The gut microbiome plays a vital role in health and wellbeing of animals, and an increasing number of studies are investigating microbiome changes in wild and managed populations to improve conservation and welfare. The short-beaked echidna (Tachyglossus aculeatus) is an iconic Australian species, the most widespread native mammal, and commonly held in zoos. Echidnas are cryptic animals, and much is still unknown about many aspects of their biology. Furthermore, some wild echidna populations are under threat, while echidnas held in captivity can have severe gastric health problems. Here, we used citizen science and zoos to collect echidna scats from across Australia to perform the largest gut microbiome study on any native Australian animal. Using 16S rRNA gene metabarcoding of scat samples, we characterised and compared the gut microbiomes of echidnas in wild (n = 159) and managed (n = 44) populations, which were fed four different diets. Wild echidna samples were highly variable, yet commonly dominated by soil and plant-fermenting bacteria, while echidnas in captivity were dominated by gut commensals and plant-fermenting bacteria, suggesting plant matter may play a significant role in echidna diet. This work demonstrates significant differences between zoo held and wild echidnas, as well as managed animals on different diets, revealing that diet is important in shaping the gut microbiomes in echidnas. This first analysis of echidna gut microbiome highlights extensive microbial diversity in wild echidnas and changes in microbiome composition in managed populations. This is a first step towards using microbiome analysis to better understand diet, gastrointestinal biology, and improve management in these iconic animals.

Despite being the fourth largest criminal market in the world, no forensic tools have been sufficiently developed to accurately determine the legal status of seized animals and their parts. Although legal trading is permissible for farmed or captive-bred animals, many animals are illegally removed from the wild and laundered by masquerading them as captive bred. Here we present high-resolution x-ray fluorescence (XRF) as a non-invasive and cost-effective tool for forensic classification. We tested the efficacy of this technique by using machine learning on a training set of zoo specimens and wild-caught individuals of short-beaked echidnas (Tachyglossus aculeatus), a small insectivorous monotreme in Australia. XRF outperformed stable isotope analysis (δ13C, δ15N), reducing overall classification error below 4%. XRF has the added advantage of providing samples every 200 μm on a single quill, enabling 100% classification accuracy by taking the consensus of votes per quill. This accurate and cost-effective forensic technique could provide a much needed in situ solution for combating the illegal laundering of wildlife, and conversely, assist with certification of legally bred animals.

Short-beaked echidnas (Tachyglossus aculeatus) are myrmecophages, or ant and termite insectivore specialists, and replicating their exact diet in captivity is problematic. Diets for captive animals often incorporate raw meat, eggs and cat food mixed together with water, and vitamin and mineral supplements. These diets have promoted a number of health problems in captive echidnas, such as gastritis, cystitis, gut impaction, obesity, and diarrhea. A manufactured diet was designed and three echidnas from two zoos were transitioned onto this diet to assess the acceptability and digestibility of this diet for echidnas. The new "test" diet was readily accepted by the echidnas with a 1 week transition period. Daily digestible energy intake was 280 kJ kg d , similar to another myrmecophagous species. Digestibility values were above 74% for all macronutrients. It was determined that this diet was an acceptable replacement for the previous diets and it was decided that the remaining echidnas at both institutions would be transitioned to the new diet. The diet will also be used for wild echidnas being rehabilitated in the zoo hospitals prior to release and commercially available within Australia. Further data are being collected to assess the use of this diet for seasonal weight management, transitioning hand-reared puggles and effects on gastrointestinal tract health. Zoo Biol. 36:56-61, 2017. © 2017 Wiley Periodicals, Inc.

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