At the last count there were 1,240 known bat species around the world, 18 British species, and even nine Scottish bat species so the odds that I would get to study a wide diversity of bats during my five year PhD were high. However what I naively failed to account for was the extreme pressures that the built environment places upon wildlife.
In 2011 we spent an enjoyable summer surveying urban woodlands throughout Central Scotland in an attempt to determine how the vegetation characteristics (e.g. tree species richness), woodland size and shape, and the surrounding landscape influence the distribution of Scottish bat species. On our first night of surveying, equipped with a detailed guide outlining the key features required to distinguish between species, I nervously approached on of our mist nets bearing the distinctive outline of a bat. Extracting it from the net, the size and its small dog-like face with its flat broad head, made it easily identifiable as one of the pipistrelle species. Although a rather stark invasion of its privacy, its orange penis identified it as a male (!) and a soprano pipistrelle (Pipistrellus pygmaeus). The following nine bats that we caught that night (7 soprano pipistrelles and 2 common pipistrelles) hinted that a pattern was emerging.
It wasn’t until the end of August, after 27 long and tiring nights of surveying which included chasing after youths who had stolen our equipment, arriving at woodland only to find it had been deforested and frequent visits from the police that we finally caught a non-pipistrelle bat. Again, my identification skills weren’t required given that its ears were nearly as long as its body; it was a brown long-eared bat (Plecotus auritus). We gleefully sent photos of us holding the bat to Rebekah Mayhew, my long suffering field assistant who had been there every morning emptying the invertebrate traps, every wet afternoon identifying tree species, and every night bat surveying with the exception of this one night… By our last survey of the season in early September (fittingly having caught a further 16 bats that night – all pipistrelles), it soon became apparent that whilst we were lacking species diversity we had a really interesting large dataset which we could use to investigate the behaviour of our commonest species.
As we were trapping bats (alongside using a bat detector to record their echolocation calls) it was possible to identify the sex, age (adult or juvenile), and reproductive state of the females. This gave us the opportunity to examine how the different demographics of a population respond to urbanisation. As we inspected the data what was most striking was that we were only catching females in particular woodlands whereas males appeared to be widespread. After the normal head scratching, numerous cups of tea, and despair that is run of the mill when dealing with complex statistics we were able to confirm our suspicions. We found that females favour high quality woodland which is well connected to other woodland patches. Males, on the other hand, seem to be less particular and are just as likely to be found in poorer-quality woodland patches surrounded by built-up areas.
The findings, published in the Royal Society journal Open Science (http://rsos.royalsocietypublishing.org/content/1/3/140200) suggest that the demands of pregnancy and raising offspring are driving females to select woodlands which provide good feeding opportunities and a safe route to fly between feeding grounds and roosting sites. As breeding females are of key importance in ensuring the survival of future generations of bat populations within the city environment, it is therefore important that we manage our urban green space for their benefit. The adaptability of many bat species to urban areas is frequently assessed by recording their echolocation calls which gives you a good indication of which habitats bats are frequently using or avoiding, however it fails to provide any information on sex differences in habitat use. By using bat call data it may therefore be relatively easy to mistake species presence across the city as adaptability (and therefore assume that a species requires less conservation effort) without first considering if there are differences in where males or females are foraging.
As I near the end of my PhD, although I haven’t studied an array of species or devised any solutions to save those species which are critically endangered, by focusing on our commoner species I have gained a greater understanding of how the pressures of urban living are shaping their behaviour and distributions. Whilst pipistrelles are relatively common throughout Britain, these are the species that people will encounter whilst on bat walks or watch flying around their back gardens and therefore have a fundamental role to play in engaging the public with science and conservation. Monitoring and conserving our commonest species will therefore not only give an indication of how our rarer (and so harder to survey) species may be responding to the urban landscape but also ensure that future generations are able to appreciate the wonder of watching bats forage at dusk from their own doorstep.
My PhD fieldwork days have come to an end and on reflection I can now appreciate how much was achieved, both good and challenging, in such a short time frame. So much happens during a field season but only the successes make it into scientific literature. For me, the gritty details and mistakes that get left behind make field work experience so much more memorable and allow you to improve for the future. I often read stories of perfect, idyllic fieldwork settings and experiments, which is fantastic, but conversely I would also encourage people to share not only the reality of setting up a field experiment, but also their fieldwork ‘bloopers’. Although urban rivers may not seem exotic, I can definitely say that I never expected them to be so entertaining. These are just a few of my PhD fieldwork blips.
Big data is something we hear more and more of, and is something I think we should all be paying attention to. The recent explosion in computing power has enabled the production of more, better and higher resolution data in various fields, and it is opening up a lot of opportunities for ecologists, along with posing a whole new set of problems. But this should not mean we shy away from it, far from it – these tools could allow us to make better, more accurate and cheaper predictions across all different fields of ecology (and other fields besides).
I have recently returned from ForestSat 2014, a conference aimed at showcasing, developing and exploring the potential of remote sensing for forest ecology. It also didn’t hurt that the conference was in Riva del Garda in Italy. We all know that if there is one thing the Italians excel at it, it is food and wine. I have never had such delicious food at a conference – and incredibly tasty wine at lunch, let alone the poster sessions. It was an absolute treat. But the wine wasn’t the only reason I was there, the main reason was that remote sensing is opening up new fields for ecologists, but still seems relatively underexplored as a useful tool. While two sessions did concentrate on how remote sensing is used for biodiversity monitoring and wildlife studies, what was clear is that currently there is a gap between the level of precision and detail this is being used for in biomass estimates and structure, and how this is being applied with ecological questions. This is a great opportunity for ecologists and remote sensors alike. Costs in terms of time and money can be greatly reduced compared to a total reliance on field data, and higher precision data can be produced. But of course for this to be effective there needs to be collaboration between the remote sensing experts who understand the intricate details of processing and understanding this data, and ecologists who can use this processing power to be able to frame these questions with ecological context and relate to field results. Often this data has not been originally collected for a primarily ecological use and there are compromises which need to be made as a result.
But this is changing. Soon the launch of the GEDI satellite (a satellite where the starting remit is collecting data for biodiversity use using LIDAR) will open up a whole new and exciting range of options; along with other missions such as NISAR (a collaboration between NASA and ISOR, the Indian Space Agency). And with open data options increasingly being considered it seems there is no better time to start exploring this exciting technology.
Advances in next generation sequencing are also happening apace. Genetic studies are becoming cheaper and more accessible, while approachable protocols are being developed and shared which mean it is accessible for people less experienced with molecular techniques, rather than just a few. This generates huge amounts of potentially incredibly useful data but the skills to actually manage this data are vital. Again cross discipline cooperation will be crucial, and a change in perspective on data ownership will likely have to follow on behind.
Increasingly projects are focusing on both regional / local and global scales. One such project is the PREDICTS database, which I was lucky enough to work on in my Masters. Recent publications in high impact journals such as Proceedings of the Royal Society B and upcoming in Ecology and Evolution demonstrate the interest in and impact of these ambitious and far reaching projects, and what has been achieved is truly remarkable. But this would not be possible without a change in attitude towards data sharing, and the precise and detailed database that has been developed would not exist without researchers donating their raw data. This is an important shift in my opinion, after all should we consider that scientific data, especially that collected for biodiversity conservation and research is solely ours? Or should there be a more open commitment that once you have published off that data, it is time to open it to the wider scientific community?
The most enjoyable and impressive part of ForestSat for me was the global representation. Nearly every continent had at least one representative, and the sense of a global community was strong. It is clearly exciting times for big data. Time for us ecologists to take full advantage.
Today Matt Tinsley, myself (University of Stirling) and Helen Roy (Centre of Ecology and Hydrology) launched a survey track the spread of a sexually transmitted fungus in UK ladybirds. If you see any ladybirds, have a closer look and see if you can spot this fungus. You can find the survey here.
Laboulbeniales are a group of fungi that infect many different insect species, including ladybirds. Hesperomyces virescens is a species of Laboulbeniales that is transmitted between ladybirds during mating, although it can sometimes spread between individuals that rub against each other when they cluster together in groups during overwintering. Infections of the fungus can be seen fairly easily because it appears as yellow, finger-like projections on the surface of the ladybird. Due to the sexual spread of this fungus, it is more often found on the underside and between the legs of males, and on the top of the wing cases of females, as these are the areas that come into contact during mating. Individuals with very heavy infections can be covered with small yellow spines, and can almost resemble miniature hedgehogs!
The beginning of October sees me in my final week of my stay at Cocha Cashu biological station, in the Manu National Park in South-East Peru. The tropical paradise was opened to researchers in the 70s by John Terborgh and has seen an unimaginably high number of important ecological research and brilliant minds disseminated into the scientific world. My arrival, with collaborator Harald Beck, mammologist from Towson University, botanical assistant Adrian Torres Paucar, and a boat engine that took 3 days to splutter and grumble its way up river, was heralded with the beautiful neo-tropical scenery of the Madre de Dios river complete with macaws, skimmers, jabirus, monkeys, caimen and even a tapir! BUT being a new and enthusiastic PhD student there was no time for loitering about to admire the (excessively distracting) scenery, so day 1 saw us marching out into the field to begin stage one of operation seedlings.
My research is based around tropical plant community assembly, I am aiming to find out how trophic interactions influence the seedling community, i.e. How seedling herbivores affect the change from seedling to adult community structures, and the relative importance of different herbivores in the maintenance of biodiversity. This information will then tell us how the loss of mammals (ie from hunting) and the change in herbivore communities due to anthropogenic impacts will impact the plant community diversity, and how this will affect the future of the neo-tropics and the people that rely on this system. To do this we have put great effort into excluding semi-factorially mammal, insect and pathogenic herbivores from seedling communities, in order to monitor the changes in seedling communities.
To start with we had to locate 384 seedling plots, set up by Timothy Paine 10 years previously, and last monitored 4 years previously. The plots were marked with a small iron rebar poking out of the leaf litter and potentially some ant gnawed/lichen covered flagging, needless to say when we were presented, by Lisa Davenport, with a metal detector our lives became simultaneously easier and more entertaining. Treefalls and hungry ants couldn’t stop senior metalico (otherwise known as Adrian) from ensuring a speedy and successful stage one of operation seedlings.
Stage two of operation seedling involved tagging and measuring hundreds of seedlings, it did not take me long to learn that most seedlings are not only generically small and green, but bear small resemblance to their adult counterparts. So we may not have a name for all of them yet but we can rest assured they all have decorative orange necklaces and my full care and attention for the foreseeable future!
Meanwhile life at Cocha Cashu goes on as usual; an after work canoe in the small oxbow lake by the station, containing numerous grumbling caimen, giant otters, piranhas, a cacophony of birdlife including daily kingfishers and the beautiful agami heron, and a tranquil reminder that I am in fact in one of the most beautiful places in the world, floating on a tropical lake surrounded by sights and sounds that should never be underappreciated; A chat with a young and enthusiastic, or a not-so-young-but-still-enthusiastic scientist, ready to share their stories over dinner; A free afternoon to watch birds and monkeys on the trails, or climb Cocha Cashu’s first (and second) canopy tower (courtesy of photo journalists Christian Ziegler and Joris van Alphen) embracing a fruiting Ficus.
Excluding mammals was the most time consuming and sweat, blood and tear producing. Starting out with dragging 80 9m iron rebars from the river to the station left us all exhausted and wondering what exactly we had gotten ourselves into. Following this up with cutting them all into pieces with a hack saw confirmed our worst suspicions in this regard (that is…more sweat, blood and tears to be produced). The 64 exclosures consist of 8 iron rebars holding out wire mesh strong enough to bounce a peccary (depending on the level of enthusiasm on the peccaries part), surrounding the seedling plots. One exclosure per transect had small agouti doors cut into it, so that small mammals (agouti sized and smaller) could enter but the larger, peccary sized mammals were kept out. These exclosures simulate a hunted forest where mammals such as peccaries maybe removed, but rodents would not. Operation seedling stage 3 complete.
The fourth and final stage of operations seedling 2014 saw the emergence of goggles, rubber gloves and chemical masks, ready for the application of pesticides. Insecticide, fungicide and water applied to all treatment plots to exclude insect herbivores and fungal pathogens. Nothing feels worse than killing things in the rainforest but there has been the odd occasion where it feels a bit like revenge for wasp stings, ticks, a healthy layer of blood sucking fly bites and the odd bullet ant sting (or 3 at once for the unfortunate Harald), I hope only that science will benefit from the loss of some of our 6+ legged friends, and that some fortunate seedlings appreciate their luck! I thank Noeme and Adrian for continuing to thrash about in the field with chemical masks so that my project may continue, and hope that no more karmic retributions from bullet ants come their way!
I recently published an article in the journal Oryx, my first in a mainstream conservation journal. As pleased as I am to see the results of our team’s hard work finally published, it’s made me think about my future research aims and priorities. You can download the paper here.
Today marks five weeks for me on the Smithsonian Tropical Research Institute’s Barro Colorado Island in Panama and surveying the bird communities in the Barro Colorado Nature Monument. I am one of Daisy Dent’s PhD students and I am currently in Panama to examine how bird species and their functional composition changes in regenerating forests. Barro Colorado Island (BCI) is located in the artificial Lake Gatun in the middle of the Panama Canal.
I’m one of those lucky people that get to work overseas for fieldwork. And not just anywhere, I get to work in the Brazilian Amazon. I hope.
I say “I hope” because the long (and I mean long) process of actually being allowed to work in the Brazilian Amazon is still ongoing, and I leave in less than two months. I wanted to write this blog because behind the scenes of any field research and conservation – the “oooo I wish I was working in XYZ like you” type – there is often a bewildering maze of bureaucracy to get there. I’m going to focus on my experiences of research visas and permits for working in Brazil, but some of the general advice will be applicable no matter the fieldwork location. Read More
I am two weeks into a five-week stay at Lopé National Park, Gabon. This is the first field trip of my PhD and I am here to meet the SEGC team and observe and learn about methodology that has been used over the last 30 years to collect the tree phenology data I will be analysing over the next few months. Firstly, Lopé is beautiful. It feels like a real privilege to be here, even for just a few weeks. The study station is a 12km drive from the nearest village in the middle of a truly un-hunted patch of forest and savanna. We regularly look up from breakfast to see or hear buffalo, elephant, duiker, colobus, parrots, mandrills (the list goes on…) just going about their business in front of us.
It discusses how modern scientific papers are too formal and that we should: “… report our research more nearly as it happened; let us overcome our fear of revealing our humanity, our good luck, even our failings, and acknowledge the contributions from our intuition and imagination as well as the hard graft in the field and at the bench.” Read More