Cat eradication on San Nicolas Island

Hanson, C.C. 2012. The removal of feral cats from San Nicolas Island, California, to Protect Native and Endemic Species: 2011 Annual Report. Island Conservation

Island Conservation, funded by the Montrose Settlements Restoration Program, began conducting a seabird restoration project on San Nicolas Island in 2009. The restoration project continued through 2011 in an effort to counter the negative impacts of feral cats on marine birds and other native wildlife through the removal of invasive feral cats.

Almost 60 feral cats airlifted from San Nicolas Island  are settling into their 

new home in Ramona at the Fund for Animals Wildlife Rehabilitation Center. 

Delilah and Sybil recently got into a tussle. - John Gastaldo / UNION-TRIBUNE

In coordination with the U.S. Navy, U.S. Fish and Wildlife Service, Institute for Wildlife Studies, and The Humane Society of the United States, Island Conservation (IC) was unable to detect any remaining cats on San Nicolas Island in 2011. A total of fifty nine feral cats have been removed to date. Of these, fifty two animals were transferred to The Humane Society of the United States, where they are housed and cared for in an outdoor, enclosed facility in Ramona, California.

On island, camera traps were strategically placed to remotely collect data for a duration of two to three months at a time. Staff would return to the island to upload, review and archive photos taken, assess the condition of the equipment and its placement, as well as relocate various cameras to new locations that were considered potential habitat for cats if any remained on island. This action was in line with current best practices and with achieving results using a detection probability analysis. The model suggested that to confirm complete removal with 99% confidence, 427-1200 camera nights or 55-75 km of sign searching should occur (Ramsey and Parks, 2010). By December 9, 2011, a total of 27,224 camera trap nights and 278.04 km of sign search had occurred with no cat detections since the last feral cat was removed on June 27, 2010. Based on information collected, efforts put toward detection, and our likelihood of detecting a feral cat had one been present, San Nicolas Island is now considered to be free of feral cats. Eradication confirmation will be publicaly declared in early 2012.

Home range of wild and domestic cats in Hungary

Biró, Z., Szemethy, L., & Heltai, M. (2004). Home range sizes of wildcats (Felis silvestris) and feral domestic cats (Felis silvestris f. catus) in a hilly region of Hungary. Mammalian Biology-Zeitschrift für Säugetierkunde,69(5), 302-310.

The most important factor concerning wild cat populations is the loss of habitat. Therefore, it is necessary to assess the size of the home ranges of wild and domestic cats along with the features of these areas (vegetation, elevation, proximity to human settlement, etc.). A total of 16 wildcats and 19 domestic cats were caught and fitted with radio collars within the period between 1989–1993. It was possible to analyze the radiotelemetry data of 4 wildcats and 3 domestic cats. It resulted that the wildcats occupied larger home ranges than the domestic cats, however, there were exceptions. Home range size variability was extensive in both species. The males occupied larger areas than the females. This was most likely due to the reproductional wandering of males into female home ranges. Also the overlap between the home ranges of males was larger than that of females. However, there were very small overlaps between the core areas. No cats used the same sites at the same time. This indicates that the home ranges of cats exist only in space and time as well. Although these animals are solitary, there was some indication that hierarchy exists between males.

Diet overlap between wild and domestic cat: advantages from being generalist

Biró, Z.,J. Lanszki, L. Szemethy, M. Heltai & E. Randi. 2005. Feeding habits of feral domestic cats (Felis catus), wild cats (Felis silvestris) and their hybrids: trophic niche overlap among cat groups in Hungary. Journal of Zoology, 266 (2): 187–196.

The feeding habits of feral domestic cats Felis catus (n=264), wild cats Felis silvestris (n=22) and their hybrids (n=30) were investigated in Hungary. Cat groups were identified taxonomically by morphological and molecular methods. Diet components were identified in stomach contents and faeces collected from the recta. In each cat group, abundant small mammals were dominant in the diet (relative frequency of occurrence: feral domestic cat, 61–82%, depending on regions; wild cat, 70%; hybrid, 59%). Birds were the second most important quarry (2–7%, 16% and 20%, respectively in the three cat groups), while the contribution of hares (1–2%, 5% and 3%, respectively) and other taxa was not significant. Every cat group preyed on small-sized animals (<50 g; 89–96%, 80% and 80%, respectively), terrestrial (91–98%, 84% and 86%, respectively) and wild (71–73%, 87% and 77%, respectively) prey. Standardized trophic niche breadth was typically very narrow (BA=0.07–0.16, 0.13 and 0.17, respectively). Feral domestic cats occasionally consumed household food (2–7%) and domestic animals (4–8%). This could mean that feral domestic cats have an advantage over wild cats that are food specialists. The trophic niche overlap between cat groups was high (77–88%). Food composition and feeding habits, (weight, zonation and environmental association of consumed prey) of feral domestic cats, however, was different compared to wild cats, which indicated the possibility of partial resource partitioning. The values for hybrids were between the two groups. As well as the stable presence of feral domestic cats (mean population density, D=1.34 individuals/1000 ha) based on field live-trapping, hybrids are also present (D=0.10), leading to continuous hybridization. This can threaten the population of wild cats, which are present at a low density (D=0.17).

Direct and indirect impacts of alien predators on seabirds Islands

Seabird Islands: Ecology, Invasion, and Restoration

Some chapters available on line regarding predators, specially cats:

Drake, D. R.; Bodey, T.; Russell, J. C.; Towns, D. R.; Nogales, M.; Ruffino, L. (2011) Direct impacts of seabird predators on island biota other than seabirds. In: Mulder, C. P. H.; Anderson W. B.; Towns, D. R.; Bellingham, P. J. (eds) Seabird Islands: Ecology, Invasion, and Restoration. Oxford University Press, New York, pp. 91-132.

Russell, J. C. (2011) Indirect effect of introduced predators on seabird islands. In: Mulder, C. P. H.; Anderson W. B.; Towns, D. R.; Bellingham, P. J. (eds) Seabird Islands: Ecology, Invasion, and Restoration. Oxford University Press, New York, pp. 261-279.

Fencing against several invasive mammals

Moseby K.E. & Read J.L. (2006) The efficacy of feral cat, fox and rabbit exclusion fence designs for threatened species protection. Biological Conservation, 127, 429-437.
Pen and field trials were used to test the effectiveness and cost-efficiency of wire netting and electric fence designs as barriers to feral cats, foxes and rabbits in northern South Australia. A 180 cm high wire netting fence with foot apron and a curved ‘floppy’ overhang effectively contained most rabbits, feral cats and foxes during pen trials and proved effective with intensively monitored paddock-scale exclosures. A reduced height fence of 115 cm did not reduce effectiveness of the fence during fence trials but paddock-scale trials are yet to be completed. Conventional 40 mm diameter hexagonal ‘‘rabbit netting’’ was not an effective barrier against young independent rabbits and it is recommended that 30 mm hexagonal netting should be used. A 60 cm wide external netting overhang, curved in an arc and supported by lengths of heavy gauge wire, effectively precluded more feral cats and foxes than a 30 cm wide overhang angled upwards. The 30 cm foot apron was augmented in erosion-prone dunes and watercourses by the addition of wider netting or rubber matting to prevent incursions. Posts, and particularly corners, were targeted by feral cats and foxes and the efficacy of the fence was improved by using steel, rather than timber posts. Electric wires offset from the netting at heights of 120 and 150 cm provided a shock to animals exploring the base of the overhang and further improved the fence efficacy. PVC conduit rollers on the top wire were not effective

Another review on dog's impacts on wildlife

Brickner, I. 2003. The impact of domestic dog (Canis familiaris) on  wildlife welfare and conservation: a literature review with a situation summary from Israel. Tel Aviv University report.

Reviews dozens of articles on dog's impact on wildlife. After discussing domestication and marooning of dogs, the author reviews behaviour, ecology and predation around the world. The document also discusses hybridization problems and diseases transmition, to wildlife and to humans. It also gives some data on domestic and feral dogs in Israel.

See more about wild canid hybridisation with dogs

Cat diet in Macaronesia (Atlantic Ocean)

More than a dozen of papers describing the diet of feral cats on most of Macaronesian islands (Cape Verde, Canary Island and Madeira), Atlantic Ocean.
Although exotic mammals represent an important proportion of their  diet, native species suffer a strong impact from cat's predation.

Macaronesia

1 Medina F. M., Oliveira P., Menezes D., Teixeira S., García R. & Nogales M. 2010. Trophic habits of feral cats in the high mountain shrublands of the Macaronesian islands (NW Africa, Atlantic Ocean). Acta Theriologica 55: 241–250.
Feral cats Felis catus Linnaeus, 1758 have contributed to the extinction of numerous native species on islands, which are clearly sources of global biodiversity. We studied the diet of this introduced predator in the Madeira and Cape Verde archipelagos, which harbour important colonies of endangered sea birds in the high mountain habitats, and compared the results with those obtained in the same habitat in the Canary Islands, Macaronesian archipelago. On Madeira, 461 prey were iden ti fied from 143 scat groups. Mammals, over all mice, constituted the basic diet appearing in 95% of cat scats. On Fogo (Cape Verde), 657 prey items were obtained from 145 scats, and mammals were also the most important prey, reaching a frequency of occurrence of 88%. Although introduced mammals were the main prey category on all Macaronesian islands, we observed variation in feral cat diet among these is lands. Birds were more frequently consumed on Madeira, lizards on Tenerife (Canaries) and invertebrates on Fogo. No specific differences were observed in relation to La Palma.We suggest that the diet composition on these islands varies according to the respective availability of the different prey types.

Canary Islands

2 Nogales, M., A. Martín, G. Delgado & K. Emmerson. 1988. Food spectrum of the feral cat (Felis catus L., 1758) in the juniper woodland on El Hierro (Canary Islands). Bonner Zoologische Beiträge 39: 1-6.
The diet of feral cats inhabiting a juniper woodland on the island of El Hierro (Canary Islands) has been studied by analyzing 248 scats. A total of 1029 prey items have been identified indicating that the introduced mammals (Oryctolagus cuniculus, Mus sp. and Rattus sp.) constitute the basis of the diet appearing in 88.3 % of the samples and representing 85.4 % of the consumed biomass. Mus sp. is the most frequently captured prey but in terms of biomass. Mus sp. is the most frequently captured prey but in terms of biomass, Oryctolagus cuniculus is the fundamental bais of the diet as has similarly been found in other areas studied. Birds can be regarded as alternative prey resources of some importance though they only account for 8 % of the biomass with Cory's shearwater (Calonectris diomedea), contributing practically half this value. Reptiles appear in 44.3 % of the scats but only represent 5.9 % of the biomass, Gallotia galloti caesaris being the most frequently captured species (64.1 %). Insects, (mainly Orthoptera & Coleoptera), despite their high frequency of apparition (45.5 % of scat groups), are insignificant due to their small size, though worthy of note is the large number of larvas of Pimelia laevigata.

3 Nogales, M., M. Abdola, C. Alonso & V. Quilis. 1990. Premiêres données sur l’alimentation du chat haret (Felis catus L., 1758) du Parc National du Teide. Ténérife (Iles Canaries) Mammalia, 54: 189-196. 

Le régime alimentaire du chat haret (Felis catus) est étudié à partir de 221 groupes d'excréments (environ 600 excréments) collectés dans le Parc National du Teide (Ténérife), apportant ainsi des données sur les proies capturées, leur fréquence d'apparition dans les groupes d'excréments et leur biomase. De l'étude de ce matériel on dégage que le régime se compose surtout d'Oryctolagus cuniculus, qui représente une biomasse de 64,4% et une fréquence d'apparition de 53,8%, et de reptiles (Principalement de Gallotia galloti, lézard endémiques des iles Canaries occidentales) avec 74,2%, une fréquence d'apparition en groupes de 74,2% et une biomasse de 20,6%.

In this paper we present preliminary data concerning the food spectrum on the feral cat in the Teide National Park on Tenerife. After having analysed 221 scats, 523 prey items have been identified. Rabbits (Oryctolagus cuniculus) are the fundamental base of the diet (frecuency of apparition 53,8% and biomass 65,4%) as has been similarly found in other areas studied. Also, reptiles (principally Gallotia galloti, an endemic lizard on the Western Canary Islands) was frequently captured, appearing in 74,2% of the scats groups and representing 20,6% of the total biomass.

4 Nogales, M., J.L. Rodríguez, G. Delgado, V. Quilis & O. Trujillo. 1992. The diet of feral cats (Felis catus) on Alegranza Island (North of Lanzarote, Canary Islands). Folia Zoologica 4: 209-212.
The diet of feral cats on Alegranza has been studied by analyzing 110 scats. A total of 199 prey items have been identified indicating that introduced mammals (Oryctolagus cuniculus and Mus sp.) constitute the basis of the diet appearing in 100 of the samples and representing 99,5% of the consumed biomass, Fortunately, it appears that breeding seabirds are not represented in their diet. However the species constitutes a potential threat to the birds if its present prey declines in number.

5 Nogales, M. & F.M. Medina. 1996. A review of the diet of feral domestic cats (Felis silvestris f. catus) on the Canary Islands, with new data from the laurel forest of La Gomera. Zeitschrift für Säugetierkunde 61: 1-6. 

In this study we present a review on the diet of the feral cat on the Canary archipelago, providing the first data from the reliet laurel forest (Garajonay National Park). Among the 403 prey items identified in this habitat, rats were most numerous followed by reptiles. A total of 1.047 scat groups has been studied in the lat eight years from the main habitats of the Canaries. Most of the 2.963 prey items identified represent introduced mammals (rabbit, Oryctolagus cuniculus; mouse, Muscf. musculus and rat, Rattus sp.). These prey were commonly captured in most habitats with the exception of high mountain scrub. In this habitat, reptiles were taken instead introduced mammals. They were also more commonly included in the diet from open ground and open forest than from the denser forest. Birds were more frecuently consumed in the forest than in open areas. Anthropods appeared in significant proportions in the scats from habitats where these items reached high numbers. The results indicate that the diet of feral cats clearly varies according to the different habitats.

6 Medina, F.M., R. García & M. Nogales, 2006. Feeding ecology of feral cats on a heterogeneous subtropical oceanic island (La Palma, Canarian Archipelago). Acta Theriologica 51: 75−83.
We found a total of 987 prey in the 500 scats of feral cats Felis silvestris catus Linnaeus, 1758 analyzed in the present study. Introduced mammals (rabbits, rats and mice) constituted the most important prey both in percentage and biomass. Reptiles were the second most important prey, being more frequent than birds and inver te brates. Mammals were the most frequently eaten group in all five main habitats of the island, being more frequent than the remainder of prey in the laurel forest. Rabbits appeared more often in the temperate forest, rats in the laurel forest and mice in the high mountain. Birds were more frequently captured in the three higher habitats (laurel and pine forest, and high mountain) than in the two lower ones (xerophytic shrub and temperate forest). Reptiles were preyed on less in the laurel forest than in the other main habitats. Morisita index indicates a high trophic overlap among the different habitats with the exception of the laurel forest which shows important differences from the other habitats. Levin’s niche-breadth was broader in the xerophytic shrub and narrower in the temperate forest, reaching in ter mediate levels in the other three main habitats. The results obtained in the present study evidence a general pattern in the trophic ecology among similar habitats in the different subtropical Canarian islands. However, some important differences exist that could be a function of the differential prey availability and composition in each ecosys tem.

7 Medina, F.M. & R. García. 2007. Predation of insects by feral cats (Felis silvestris catus L., 1758) on an oceanic island (La Palma, Canary Islands). Journal of Insect Conservation 11: 203-207.

Predation of insects by feral cats (Felis silvestris catus) on a heterogeneous oceanic island (La Palma, Canary Islands) was studied. A total of 127 invertebrates were identified in the analysis of 500 scats (100 from each habitat of the Island). Invertebrates appear in 18.00% of the scats, representing an insignificant percentage of the total consumed biomass by feral cats on La Palma Island (0.05%). Insects were the most common invertebrate prey both in percentage of occurrence (90.6%) and invertebrate biomass (93.53%), with a total of 115 prey items. Orthoptera, Lepidoptera and Coleoptera were the main prey groups. Among the five main habitats present in La Palma Island, the temperate forest shows the lowest consumption of invertebrates, although insect consumption did not show statistical differences. However Orthoptera and Lepidoptera were more frequently preyed on in the pine forest and in the xerophytic shrub, respectively. Moreover, applying the Simplified Morisita index, a different insect composition of the diet was observed among habitats. Although, none of insects predated by feral cats are threatened, the identification of invertebrate component of the feral cats’ diet is an important tool for the correct understanding of predation significance and to prevent damage to endangered insect species.

8 Medina, F.M. & M. Nogales. 2009. A review on the impacts of feral cats (Felis silvestris catus) in the Canary Islands: implications for the conservation of its endangered fauna. Biodiversity and Conservation 18: 829-846.
Feral cats have been directly responsible for the extinction of numerous species on islands worldwide, including endemic species of mammals, birds and reptiles. The diet of feral cats in the main habitats of the Canary Islands, as generally occurred on oceanic islands, is mainly composed of introduced mammals, and native species of birds, reptiles and insects. The impact of feral cat upon the endangered species was assessed by evaluating their relative abundance in the cats’ diet and by considering their current conservation status. A total of 68 different preys were identified at species level in all studies carried out in the Canary Islands (5 mammals, 16 birds, 15 reptiles and 32 invertebrates). From all the species preyed by feral cats in the Canary Islands, only four of them are considered threatened by the IUCN Red List of Threatened Species: one endemic bird Saxicola dacotiae and three endemic giant lizards, Gallotia simonyi, Gallotia intermedia, and Gallotia gomerana. Although some efforts on management control have been carried out, it is necessary to enforce these conservation activities on those areas of Tenerife, La Gomera and El Hierro where giant lizards are still present. Furthermore some local areas where endangered bird species are highly predated should be protected. Nevertheless, it is important to take into account the presence of other introduced species such as rats, mice or rabbits in order to avoid problems derived from the hyperpredation process and mesopredator release effect.

9 Nogales, M. & F.M. Medina. 2009. Trophic ecology of feral cats (Felis silvestris f. catus) in the main environments of an oceanic archipelago (Canary Islands): An updated approach. Mammalian Biology 74: 169-181. 
The diet of feral cats in the main habitats of the Canary Islands is composed of introduced mammals, birds, reptiles and insects. However, introduced mammals constitute the main source of biomass consumed, followed in importance by reptiles and birds. PCA analysis of biomass revealed the ordination of three different groups, corresponding to the diet in the laurel forest (La Gomera), thermophilous forest (El Hierro) and one large group that include the rest of habitat types. A similar pattern was observed when these habitats were analyzed in a single island (La Palma). Oryctolagus cuniculus was an important prey in practically all habitats, while Rattus rattus was frequently captured in the laurel forest, Mus musculus domesticus in the open shrubs (both xeric and high mountain), reptiles (mainly lizards genus Gallotia) in the open habitats of Tenerife, birds play a relative role in forest habitats, and large invertabrates (basically Orthoptera and Coleoptera) in the three forest habitats and in the xerophytic shrub of Fuerteventura. Morisita’s index of similarity of diet showed maximum differences between the forest habitats (pine and thermophilous vs. laurel forest), indicating an important heterogeneity in the diet of feral cats in these environments. Shrub habitats showed smaller values of Levin’s niche breadth than those from the forest habitats, showing a broader diet in the latter. Lastly, the diet of feral cats on the Canary Islands follows the general pattern of other islands located at similar latitude and mainly composed by rabbits and mice. However, specific preys such as lizards, rats or birds, play an important role in particular habitats in which they are abundant.

10 Medina, F.M. & M. Nogales. 2007. Habitat use of feral cats in the main environments of an Atlantic Island (La Palma, Canary Islands). Folia Zooliga 56(3): 277–283

In this study we assess the habitat use of feral cats in the five main habitats represented on La Palma Island in the Canary Islands. We determined habitat use by the presence of faeces. Faeces persistence time was significantly different between habitats, being clearly lower in the laurel forest (the wettest) than in the other habitats. This humid environment promotes the high presence of invertebrate decomposers such as Isopoda and Diplopoda. Once the effect of differential persistence times for faeces among the different habitats was controlled for, data obtained indicated that feral cats showed no differences in the use of the five main habitats present on La Palma Island. Although cats selected closed habitats more frequently than open ones, because they prefer cover for hunting, no statistical differences were found in the island habitats studied.

11 Medina, F. M., M. López-Darias & M. Nogales. 2008. Food habits of feral cats (Felis sylvestris f. catus, L. 1758) in insular semiarid environments (Fuerteventura, Canary Islands). Wildlife Research 35: 162-169.
In this study, we present the first data on diet and impacts of feral cats on a semiarid island (Fuerteventura, Canary Islands). A total of 614 prey was identified in the 209 scats analysed. Introduced mammals, specially rabbits and mice, were the most consumed vertebrate prey and constituted more than 90% of biomass. Barbary ground squirrels, Algerian hedgehogs, and rats were preyed upon less even though they were abundant on the island. Invertebrates, mainly Orthoptera, Coleoptera, Hymenoptera and Odonata, were the second most important prey items (in terms of actual numbers) but they contributed only minimally with respect to biomass (<1.1%). The presence of terrestrial molluscs in the diet was interesting because they are a rare prey in an insular context. Birds and reptiles occurred at a low frequency. A total of 677 seeds was counted, mainly belonging to Lycium intricatum (Solanaceae) and two unidentified plant species. Levin’s niche breadth was narrow due to the high consumption of mammals. Morisita’s index showed a similar trophic overlap in diet with respect to the other xeric habitats of the Canarian archipelago. Considering that more than 90% of biomass corresponded to introduced mammals, we conclude that feral cats are not having a large direct impact on the native prey species.

12 Medina, F.M. y M. Nogales. 1993. Diet of the feral cat (Felis catus L.) in the xerophytic zone of the Macizo de Teno (Northwestern Tenerife. Doñana Acta Vertebrata, 20 (2): 291-297

The diet of the Feral cat (Felis catus) was studied in the xerophytic zone of Tenerife, by analyzing 200 scats. A total of 477 prey items were identified. Mammals (Oryctolagus cuniculus, Mus musculus and Rattus  sp.) constitued the basis of the diet occurring in 86% of the samples and representing 85,4% of the consumed biomass. Reptiles occurred in 57% of the scats and representing 13,6% of the biomass. The lizard (Gallotia galloti), endemic of the western Canary Islands, was frequenetly captured, occurring in 54% of the scat groups and representing 13% of the total biomass. This percentage is very importan in the world context of the diet. Birds and insects (frequence of occurrence less than 5%) were insignificant in the diet.


Cabo Verde
13 Medina, F. M., P. Oliveira, P. Geraldes, J. Melo & N. Barros. 2012. Diet of feral cats Felis catus L., 1758 on Santa Luzia, Cape Verde Islands. Zoologia Caboverdiana 3 (2): 67-73.

The diet of feral cats Felis catus on Santa Luzia, Cape Verde Islands, was studied. A total of 147 prey items were identified during the analysis of 26 scat groups collected during the summer of 2010. House mouse Mus musculus was the most important prey, both in percentage of biomass and number of preys consumed (89.7% and n= 117, respectively). Reptiles were the second most important prey, represented by one skink species (Chioninia stangeri) and an unidentified gecko species. The remainder of the identified prey consisted of one bird species (Passer iagoensis) and one undetermined Tettigoniidae species (Insecta). No endangered species were identified in scats of this introduced predator, but future surveys must be carried out to further avoid threats to the island’s biodiversity. 

Diet of feral cats in Falkland Islands

Matias, R. & P. Catry (2008) The diet of feral cats at New Island, Falkland Islands, and impact on breeding seabirds. Polar Biology 31: 609–616.

We studied the diet of feral cats (Felis catus) on New Island, Falkland Islands, through the analysis of 373 scats collected during the austral summers of 2004/2005 and 2005/2006. The most frequent prey were three introduced mammals (house mice Mus musculus, ship rats Rattus rattus and rabbits Sylvilagus sp.) and the thin-billed prion Pachyptila belcheri (each season present on ca. 21% of the analysed scats). These represent the first systematic data on feral cat diet for the Falklands. A simple bioenergetics model suggests that cats could be eating in the region of 1,500–11,000prions per season, representing <1% of the local adult and subadult population. Predation on other seabirds nesting on New Island (several penguin species, albatrosses and cormorants) was unimportant, with the possible exception of white-chinned petrels Procellaria aequinoctialis, which nest locally in very small numbers. For each prion eaten, cats were estimated to have killed 1.1–1.9 ship rats during the summer season, and probably more in autumn and winter. Knowing that ship rats are prion predators, it is conceivable that, on the whole, cats are having a positive impact on the prion population, a scenario predicted by general theoretical models. Thus, considering the available information, we would not recommend the implementation of any eradication programme on New Island that would target cats in isolation. Nevertheless, it would be prudent to consider some local action targeting cats and rats around the small New Island white-chinned petrel colony.

Cat Act: Aussie legislation on pet cats

Western Australia legislates on responsible cat ownership:

The Cat Act 2011 requires the identification, registration and sterilisation of domestic cats, and gives local governments the power to administer and enforce the legislation.

The legislation will take full effect from 1 November 2013 and provide for better management of the unwanted impacts of cats on the community and the environment, as well as encourage responsible cat ownership.

From 1 November 2012, some provisions of the Act will commence to allow local governments to prepare to administer and enforce the legislation.

From 1 November 2013, the full Cat Act 2011 takes effect and will require all cats that have reached six months of age to be:

1. Microchipped;
2. Sterilised; and
3. Registered with the relevant local government. Cats will be required to wear a collar and registration tag to ensure that owned cats can be easily identified and returned to their owner.

What do the new laws mean for you and your feline friend?

Breeding Cats

The legislation requires that a person who chooses to breed cats must apply to their local government for a permit.

When a cat is sold, the seller must ensure the cat is microchipped and sterilised prior to transfer. If the cat cannot be sterilised due to its young age, a voucher must be issued to the new owner.

Limits on cat numbers

The legislation does not limit the number of cats that can be owned. This will fall to local governments who may choose to introduce a local law.

If a local government introduces a local law limiting cat numbers, it will not apply to cats currently owned. However an owner will not be able to replace a cat if it is sold, given away or dies, until they are down to the required number.

Responsible cat ownership checklist

Even though the laws do not commence until November 2013, as a responsible pet owner you are still encouraged to:

1. Keep your cat confined to your property, especially at night.
2. Ensure your cat is easily identifiable with a collar and a name tag.
3. Microchip your cat.
4. Sterilise your cat.
5. Vaccinate your cat.

Apparent lack of influence of cat regulations on small size mammals abundance in urban bushland

Lilith, M., Calver, M., & Garkaklis, M. (2010). Do cat restrictions lead to increased species diversity or abundance of small and medium-sized mammals in remnant urban bushland?. Pacific Conservation Biology, 16(3), 162.

We took advantage of cat regulations enacted within differing subdivisions in the City of Armadale, Western Australia, to test the hypotheses that the species diversity (measured by the Shannon-Weiner index) and abundance of small and medium-sized mammals should be higher in native bushland within or adjacent to subdivisions where cats are restricted compared to similar areas where cats are not restricted. There were three different regimes of cat regulation: no-cat zone (strict prohibition of cat ownership applying in one site), compulsory belling of cats and night curfew at one site, and unregulated zones (free-roaming cats applying at two sites). Both sets of cat regulations were in place for approximately 10 years prior to our survey. We also measured structural and floristic features of the vegetation at each site that might influence the species diversity and abundance of small and medium-sized mammals independently or interactively with cat activity.

No significant differences in species diversity were found across the sites and KTBA (known-to-be-alive) statistics for Brushtail Possums Trichosurus vulpecula and Southern Brown Bandicoots Isoodon obesulus, the two most abundant medium-sized mammals present, were similar across all sites. The smaller Mardo Antechinus flavipes, which could be regarded as the most susceptible to cat predation of all the native species trapped because of its size, was trapped mostly at an unregulated cat site. Total mammals trapped at the unregulated cat sites exceeded those caught at the two sites with restrictions, but these unregulated sites also had significantly denser vegetation and there was a borderline (p = 0.05) rank correlation between vegetation density and mammal captures across all sites. It appears that pet cats are not the major influence on the species diversity or abundance of small and medium-sized mammals at these sites and that vegetation characteristics may be more important.

Read a short review about belling effectiveness

Estimating feral cats density on Corvo island (Azores)

Oppel, S., , Hervias, S., Oliveira, N., Pipa, T., Cowen, H., Silva, C., Geraldes, P., 2012 Estimating feral cat density on Corvo island, Azores, to assess the feasability of feral cat eradication. Airo, 22: 3-11.

Feral cats have had negative effects on native biodiversity on many islands worldwide. Eradicating feral cats from islands is often feasible, and can yield great benefits to native biodiversity, especially for seabirds. Corvo Island (Azores) is an important island where feral cats limit the distribution and abundance of breeding seabirds. To assess whether the eradication of feral cats on Corvo would be feasible we used camera traps to estimate the density of feral cats. We deployed 24 camera traps at 253 locations around the island for 14 months, and identified cats detected by camera traps individually based on the coat colour. We then used spatially explicit capturere-capture models to estimate cat density for Corvo. Cat density in the uninhabited upland part of Corvo, which is dominated by cow pastures, was 0.036 (95% CI 0.025–0.054) cats/ha. The lowland part of Corvo, which is inhabited by humans and contains domestic cats, had an estimated cat density of 0.734 (0.581 – 0.927) cats/ha. Overall, we estimated that the cat population on Corvo during our study period included 163 (123 - 228) individuals. The estimated cat densities are within the range of cat densities from other islands where cats have been successfully eradicated, and we conclude that feral cat eradication on Corvo would be technically feasible. However, the co-existence of feral and domestic cats would create operational challenges, and the current lack of a legal framework to ensure that all domestic cats are sterilised would increase the risk of a feral cat population becoming re-established after eradication.

Native bilbies fight back

From ABC 26/03/2013

One of Australia's best known threatened species, the bilby, is having a tough time. Its numbers are in deep decline with feral cats the chief cause. But a seven year old boy who was moved by the plight of the cute marsupial proved he could make a difference. Here's Peter McCutcheon with a story that's both tragic and inspirational.

Click to play

Human influence on the range of domestic cats in sensitive areas

Ferreira, J.P., Leitão, I., Santos-Reis, M. & Revilla E. 2011. Human-Related Factors Regulate the Spatial Ecology of Domestic Cats in Sensitive Areas for Conservation. PLoS ONE 6(10): e25970. doi:10.1371/journal.pone.0025970

Background

Domestic cats ranging freely in natural areas are a conservation concern due to competition, predation, disease transmission or hybridization with wildcats. In order to improve our ability to design effective control policies, we investigate the factors affecting their numbers and space use in natural areas of continental Europe.

Methodology/Principal Findings

We describe the patterns of cat presence, abundance and space use and analyse the associated environmental and human constraints in a well-preserved Mediterranean natural area with small scattered local farms. We failed in detecting cats in areas away from human settlements (trapping effort above 4000 trap-nights), while we captured 30 individuals near inhabited farms. We identified 130 cats, all of them in farms still in use by people (30% of 128 farms). All cats were free-ranging and very wary of people. The main factor explaining the presence of cats was the presence of people, while the number of cats per farm was mostly affected by the occasional food provisioning with human refuse and the presence of people. The home ranges of eight radio tagged cats were centred at inhabited farms. Males went furthest away from the farms during the mating season (3.8 km on average, maximum 6.3 km), using inhabited farms as stepping-stones in their mating displacements (2.2 km of maximum inter-farm distance moved). In their daily movements, cats notably avoided entering in areas with high fox density.

Conclusions

The presence, abundance and space use of cats were heavily dependent on human settlements. Any strategy aiming at reducing their impact in areas of conservation concern should aim at the presence of settlements and their spatial spread and avoid any access to human refuse. The movements of domestic cats would be limited in areas with large patches of natural vegetation providing good conditions for other carnivore mammals such as red foxes.

Natural born killers: the problem with cats - Australian Geographic

Australia
An awareness article about pet cats on Australian Geographic

A display at the Alice Springs museum illustrates the toll feral cats have on Aussie native wildlife.
(Credit: Lisa Wilson)

Cats to go

An initiative in New Zealand to reduce the impact of cats in nature

http://theoatmeal.com/comics/cats_actually_kill

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.