Publications by authors named "Sebastien Comte"

Article Synopsis
  • Shifts in Tasmanian devil reproduction were observed after a deadly cancer outbreak, with females starting to breed at a younger age (one year old) as a response to population decline.
  • Over 18 years of data analysis, researchers found that the rates of precocial (early) breeding in females stabilized at around 50%, without further increase after the initial rise.
  • The study revealed no significant impact of body size on breeding success or evidence of inbreeding depression affecting reproductive outcomes for either younger or older females.
View Article and Find Full Text PDF

Emerging infectious diseases (EIDs) not only cause catastrophic declines in wildlife populations but also generate selective pressures that may result in rapid evolutionary responses. One such EID is devil facial tumour disease (DFTD) in the Tasmanian devil. DFTD is almost always fatal and has reduced the average lifespan of individuals by around 2 years, likely causing strong selection for traits that reduce susceptibility to the disease, but population decline has also left Tasmanian devils vulnerable to inbreeding depression.

View Article and Find Full Text PDF
Article Synopsis
  • Top carnivores, like Tasmanian devils, influence ecological communities through competition and predation, but human habitat disturbance also plays a significant role.
  • A study analyzing stable isotopes showed that the decline of Tasmanian devils affected both their own and spotted-tailed quolls' ecological niches, with narrower niches observed in human-altered environments.
  • Overall, the research found that anthropogenic disturbances impact mammalian carnivore niches more than the decline of top carnivores themselves, suggesting a complex interplay between these factors.
View Article and Find Full Text PDF

Coevolution is common and frequently governs host-pathogen interaction outcomes. Phenotypes underlying these interactions often manifest as the combined products of the genomes of interacting species, yet traditional quantitative trait mapping approaches ignore these intergenomic interactions. Devil facial tumor disease (DFTD), an infectious cancer afflicting Tasmanian devils (), has decimated devil populations due to universal host susceptibility and a fatality rate approaching 100%.

View Article and Find Full Text PDF

Tasmanian devils have spawned two transmissible cancer lineages, named devil facial tumor 1 (DFT1) and devil facial tumor 2 (DFT2). We investigated the genetic diversity and evolution of these clones by analyzing 78 DFT1 and 41 DFT2 genomes relative to a newly assembled, chromosome-level reference. Time-resolved phylogenetic trees reveal that DFT1 first emerged in 1986 (1982 to 1989) and DFT2 in 2011 (2009 to 2012).

View Article and Find Full Text PDF

Although the home range and habitat selection of animal species is among the fundamental pieces of biological information collected by research projects during recent decades, published information on the snow leopard (Panthera uncia) home range is limited. The Altai Mountains of central Asia contain some of the largest and most important remaining conservation landscapes for snow leopards globally, but there is a limited understanding of the species' ecology in this region. First, we used the data from 5 snow leopards equipped with GPS collars at four study sites in the Altai Mountains of Mongolia to broadly characterize patterns of home range use between 2013 and 2019.

View Article and Find Full Text PDF

Globally, many wild deer populations are actively studied or managed for conservation, hunting, or damage mitigation purposes. These studies require reliable estimates of population state parameters, such as density or abundance, with a level of precision that is fit for purpose. Such estimates can be difficult to attain for many populations that occur in situations that are poorly suited to common survey methods.

View Article and Find Full Text PDF

Movements that extend beyond the usual space use of an animal have been documented in a range of species and are particularly prevalent in arid areas. We present long-distance movement data on five feral cats () GPS/VHF-collared during two different research projects in arid and semi-arid Australia. We compare these movements with data from other feral cat studies.

View Article and Find Full Text PDF

Devil facial tumor disease (DFTD) is a transmissible cancer affecting Tasmanian devils . The disease has caused severe population declines and is associated with demographic and behavioral changes, including earlier breeding, younger age structures, and reduced dispersal and social interactions. Devils are generally solitary, but social encounters are commonplace when feeding upon large carcasses.

View Article and Find Full Text PDF

Epidemiological studies commonly monitor host population density but rarely account for how transmission dynamics might be influenced by changes in spatial and social organization that arise from high mortality altering population demography. Devil facial tumour disease (DFTD), a novel transmissible cancer, caused almost 100% mortality of its single host, the Tasmanian devil, and a >90% local population decline since its emergence 20 years ago. We compare size and overlap in home ranges in a devil population before and 15 years after disease outbreak.

View Article and Find Full Text PDF

Infectious diseases are strong drivers of wildlife population dynamics, however, empirical analyses from the early stages of pathogen emergence are rare. Tasmanian devil facial tumour disease (DFTD), discovered in 1996, provides the opportunity to study an epizootic from its inception. We use a pattern-oriented diffusion simulation to model the spatial spread of DFTD across the species' range and quantify population effects by jointly modelling multiple streams of data spanning 35 years.

View Article and Find Full Text PDF
Article Synopsis
  • Emerging infectious diseases, like Tasmanian devil facial tumor disease (DFTD), are big threats to both human health and animal species.
  • Scientists are using a method called phylodynamics to understand how diseases spread, including studying DFTD, which is a rare and deadly cancer affecting Tasmanian devils.
  • Good news! The transmission of DFTD is decreasing, which raises hopes that Tasmanian devils might not go extinct after all, and this research method can be used to study other diseases too.
View Article and Find Full Text PDF

Devil facial tumour 1 (DFT1) is a transmissible cancer clone endangering the Tasmanian devil. The expansion of DFT1 across Tasmania has been documented, but little is known of its evolutionary history. We analysed genomes of 648 DFT1 tumours collected throughout the disease range between 2003 and 2018.

View Article and Find Full Text PDF

The impact of emerging infectious diseases is increasingly recognised as a major threat to wildlife. Wild populations of the endangered Tasmanian devil, , are experiencing devastating losses from a novel transmissible cancer, devil facial tumour disease (DFTD); however, despite the rapid decline of this species, there is currently no information on the presence of haemoprotozoan parasites. In the present study, 95 Tasmanian devil blood samples were collected from four populations in Tasmania, Australia, which underwent molecular screening to detect four major groups of haemoprotozoa: (i) trypanosomes, (ii) piroplasms, (iii) , and (iv) haemosporidia.

View Article and Find Full Text PDF

Studies of impacts of fragmentation have focused heavily on measures of species presence or absence in fragments, or species richness in relation to fragmentation, but have often not considered the effects of fragmentation on ranging behavior of individual species. Effective management will benefit from knowledge of the effects of fragmentation on space use by species.We investigated how a woodland specialist, the eastern bettong (), responded to fragmentation in an agricultural landscape, the Midlands region of Tasmania, Australia.

View Article and Find Full Text PDF

In an era of unprecedented global change, exploring patterns of gene expression among wild populations across their geographic range is crucial for characterizing adaptive potential. RNA-sequencing studies have successfully characterized gene expression differences among populations experiencing divergent environmental conditions in a wide variety of taxa. However, few of these studies have identified transcriptomic signatures to multivariate, environmental stimuli among populations in their natural environments.

View Article and Find Full Text PDF
Article Synopsis
  • Emerging infectious diseases are increasing globally, and studying host-pathogen interactions is crucial for understanding the evolution and management of these diseases.
  • The Tasmanian devil population is endangered due to two transmissible cancers, devil facial tumour disease (DFTD) and a newly identified strain, devil facial tumour 2 (DFT2), which appears to be confined to southeast Tasmania.
  • Recent findings show significant differences in tumor location and sex bias for DFT2, with males more frequently affected, indicating potential evolutionary dynamics between the two diseases.
View Article and Find Full Text PDF

Identifying the genetic architecture of complex phenotypes is a central goal of modern biology, particularly for disease-related traits. Genome-wide association methods are a classical approach for identifying the genomic basis of variation in disease phenotypes, but such analyses are particularly challenging in natural populations due to sample size difficulties. Extensive mark-recapture data, strong linkage disequilibrium and a lethal transmissible cancer make the Tasmanian devil (Sarcophilus harrisii) an ideal model for such an association study.

View Article and Find Full Text PDF

In zoonotic infections, the relationships between animals and humans lead to parasitic disease with severity that ranges from mild symptoms to life-threatening conditions. In cities and their surrounding areas, this statement is truer with the overcrowding of the protagonists of the parasites' life cycle. The present study aims to investigate the distribution of a parasite, Echinococcus multilocularis, which is the causative agent of alveolar echinococcosis, using copro-sampling in historically endemic rural settlements of the eastern part of France and in newly endemic areas including urban parks and settlements surrounding Paris.

View Article and Find Full Text PDF

With the ongoing spread of Echinococcus multilocularis in Europe, sanitary authorities are looking for the most efficient ways of reducing the risk for human populations. Fox culling is one particular tool that has recently shifted from predation control to population health management. Our study aims to assess the effectiveness of this tool in limiting E.

View Article and Find Full Text PDF

Alveolar echinococcosis is considered to be the most serious zoonosis in the Northern Hemisphere's cold or temperate regions. In Europe, the parasite has a sylvatic life cycle based on predator-prey interactions, mainly between red foxes and small rodents. Echinococcus multilocularis has been observed to have spread across Europe over the last three decades.

View Article and Find Full Text PDF

Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a severe zoonotic disease. It is maintained through a sylvatic life cycle based on predator-prey interactions mainly between foxes and rodents. Dogs are also good definitive hosts; and due to their close proximity to humans, they may represent a major risk factor for the occurrence of human cases.

View Article and Find Full Text PDF

The oncosphere stage of Echinococcus multilocularis in red fox stools can lead, after ingestion, to the development of alveolar echinococcosis in the intermediate hosts, commonly small mammals and occasionally humans. Monitoring animal infection and environmental contamination is a key issue in public health surveillance. We developed a quantitative real-time PCR technique (qPCR) to detect and quantify E.

View Article and Find Full Text PDF

During 2005-2010, we investigated Echinococcus multilocularis infection within fox populations in a large area in France. The parasite is much more widely distributed than hitherto thought, spreading west, with a much higher prevalence than previously reported. The parasite also is present in the large conurbation of Paris.

View Article and Find Full Text PDF

The life cycle of the zoonotic parasite Echinococcus multilocularis is predominantly sylvatic, involving foxes as definitive hosts infected by predation of rodents, the intermediate hosts. The North-Eastern French departments of Meuse and Haute-Saône are highly endemic, with an estimated fox prevalence of 41% and 36% respectively. Although most of the parasites' biomass occurs in foxes, domestic dogs can also be infected, leading to a major risk of human infection due to the close proximity of dogs and owners.

View Article and Find Full Text PDF