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

Historical natural history collections allow the description of a new and presumably extinct species of dwarf gecko (Squamata: Gekkonidae: Lygodactylus Gray, 1864) from Fernando de Noronha Island, Brazil

A series of specimens of an unidentified species of the genus Lygodactylus from Fernando de Noronha Island were found in the herpetological collections of the Museu Nacional, Rio de Janeiro (Brazil). No species of this genus were known to occur in the archipelago. A review of the historical reports regarding the herpetofauna of the island failed to provide evidence regarding the presence of the species in the last centuries. Morphological comparisons with the two other species of the genus occurring in South America, L. klugei and L. wetzeli, allowed us to confidently confirm that the Fernando de Noronha population belonged to a putatively new species. Here we describe this population as a new species and discuss its possible extinction causes in the archipelago. We also debate the importance of historical natural history collections to the study of biodiversity.

Application of genetic and Spatially Explicit Capture-Recapture analyses to design adaptive feral cat control in a large inhabited island

Faunas of oceanic islands have a high proportion of endemic species which contribute to the uniqueness of island communities. Island species are particularly naïve and vulnerable to alien predators, such as cats (Felis catus). On large, inhabited islands, where the complete eradication of feral cat populations is not considered feasible, control represents the best management option to lower their detrimental effects on native fauna. The first objective of our study was to investigate population genetics of feral cats of Réunion Island. The second objective was to understand the space use of feral cats established near the breeding colonies of the two endemic and endangered seabirds of Réunion Island, the Barau’s Petrel (Pterodroma baraui) and the Mascarene Petrel (Pseudobulweria aterrima). We evaluated genetic diversity, population structure and gene flow amongst six groups of feral cats located at a maximum of 10 km from known petrel colonies. We also analysed the behaviour and space use of one of these feral cat groups using camera-trap data and Spatially Explicit Capture-Recapture (SECR) models. Genetic analyses revealed that feral cats were structured in three genetic clusters explained mostly by the island topography. Two clusters were observed at five sampled sites, suggesting high connectivity amongst these sites. The last cluster was found in only one site, suggesting high isolation. This site was a remote mountain area located in the vicinity of one of the main Barau’s Petrel colonies. The behavioural study was conducted on this isolated feral cat population. Mark recapture analysis suggested that feral cats were present at low density and had large home ranges, which is probably explained by reduced food availability. Finally, we make several recommendations for refining feral cat management programmes on inhabited islands.

Seropositivity of Anti-Toxoplasma gondii Antibodies in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Southern Brazil

Although toxoplasmosis has been considered among the most neglected zoonoses worldwide, no study has focused on the frequency and associated risk factors of owners and their dogs living on an island and mainland seashore areas. Accordingly, anti-Toxoplasma gondii IgG antibodies were screened by indirect fluorescent antibody test (IFAT) in owners and dogs from three oceanic islands and two nearby mainland harbor areas, with associated risk factors for toxoplasmosis assessed by univariable and multivariable logistic regression models. Overall, anti-T. gondii seropositivity was observed in 59/328 (18.0%) owners and 66/283 (23.3%) dogs, with no statistical difference between owners (p = 0.360) and dogs (p = 0.655) from islands and mainland areas. Consumption of local water springs (p = 0.016; OR = 2.11) was an associated risk factor for T. gondii seropositivity, and owners with the habit of spring water intake were twice more likely seropositive (p = 0.014; OR = 2.14). Presence of anti-T. gondii antibodies in dogs was associated with seropositive owners (p = 0.008; OR = 2.81), household consumption of beef meat (p = 0.042; OR = 1.7) and chicken (p = 0.026; OR = 2.9). Despite being lower than the worldwide prevalence, toxoplasmosis seropositivity in owners and their dogs in southern Brazil was influenced by the positive owner, water source, and meat consumption, and not by inhabiting islands or seashore mainland areas, presence of dogs, cats, or both. In addition, drinking water quality should always be considered a critical risk factor for toxoplasmosis on islands.

Cross-sectional survey for Toxoplasma gondii infection in humans in Fernando de Noronha island, Brazil

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is zoonotic disease and is one of the most important foodborne parasitic diseases globally. The prevalence in humans is highly variable, being influenced by cultural habits, socioeconomic, and environmental conditions. The objective of this study was to estimate the prevalence of T. gondii infection in humans on the archipelago of Fernando de Noronha, Pernambuco State, Brazil, and to identify the risk factors associated with this infection. The seroprevalence of immunoglobulin G anti-T. gondii antibodies was 50.4% (172/341, 95% CI: 45.2%-55.7%). Factors associated with the infection were consumption of well water or rainwater (odds ratio [OR]: 2.43, p=0.020) and consumption of game meat (OR: 1.80, p=0.026). This is the first study to provide epidemiological information of T. gondii infection among the residents of the Island of Fernando de Noronha, revealing a considerable antibody seroprevalence in this population. This study provides information for the adoption of prevention and control measures in island environments.

Seroepidemiological investigation of animal leptospirosis and molecular characterization of the first Leptospira strain isolated from Fernando de Noronha archipelago, Brazil

Leptospirosis has been widely reported in insular environments worldwide, characterizing a major public health threat. Although low-genetic biodiversity is expected in these regions, the introduction of domestic and synanthropic mammals may contribute to the wider diversity of leptospiral strains in insular settings. This study proposes a large-scale seroepidemiological investigation of Leptospira infection in animals from Fernando de Noronha archipelago and describes the characterization of the first leptospiral strain ever isolated from an insular setting in Brazil. A total of 1,265 blood samples from domestic (n = 682), synanthropic (n = 133) and wild (n = 450) animals were collected between 2007 and 2014, totalling 12 species. The presence of anti-Leptospira spp. antibodies was investigated by the microscopic agglutination test (MAT), and kidney samples from 20 synanthropic rodents were collected for the isolation of Leptospira spp. The leptospires recovered were further characterized by serogrouping with polyclonal antibodies, whole-genome sequencing and multilocus sequence typing (MLST). The MAT results revealed the presence of agglutinins in 90 samples (7.1%) and the most frequently found serogroup was Icterohaemorrhagiae (n = 57) in practically all species included. Viable leptospires were recovered from one brown rat, and characterization revealed that the isolate belongs to L. interrogans serogroup Pyrogenes. The results suggest that synanthropic rodents might play an important role in leptospiral infection among wildlife and domestic species in the archipelago.

Global Strategies for Population Management of Domestic Cats (Felis catus): A Systematic Review to Inform Best Practice Management for Remote Indigenous Communities in Australia

Simple Summary

A systematic review process was used to identify the current global cat population management practices for owned, free-roaming cat populations, particularly those suited to remote Indigenous communities in Australia. Based on this review, a combination of three methods is recommended. The first method, Surgical Sterilisation (SS), requires owners to take their socialised cats to a facility for surgical sterilisation and then take them home. The second method, Trap-Neuter-Release (TNR) traps, neuters (sterilises) and returns healthy owned cats, which are unsocialised to the point where trapping is necessary, to their homes, and the third method, Trap-Remove (TR), traps and removes unwanted social cats via adoption and unhealthy cats via euthanasia. Conducting these three methods together over a long-term period appears to be consistent with current global best practice for humane and ethical management of cat populations in these communities.

Abstract

Pet domestic cat (Felis catus) populations are increasing all around the world, resulting in an increase in contact with humans and wildlife, potentially spreading zoonotic diseases and predating on wildlife. With the recently identified rise in cat populations in remote Indigenous communities in Australia, culturally appropriate cat population management strategies are required. A systematic review process was conducted to review the current global cat population management practices that are suitable for owned, free-roaming cat populations in these communities. Eight articles on in-situ field cat populations and five studies simulating computer modelled cat populations reported results of 66 population management interventions. Surgical Sterilisation (SS) was used in all socialised owned cat articles. The trap–neuter–release (TNR) method was used most frequently on unsocialised cats and gained the best results when the trap–remove (TR) method was used concurrently to adopt out unwanted social cats and euthanise ill or injured cats. The results of this review suggest that long-term TNR/SS programs supplemented with TR provide the current most ethically sound best practice, humane method of managing cat populations in remote Australian Indigenous communities. It is also recognised that no one plan will fit all, and that further research on the micro-level techniques used to deploy both TNR and TR needs to occur, and that culturally appropriate community consultation during all processes is vital in achieving a sustainable management program.

A population genetic study of feral cats on Christmas Island

Feral and stray cats are a major threat for endemic species on Christmas Island and have been contributing to their decline. Cats were introduced to Christmas Island in 1888 and are now distributed across the whole island. We analysed the genetic population structure and diversity of feral and stray cats on Christmas Island to evaluate connectivity across the island and the possibility of discernible populations that could be targeted separately. Results indicate no differentiated population structure across the island, with cats facing no habitat obstacles to reduce their dispersal abilities across the island. We found high kin structure, suggesting individuals breeding successfully on the whole island. With the management of domestic and feral/stray cats since 2010, removal efforts targeting the whole island have successfully reduced the effective population size of feral/stray cats in the last five years. We suggest the use of various management techniques to facilitate future removal efforts, especially in areas on the island that are difficult to access.