Genetics of CDV in East African carnivores

Carpenter, M. A., Appel, M. J., Roelke-Parker, M. E., Munson, L., Hofer, H., East, M., & O'Brien, S. J. (1998). Genetic characterization of canine distemper virus in Serengeti carnivores. Veterinary immunology and immunopathology, 65(2), 259-266.

The lion (Panthera leo) population in the Serengeti ecosystem was recently afflicted by a fatal epidemic involving neurological disease, encephalitis and pneumonia. The cause was identified as canine distemper virus (CDV). Several other species in the Serengeti were also affected. This report presents CDV H and P gene sequences isolated from Serengeti lions (Panthera leo), spotted hyenas (Crocuta crocuta), bat-eared fox (Otocyon megalotis) and domestic dog (Canis familiaris). Sequence analyses demonstrated that the four Serengeti species carry closely related CDV isolates which are genetically distinct from other CDV isolates from various species and locations. The results are consistent with the conclusions that: (1) a particularly virulent strain of CDV emerged among Serengeti carnivores within the last few years; (2) that strain has recognizable shared-derived (synapomorphic) genetic differences in both H and P genes when compared to CDV from other parts of the world; and (3) that the CDV strain has frequently crossed host species among Serengeti carnivores.

Agonistic behaviour of free-ranging dogs

Pal, S. K., Ghosh, B., & Roy, S. (1998). Agonistic behaviour of free-ranging dogs (Canis familiaris) in relation to season, sex and age. Applied Animal Behaviour Science, 59(4), 331-348.

Observations on the agonistic behaviour of 12 free-ranging dogs from two neighbouring groups were recorded in Katwa town, India. Both intra- and inter-group agonistic encounters were recorded on a seasonal basis. Mean (±S.E.) seasonal number of intra-group agonistic encounters of individual dog was greatest in winter (13.33±1.89) and then in late monsoon (12.33±1.99), when the females were lactating and in oestrus, respectively. Similarly, the mean (±S.E.) seasonal number of inter-group agonistic encounters of individual dog was greatest in winter (32.25±4.43) and then in late monsoon (27.75±2.01). There was a significant difference between the intra- and inter-group agonistic encounters. Dominance hierarchies were established among the adult dogs of either sex based on aggressive encounters. Although individual differences in agonism were observed, overall levels of aggression were higher among the adult females than for other groups. In contrast, overall levels of submission were higher among the juvenile males than for other groups. The results from this study suggest that reproductive season, sex and age have a significant effect on the agonistic behaviour of free-ranging dogs.

Dog diseases threat Ethiopian wolf

Laurenson, K., Sillero‐Zubiri, C., Thompson, H., Shiferaw, F., Thirgood, S., & Malcolm, J. (1998). Disease as a threat to endangered species: Ethiopian wolves, domestic dogs and canine pathogens. Animal Conservation, 1(4), 273-280.

With increasing awareness of disease as an endangering process, an assessment of which pathogens might pose a problem and their patterns of infection in natural hosts is necessary. This paper examines the exposure of sympatric Ethiopian wolves (Canis simensis) and domestic dogs to canine distemper virus (CDV), canine adenovirus (CAV) and canine parvovirus (CPV) in the Bale region, Ethiopia and then relates these data to population trends of wolves. Wolves (n= 30) sampled between 1989 and 1992 had been exposed to CDV, CAV and CPV, but only CAV might be able to persist in this wolf population. Anecdotal and serological evidence suggested that an epidemic of CDV occurred in the dog population of the Bale Mountains National Park (BMNP) in 1992–93. All park dogs born since this time were seronegative to CDV, although some young dogs in the nearby urban population were seropositive. Despite evidence of CAV infection in wolves, none of the dogs sampled in the park were CAV seropositive, although this virus appeared highly seroprevalent and endemic in urban dogs. All dogs tested for CPV antibodies were seropositive. The BMNP wolf population declined in the late 1980s and early 1990s, with rabies responsible for a dramatic population reduction between 1990 and 1992. Although the population declined further up until 1995, it is not possible to assess whether the concurrent canine distemper epidemic in park dogs also affected wolves. Nevertheless, with evidence of rabies, CDV, CAV and CPV infections in sympatric domestic dogs and Ethiopian wolves, canid diseases clearly pose a significant threat to the future persistence of this Ethiopian wolf population.

FIV epidemiology in rural cats

Courchamp, F., N. Yoccoz, M. Artois & D. Pontier. 1998. At-risk individuals in Feline Immunodeficiency Virus epidemiology: evidence from a multivariate approach in a natural population of domestic cats (Felis catus). Epidemiology and Infection. 121: 227-236.

Prevalence of Feline Immunodeficiency Virus (FIV) infection was measured during 6 consecutive years in a natural rural population of domestic cats. Sex, age, weight, origin, group size and presence of antibodies to FIV were recorded for each sampled cat. Logistic regressions were used to estimate the influence of the recorded parameters on infection. FIV prevalence rates are as high as 19.6% in the total population, and do not statistically change between years, after controlling for changes in samples' age structure. FIV infection is characterized by risk factors linked to aggressive behaviour: old mature male adults having dispersed are more likely to be infected. A study of the cats group size and of the spatial distribution of infected individuals indicates the absence of infection clusters in males, and suggests the importance of roaming in the spreading of FIV. In conclusion, FIV infection spreads, with low contagiousness, mainly between particularly aggressive individuals, and the virus is endemic in this population.

Trends in the prey size-based trophic niches of feral and house cats

Pearre, S., Maass, R., & Maass, R. (1998). Trends in the prey size-based trophic niches of feral and House Cats Felis catus L. Mammal Review, 28(3), 125-139.

House Cats Felis catus L., whether attached to human households or not, appear to be versatile opportunistic predators. Their principal prey in most areas are mammals (rodents and rabbits), with bird prey secondary. Trophic niche breadth, as measured by the standard deviation of the spectrum of logarithmically transformed prey sizes (‘SLH’), shows a latitudinal trend, being greater in low latitudes: it is also greater in periods of high prey availability. This appears to be influenced by inclusion of very small prey, especially insects, in areas and seasons when they are available. Both the niche breadth and the mean prey size (niche position) appear to be constant as population mean cat size increases. The most common prey size for cats is about 1% of their own body weights, which is much less than most previously reported values for carnivores.

Community turtle conservation in Costa Rica

Govan, H. (1998). Community turtle conservation at Rio Oro on the Pacific coast of Costa Rica. Marine Turtle Newsletter, 80, 10-11.

In June 1996, ADECORO started community-based management of the beach which involved both the participation of community members in controlling movements of their animals, and the removal of feral dogs which was carried out in conjunction with local authorities.

	Total Predated	% Predated
1994	417	15%
1996	292	9%

A marked reduction can be seen in predation levels subsequent to the commencement of this initiative. It is almost certain that the reduction of dog predation is the result of a combination of the activities of the beach patrols and general increasing awareness in the community. Increased public awareness is likely to have contributed to the decrease in the activities of human egg collectors. The number of nests collected by humans fell from 344(12%) in 1994, to 122 (4%) in 1996

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Teaching the impact of introduced predators

Calver, M. C., King, D. R., & Short, J. (1998). Ecological blunders and conservation: the impact of introduced foxes and cats on Australian native fauna. Journal of Biological Education, 32(1), 67-72.

Many vertebrate extinctions followed the introduction of the exotic predators, the fox and the cat, to Australia. While experiments have confirmed the case against the fox as a serious threat to endangered species, there are no direct experimental links showing recovery of prey populations following culling of cat numbers. This, coupled with the emotional attachment of many people to cats, has led to some opposition to their control, especially when limitations on the freedom of pets to roam are proposed. The introduced predator case is a stimulating example for teaching aspects of the emerging discipline of conservation biology and highlights the interplay of bioethics, public opinion, and biological principles in conservation decision-making. Suggested classroom exercises allow students to compare and contrast experimental and non-experimental approaches to assessing predator impact, consider ethical issues in controlling predators for conservation, and reach their own conclusions on the impact of cats on local wildlife.

Alien carnivores' diet in New South Wales

Meeks, P.D. & B. Triggs. 1998. The food of foxes, dogs and cats on two peninsulas in Jervis Bay, New South Wales. Proceedings of The Linnean Society of New South Wales 120: 117-127

European Red Fox Vulpes vulpes (L.), Dog Canis lupus familiaris/dingo (L.), and Cat Felis catus (L.) scats were analysed to assess the food, and report on the diet of these predators from two peninsulas at Jervis Bay, NSW. The main food items of V. vulpes comprise mammal, Pseudocheirus peregrinus (26.8%) on Bherwerre Peninsula, and Rattus rattus (37.9%) on Beecroft Peninsula. Invertebrates, vegetation and birds were also important food items of V. vulpes on both peninsulas. The diet of C. lupus familiaris consisted mainly of Wallabia bicolor on both peninsulas, while P. peregrinus, Oryctolagus cuniculus and R. rattus were also eaten. F. catus favoured mammals over invertebrates, birds and vegetation. An important finding from the survey was the occurrence of four locally endangered species; Pseudomys gracilicaudatus, Sminthopsis leucopus and Litoria aurea on Bherwerre Peninsula and Rattus lutreolus on Beecroft Peninsula. Differences in predator food preferences between Beecroft and Bherwerre reflect the differences in prey diversity on each peninsula, and supports the theory that V. vulpes and F. catus are opportunistic feeders that select the most abundant food items. In contrast C. lupus familiaris were more selective and favoured medium to large macropods.

Bells and electronic sonic device reducing predation by cats in UK

Nelson, S. H., Evans, A. D., & Bradbury, R. B. (2005). The efficacy of collar-mounted devices in reducing the rate of predation of wildlife by domestic cats. Applied Animal Behaviour Science, 94(3), 273-285.

Volunteer cat owners from across the UK were recruited to take part in two trials designed to test the efficacy of collar-mounted warning devices in reducing cat predation rates of native wildlife. Cats equipped with a bell returned 34% fewer mammals and 41% fewer birds than those with a plain collar. Those equipped with an electronic sonic device returned 38% fewer mammals and 51% fewer birds compared with cats wearing a plain collar. There was no significant difference in prey return rates by cats wearing collars equipped with one bell, two bells or the sonic device. Warning devices mounted on quick-release collars are recommended as an effective way of reducing wildlife kill rates by domestic cats. Future research and development aimed at further improving the efficacy of sonic devices is recommended.

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You can see early reports of CatAlert device here

Clark, N. A. & N.H.K. Burton (1998). A pilot field trial into the effectiveness of the CatAlert™ collar at reducing predation by domestic cats. British Trust for Ornithology.

Clark, N. A. (1999). Progress report on the effectiveness of the Mark II CatAlert™ collar at reducing predation by domestic cats. British Trust for Ornithology.

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Predation by house cat in Canberra

Barratt, D. G. (1997). Predation by house cats, Felis catus (L.), in Canberra, Australia. I. Prey composition and preference. Wildlife Research, 24(3), 263-277.

This paper attempts to apply theory from more than 100 years of scientific experience and experimentation in predator-prey ecology and introduced species ecology to predict the likely effects of predation by domestic cats (Felis catus) on prey populations and community structure. Those aspects of the predatory behaviour of domestic cats which are of most importance in predicting their impact on prey populations: I) the degree of prey selectivity or 'dietary preference'; 2) the exhibition of switching behaviour; 3) changes in predatory activity in response to changes in prey density; and 4) the extent to which high and constant densities of the predator are ameliorated by reduced prey consumption rates as a result of dietary supplement.

In suburban environments, the influence of predation by domestic cats on prey abundance and community structure probably increases, relative to the influence of habitat change, with increasing suburb age, particularly in the absence of physical disturbances such as fire. However, it may never be as important as habitat availability and indeed may never be significant at all. Removal of the predator may allow some animal species to increase in abundance but others may decline. The details of these changes are very difficult to predict. Similarly, following predator removal, total species diversity is as likely to decline due to increased inter-specific competition, as it is to increase due to the invasion of species previously excluded by predation.

In remnant habitat, the impact of predation by domestic cats is probably less likely to be important in determining the relative abundance of the more common species than in suburban environments, but more likely to contribute to local extinctions of rare species. As in suburban environments, predation on introduced species in remnant habitat may reduce predation on native species. However, the ability of domestic cats to control introduced species which prey on, or compete with, native species will be difficult to demonstrate. In light of this uncertainty, any attempt to prevent domestic cats hunting in remnant habitat patches should be integrated with a program to eliminate or control populations of other introduced species, such as black rats and rabbits, which are preyed upon by domestic cats and are known to prey on or compete with native species

Barratt, D. G. (1998). Predation by house cats, Felis catus (L.), in Canberra, Australia. II. Factors affecting the amount of prey caught and estimates of the impact on wildlife. Wildlife Research, 25(5), 475-487.

Information on the amount of vertebrate prey caught by house cats in Canberra was collected by recording prey deposited at cat owners’ residences over 12 months. The amount of prey taken was not significantly influenced by cat gender, age when neutered, or cat breed. Nor did belling or the number of meals provided per day have a significant influence on the amount of prey caught. The age of the cat and the proportion of nights spent outside explained approximately 11% of the variation in the amount of prey caught by individual cats. In all, 43% of variation in predation on introduced species (predominantly rodents) was explained by distance from potential prey source areas (i.e. rural/grassland habitat) and cat density. The mean number of prey reported per cat over 12 months (10.2) was significantly lower than mean predation per cat per year based on estimates made by cat owners before the prey survey began (23.3). Counts of the amount of prey caught by house cats were highly positively skewed. In all, 70% of cats were observed to catch less than 10 prey over 12 months, but for 6% of cats, more than 50 prey were recorded. Estimates of predation by house cats, particularly extrapolated estimates, should be treated with caution. The total number of prey caught by house cats in Canberra estimated using the sample median was approximately half the estimate based on the sample mean. Predation estimates alone do not prove that prey populations are detrimentally affected, especially in highly disturbed and modified environments such as suburbs. Impacts on native fauna are likely to be most significant in undisturbed habitat adjacent to new residential developments.



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Cats predation on kakapo leads to translocation

Clout M.N. & Merton D.V. (1998) Saving the kakapo: the conservation of the world's most peculiar parrot.Bird Conservation International, 8, 281-296.

We review the conservation history and describe the current status of the Kakapo Strigops habroptilus, a large New Zealand parrot which has been reduced to only 54 individuals through predation by introduced mammals, and is now threatened with extinction. Unique amongst parrots, Kakapo are both flightless and nocturnal. They have an unusual mating system in which females nest and raise their young unaided by males, after mating at traditional “courts” at which males display visually and vocally. Mating occurs naturally only in seasons of heavy fruiting of podocarp trees. A decline in range and abundance of Kakapo followed the introduction of alien mammals last century, and culminated in their reduction to a single breeding population on Stewart Island. Following a severe episode of predation by feral cats Felis catus, all known birds from this last population were translocated to a series of cat-free offshore islands. Adult survival on these island sanctuaries has been high (c. 98% per annum), but productivity has been low, with only six young (including a single female) raised to independence since 1982. Reasons for this low productivity are the naturally intermittent breeding of Kakapo, the low numbers of nesting females, high rates of egg infertility (~ 40%), and the early death of most nestlings through starvation or suspected predation by Polynesian rats Rattus exulans. These rats are present on both of the island sanctuaries where nesting has occurred. The Kakapo sex ratio is biased in favour of males (34:20) and only 8 of the 19 adult females are known to have laid fertile eggs in the past 10 years. Management of all remaining birds is now highly intensive, involving radio-tagging of all individuals, the provision of supplementary food, attempts to manipulate matings, nest surveillance, and protection against rat predation.

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.

Domestic cat diet within an Australian National Park

Meek, P.D. 1998. Food items brought home by domestic cats Felis catus (L) living in Booderee National Park, Jervis Bay. Proceedings of The Linnean Society of New South Wales 120: 43-47

Cat owners kept records or the food items brought home by domestic cats living in two adjacent villages surrounded by Booderee National Park, NSW. Durint a 12 motn period food items brought home by seven cats comprise eleven native and three introduced species. One endangered bird was recorded although mammals were the largest prey group.