Bat eDNA. What is it? How does it work? And How is it allowing us to be at the forefront of ecology?
Although Environmental DNA has revolutionised the way we use forensic science within ecology within in water for a few years now, the advances in bat eDNA extraction made by our partner SureScreen, means we are now able to easily identify bat species via a simple bat eDNA process.
But what is Bat eDNA and how is it helping us to stay at the forefront of ecological consultancy?
Some bat species can be difficult to differentiate from droppings alone. Naturally, this can represent an enormous source of frustration for ecologists and scientists wanting to research the species or determine the impact of any development projects on bats as a species and local biodiversity. Some planning developments can affect our biodiversity greatly, thus, it is extremely important to carry out extensive surveys, a priori, to prevent damage and disturbance to the environment.
Among the most desired outcomes of any protected species survey is to find effective ways to protect and increase our biodiversity and wildlife populations.
As one of the UK’s leading ecological consultancies, We’re always investing in research and technology to ensure we can supply a fast and effective service to our clients, which is not only cost-effective to developments but also ensure the least disturbance to any bat species.
With 17 bat species known to be breeding in the UK, and much less difference in bat guano looks.
Let’s take, for example, we find a cluster of myotis droppings within a kitchen cupboard as we did during Bat surveys in Aylesbury throughout 2019 and 2020. With 6 Myotis species breeding in the UK and another which overwinters on our shores, differentiating between the species on dropping visuals alone is virtually impossible. Myotis is are also very difficult to correctly identify from echolocation recordings too, as they are very similar, and analysing several hundred bats calls is a cost and time-consuming exercise for our clients.
By using bat eDNA as a valuable tool, we were able to determine the species quickly and much more cost-effectively.
In turn that allowed us to plan very early any mitigation strategy for the species to ensure we are preserving the species further.
Bat eDNA works via the use of Metagenomics within the bat guano.
Metagenomics is a branch of bioinformatics that deals with the study of metagenomes, a genetic sample obtained directly from the environment. It is a field of forensic science that has become extremely popular in the last few years. It provides access to the functional composition of genes of microbial communities and gives us genetic information about microbial diversity and the ecological makeup of a specific environment.
All important factors when the requirement to mitigate bat species from a building development may present itself.
In short, thanks to this new bat eDNA science, we’re helping to save the species and make fast and cost-effective decisions for our client.
But, how does bat eDNA differ from traditional sampling methods?
Traditional sampling methods for bat species identification
Before bat eDNA, the most common ways to detect and identify bat activity included complex and time-consuming bat surveys that were more often than not extremely expensive.
Ok, so we still have to undertake activity bat surveys, during a mitigation process but three visits are normally sufficient, instead of several site visits to try and determine the exact species, along with having to record calls, analyse hundreds, if not, thousands of bat echolocation data files.
Other methods such as; static acoustic bat detectors, infrared imaging, thermal imaging, fixed ground radars, and visual identification, mist nets, and harp traps, involve some kind of limitation and unique challenges, such as time to set up the examination zone and needed equipment, utilising extensive training to avoid human error and common biasses, and of course, the time it takes in acquiring special permits for bat trapping.
There is an equipment limitation like range limitation of bat detectors and the power of an IR floodlight or special environmental aspects an observer has to consider, for instance, light, night vision, and overall surroundings. Moreover, some surveys, like bat trapping, are causing stress to captured bats and harshly invade their habitats.
And even when these methods are undertaken, it can be very difficult to still tell the difference between certain bat species which are 99.9% genetically matched, such as Whiskered & Brandt’s Myotis.
Bat eDNA is allowing us to be much more efficient within our process. By taking a sample of the bat droppings from a site we can receive accurate results in days instead of weeks or even months. Bat eDNA delivers an unobtrusive and bat-friendly method for detecting whether a certain ecosystem is occupied by these incredible creatures.
What is bat eDNA and bat speciation?
Bat eDNA is DNA extracted from the traces inadvertently left in the environment bats interact most with. Examples include, although not limited to, feaces, shed skin cells, mucus, saliva, and hair sampling. As bats have been receiving a lot of attention since the start of the pandemic, ecologists are worried people will forget that bats represent an important part of the healthy ecosystem.
Bat eDNA helps to detect them in the natural habitat or close to man-made structures, without threatening or endangering the species. Capturing or seeing any bat species is no longer a requirement to determine a species – we can identify them only by sampling from their environment.
Despite being protected as an endangered species, the population of bats in the UK is in a significant decline. Now more than ever unharmful methods, such as bat eDNA, should be used whenever the bat’s existence has to be confirmed. DNA analysis of bat droppings can pinpoint not only their presence but also the morphology of any of the 18 bat species in the UK or from around the world.
By determining the species we can then create the correct methodology to ensure the habitat of any roost can be saved or recreated correctly during a mitigation strategy.
What is DNA and how is it extracted from bat guano?
As with all living mammals, bats organisms are made up of cells whose nuclei contain all the information necessary for their life.
This information is written in DNA molecules.
DNA molecules carry information about the development of any living beings, that is information about how proteins are built. Information about protein synthesis is found in the parts of the DNA molecule that we commonly call genes.
DNA is a long molecule made up of two strands connected by hydrogen bonds in a helix. Each strand consists of a large number of linked nucleotides made up of sugars, phosphates, and nitrogenous bases. Sugars and phosphates form the backbone, and bases are located at the centre of the molecule. There are four types of bases: adenine (A), guanine (G), cytosine (C), and thymine (T) which pair in a specific way (A merges with T and C merges with G).
The choice of the extraction method is very important. A non-efficient method would pile up unnecessary costs, and would most probably end up with unreliable results. Bat eDNA extracted from bat guano provides insightful information about diet, diseases, and animals that produce faecal pellets or bat droppings.
DNA extraction removes DNA from within the cell in a series of steps that ensure the maximum amount of clean DNA has been extracted from single droppings. By using the process called polymerase chain reaction (PRC), bat DNA is separated from other DNA sources like those of bacteria or viruses living within the bat.
Through heating and cooling cycles, primers multiply only the target DNA, resulting in millions of pure bat DNA strands. This pure bat DNA is amplified and sequenced and then compared with the sequences of the known bat species.
How Bat eDNA is helping ecologists to save protected bat species?
Using the bat eDNA approach, ecologists are choosing the least harmful method for determining which bat species are present in the specific environment.
Having endangered species on their hands, they are minimising the contact between humans and bats while successfully identifying bat species outdoors. These approaches not only limit the interaction with animals but also avoid any activities that can endanger them physically or emotionally.
Having a 100% reliable identification of a species means we can develop a plan for either the correct mitigation methodology for removing them from certain man-made structures or protecting their habitat from devastation.
Because it is the only 100% reliable method to identify between certain species, bat eDNA is becoming more of a monitoring tool for conserving protected bat species, understanding bat ecology, and observing their behavior.