Garbage dumps and rabies in Cameroon

Raymond, T. N., Roland, M. E., Francoise, K. F. M., Francis, Z., Livo, E. F., & Clovis, S. T. (2015). Do open garbage dumps play a role in canine rabies transmission in Biyem-Assi health district in Cameroon?. Infection Ecology & Epidemiology, 5.

Background: Rabies is a neglected enzootic disease which represents a serious public health problem. In Cameroon, efforts to prevent human deaths caused by rabies are often thwarted by the lack of community awareness. The community knowledge, as well as attitudes and perception on rabies, is therefore important for both prevention of human deaths and control in animals.

Methods: A cross-sectional study was carried out to evaluate the level of community knowledge as well as the role of open garbage dumps (OGDs) in the epidemiology of human rabies. Overall 420 heads of household were interviewed in the Biyem-Assi health district of Yaoundé. OGDs were identified through a systematic check, and household wastes they contained were characterized.

Results: Although 66.9% of respondents have knowledge on stray dogs, only 35% of respondents knew the role of OGDs in the increase of stray dog population. Overall OGDs consisted of fermentable wastes. Nutrition places for stray dogs were wild garbage dumps (68.1%), markets (18.3%), and houses (13.6%). The feeding behavior of stray dogs correlated significantly with the human rabies transmission (χ²=154.12, df=4, p<0.05).

Conclusion: Most participants knew that rabies could be transmitted by a dog bite as well as the measures to be taken in this type of situation. Increased knowledge of respondents on rabies showed OGDs and stray dogs as significant risk factors for canine rabies in Biyem-Assi health district.

Factors affecting the presence of dogs in streets

Ibarra, L., F. Espínola, M. Echeverría. 2006. Factors related to the presence of dogsin the streets of Santiago City, Chile. Avances en Ciencias Veterinarias, 21: 21-26

In roles to know which are the factors related to the dogs in the streets and as a contribution to designing of sanitary measures for canine population surveillance and controlling, a research was carried out in 34 districts from the Metropolitan Region that conform Santiago city. The sampling unit was the street block and the specific information was obtained through direct observation of 864 city blocks from Santiago, by giving a minimum of 25 city blocks by district, randomly chosen. The street canine population characteristics, the urban structure an the habitat were registered to investigate the relationship among them.

The results show that the amount and types of dogs observed in the streets of Santiago are related to the existence of “shelter like” places and water and food sources in the urban structure of Santiago. The presence of dogs is also related to the garbage location in the street design, because the amount of dogs is significantly smaller if there are storing facilities or baskets in height that prevent the animal access to the garbage.

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.

Attractans for feral cats

Clapperton, B. K., Eason, C. T., Weston, R. J., Woolhouse, A. D., & Morgan, D. R. (1994). Development and testing of attractants for feral cats, Felis catus L. Wildlife Research, 21(4), 389-399.

As part of a programme to improve feral-cat control and eradication techniques, various odours were tested as candidate lures. They included food odours (fish oils), social odours (urine and its components, anal-sac secretions and commercial wild-animal lures) and plant materials (catnip, matatabi and their essential oils). Pen bioassay experiments used a preference procedure on captive feral and domestic cats to compare the time spent investigating the odours and the number of cats visiting each odour. Field trials at rubbish dumps used scent stations to assess cat activity. Catnip and matatabi were the most promising candidate lures in both the pen bioassay and the field trials. Future directions for lure developments are suggested.

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.

Social and genetic analysis of a population of free-living cats at a waste disposal site

Denny, E., Yakovlevich, P., Eldridge, M. D., & Dickman, C. (2002). Social and genetic analysis of a population of free-living cats (Felis catus L.) exploiting a resource-rich habitat. Wildlife Research, 29(4), 405-413.

Free-living cats (Felis catus L.) exploiting a waste-disposal site in rural Australia were studied for two years to investigate population structure and dynamics, and the relatedness of constituent individuals. The density of the population was equivalent to 700–750 cats  km^-2  the sex ratio was heavily skewed towards males, breeding occurred from July to April, and kitten survival rates were low. A combination of observational data, biometrics and microsatellite loci analyses was used to assess the relatedness of individuals in the population; these methods yielded highly congruent results. Thus, a female kin-group of three was identified, there was no female immigration, the average relatedness amongst the population was high and there was no indication of male dominance. The results indicate that cats at the site formed a tightly structured group, rather than an ad hoc collection of individuals. The stable, resource-rich habitat of waste-disposal sites may generally support high densities of group-forming cats in rural Australia, and pose broad-scale but previously unrecognised problems for effective management of free-living cats.

Feral dogs' ecology in Alabama

Scott, M. D., & Causey, K. (1973). Ecology of feral dogs in Alabama. The Journal of Wildlife Management, 37 (3): 253-265.

Feral dog ecology was investigated in two areas in Alabama during 1970 and 1971 utilizing live-trapping and radiotelemetry techniques. The very aggressive behavior of feral dogs when trapped was used to distinguish them from free-ranging and tame dogs. Confirmation of the dog's classification was provided by telemetric procedures. Three feral packs and two solitary feral dogs were studied. Feral dogs were retrapped significantly more times than other dogs. Morphological characteristics did not differ. Pack sizes varied from two to five adult dogs, with home ranges covering 444 to 1,050 hectares (1,100-2,600 acres). Packs utilized moist flood-plain areas during warm weather and dry upland sites during cool weather. Daytime activity and distances traveled were greater during cool weather than in hot weather but dogs were most active at night during all seasons. Distances moved by packs during diel (24-hour) periods ranged from 0.5 to 8.2 km (0.3-5.1 miles). Sources of feral dogs were reproduction in the wild and recruitment from tame and free-ranging dogs. Feral dogs studied did not appear to be preying on white-tailed deer (Odocoileus virginianus) or cattle. Foods eaten included small mammals, garbage, and vegetable material.

Dogs outcompete Indian foxes for human-derived food

Vanak, A. T., & Gompper, M. E. (2009). Dietary niche separation between sympatric free-ranging domestic dogs and Indian foxes in central India. Journal of Mammalogy, 90(5), 1058-1065.

The competitive dynamics between domestic and native carnivores are poorly studied. We examined competition for food between sympatric populations of free-ranging dogs (Canis familiaris) and Indian foxes (Vulpes bengalensis) through dietary analysis in a protected, dry grassland habitat in central India. We expected significant dietary overlap between dogs and foxes because of clear evidence of interference competition between dogs and foxes in this area. However, dogs subsisted largely on human-derived foods (HDFs) from direct feeding, and scavenging on garbage, crop residue, and livestock carcasses (83% relative occurrence [RO]). Wild-caught foods constituted only 11% RO of the diet of dogs. The majority of the diet of Indian foxes consisted of invertebrates (33% RO), rodents (20% RO), and fruits of Zizyphus (18.5% RO). Indian foxes did not consume HDF, nor did they scavenge from large-mammal carcasses, and included only a small portion of agricultural produce in their diet. The low contribution of HDF and agricultural food sources to the diet of Indian foxes was surprising because this species is a generalist omnivore. Dogs may be preventing foxes from accessing agricultural lands and human-associated foods by interference competition.

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Domestic dogs and edge effect

Lacerda, A. C. R., Tomas, W. M., & Marinho‐Filho, J. (2009). Domestic dogs as an edge effect in the Brasília National Park, Brazil: interactions with native mammals. Animal Conservation, 12(5), 477-487.

Edge effects are a well-known result of habitat fragmentation. However, little has been published on fragmentation, isolation and the intrusive influence from the surrounding matrix at the landscape level. The objectives of the present study are to evaluate the presence of dogs in the Brasília National Park (BNP) in relation to habitat type and the influence from the surrounding matrix. In addition, this study examines the response of the native mammal fauna to the presence of dogs. Track stations were built along dirt roads in the BNP and subsequently examined for the presence or absence of tracks. We used a stepwise logistic regression to model the occurrence of five mammal species relative to habitat variables, with an α=0.05 to determine whether to enter and retain a variable in the model. A simulation of each species occurrence probability was conducted using a combination of selected habitat variables in a resource selection probability function. Results indicate a negative relationship between distance from the BNP edge and the probability of dog occurrences. From an ecological perspective, the presence of dogs inside the BNP indicates an edge effect. The occurrence of the maned wolf was positively associated with distance from a garbage dump site and negatively associated with the presence of dog tracks. The maned wolf and giant anteater seem to avoid areas near the garbage dump as well as areas with dog tracks. There is no support for the possible existence of a feral dog population inside the BNP, but the effects of free-ranging dogs on the wildlife population in such an isolated protected area must not be neglected. Domestic dog Canis familiaris populations and disease control programs should be established in the urban, sub-urban and rural areas surrounding the BNP, along with the complete removal of the garbage dump from the BNP surroundings.

Cat range on a small island

YAMANE, A., ONO, Y., & DOI, T. (1994). Home range size and spacing pattern of a feral cat population on a small island. Journal of the Mammalogical Society of Japan, 19(1), 9-20.

Home range size and spacing patterns of feral cats (Felis catus) were investigated and data analyzed quantitatively, to clarify the factors affecting their social organization. "Feeding groups" were identified. These consisted of male and female members which used the same garbage site mainly for feeding (Izawa et al. 1982). The spacing patterns of females showed that they defended their feeding sites from use by females of other groups. During each season mean home range size was significantly greater for males than for females. Males expanded their ranges during the females' estrous season when their mean size exceeded the predicted size based purely on metabolic requirements. Furthermore, male home range size (during the estrous season) was correlated directly with the number of females they courted. These results suggest that the mating resource, the number of receptive females, is more important in determining male home range size during the estrous season than is the food resource.

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

Intraguild interactions between dogs and wild carnivores

Vanak, A.T. 2008. Intraguild interactions between native and domestic carnivores in Central India. PhD. University of Missoury

I determined the various factors affecting the resource selection and spatial ecology of the Indian fox Vulpes bengalensis, a small canid endemic to the Indian subcontinent. Despite being widespread throughout India, and commonly occurring in many dry grassland habitats, little is known about the ecology of this species. I investigated habitat selection by the Indian fox in a grassland region in central India that represents a mix of natural and human-dominated habitats to discern if and how foxes respond to human encroachment on native habitats. I collected home range and habitat selection data on 32 radio-collared Indian foxes in the Great Indian Bustard Wildlife Sanctuary, Nannaj, Maharashtra over a one year period. Adult Indian fox 95% kernel density home-range sizes varied between sexes and among seasons. Males had consistently larger home-ranges than females across all seasons but there was no interseasonal variation. Females had smaller home-range sizes during the cool-dry season which is also the denning period, than during any other season. Compositional analysis of Indian fox selection of home-ranges at the landscape level showed heavy influence of the presence of grasslands, plantations and fallow land. Indian foxes avoided humanmodified habitat such as agricultural land and human settlements. The presence of grasslands was also the dominant predictor of Indian fox habitat selection across seasons within the home-range as determined by AIC ranked discrete-choice models. The results indicate that Indian foxes select for natural grasslands and avoid human-modified habitat.
The distribution, abundance and resource selection patterns of meso-carnivores such as the Indian fox are also heavily influenced by the effects of top-down intraguild competition with sympatric larger carnivores. Competitive dynamics among carnivores are asymmetric and interference competition and the associated occurrence of intraguild predation are unidirectional, with larger carnivores negatively influencing smaller carnivores. Competition can affect the subordinate competitor in several ways: by limiting spatial distributions resulting in scattered interspecies territories, constraining habitat selection, reducing prey encounter rates and food intake, or requiring increased hunting effort.
In my study area, the domestic dog Canis familiaris, is the most common midsized carnivore. As the world’s most common carnivore, dogs are known to interact with wildlife as predators, prey, competitors, and disease reservoirs or vectors. Despite these varied roles in the community, the interaction of dogs with sympatric carnivores is not well understood. Dogs have the potential to be exploitative, interference and apparent competitors with sympatric carnivores.
I examined competition for food between dogs and the Indian fox through dietary analysis. Dogs subsisted largely on human derived material from direct feeding, and scavenging on garbage, crop residue and livestock carcasses (83% relative occurrence).

Wild caught foods constituted only 11% relative occurrence of dog diet. Indian foxes are omnivorous and included a wide variety of food types in their diet. The majority of  Indian fox diet consisted of invertebrates (33% relative occurrence), rodents (20% relative occurrence) and fruits of Zizyphus mauritiana (18.5% relative occurrence). Indian foxes did not include any human derived material, nor did they scavenge from large mammal carcasses, and included only a small portion of agricultural produce in their diet. The diet of free-ranging dogs is typical of dogs from other parts of the world. However, the low contribution of human-derived food sources to the diet of Indian foxes was surprising since the species is a generalist carnivore. Although there was limited dietary overlap between dogs and foxes in this study, dogs may actually be preventing foxes from accessing agricultural lands and human associated foods by interference competition.

Dogs have the potential to be effective interference competitors, especially with medium and small-sized carnivores, and may fulfill the role of a mid-sized canid, especially in areas where the native large carnivore community is depauperate. I experimentally examined the behavioral responses of the Indian fox to the presence of dogs and dog odors. Since resource competition between dogs and foxes is low, it is unclear whether foxes perceive dogs as interference competitors. To test this I exposed foxes to neutral, live dog, and animal odor cues at food trays and recorded the amount of food eaten, time spent at food trays, and vigilance and non-vigilance behaviors. When dogs were visible, foxes continued to visit the food trays, but reduced the amount of time spent (by 83%) and food eaten (by 70%) at those trays. Foxes were 10 times more vigilant during dog trials than during neutral and odor trials and also exhibited lower levels of non-vigilance behavior (resting, playing) when dogs were visible. In contrast, dog odors did not affect fox foraging and activity. These results show that vigilance/foraging tradeoffs due to interference competition can occur between native and domestic carnivores, despite low dietary overlap.

To avoid the effects of interference competition and intraguild predation, subordinate competitors such as the Indian fox can alter space use patterns which may result in a reduction of foraging opportunities. To determine if interference competition between dogs and foxes influences the space use patterns of foxes at a landscape level, I conducted a radio-telemetry study of 32 Indian foxes and 25 free-ranging dogs in and around the Great Indian Bustard Wildlife Sanctuary in central India. Using a logistic regression analysis in an information theoretic framework, I determined the effects of landcover type, primary prey abundance (rodents) and dog presence on the landscape on the space use of foxes. As expected, Indian foxes showed low overlap with dogs based on the volume of intersection index. Top AIC ranked models showed a positive influence of grasslands and a negative influence of agricultural land and dog presence. Rodent abundance only had a weak positive effect. This suggests that fox space use is determined not only by habitat type, but also influenced by the presence of a mid-sized carnivore, the dog.

These results suggest that the competitive intraguild dynamics that are seen among wild carnivores can also occur between wild and domestic carnivores, despite a seeming lack of competition for food and other resources. The role of dogs as intraguild competitors of wild carnivores has thus far been under-recognized. Dogs are among the world’s most common carnivores and are heavily subsidized by humans. As a result, they can occur at high densities even in rural areas, where they tend to range freely into wild habitats. Therefore, dogs can pose threats to native carnivore communities, and extend the edge of anthropogenic disturbance well beyond the borders of human settlements.

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