Dr Natalie Schmitt, front right, on an Australian Antarctic Division research expedition, using genetic sampling on the humpback whale. (Photo David Donnelly.)
Guest blogger, Dr Natalie Schmitt, a biologist researching the humpback whale turns her focus and skills to snow leopards. She shares her journey with us here.
“In biological terms, a “rare” animal is one that is in low abundance or restricted geographical distribution or both, whereas an “elusive” animal refers to one that has a low probability of detection. As a conservation geneticist, documentary film maker and presenter I’ve always had a deep fascination with these mysterious and intriguing animals, particularly apex predators, as they offer insight into the health and wellbeing of our planet’s ecosystems. These ‘keystone species’ play a critical role in maintaining the structure of an ecological community, affecting many other organisms and helping to determine the types and numbers of various other species within the community. Without them, an ecosystem can collapse. These species however, prove tremendously challenging to study and it has taken science many years of visionary development to enable us to begin to understand and monitor these important animals.
From whales to Tasmanian devils to snow leopards
Whilst filming a documentary on the Tasmanian Devil in 2004 and 2005, I discovered the usefulness of video camera traps in understanding the behavioural parameters of individuals and populations in cryptic species.
A snow leopard often leaves hair on rocks when it rubs itslef to leave messages for other cats sharing its home range. Jigmet Dadul of the SLC IT points out hair stuck to a rock outcrop in Hemis National Park, India. This hair can be used in genetic sampling to provide data on each animal. (Photo Sibylle Noras).
However, I really wanted to find a method or a tool that could permit us to study many more aspects of these animals that are key to their conservation; methods and tools that can continually evolve to unlock more of the mysteries that enshroud them. Welcome to the amazing, ever-evolving and useful world of noninvasive genetic sampling!
Why do wildlife biologists need this technique?
This type of sampling has become particularly appealing to wildlife biologists studying rare and elusive species, as they are able to obtain critical data without capturing, handling or even observing an animal. Using hair, faeces or skin samples and the DNA that can easily be extracted from them, this method has the power to assess genetic diversity, population structure and social structure, estimate abundance, track an animal’s movement, identify where populations are mixing, determine sex and today we are very close to being able to estimate age. And these are not the limit of the applications! Given the endless utility of noninvasive genetic sampling, I jumped at the opportunity to study these methods through a PhD with the Australian Antarctic Division, using the humpback whale as my model species; a highly mobile, migratory animal that is largely inaccessible, is wide-ranging and their populations are not easily distinguishable.
With the development of new molecular techniques such as the polymerase chain reaction, we are now able to look at variations in DNA sequences and use those variations to identify species, populations, individuals, sex and now reconstruct age; these are what we call molecular markers. Which marker we use depends on how distinguishable the entities are that we are studying. For example, using maternally inherited mtDNA, I was able to look at broad genetic differences between humpback whales that breed around Australia and the South Pacific, as this marker is highly variable among whale populations as well as species.
A snow leopard marks its territory and leaves hair and whiskers behind. (Photo SLC).
To detect fine-scale structure however, when you’re trying to distinguish between or track individuals or genetically similar populations, biparental nuclear markers such as microsatellites are used, as sequence fragment lengths vary considerably. Through the combination of both these powerful markers I discovered that humpback whales breeding along eastern Australia mix with a genetically similar endangered South Pacific population on their Southern Ocean feeding grounds. This discovery will help us determine the true impact of whaling on breeding populations as well as how we should manage these populations in the future.
From whales to snow leopards……
Snow leopards are also highly mobile, rare and elusive creatures that are extremely difficult to study simply because they are so rarely seen….and they happen to be one of my favourite animals! However, the same genetic markers that helped me understand humpback whales can also help fill in the knowledge gaps for snow leopards. Using hair follicle and scat samples combined with genetic markers, we can now start to understand their migration and dispersal routes, their social and population structure, population size and food habits, age structure and even track snow leopards in the illegal trade in wildlife parts, at a relatively low cost. My hope is to work with members and researchers of the Snow Leopard Network to help turn this dream into a reality!”
Thank you Natalie and good luck with in using this research technique to assist snow leopard research and conservation.