DNA metabarcoding reveals a broad dietary range for Tasmanian devils introduced to a naive ecosystem.

Top carnivores are essential for maintaining ecosystem stability and biodiversity. Yet, carnivores are declining globally and current in situ threat mitigations cannot halt population declines. As such, translocations of carnivores to historic sites or those outside the species' native range are becoming increasingly common. As carnivores are likely to impact herbivore and small predator populations, understanding how carnivores interact within an ecosystem following translocation is necessary to inform potential remedial management and future translocations. Dietary analyses provide a preliminary assessment of the direct influence of translocated carnivores on a recipient ecosystem. We used a metabarcoding approach to quantify the diet of Tasmanian devils introduced to Maria Island, Tasmania, a site outside the species' native range. We extracted DNA from 96 scats and used a universal primer set targeting the vertebrate 12S rRNA gene to identify diet items. Tasmanian devils on Maria Island had an eclectic diet, with 63 consumed taxa identified. Cat DNA was detected in 14% of scats, providing the first instance of cats appearing as part of Tasmanian devil diets either via predation or scavenging. Short-tail shearwaters and little penguins were commonly consumed, corresponding with previous surveys showing sharp population declines in these species since the introduction of Tasmanian devils. Our results indicate that the introduction of carnivores to novel ecosystems can be very successful for the focal species, but that commonly consumed species should be closely monitored to identify any vulnerable species in need of remedial management.

Looking like the locals - gut microbiome changes post-release in an endangered species.

BACKGROUND: Captivity presents extreme lifestyle changes relative to the wild, and evidence of microbiome dysbiosis in captive animals is growing. The gut microbiome plays a crucial role in host health. Whilst captive breeding and subsequent reintroduction to the wild is important for conservation, such efforts often have limited success. Post-release monitoring is essential for assessing translocation success, but changes to the microbiome of released individuals are poorly understood. The Tasmanian devil was previously shown to exhibit loss of microbiome diversity as a result of intense captive management. This current study examines changes in the devil gut microbiome in response to translocation and aims to determine if perturbations from captivity are permanent or reversible. METHODS: Using 16S rRNA amplicon sequencing, we conducted temporal monitoring of the gut microbiome of released devils during two translocation events, captive-to-wild and wild-to-wild. To investigate whether the microbiome of the released devils changed following translocation, we characterized their microbiome at multiple time points during the translocation process over the course of 6-12 months and compared them to the microbiome of wild incumbent devils (resident wild-born devils at the respective release sites). RESULTS: We showed that the pre-release microbiome was significantly different to the microbiome of wild incumbent animals, but that the microbiomes of animals post-release (as early as 3 to 4 weeks post-release) were similar to wild incumbents. The gut microbiome of released animals showed significant compositional shifts toward the wild incumbent microbiome of both translocation events. CONCLUSION: Our results suggest that the devil gut microbiome is dynamic and that loss of microbiome diversity in captivity can be restored following release to the wild. We recommend the broader application of microbiome monitoring in wildlife translocation programs to assess the impacts of translocation on animal microbiomes.

Density trends and demographic signals uncover the long-term impact of transmissible cancer in Tasmanian devils.

1. Monitoring the response of wild mammal populations to threatening processes is fundamental to effective conservation management. This is especially true for infectious diseases, which may have dynamic and therefore unpredictable interactions with their host. 2. We investigate the long-term impact of a transmissible cancer, devil facial tumour disease (DFTD), on the endemic Tasmanian devil. We analyse trends in devil spot-light counts and density across the area impacted by the disease. We investigate the demographic parameters which might be driving these trends, and use spatial capture-recapture models to examine whether DFTD has affected home range size. 3. We found that devils have declined by an average of 77% in areas affected by DFTD, and that there is a congruent trend of ongoing small decline in spotlight counts and density estimates. Despite this, devils have persisted to date within each of nine monitoring sites. One site is showing as yet unexplained small increases in density 8-10 years after the emergence of DFTD. 4. We also found the prevalence of DFTD has not abated despite large declines in density and that diseased sites continue to be dominated by young devils. The long-term impact of the disease has been partially offset by increased fecundity in the form of precocial breeding in 1-year-old females, and more pouch young per female in diseased sites. The lower densities resulting from DFTD did not affect home range size. 5. Synthesis and applications. Transmission of devil facial tumour disease continues despite large declines in devil density over multiple generations. Plasticity in life history traits has ameliorated the impact of devil facial tumour disease, however broad-scale trends in density show ongoing decline. In light of this, devil facial tumour disease and the impact of stochastic events on the reduced densities wrought by the disease, continue to threaten devils. In the absence of methods to manage disease in wild populations, we advocate managing the low population densities resulting from disease rather than disease per se.

Epididymal Cysts: Are They Associated With Infertility?

Scrotal sonography is commonly used for evaluation of the infertile male. While epididymal cysts are frequently observed during sonographic assessment, their presence has uncertain import. This study is a retrospective case-control sonographic and chart review comparison of infertile men and fertile volunteers to clarify the possible association of epididymal cysts and infertility. The study included 91 consecutively recruited patients from January 2012 to December 2014. The infertile group consisted patients with male factor infertility who underwent scrotal sonography ( n = 67). The fertile group consisted of men requesting vasectomy who were recruited for study involvement and consented to undergo scrotal sonography ( n = 24). The main outcome measure was infertility. The existence of epididymal cysts on scrotal sonography was the main risk factor. Predictably, the only sonographic findings associated with infertility were small testes (right: t(df = 89) = -2.52; left: t(df = 89) = -2.28, both p = .01) and the presence of a varicocele, χ2(df = 1) = 5.766 with p = .02. The infertile men were also younger and more likely to use alcohol. Of the 91 men studied, 71% demonstrated epididymal cysts (73% of infertile and 67% of fertile men). Epididymal cysts were not be associated with infertility, χ2(df = 1) = 0.362 with p = .55. This occurrence of epididymal cysts is the highest ever reported (71% of all men). While the occurrence of epididymal cysts in this cohort is unexplained, our observation that these cysts are not associated with infertility will be useful for those clinicians counseling patients observed to have these structures.