, than did cage traps. Mouse carcases and rabbit pieces were significantly more effective as lures when rabbits (the major food of cats at the site) were at low densities, whereas the success of commercial scent lures was unrelated to food availability. Significantly more cats than expected were caught using food as an attractant at times of food shortage (late summer, autumn and early winter) for both scavenging and hunting cats. In contrast, scent lures caught significantly more cats than expected in spring and summer when cats were defending access to mates and/or territory. Hence, no single trap type, trap set, or lure provided unequivocally superior performance over others. Control is likely to be best achieved by a variety of trapping methods and lure types used in combination, supplementing well timed poisoning efforts. Trap success is likely to be maximised by trapping at times when the dominant prey of cats are scarce relative to the number of cats and are decreasing in abundance.

Short, J., & Turner, B. (2005). Control of feral cats for nature conservation. IV. Population dynamics and morphological attributes of feral cats at Shark Bay, Western Australia. Wildlife Research, 32(6), 489-501.

The dynamics of feral cats (Felis catus) were assessed at Shark Bay at two adjoining sites subject to differing intensities of predator control. The Heirisson Prong conservation reserve (12 km²) was fenced to exclude predators and was subject to intensive control actions, while a portion of the adjoining Carrarang pastoral lease (60 km²) was subject to a lesser level of control. Foxes (Vulpes vulpes) were largely absent at both sites owing to effective control. Densities of cats were highly variable over time, showing strong annual fluctuations over 14 years of records Three independent estimates of peak density were made, varying between 1.5 and 2.8 km^-2. Rate of increase was assessed as 0.98 on the pastoral lease and 0.99 on the conservation reserve (to give an approximate doubling of the population every 8.5 months). A logistic model, with K = 1.5 km^-2 and r of 0.98, gave a maximum sustained yield of 0.37 cats km^-2 year^-1 and a harvest rate of >0.6 cats km^-2 year^-1 for their elimination in 5 years or less (for K = 2.8 km^-2  these values increase to 0.69 and >1.05 km^-2 year^-1 respectively). Harvest outcomes at both sites were consistent with these models. However, the effort required to maintain a given offtake rate increased 6-fold at low cat densities and offtake by trapping as a function of cat density took the form of a Type 3 functional response. The functional response for cat trapping (the offtake with constant effort per unit time) overlaid against the curve of cat productivity suggested a stable equilibrium point at low cat densities (0.07–0.13 cats km^-2). Hence, trapping effort needed to be greatly intensified at low cat densities and/or augmented by other methods of control to eradicate cats from the closed system of the reserve. The strongly male-biased sex ratio of captures at the barrier fence suggested high levels of reinvasion from beyond the harvested area of the pastoral lease and this made effective control in this open system difficult.

Reducing feral cats' threats to human health and biodiversity

USDA. (2003). Management of feral and free-ranging cat populations to reduce threats to human health and safety and impacts to native wildlife species in the Commonwealth of Puerto Rico. USDA. APHIS. 69 pp.


No abstract available. Click for full text.

Control of feral cats on Cocos (Keeling) Islands

Algar, D., G.J. Angus, R.I. Brazell, C. Gilbert & D.J. Tonkin. 2003. Feral cats in paradise: Focus on Cocos. Atoll Research Bulletin, 505: 1-12.

The Department of Conservation and Land Management was approached by the Shire council of the Cocos (Keeling) Islands to provide a long-term solution to the feral cat problem on the islands. Researchers in the Department have developed a number of techniques and strategies to control feral cats. The project on the islands provided the opportunity to assess these procedures on a closed population in a wet tropical climate. A control program resulted in the removal of approximately 90% of the ferallstray cats on the islands. It is anticipated that Shire officers that were trained in trapping techques during the control program will remove the remaining individuals

Cats and habitat fragmentation affecting distribution of small mammals

Baker, P. J., Ansell, R. J., Dodds, P. A., Webber, C. E., & Harris, S. (2003). Factors affecting the distribution of small mammals in an urban area. Mammal review, 33(1), 95-100.


We investigated the distribution of a range of small mammal species in five urban habitats in north-west Bristol: residential gardens, woodlands, allotment gardens, scrub and a cemetery. Wood mouse Apodemus sylvaticus abundance in residential gardens was negatively related to the abundance of cats and the distance to the nearest patch of natural or seminatural vegetation. These results suggest that urban small mammal populations may be limited by predation and habitat fragmentation, although the effects of the latter may be offset by the availability of good quality gardens

Mammals invaders on islands

Courchamp, F., J.-L. Chapuis & M. Pascal. 2003. Mammal invaders on islands: Impact, control and control impact. Biological Reviews, 78 (3): 347-383.

The invasion of ecosystems by exotic species is currently viewed as one of the most important sources of biodiversity loss. The largest part of this loss occurs on islands, where indigenous species have often evolved in the absence of strong competition, herbivory, parasitism or predation. As a result, introduced species thrive in those optimal insular ecosystems affecting their plant food, competitors or animal prey. As islands are characterised by a high rate of endemism, the impacted populations often correspond to local subspecies or even unique species. One of the most important taxa concerning biological invasions on islands is mammals. A small number of mammal species is responsible for most of the damage to invaded insular ecosystems: rats, cats, goats, rabbits, pigs and a few others. The effect of alien invasive species may be simple or very complex, especially since a large array of invasive species, mammals and others, can be present simultaneously and interact among themselves as well as with the indigenous species. In most cases, introduced species generally have a strong impact and they often are responsible for the impoverishment of the local flora and fauna. The best response to these effects is almost always to control the alien population, either by regularly reducing their numbers, or better still, by eradicating the population as a whole from the island. Several types of methods are currently used: physical (trapping, shooting), chemical (poisoning) and biological (e.g. directed use of diseases). Each has its own set of advantages and disadvantages, depending on the mammal species targeted. The best strategy is almost always to combine several methods. Whatever the strategy used, its long-term success is critically dependent on solid support from several different areas, including financial support, staff commitment, and public support, to name only a few. In many cases, the elimination of the alien invasive species is followed by a rapid and often spectacular recovery of the impacted local populations. However, in other cases, the removal of the alien is not sufficient for the damaged ecosystem to revert to its former state, and complementary actions, such as species re-introduction, are required. A third situation may be widespread: the sudden removal of the alien species may generate a further disequilibrium, resulting in further or greater damage to the ecosystem. Given the numerous and complex population interactions among island species, it is difficult to predict the outcome of the removal of key species, such as a top predator. This justifies careful pre-control study and preparation prior to initiating the eradication of an alien species, in order to avoid an ecological catastrophe. In addition, long-term monitoring of the post-eradication ecosystem is crucial to assess success and prevent reinvasion.

Exurban development brings cats and dogs and changes bird communities

Maestas, J. D., Knight, R. L., & Gilgert, W. C. (2003). Biodiversity across a Rural Land‐Use Gradient. Conservation Biology, 17(5), 1425-1434.

Private lands in the American West are undergoing a land-use conversion from agriculture to exurban development, although little is known about the ecological consequences of this change. Some nongovernmental organizations are working with ranchers to keep their lands out of development and in ranching, ostensibly because they believe biodiversity is better protected on ranches than on exurban developments. However, there are several assumptions underlying this approach that have not been tested. To better inform conservation efforts, we compared avian, mesopredator, and plant communities across the gradient of intensifying human uses from nature reserves to cattle ranches to exurban developments. We conducted surveys at randomly selected points on each type of land use in one Colorado watershed between May and August of 2000 and 2001. Seven bird species, characterized as human commensals or tree nesters, reached higher densities (all p < 0.02) on exurban developments than on either ranches or reserves. Six bird species, characterized as ground and shrub nesters, reached greater densities (all p < 0.015) on ranches, reserves, or both of these types of land use than on exurban developments. Domestic dogs (Canis familiaris) and house cats (Felis catus) were encountered almost exclusively on exurban developments, whereas coyotes (Canis latrans) were detected more frequently (p = 0.047) on ranchlands than exurban developments. Ranches had plant communities with higher native species richness and lower non-native species richness and cover than did the other types of land use (all p < 0.10). Our results support the notion that ranches are important for protecting biodiversity and suggest that future conservation efforts may require less reliance on reserves and a greater focus on private lands.

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Los terrenos privados del oeste de América están experimentando una conversión del suelo de un uso agrícola a un uso urbano, aunque se conoce poco acerca de las consecuencias ecológicas de este cambio. Algunas organizaciones no gubernamentales están trabajando con granjeros para que sus tierras permanezcan sin urbanizar, ostensiblemente porque piensan que la biodiversidad se protege mejor en tierras rurales que en urbanizaciones. Sin embargo, hay varios supuestos subyacentes a este modelo que no han sido comprobadas. Para informarnos mejor sobre los esfuerzos de conservación, comparamos comunidades de aves, mesodepredadores y plantas a lo largo del gradiente de intensidad de uso humano de reservas naturales, granjas y zonas de urbanización. Realizamos muestreos en sitios seleccionados aleatoriamente en cada uso de suelo en una cuenca del Colorado entre mayo y agosto de 2000 y 2001. Siete especies de aves, caracterizadas como comensales humanos o nidificantes arbóreos, alcanzaron densidades más altas (todas p < 0.02) en urbanizaciones nuevas que en granjas o reservas. Seis especies de aves, caracterizadas como nidificantes de suelo y arbustos, alcanzaron densidades mayores (todas p < 0.015) en granjas, reservas o usos mixtos del suelo que en las nuevas urbanizaciones. Se encontraron perros (Canis familiaris) y gatos (Felis catus) domésticos casi exclusivamente en nuevas urbanizaciones, mientras que se detectaron coyotes (Canis latrans) más frecuentemente (p = 0.047) en granjas que en nuevas urbanizaciones. Las granjas tenían comunidades de plantas con mayor riqueza de especies nativas y menor riqueza y cobertura de especies no nativas que en todos los demás usos de suelo (todas p < 0.10). Nuestros resultados apoyan la noción de que las granjas son importantes para la protección de la biodiversidad y sugieren que los futuros esfuerzos de conservación pueden requerir de menos confianza en las reservas y un mayor enfoque en terrenos privados.

Dispersal partner of domestic cats

Devillard, S., Say, L., & Pontier, D. (2003). Dispersal pattern of domestic cats (Felis catus) in a promiscuous urban population: do females disperse or die?.Journal of animal ecology, 72(2), 203-211.

1. The domestic feral cat (Felis catus L.) is a good model for studying intraspecific variability of dispersal patterns in mammals because cats live under a large diversity of socio-ecological conditions. We analysed both the natal and breeding dispersal patterns of domestic cats in a promiscuous urban population and tested whether or not it differed from the male-biased natal dispersal pattern observed for polygynous rural populations.
2. During an 8-year study we recorded the exact date of in situ death for 148 marked cats and the exact date of disappearance from the population for 99 other cats. Because undiscovered deaths might over-estimate dispersal probabilities when considering only disappearance probabilities, we made an novel application of multistrata capture–recapture methods in order to disentangle dispersal from true mortality.
3. We showed that mature females dispersed, both before and after their first reproduction, at 1 and 2 years old. Contrary to females, no dispersal seemed to occur in males. Before sexual maturity, females that disappeared at 1 and 2 years old were in worse body condition than females that stayed in the population area after 2 years old. However, they did not reproduce less successfully before their disappearance than females that died later in the population area.
4. The female-biased and low natal dispersal pattern in this population was atypical compared to other promiscuous/polygynous mammals and differed from that observed in rural polygynous populations of domestic cat. Neither local mate competition nor inbreeding avoidance appeared to be sufficient pressures to counterbalance ecological constraints on dispersal in an urban environment. However, local resource competition for den sites between potential matriarchies could lead to the breeding dispersal of less competitive females.

Diet of feral cats at a rubbish dump

Hutchings, S. 2003. The diet of feral house cats (Felis catus) at a regional rubbish tip, Victoria. Wildlife Research, 30:103-110.

The diet of feral cats (Felis catus) inhabiting a regional rubbish tip (dump) in Victoria was studied to determine whether cats utilised garbage or live prey from the surrounding heathlands for food. Between 30 and 50 cat scats were collected from the tip over two years in each of four sampling periods: spring 1997, autumn 1998, spring 1998 and autumn 1999. The scats were analysed to determine major dietary components, dietary breadth and seasonal overlap of diet. Bone fragments from meat scraps were the most frequent dietary item detected in the scats. Vertebrate prey species occurred less often in the cats' diet but a variety of both introduced and native species were represented. Analysis of dietary breadth confirmed that cats selected mainly meat and chicken scraps from the garbage but indicated that vertebrates were hunted opportunistically. Control measures are suggested to reduce cat numbers at regional rubbish tips to relieve potential impact on native wildlife.

TNR ineffective in controlling cat colonies

Castillo, D. and Clarke, A.L. 2003. Trap/neuter/release methods ineffective in controlling domestic cat "colonies" on public lands. Natural Areas Journal. 23 (3): 247-253. 

Domestic cat (Felis catus L.) advocates have formed coalitions whose goals are to promote the welfare of cats through the use of a specific nonlethal population control method. This method consists of trapping, neutering. and releasing cats into supervised cat colonies located on private and public lands, including state and county parks and natural areas. Advocates believe that this method will help reduce the number of unwanted cats and stabilize the population of unwanted cats over time. Furthermore, advocates claim that established colonies are temporary in nature and will decrease in size over time through death and adoption. This claim was tested through photographic and observational capture-recapture technique.~ in Miami-Dade County, Florida, USA, in two Metro-Dade County parks (A. D. Barnes Park and Crandon Marina). Although the number of original colony members decreased over time, illegal dumping of unwanted cats and the attraction of stray cats to provisioned food offset reductions in cat numbers caused by death and adoption. Furthermore, overall population size of the colony at A. D. Barnes Park increased over time, and at Crandon Marina neither decreased nor increased over time. Our study suggests that this method is not an effective means to control the population of unwanted cats and confirms that the establishment of cat colonies on public lands encourages illegal dumping and creates an attractive nuisance. We recommend that advocates of cat colonies seek a longterm solution to the pet overpopulation issue by redirecting their efforts toward the underlying problem of managing irresponsible pet owners.

Cat eradication decreases shearwater mortality

Keitt, B.S. & Tershy, B.R. (2003) Cat eradication significantly decreases shearwater mortality. Animal Conservation, 6, 307-308

Introduced predators are a leading threat to seabird populations world-wide and cats (Felis catus) have probably had the most universally damaging effect (Moors & Atkinson, 1984). Eradication of feral cat populations from seabird colonies is a conservation priority (Tershy et al., 2002) and there are many studies that demonstrate the benefits of these actions for seabirds (e.g. Forsell, 1982; Cooper et al., 1995). However, detailed estimates of the effects of cat predation on seabird population viability are lacking in spite of the fact that such data could provide important support for land managers attempting to promote eradication programmes for seabird restoration.

See also in Conservation Evidence

Introgression of domestic dog haplotype in coyote

Adams, J. R., Leonard, J. A., & Waits, L. P. (2003). Widespread occurrence of a domestic dog mitochondrial DNA haplotype in southeastern US coyotes.Molecular Ecology, 12(2), 541-546.

Sequence analysis of the mitochondrial DNA control region from 112 southeastern US coyotes (Canis latrans) revealed 12 individuals with a haplotype closely related to those in domestic dogs. Phylogenetic analyses grouped this new haplotype in the dog/grey wolf (Canis familiaris/Canis lupus) clade with 98% bootstrap support. These results demonstrate that a male coyote hybridized with a female dog, and female hybrid offspring successfully integrated into the coyote population. The widespread distribution of this haplotype from Florida to West Virginia suggests that the hybridization event occurred long ago before the southeastern USA was colonized by coyotes. However, it could have occurred in the southeastern USA before the main front of coyotes arrived in the area between male coyotes released for sport and a local domestic dog. The introgression of domestic dog genes into the southeastern coyote population does not appear to have substantially affected the coyote's genetic, morphological, or behavioural integrity. However, our results suggest that, contrary to previous reports, hybridization can occur between domestic and wild canids, even when the latter is relatively abundant. Therefore, hybridization may be a greater threat to the persistence of wild canid populations than previously thought.

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Cat predation on rural and urban landscapes

Lepczyk, C.A., Mertig, A.G. & Liu, J. (2003) Landowners and cat predation across rural-to-urban landscapes. Biological Conservation 115: 191–201

Fluctuations of bird abundances have been attributed to such factors as supplemental feeding, landscape change, and habitat fragmentation. Notably absent from consideration, however, is the role of private landowners and their actions, such as owning free-ranging domestic cats (Felis catus; cats allowed free access to the outdoors). To understand the impacts of cat predation on birds, we surveyed all 1694 private landowners living on three breeding bird survey (BBS) routes (∼120 km) that represent a continuum of rural-to-urban landscapes in Southeastern Michigan, where the majority (>90%) of land is privately owned. Our data indicate that among the 58.5% of landowners that responded, one quarter of them owned outdoor cats. On average a cat depredated between 0.7 and 1.4 birds per week. A total of 23+ species (12.5% of breeding species) were on the list of being killed, including two species of conservation concern (Eastern Bluebirds and Ruby-throated Hummingbirds). Across the three landscapes there were ∼800 to ∼3100 cats, which kill between ∼16,000 and ∼47,000 birds during the breeding season, resulting in a minimum of ∼1 bird killed/km/day. While the number and density (no./ha) of free-ranging cats per landowner differed across the rural to urban landscapes, depredation rates were similar. Landowner participation in bird feeding showed no relationship with the number of free-ranging cats owned. Similarly, selected demographic characteristics of landowners were not significantly related to the number of free-ranging cats owned. Our results, even taken conservatively, indicate that cat predation most likely plays an important role in fluctuations of bird populations and should receive more attention in wildlife conservation and landscape studies.

Domestic cat gene introgression into wild cat in Europe

Randi, E., Pierpaoli, M., Beaumont, M., Ragni, B., & Sforzi, A. (2001). Genetic identification of wild and domestic cats (Felis silvestris) and their hybrids using Bayesian clustering methods. Molecular Biology and Evolution, 18(9), 1679-1693.

Crossbreeding with free-ranging domestic cats is supposed to threaten the genetic integrity of wildcat populations in Europe, although the diagnostic markers to identify "pure" or "admixed" wildcats have never been clearly defined. Here we use mitochondrial (mt) DNA sequences and allelic variation at 12 microsatellite loci to genotype 128 wild and domestic cats sampled in Italy which were preclassified into three separate groups: European wildcats (Felis silvestris silvestris), Sardinian wildcats (Felis silvestris libyca), and domestic cats (Felis silvestris catus), according to their coat color patterns, collection localities, and other phenotypical traits, independently of any genetic information. For comparison, we included some captive-reared hybrids of European wild and domestic cats. Genetic variability was significantly partitioned among the three groups (mtDNA estimate of F(ST) = 0.36; microsatellite estimate of R(ST) = 0.30; P < 0.001), suggesting that morphological diversity reflects the existence of distinct gene pools. Multivariate ordination of individual genotypes and clustering of interindividual genetic distances also showed evidence of distinct cat groups, partially congruent with the morphological classification. Cluster analysis, however, did not enable hybrid cats to be identified from genetic information alone, nor were all individuals assigned to their populations. In contrast, a Bayesian admixture analysis simultaneously assigned the European wildcats, the Sardinian wildcats, and the domestic cats to different clusters, independent of any prior information, and pointed out the admixed gene composition of the hybrids, which were assigned to more than one cluster. Only one putative Sardinian wildcat was assigned to the domestic cat cluster, and one presumed European wildcat showed mixed (hybrid) ancestry in the domestic cat gene pool. Mitochondrial DNA sequences indicated that three additional presumed European wildcats might have hybrid ancestry. These four cats were sampled from the same area in the northernmost edge of the European wildcat distribution in the Italian Apennines. Admixture analyses suggest that wild and domestic cats in Italy are distinct, reproductively isolated gene pools and that introgression of domestic alleles into the wild-living population is very limited and geographically localized.

Pierpaoli, M., Birò, Z.S., Herrmann, M., Hupe, K., Fernandes, M., Ragni, B., Szemethy, L. & Randi, E. (2003). Genetic distinction of wildcat (Felis silvestris) populations in Europe, and hybridization with domestic cats in Hungary. Molecular Ecology 12: 2585-2598.

The genetic integrity and evolutionary persistence of declining wildcat populations are threatened by crossbreeding with widespread free-living domestic cats. Here we use allelic variation at 12 microsatellite loci to describe genetic variation in 336 cats sampled from nine European countries. Cats were identified as European wildcats (Felis silvestris silvestris), Sardinian wildcats (F. s. libyca) and domestic cats (F. s. catus), according to phenotypic traits, geographical locations and independently of any genetic information. Genetic variability was significantly partitioned among taxonomic groups (FST = 0.11; RST = 0.41; P < 0.001) and sampling locations (FST = 0.07; RST = 0.06; P < 0.001), suggesting that wild and domestic cats are subdivided into distinct gene pools in Europe. Multivariate and Bayesian clustering of individual genotypes also showed evidence of distinct cat groups, congruent with current taxonomy, and suggesting geographical population structuring. Admixture analyses identified cryptic hybrids among wildcats in Portugal, Italy and Bulgaria, and evidenced instances of extensive hybridization between wild and domestic cats sampled in Hungary. Cats in Hungary include a composite assemblage of variable phenotypes and genotypes, which, as previously documented in Scotland, might originate from long lasting hybridization and introgression. A number of historical, demographic and ecological conditions can lead to extensive crossbreeding between wild and domestic cats, thus threatening the genetic integrity of wildcat populations in Europe.

Lecis, R., Pierpaoli, M., Biro, Z. S., Szemethy, L., Ragni, B., Vercillo, F., & Randi, E. (2006). Bayesian analyses of admixture in wild and domestic cats (Felis silvestris) using linked microsatellite loci. Molecular Ecology, 15(1), 119-131.

Methods recently developed to infer population structure and admixture mostly use individual genotypes described by unlinked neutral markers. However, Hardy–Weinberg and linkage disequilibria among independent markers decline rapidly with admixture time, and the admixture signals could be lost in a few generations. In this study, we aimed to describe genetic admixture in 182 European wild and domestic cats (Felis silvestris), which hybridize sporadically in Italy and extensively in Hungary. Cats were genotyped at 27 microsatellites, including 21 linked loci mapping on five distinct feline linkage groups. Genotypes were analysed with structure 2.1, a Bayesian procedure designed to model admixture linkage disequilibrium, which promises to assess efficiently older admixture events using tightly linked markers. Results showed that domestic and wild cats sampled in Italy were split into two distinct clusters with average proportions of membership Q > 0.90, congruent with prior morphological identifications. In contrast, free-living cats sampled in Hungary were assigned partly to the domestic and the wild cat clusters, with Q < 0.50. Admixture analyses of individual genotypes identified, respectively, 5/61 (8%), and 16–20/65 (25–31%) hybrids among the Italian wildcats and Hungarian free-living cats. Similar results were obtained in the past using unlinked loci, although the new linked markers identified additional admixed wildcats in Italy. Linkage analyses confirm that hybridization is limited in Italian, but widespread in Hungarian wildcats, a population that is threatened by cross-breeding with free-ranging domestic cats. The total panel of 27 loci performed better than the linked loci alone in the identification of domestic and known hybrid cats, suggesting that a large number of linked plus unlinked markers can improve the results of admixture analyses. Inferred recombination events led to identify the population of origin of chromosomal segments, suggesting that admixture mapping experiments can be designed also in wild populations.


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