Short beaked echidnas are one of Australia’s most iconic animals, and being one of the few species of mammals that lay eggs, also known as a monotreme, are desirable as zoo animals around the world. Unfortunately, due to the very large numbers of animals available ‘for sale’ in South East Asia, it appears a black market for echidnas may have developed (and has been communicated to us through the non-government organisation TRAFFIC (Beastall and Shepherd 2013). My PhD research is on developing a wildlife forensic toolbox to help combat this trade.
Echidnas are found in every state and territory in Australia, and there is also a subspecies that lives in New Guinea. The reproductive process of echidnas is very interesting and complicated (at least to us humans!). It is also notoriously difficult to replicate within captivity resulting in very few animals being born this way. Only four Australian zoos have successfully bred echidnas, with most of the success being in the past 10 years after thorough and intensive investigation on how animals might reproduce in captivity. To further demonstrate how rare this is, among all Australian zoos, there have been fewer than 30 puggles (baby echidnas), within the last ten years. Each echidna only lays one egg per breeding season, and in some cases the puggles don’t survive past one year.
It is this very low captive breeding success rate at highly reputable Australian zoos and wildlife parks, that suggests that the number of animals “captive bred animals for sale”, which has been as high as 70 animals per year, should be closely scrutinised. The alternative explanation for these animals for sale is that they have been illegally taken from the wild and are being falsely claimed as ‘captive bred’.
To help determine exactly where are these animals coming from (e.g. Australia or New Guinea), one aspect of my PhD is to investigate whether we can distinguish between echidnas collected in Australia and those collected in New Guinea, using wildlife forensic genetic techniques. To do this, I sourced samples from a number of Australian zoos and museums, as well as utilising samples previously collected by Australian Museum staff in the field in New Guinea.
Firstly, I looked at whether I could get DNA out of quills of echidnas, as they can be plucked or are easily shed, like human hair making this a non-invasive method of collecting samples. This was successful and one of the positive outcomes from this work is that DNA can be retrieved without having to put an echidna under anaesthetic to take a blood sample. I then developed echidna specific DNA sequences (or primers) that would target a specific region of mitochondrial DNA which is known to be good for differentiating between populations in other species with similarly broad geographic distributions. When analysing DNA sequences from all samples collected in this study, it became clear that all the New Guinea samples were indeed clustering together and could be statistically separated from the DNA sequences of the Australian samples. The outcome is that DNA sequences from these echidna-specific primers allowed us to easily distinguish which country a particular sample has come from (thereby allowing us to determine if an individual is from Australia or New Guinea). Importantly, this test was then ‘validated’ which is a forensic term to demonstrate this test is robust, species specific, and we understand the limits of the test. Validation is an essential part of our work in the forensic sciences, even when we are dealing with wildlife.
This test is part of a toolbox of tests that I have developed for echidna as part of my PhD. In the event an echidna is traded, this test can be implemented to first determine the source country of the animal. Following that, I am developing further markers that can be analysed to determine if the animal is captive bred or taken illegally from the wild. These tests have the potential to provide useful intelligence to law enforcement and be a routine test put in place to ensure legitimate breeding. Ideally this will help reduce or stop any illegal trade in echidnas, while also providing a wildlife forensic model that can be extrapolated to other species targeted in the illegal wildlife trade.
Alexandra Summerell, PhD Candidate at Australian Centre for Wildlife Genomics and the University of Technology Sydney. Supervised by Dr Rebecca Johnson, Dr Greta Frankham, and Dr Peter Gunn.
- Summerell, A. E., Frankham, G. J., Gunn, P., & Johnson, R. N. (2018). DNA based method for determining source country of the short beaked echidna (Tachyglossus aculeatus) in the illegal wildlife trade. Forensic Science International. 295. Pp 46-53