Les hommes ont oublié cette vérité. Mais tu ne dois pas l'oublier, dit le renard. Tu deviens responsable pour toujours de ce que tu as apprivoisé.
Le Petit Prince, chap. 21

Thursday 17 January 2019

‘Science denialism’ is also about outdoor cats

Loss, S. R., Will, T., Longcore, T., & Marra, P. P. (2018). Responding to misinformation and criticisms regarding United States cat predation estimates. Biological Invasions, 20(12), 3385-3396.
Misinformation (or denialism), the disingenuous assertion of information contradicting overwhelming scientific consensus, increasingly poses a challenge for invasion biology. The issue of free-ranging domestic cats (Felis catus) provides an example of this misinformation: overwhelming consensus shows that cats are invasive species that impact wildlife and human health yet free-ranging cat advocates propagate misinformation about such impacts to support policies keeping cats on the landscape. These advocates also attempt to discredit peer-reviewed scientific research on cat impacts, as exemplified by the response to a high-profile paper estimating cats annually kill billions of U.S. birds and mammals (Loss et al. in Nat Commun 4:1396, 2013). Although favorably received by scientific and invasive species management communities, an effort was launched to discredit this paper by criticizing its methods, including a report commissioned by a feral cat advocacy group and a post by a feral cat blogger. These same organizations and individuals have made similar criticisms at scientific conferences and policy roundtables. Given the realized effects of this campaign in influencing invasive species policy, we here respond to these criticisms and show they are characterized by numerous errors and misrepresentations. We conclude that the criticisms are part of the broader campaign to fabricate doubt about outdoor cat impacts and stymie policies favoring removal of cats from the landscape. Because misinformation surrounding cats is emblematic of the broader issue of misinformation and denialism, this response will not only facilitate evidence-based policy for managing cats but also stimulate research and discussion into causes and impacts of misinformation in invasion biology.

Tuesday 20 June 2017

The palaeogenetics of cat dispersal in the ancient world

Ottoni, C. et al. (2017) The palaeogenetics of cat dispersal in the ancient world. Nat. Ecol. Evol. 1, 0139.

The cat has long been important to human societies as a pest-control agent, object of symbolic value and companion animal, but little is known about its domestication process and early anthropogenic dispersal. Here we show, using ancient DNA analysis of geographically and temporally widespread archaeological cat remains, that both the Near Eastern and Egyptian populations of Felis silvestris lybica contributed to the gene pool of the domestic cat at different historical times. While the cat’s worldwide conquest began during the Neolithic period in the Near East, its dispersal gained momentum during the Classical period, when the Egyptian cat successfully spread throughout the Old World. The expansion patterns and ranges suggest dispersal along human maritime and terrestrial routes of trade and connectivity. A coat-colour variant was found at high frequency only after the Middle Ages, suggesting that directed breeding of cats occurred later than with most other domesticated animals.

Friday 19 May 2017

New insights into the genetic composition and phylogenetic relationship of wolves and dogs in the Iberian Peninsula

Pires, A. E., Amorim, I. R., Borges, C., Simões, F., Teixeira, T., Quaresma, A., ... & Matos, J. (2017). New insights into the genetic composition and phylogenetic relationship of wolves and dogs in the Iberian Peninsula. Ecology and Evolution.

This study investigates the gene pool of Portuguese autochthonous dog breeds and their wild counterpart, the Iberian wolf subspecies (Canis lupus signatus), using standard molecular markers. A combination of paternal and maternal molecular markers was used to investigate the genetic composition, genetic differentiation and genetic relationship of native Portuguese dogs and the Iberian wolf. A total of 196 unrelated dogs, including breed and village dogs from Portugal, and other dogs from Spain and North Africa, and 56 Iberian wolves (wild and captive) were analyzed for nuclear markers, namely Y chromosome SNPs, Y chromosome STR loci, autosomal STR loci, and a mitochondrial fragment of the control region I. Our data reveal new variants for the molecular markers and confirm significant genetic differentiation between Iberian wolf and native domestic dogs from Portugal. Based on our sampling, no signs of recent introgression between the two subspecies were detected. Y chromosome data do not reveal genetic differentiation among the analyzed dog breeds, suggesting they share the same patrilineal origin. Moreover, the genetic distinctiveness of the Iberian wolf from other wolf populations is further confirmed with the description of new mtDNA variants for this endemism. Our research also discloses new molecular markers for wolf and dog subspecies assignment, which might become particularly relevant in the case of forensic or noninvasive genetic studies. The Iberian wolf represents a relic of the once widespread wolf population in Europe and our study reveals that it is a reservoir of unique genetic diversity of the grey wolf, Canis lupus. These results stress the need for conservation plans that will guarantee the sustainability of this threatened top predator in Iberia.

Integrating social ecology in explanations of wolf–dog behavioral differences

Marshall-Pescini, S., Cafazzo, S., Virányi, Z., & Range, F. (2017). Integrating social ecology in explanations of wolf–dog behavioral differences. Current Opinion in Behavioral Sciences, 16, 80-86.

• Wolf–dog differences have been explained as a result of human selection for desirable behaviours.
• But wolves and dogs also have different feeding ecologies and social organizations.
• Wolves rely on pack members for group hunting and pup-rearing.
• Dogs mostly forage alone on human refuse and show little allomaternal care.
• Social ecology helps explain observed wolf–dog differences in comparative studies.

Whereas studies in comparative cognition normally invoke ecology and social organization to account for differences in social behaviour and cognition across species, dog–wolf differences have so far been explained mostly as a result of direct human selection for desirable traits (e.g., tameness, attention to humans, sociability). Yet, as will be reviewed in this paper, dogs and wolves also differ considerably in both their feeding niche and social organization (which together we refer to as ‘social ecology’). We suggest that observed wolf–dog differences especially in their interaction with the environment (e.g., neophobia, persistence, risk taking) and conspecifics (e.g., tolerance, cooperation, communication) need to be considered also in regard to their social ecology. We propose that social ecology alongside human selection should be recognized as a potentially important factor affecting dogs’ behaviour, and suggest a number of potential avenues for future research, which can more directly test the relative importance of these selection forces.

Changes in the feeding ecology and social organization from wolves to dogs and how these may affect their behaviour towards conspecifics and the environment.

Thursday 18 May 2017

A Dogged problem for Wildlife?

Prospects for domestic and feral cat management on an inhabited tropical island

Dias, R. A., Abrahão, C. R., Micheletti, T., Mangini, P. R., de Oliveira Gasparotto, V. P., de Jesus Pena, H. F., ... & Silva, J. C. R. 2017. Prospects for domestic and feral cat management on an inhabited tropical island. Biological Invasions, 1-15.

Cat management campaigns have been implemented on several islands worldwide. However, few successful campaigns have occurred on permanently inhabited islands. Cats are known for causing severe impacts on the native insular fauna, posing an important threat to biodiversity. Moreover, this species is also responsible for zoonosis maintenance and transmission. A thorough understanding of cat population structure (e.g., supervised vs. unsupervised) is strongly suggested as a management action on inhabited islands, as it might promote more efficient and effective management of this species. Fernando de Noronha is an archipelago in the tropical Atlantic Ocean. The total cat population on the main island was estimated at 1287 animals, most of them supervised and subsidized around inhabited areas. Free-roaming cats currently threaten the endemic terrestrial fauna of Fernando de Noronha, and the cat density found by the present work is among the highest ever recorded on an island. Using population dynamic simulations, the long-term effects of reproduction control and removal of cats from the archipelago were assessed. Removal of cats was also suggested as a necessary management strategy to achieve negative population growth. In addition, it was more cost-effective than reproduction control. However, applying both removal and sterilization strategies to this population resulted in a higher population decrease than removal alone. For these reasons, a combination of reproductive control and cat eradication should be implemented in Fernando de Noronha.

Tuesday 2 May 2017

Domestic dogs threaten endangered species worldwide

Humans and their canine companions share many close bonds. Wolves (Canis lupus) were the first animal domesticated by people, some time between 15,000 and 50,000 years ago. 

There are now an estimated 1 billion domestic dogs across their near-global distribution.

Sunday 5 February 2017

Other environmental factors affects more Island foxes diet than competition with feral cats

Cypher, B.L. , Kelly E.C., Ferrara, F.J., Drost C.A., Westall, T.L. & Hudgens, B.R. 2017. Diet patterns of island foxes on San Nicolas Island relative to feral cat removal. Pacific Conservation Biology 23(2) 180-188

Island foxes (Urocyon littoralis) are a species of conservation concern that occur on six of the Channel Islands off the coast of southern California. We analysed island fox diet on San Nicolas Island during 2006–12 to assess the influence of the removal of feral cats (Felis catus) on the food use by foxes. Our objective was to determine whether fox diet patterns shifted in response to the cat removal conducted during 2009–10, thus indicating that cats were competing with foxes for food items. We also examined the influence of annual precipitation patterns and fox abundance on fox diet. On the basis of an analysis of 1975 fox scats, use of vertebrate prey – deer mice (Peromyscus maniculatus), birds, and lizards – increased significantly during and after the complete removal of cats (n = 66) from the island. Deer mouse abundance increased markedly during and after cat removal and use of mice by foxes was significantly related to mouse abundance. The increase in mice and shift in item use by the foxes was consistent with a reduction in exploitative competition associated with the cat removal. However, fox abundance declined markedly coincident with the removal of cats and deer mouse abundance was negatively related to fox numbers. Also, annual precipitation increased markedly during and after cat removal and deer mouse abundance closely tracked precipitation. Thus, our results indicate that other confounding factors, particularly precipitation, may have had a greater influence on fox diet patterns.

Bait delivery for cats using drons

Johnston, M., McCaldin, G., & Rieker, A. (2016). Assessing the availability of aerially delivered baits to feral cats through rainforest canopy using unmanned aircraft. Journal of Unmanned Vehicle Systems, 4(4), 276-281.

At least eight threatened wildlife species are at direct risk from predation by cats (Felis catus) on Christmas Island (Director of National Parks. 2014. Christmas Island biodiversity conservation plan. Canberra. Australia: Department of the Environment.). A range of strategies are now being used to manage cats across the island, including responsible ownership methods for domestic cats and lethal control tools to remove feral cats outside the township area. Unmanned aerial vehicles (UAVs) were used to drop non-toxic baits through the rainforest canopy to assess whether aerial baiting could be undertaken successfully on the island. Ground crews located 88% of baits, indicating that sufficient baits would be accessible to feral cats if broad-scale aerial baiting was to be undertaken in the future.

Saturday 4 February 2017

Dogs, catas and the fear of pest rodents

Themb’alilahlwa, A. M., Monadjem, A., McCleery, R., & Belmain, S. R. (2017). Domestic cats and dogs create a landscape of fear for pest rodents around rural homesteads. PloS one, 12(2), e0171593.

Using domestic predators such as cats to control rodent pest problems around farms and homesteads is common across the world. However, practical scientific evidence on the impact of such biological control in agricultural settings is often lacking. We tested whether the presence of domestic cats and/or dogs in rural homesteads would affect the foraging behaviour of pest rodents. We estimated giving up densities (GUDs) from established feeding patches and estimated relative rodent activity using tracking tiles at 40 homesteads across four agricultural communities. We found that the presence of cats and dogs at the same homestead significantly reduced activity and increased GUDs (i.e. increased perception of foraging cost) of pest rodent species. However, if only cats or dogs alone were present at the homestead there was no observed difference in rodent foraging activity in comparison to homesteads with no cats or dogs. Our results suggest that pest rodent activity can be discouraged through the presence of domestic predators. When different types of predator are present together they likely create a heightened landscape of fear for foraging rodents.

Sunday 29 January 2017

Cats and Tropci birds

Boeken, M. (2016). Breeding success of Red-billed Tropicbirds Phaethon aethereus on the Caribbean island of Saba. Ardea, 104(3), 263-271.

In 2011 and 2012 the breeding success of Red-billed Tropicbirds Phaethon aethereus mesonauta was monitored on Saba, a 13-km2 island in the Caribbean Netherlands. The two colonies on the south and south-west side of the island both contain approximately 100–300 nests; breeding success was zero at these sites, due to predation of newly hatched chicks by Feral House Cats. In the single large colony of Old Booby Hill (estimated to contain approximately 1000 nests) on the east side of the island, rates of predation were lower, resulting in a breeding success (survival from laying until fledging, as far as observed) of 65%. Calculations of daily survival of eggs and chicks following Mayfield, resulted in a nesting success of 48% per pair. I conservatively estimated the size of the Saba breeding population to be at least 1300–1500 pairs, which is larger than the previous estimate of 750–1000 pairs. Potentially, the number of breeding pairs may be as high as 1850 pairs.

Saturday 21 January 2017

Invasive mesopredators should be controlled at the same time

Molsher, R., Newsome, A. E., Newsome, T. M., & Dickman, C. R. (2017). Mesopredator Management: Effects of Red Fox Control on the Abundance, Diet and Use of Space by Feral Cats. PloS one, 12(1), e0168460.

Apex predators are subject to lethal control in many parts of the world to minimize their impacts on human industries and livelihoods. Diverse communities of smaller predators—mesopredators—often remain after apex predator removal. Despite concern that these mesopredators may be 'released' in the absence of the apex predator and exert negative effects on each other and on co-occurring prey, these interactions have been little studied. Here, we investigate the potential effects of competition and intraguild predation between red foxes (Vulpes vulpes) and feral cats (Felis catus) in south-eastern Australia where the apex predator, the dingo (Canis dingo), has been extirpated by humans. We predicted that the larger fox would dominate the cat in encounters, and used a fox-removal experiment to assess whether foxes affect cat abundance, diet, home-range and habitat use. Our results provide little indication that intraguild predation occurred or that cats responded numerically to the fox removal, but suggest that the fox affects some aspects of cat resource use. In particular, where foxes were removed cats increased their consumption of invertebrates and carrion, decreased their home range size and foraged more in open habitats. Fox control takes place over large areas of Australia to protect threatened native species and agricultural interests. Our results suggest that fox control programmes could lead to changes in the way that cats interact with co-occurring prey, and that some prey may become more vulnerable to cat predation in open habitats after foxes have been removed. Moreover, with intensive and more sustained fox control it is possible that cats could respond numerically and alter their behaviour in different ways to those documented herein. Such outcomes need to be considered when estimating the indirect impacts of fox control. We conclude that novel approaches are urgently required to control invasive mesopredators at the same time, especially in areas where apex predators are absent.

Sunday 15 January 2017

Exposure to predators reduce immune response in birds

Navarro, C., De Lope, F., Marzal, A., & Møller, A. P. (2004). Predation risk, host immune response, and parasitism. Behavioral Ecology, 15(4), 629-635.

Predation risk may affect the allocation priorities of limiting resources by potential prey. Investment in immune function should receive reduced priority, when hosts are exposed to predators because of the costs of immune function. We tested this hypothesis by randomly exposing adult house sparrows, Passer domesticus, to either a cat, Felis catus, or a rabbit, Oryctolagus cuniculus, for 6 h while assessing their ability to raise a T-cell–mediated immune response to a challenge with phytohemagglutinin. Sparrows exposed to a cat had a significant reduction of, on average, 18% and 36% in T-cell response in two different experiments compared with sparrows that were exposed to a rabbit. In a field experiment with a barn owl, Tyto alba, or a rock dove, Columba livia, placed next to a nest-box during laying, we found a mean reduction in T-cell–mediated immune response of 20%. In males, the reduction in cell-mediated immune response owing to cat exposure increased with increasing size of the badge, which is a secondary sexual character, but only during the breeding season. In a third experiment, house sparrows were either exposed to a barn own, T. alba, or a rock dove, C. livia, and development of malarial infections was recorded during the following 6 weeks. Individual sparrows exposed to a predator had a higher prevalence and intensity of Haemoproteus malarial infection than did control individuals. Therefore, exposure to predators reduced their ability of hosts to cope with parasitism mediated through effects on immune function.

Ecology of feral cats on a Tasmanian Island

Hayde, K. A. (1992). Ecology of the feral cat Felis catus on Great Dog Island (Doctoral dissertation, University of Tasmania).

Aspects of the ecology of feral cats on Great Dog Island, Bass Strait, were investigated from May to September 1991. Population structure and dynamics, morphology and phenotypes, condition and gastro-intestinal parasites and diet were studied. A culled sample of 189 feral cats displayed a male: female ratio of 1:1 and indicated a pre-eradication density of at least 56.9 cats/km2• Juveniles and sub-adults made up 44.9% of the population. A breeding season was inferred by kitten age and by changes through time in the population structure. Approximate life expectancy was estimated to be 73-84 months for males and 85-96 months for females. Counting cementum annuli in the teeth was shown to be an effective method of age determination. The length and weight of male and female feral cats of Great Dog Island was comparable to that of feral cats found on the mainland Australian. However, a decline in the weight of females between autumn and winter suggested the occurrence of a seasonal nutritional stress. The relationship between age and length in adult males suggests that greater length offers an advantage to longevity. The presence of seven mutant pelagerelated genes, in addition to the wild type, indicated a comparatively high degree of genetic diversity within the feral cat population of Great Dog Island. The long hair allele is probably being selected against as juveniles suffer high mortality. The expression of the inhibitor allele is bias toward males. No significant relationships were found to occur between coat colour and weight or length. The analysis of gut contents showed that a total of 26 species were ingested: 2 bird, 1 mammal, 5 reptile and 18 arthropod species. The gut of 16 cats were either empty or contained only residual food stuffs. Most cats had soil and plant matter in the gut. There was no evidence of cannabalism and no human refuse was present. It is likely that some artht:opod prey were excavated. There was no advantage in age or body size in obtaining prey species. Generally, the coat skin and tooth condition of cats on Great Dog Island was very good. The nutritional condition (fat deposits) of cats suggested that cats were generally in good condition in autumn. Both males and females underwent a large decline in fat reserves from autumn to winter and reserves were further depleted as winter progressed. This resulted in the general nutiitional condition of the winter cats being poor. Gastro-intestinal parasites present were Taenia taeniaeformis, Toxocara cati and Cylicospirura felineus . Parasite infestation was biased toward females. Loss of condition did not generally result in increased susceptibility to parasite infestation. This was instead better explained as a response to diet and climate.

Monday 9 January 2017

Impacts of introduced mammalian predators on New Zealand’s alpine fauna

O’Donnell, C. F., Weston, K. A., & Monks, J. M. (2017). Impacts of introduced mammalian predators on New Zealand’s alpine fauna. New Zealand Journal of Ecology, 41(1), 01-22.

Alpine zones are threatened globally by invasive species, hunting, and habitat loss caused by fire, anthropogenic development and climate change. These global threats are pertinent in New Zealand, with the least understood pressure being the potential impacts of introduced mammalian predators, the focus of this review. In New Zealand, alpine zones include an extensive suite of cold climate ecosystems covering c. 11% of the land mass. They support rich communities of indigenous invertebrates, lizards, fish, and birds. Many taxa are obligate alpine dwellers, though there is uncertainty about the extent to which distributions of some species are relicts of wider historical ranges. The impacts of introduced mammalian predators are well described in many New Zealand ecosystems, though little is known about the impacts of these predators on alpine fauna. Here we review the importance of alpine habitats for indigenous fauna and the impacts of introduced mammalian predators; and develop a conceptual model explaining threat interactions. Most evidence for predation is anecdotal or comes from studies of species with wider ranges and at lower altitudes. Nevertheless, at least ten introduced predator species have been confirmed as frequent predators of native alpine species, particularly among birds and invertebrates. In the case of the endangered takahe (Porphyrio hochstetteri) and rock wren (Xenicus gilviventris), stoats (Mustela erminea) are primary predators, which are likely to be impacting significantly on population viability. We also document records of mammalian predation on alpine lizards and freshwater fish. While the precise impacts on the long-term viability of threatened species have not been evaluated, anecdotal evidence suggests that predation by mammals is a serious threat, warranting predator control. Future research should focus on predicting when and where mammalian predators impact on populations of indigenous fauna, furthering our understanding of the alpine predator guild particularly through adaptive management experiments, and exploring interactions with other threats.
Related Posts Plugin for WordPress, Blogger...