In this blog post, Taylor Craft discusses the use of GPS tracking and satellite imagery to uncover the lives of Black-tailed Godwits in the Senegal Delta. You can read their latest study, published alongside co-authors, here.
A pressing challenge
The landscapes of the endangered continental Black-tailed Godwit face increasing pressures at nearly every key site along their migratory route. With poor recruitment limiting population growth, protecting the long-lived adult birds is essential to maintain this trans-continental migrant’s dwindling population.
Post-breeding GPS tracks and location densities of Dutch and German-breeding godwits in 2022, depicting main breeding sites (A), stopover sites (B), and wintering sites (B and C)
The secret lives of Godwits
Until recently, the lives of godwits outside of Europe were largely a mystery. Ring recoveries and sporadic re-sightings provided limited insight into their non-breeding habits or responses to environmental changes in West Africa. Enter satellite telemetry: a rapidly advancing tool allowing for real-time monitoring of individual animals anywhere in the world.
Equipped with GPS tracking devices during the spring 2022 breeding season, 22 godwits from Dutch and German breeding populations migrated south to the Senegal Delta, a vital non-breeding habitat.
Combining satellite imagery with field expeditions, we created a detailed land cover map of the Senegal Delta with key habitats such as floodplain wetlands and rice fields, as well as large areas dominated by invasive plants. Tracks from our GPS-tagged birds showed that during the early stages of the non-breeding (wet) season, godwits used both floodplain wetlands and rice fields, while later in the year (dry season), they abandoned rice fields and concentrated in floodplain wetlands within Protected Areas.
Land cover map of the Senegal Delta overlaid with core areas of 22 godwits throughout the wet and dry seasons of the 2022-2023 nonbreeding period. Protected Areas, outlined in black, include: 1.) Chat Tboul lagoon, 2.) Diawling National Park, 3.) Djoudj National Bird Sanctuary, and 4.) Ndiael Reserve
Management recommendations
Based on our analysis, two key management recommendations emerge:
Enhancing Rice Fields for Wader Habitat: Rice fields serve as vital alternative habitats for godwits and other waders during the wet growing season from July to November. To optimize their value for godwits, phased cultivation – staggering rice planting at different times – can create a mosaic of habitats that remain suitable throughout the season. As early-planted fields become densely vegetated and less accessible for foraging, godwits can shift to later-planted fields with sparser vegetation, ensuring continuous access to feeding grounds. Additionally, preserving lower-lying drainage areas by limiting the use of diversion pumps can further enhance habitat quality. Limiting the use of agrochemicals is also crucial, as the runoff often seeps into neighboring protected areas and affects the invertebrates that godwits feed on.
Eradicate Invasive Plants in Protected Areas: Protected areas are critical godwit habitats throughout the wintering season, particularly during the drier months at the end of their wintering period. However, large swaths of protected areas are currently dominated by cattail vegetation, which limits their suitability for godwits. Prioritizing the removal of invasive cattail will expand available habitat, especially during the dry season, when wetland habitats become scarce.
As part of Journal of Applied Ecology’s efforts to discuss how real-world impact can be achieved following research, we’re talking to authors about their studies. In this post, Edward Straw discusses his first experience with sharing research via social media.
I think it’s fair to say that my experience publishing my first paper was atypical. Not many papers, let alone first papers, end up glued to the front door of a pesticide company by protestors. So, I wanted to take a moment, to reflect on science communication and present you with some of the behind-the-scenes numbers on what a widespread science communication campaign actually looks like.
For a little context, my first paper was a fairly simple experiment where we sprayed herbicides on bees and recorded which bees died. We found that some types of herbicides killed the bees, which we didn’t expect because herbicides should be non-lethal to bees.
The numbers
After the paper came out, I figured it’d be a good idea to write a Twitter (now known as X) thread about it. So, one morning early in lockdown I sat down for about an hour and typed one out. That Twitter thread ended up being seen by a colossal 623,000 people. Vastly more than I’d anticipated.
I was tracking engagement using Altmetric and could see that the thread went far and wide, reaching every corner of the planet. There were Tweets in a dozen languages about it, and it spread onto Facebook, news sites, Wikipedia and Reddit (reaching its front page via R/Science). On Twitter, my thread got 38,461 engagements (likes, re-tweets or replies).
Reading other people’s comments about my research was rather depressing. Specifically, the number of comments (from both a pro and anti-pesticide perspective) that clearly showed the commenter hadn’t even read the paper’s abstract before posting about it. To put numbers to this, over half a million people read the thread on Twitter, 38,461 interacted with it, while just a poultry 1,875 people clicked on the link to the paper through Twitter. That’s 0.3% of viewers, and 5% of ‘interactors’ actually clicking through to the paper. More people will offer their opinion on an article than will actually read the article itself. This statistic can help us understand the quality of online discussions about science.
Using conflict
Had I known I’d be reaching probably my largest ever audience, I’d have spent more than an hour writing the thread and been a touch more delicate in how it was written. One of the reasons I’d have spent longer is that I work on bees (which everyone loves) and pesticides (which a lot of people dislike), which makes it an evocative topic.
So, in publishing a paper finding a pesticide could (under certain conditions) kill bees, a lot of environmentalists rallied around the flag and said pesticides were the worst thing in the world. Conversely, a lot of farmers got their backs up and called the research terrible, called me an ‘idiot’ in Swedish and described me as someone who ‘doesn’t understand farming’.
I will add that a few months later I published a paper finding the worlds most used herbicide, glyphosate, doesn’t kill bees. And once that one came out, the teams swapped around and the farmers liked me, while some environmentalists called me a ‘propagandist for Monsanto’. The mob is fickle, take little heed of them!
The conflict my thread generated is, in my mind, why the article was so widely shared. An unfortunate feature of social media, whereby conflict generates engagement that triggers the algorithm to promote the post. But what it did teach me is that you can harness conflict to promote science. If done deliberately, and ethically, it can be a powerful tool for driving engagement.
An example of when I consciously employed this was an article I wrote for the Irish Farmers Journal where I advocated for banning pesticides for use in gardens. A totally honest title to the article would have been ‘Let’s ban garden pesticides’, and there’s nothing wrong with that title, but it is boring. Farmers aren’t going to click on that article because it’s not relevant to them. But I wanted farmers to click on the article, because I wanted to try and influence this stakeholder group to get them behind the idea.
So, to really get the clicks, I went with the slightly provocative title: ‘Let’s ban pesticides – just not the ones you’re thinking about’. A combination of conflict and clickbait. Conflict because most farmers don’t like the idea of banning pesticides. And clickbait because the title obviously doesn’t tell the whole story. To me, this was an ethical application of these principles because the article delivered on the promise of the title. Here, I used conflict to get a group of people with a particular viewpoint (don’t ban pesticides) to interact with a set of policy ideas they may well agree with but wouldn’t normally engage with.
Sometimes, we as scientists forget that our science communication content is competing for attention with everything else in a newspaper, magazine or social media feed, all of which is optimised for views. And not just low-brow content either, increasingly reputable publications are competing for views using more internet savvy methods. So, for scientists to gain attention they need to stand out. Leaning into conflict, in a conscious manner, can help drive engagement.
Confirmation bias
As part of the dissemination strategy for the bee-herbicide paper, an American biodiversity charity reached out to me to write a press release for the American market. They wanted to use the research to promote better pesticide regulation. Over a few drafts we wrote up a press release calling for better pesticide testing. All was going well until they inserted a paragraph at the end talking about how glyphosate (the main ingredient in the herbicides we tested) was harmful to wildlife, and calling for it to be banned.
This was an odd addition, as the research explicitly found that glyphosate wasn’t causing any toxicity in this set-up. A direct quote from the abstract: “…demonstrating that the active ingredient, glyphosate, is not the cause of the mortality.”. I pointed this out and asked for that paragraph to be removed. They refused, so I politely declined to work with them further. They published the press release about the paper without reference to me and with the paragraph criticising glyphosate.
What this highlighted for me, was that people will read whatever they want into science and will use it to further their agenda however they want. Saying “you are mis-interpreting my research” isn’t enough to get some people to change their behaviour. The actual science can become irrelevant if it isn’t furthering an agenda.
Theory in practice: Glue
The paper I’m framing this blog around really was glued to the front door of a pesticide company by protestors. While this isn’t really central to the content of the blog, it is kind of exciting. By introducing this conflict right at the top of the article, it encourages a reader to read on.
The story behind this is that in 2022 German Extinction Rebellion protesters targeted Bayer’s central offices. They glued themselves to the ground and glued a bunch of ‘anti’-pesticide papers to the doors of the building. Whether these protesters really understood what the paper was about I’ll never really know. Similarly, I’ll never know whether the pesticide company employees read the paper that’d been glued to their front door. But, if real life is anything like social media, there’s just a 5% chance that someone who’s interacted with the paper has actually read it.
In late 2015 I was asked to be involved in a study to identify the ‘risks and benefits of continued livestock grazing in conservation reserves’ by the government agency I worked for in New South Wales, Australia. The project arose because former forests, which had current livestock grazing leases, were to be incorporated into the national park estate. But grazing was inconsistent with conservation in national parks, so this posed a major dilemma for the government.
Rather than just cancel a handful of leases, the government at the time decided that a study was needed to see if there were potential benefits of livestock grazing. These benefits, it was claimed, could include weed removal and a reduction in fire hazard. Along with this study came millions of dollars in cash, and in-kind contributions, but a great opportunity for cash-strapped scientists to do some applied science.
Australia: a short evolutionary history of livestock grazing
Yet, any ecologists working in Australia will tell you that livestock grazing is unlikely to have conservation benefits in Australia simply because Australia has had a very short evolutionary history of grazing by European livestock (about 250 years). Our plants, animals and soils have just not had enough time to adapt to livestock grazing. Nevertheless, despite the folly, and in my view wasteful expenditure of scarce research money, this was a great opportunity to ask some great questions about grazing, to have fun, and to do science that was clearly linked to government policy, something that government scientists love to do.
Not surprisingly, after three years of research, we found that livestock grazing had negative effects on native plants, soil function, soil health, reptiles, and birds, and there were even major impacts on microbes. Some of these results were published in our favourite scientific journal (Journal of Applied Ecology, Eldridge et al. (2016), Eldridge et al. (2018), Val et al. (2018) and Val et al. (2019)).
After five years we had published about 25 papers, produced videos, given tens of presentations, hit the media hard, and had a lot of fun along the way. The message was clear: grazing and conservation are incompatible, at least in our environment in eastern Australia across more than 0.4 million km2.
Plan, plan, plan and collaborate
The success of a study of this kind (multi-site, multi-community, multi-dimensional, multi-species, multi-season) requires a dedicated team of professionals with the same vision, passion, level of energy, and respect for one another, who all work well together, and enjoy each other’s company. I was extremely fortunate to be working with a team that shared all of these important attributes.
However, this needs to be matched with support from upper-level managers, and support of different government agencies that don’t often collaborate. We were fortunate to have great managers at all levels from the Science Director right down to our immediate line manager. We could never have produced the type of science we did without the support and encouragement of all of these people.
Planning was critical, right down to the way we coded each of our 451 sites. Establishing databases, checking plant names, the list goes on and on and on. And then there were the endless meetings and discussions needed so that we could agree on an appropriate research approach, not to mention field methodologies, statistical approaches and the need for pilot trials. All of this seemed very unnecessary and tedious to me. I’m a little bit overactive, and all I wanted to do was to get out in the field and start collecting data and do the analyses. But fortunately for me, this planning was unavoidable, and I soon learnt that planning meetings (at least it was pre-Covid, so there were no dreaded Teams/Zoom meetings) were critical and fundamental to a successful outcome.
The result of all this planning and contingency assessment was more rigorous science, and a client (the New South Wales Government) that not only felt ownership of the study, but was entirely confident in the rigour of the work. This science rigour also helped to show other parts (non-science) of the agency that science is an integral component of environmental management, and was needed to deliver rigorous and defensible outcomes.
One drawback of our study was that despite the unequivocal evidence that there were no conservation benefits of continued livestock grazing in the conservation reserves, the government decided not to revoke the grazing leases, but to let them run their course and then not review them. We all learned a great lesson; politics sometimes trumps good science. The cynic in me might say that it always trumps good science, but that’s a discussion for another day.
I found it extremely exhilarating to work with such a great bunch of dedicated scientists for three years on a specific project that was not only lots of fun, but answered some really important questions about how grazing affects semiarid ecosystems.
And it’s not over yet; data from the project still keep giving. The data are still being used and reused in various studies worldwide. Our study has even been termed ‘data piñata’ by our Spanish colleagues (‘all we have to do is hit you and out comes these beautiful data’).
So, what did we learn from all this? Preparation is key. If you iron out the bugs at the beginning, then things will go more smoothly. Try to work with people that you like; it’s not always possible, but it certainly makes work more enjoyable and rewarding. And finally, don’t expect that your science is going to change the world. We might have failed to change policy in relation to grazing, but we managed to generate some fantastic science that led to other great opportunities and future collaborations.
In this blog post, Emily Hague and team discuss their latest research into the importance of careful consideration of collision-mapping approach and data selection when it comes to predicting high-risk vessel collision areas for whales.
For conservationists and those that care about nature and our planet, the news can feel incredibly bleak, with daily (deservedly) scary stories of extreme climate change related temperatures, species fighting extinction, and nature suffering at the hands of humans.
But, whales must now coexist with a number of modern day threats – pollution, fishing gear, and ships, to name a few. Whilst impressive efforts are being made globally to help reduce such threats to our recovering whales, sadly, fatalities are still happening, and for some populations these occur at an alarming rate. Fatalities from entanglement in fishing gear and vessel strikes may be the ‘new’ modern day whaling for the North Atlantic right whale (I hugely recommend Michael Moore’s ‘We are all Whalers’ for a both enlightening and uncomfortable read on this topic).
The good news is, unlike the days of whaling, the vast majority of the globe no longer wants to harm whales. As such, there is a real drive to reduce our human footprint on whale recovery, including reducing and mitigating the impacts of maritime traffic.
Reducing vessel-whale impacts
In some areas, vessel operators are already taking action to reduce their impacts on whales – from slowing down to altering their course when whales are known to be in the area. But there are many areas where we are still learning where whales and vessels overlap, and where the risk might be. In these cases, academics and managers rely on risk prediction tools to help them understand where to focus their efforts. A number of approaches have been developed to predict the risk of collision between whales and vessels, but so far, they haven’t been compared to figure out whether they can be used and interpreted interchangeably.
To dive into this further, we used a dataset collected on a fascinating whale species unique to Arctic waters – the bowhead whale. Historically, they might not have encountered many vessels, given a large portion of their habitat remains ice covered for much of the year, limiting vessel traffic. However, climate change means the Arctic ice-free season is extending, allowing more traffic to transit these waters year on year. Given this, we thought bowhead whales in the Davis-Baffin Arctic marine area would make the perfect case study for comparing vessel-risk prediction models, as despite having low historic exposure levels, we know bowheads are vulnerable to vessel collisions.
Our study
We used the same dataset of predicted bowhead whale distribution, and vessel data (as Automatic Identification System (AIS) data – which gives information on vessel identity, size, location and speed). We applied these datasets to eight different pre-published methodologies, that have previously been used to evaluate and forecast the likelihood of ships striking whales.
An explainer video of the study
Our results
Interestingly, we found some significant inconsistencies in the total area each approach predicted as high risk, and in the actual geographical area identified as high risk.
Our study dives into the reasons for the inconsistencies, and highlights the importance of careful consideration when deciding upon which data to use, and which approaches are most appropriate for a given risk mapping circumstance. The choices of data and approach have real implications on the areas identified, which means they have subsequent implications for management or policy decisions that are made based on the results.
We hope this work can improve the transparency when it comes to risk mapping, and that it sparks a healthy discussion in terms of the limitations and strengths of each approach, and the data we need collect to inform and improve these models going forward.
Take home message
We now have a second chance with these animals, after commercial hunting pushed many species to the brink of extinction. Fortunately, there are many species now showing signs of recovery, but our maritime sector has largely evolved without the presence of large whales in any great numbers. We know that for some populations of whales, vessel strikes are now one of the primary threats to their recovery, so we need to be proactive and take the steps needed to protect them.
Through informed risk mapping and modelling, accompanied by positive collaborations with ship operators and other maritime sectors, and adaptive management able to evolve to mitigate new or changing impacts, we can help support these fantastic ocean giants continue to recover and thrive.
Leon Green-Tkacenko and co-authors share insight into their recent study that explores how existing vulnerability indices for seabirds can be applied to migrating songbirds, and potentially other migrating birds, in evaluating vulnerability to offshore wind turbine morality.
What is the problem?
Climate change is the most pressing threat to biodiversity in the 21st century and addressing this threat will require substantial changes to how we generate electricity. Currently, in the United States around 60% of electricity is generated by fossil fuels. Globally, as we transition away from fossil fuels, we must increase renewable sources of electricity production, but these renewable sources are not entirely without ecological impacts.
Offshore wind energy is one of the most promising forms of renewable energy currently under development in North America, with over 9,000 sq km of offshore wind farm areas planned. Offshore wind has proven to be an effective and green means of energy production in Europe, where its ecological impacts have been relatively well studied. One potential effect of offshore wind turbines is their potential to act as a barrier for some species (above or below water) in an area that, for all of history, has been free of such obstacles.
Despite extensive research for some groups like cetaceans and seabirds, one group of species for which little research has been completed are the migratory songbirds of eastern North America. Some of these species migrate at night over the open ocean during their fall migration, potentially putting them at risk of collision with offshore wind facilities.
What did we do?
My co-authors and I had originally hoped to model the risks facing migratory songbirds from offshore wind facilities, but we quickly realized that so little information is available for these species offshore that we could not make much headway. The lack of basic information on songbird migration over open ocean is due, in part, to the substantial difficulty in conducting research offshore on small flying animals, which largely migrate at night.
Instead, we looked to the early research on the impacts of offshore wind facilities on European seabirds as a potential model. We found that European researchers began by documenting different factors about each species’ biology and behavior to help them gauge the relative risk that each species might face from the siting and operation of offshore wind facilities. We sought to do the same for the migratory songbirds in eastern North America.
We created an ecological vulnerability index for 101 species of migratory songbirds that could reasonably be expected to traverse the open ocean in their autumn migration across the northwest Atlantic ocean. An ecological vulnerability index is a method of estimating relative risk in a transparent and repeatable way. We combined six different factors that could influence in-flight collision risk from offshore wind facilities.
Two of the factors represented how ‘sensitive’ a species is to offshore wind; that is, what is their relative ability to avoid collision with them. Two factors represented relative ‘exposure’ to offshore wind; in other words, to what extent are they physically present in the area where offshore wind is planned and when during the day are they there. Finally, we looked at two factors that impact how resilient a species might be to additional mortality, their population status and trend.
What did we find?
We found that many migratory song birds in the Northwest Atlantic are not particularly vulnerable to offshore wind facilities, but that several species appear to be at potentially outsized risk. In particular, we found that Blackpoll Warbler, Common Yellowthroat, and Bicknell’s Thrush topped our list of most exposed species. Blackpoll Warbler was the most vulnerable species identified in our study. This makes sense as the entire global population of Blackpoll Warbler is thought to migrate over the Northwest Atlantic every fall.
We also explored how conservation efforts on land might impact how vulnerable a migratory songbird species may be to offshore wind facility collisions. We found that, for many species, moving their population trend in a more positive direction via land based conservation efforts has the potential to dramatically reduce their overall vulnerability to additional mortality from offshore wind.
We hope that our research can serve as a jumping off point for future research towards ensuring an environmentally responsible green energy transition. Researching migrating songbirds offshore is difficult. Using ecological vulnerability indices to identify the species that migrate over open ocean in the Northwest Atlantic that are most at risk of mortality from offshore wind is a first step. Field biologists and regulators can then take this information and focus their efforts on species most in need to ensure that any substantial risks are reduced, if not eliminated, via mitigation actions.
Author Valerio Sbragaglia and his colleagues guide us through a recent study which advances the understanding of spearfisher-fish behavioural interaction by integrating ecological indicators (i.e., flight and post flight behaviour of fish) with spearfishers’ likelihood to catch a fish. Through modelling and simulating scenarios, their study sheds light on management implications in exploited fish populations.
Exploring spearfishing and fish behaviour
If you ask spearfishers, they will likely tell you that they already know about what we show in our paper. Spearfishers (and fishers in general) always observe and interpret fish behaviour because behaviour is intimately linked to catchability and, consequently, to fishing success. We are passionate about spearfishing ourselves and we did what any other spearfisher would have done – but, instead, we used an explicitly scientific approach.
By looking at the accumulating scientific evidence on fish behavioural reactions to underwater human presence we realized that the elements researchers were using to represent spearfisher-fish behavioural interactions omitted essential parts of the interaction, and this over-simplification may result in incorrect conclusions drawn from the research. Moreover, we changed our point of view by looking at spearfisher-fish behavioural interactions not only from the fish perspective, but also from the spearfishers’ perspective. This led to us deciding to integrate another element of reality into our study: ‘spearfishers fail…and a lot’ as we explain below.
What did we do?
Spearfisher-fish behavioural interaction can be conceptualized as a predator-prey system. With this in mind, we considered two ecological indicators previously used to measure fish behavioural responses to underwater human presence and combined them into one single integrated model.
The first indicator was flight initiation distance (the distance at which animals decide to escape from an approaching predator), while the second indicator was post-flight behaviour, which looks at what fish do immediately after fleeing from an approaching predator (for example, fish may flee but remain in the proximity which could still make them vulnerable to the approaching threat). There is evidence that these two indicators can be used to estimate fish behavioural reaction to underwater human presence, but their functional integration into one cohesive model representing spearfisher-fish behavioural interactions has not been explored.
Moreover, despite previous studies suggested that fish behavioural responses to spearfishing pressure may be used to model fishing mortality (an important parameter to assess dynamics in exploited populations), no studies estimated and integrated the role of spearfishers’ efficiency. We did this for the first time by estimating the decreasing probability to catch a fish at increasing distance from a speargun, and integrating it into the model together with the two ecological indicators mentioned above (flight and post-flight behaviour).
What did we find?
We showed that the two ecological indicators for flight and post-flight behaviour provide complementary information to quantitatively measure the response of fish to the risk associated to being caught by spearfishers. Once we ran our integrated model combining the empirical observations on fish behaviour with the estimates obtained from spearfishers (related to the probability to catch a fish at increasing distance from the speargun), we realized that the results were providing a new view of spearfisher-fish behavioural interactions with important ramifications for management.
Specifically, our integrative model drastically reduces estimates of likelihood of capture outside marine protected areas compared with previous estimates by solely using flight initiation distance as a single indicator of catchability.
Why it is important?
Despite spearfishing being practiced by only a small proportion of recreational (about 5%) and subsistence fishers around the world, there are important ramifications of our study. First, when managing spearfishing through temporal restrictions (e.g., seasonal or periodic closures) it is important to use an integrative ecological indicator that captures more realistic changes of fish behaviour in response to spearfishing – such as the one presented in our study. This would allow managers to, for example, open and close areas in a more functional way that is sensitive to actual fishing dynamics.
Second, the estimates of fishing mortality suggested by the model may be crucial to understand population dynamics and to plan long-term management actions with the aim to keep stock productivity high and to a sustainable level of harvesting.
This research received funding from the Spanish Ministry of Science and Innovation with the “Ramón y Cajal” research fellowships (RYC2021-033065-I) granted to Valerio Sbragaglia.
In this blog post, Nicola Jackson shares the findings from their latest study looking at how sampling air particles to detect DNA can be useful in monitoring and conserving koalas.
Perched high up in a Eucalyptus tree, swaying from side to side, lies a sleepy koala unaware of the means spent each year trying to obtain accurate baseline information about its presence. We have thrown all we could at it, from human led surveys to night spotting, bioacoustics, detection dogs, and drones equipped with thermal cameras. Yet, whilst critical to its conservation and management efforts, finding a koala remains an ambitious, time-consuming, and costly endeavour often producing insufficient results. Little did we know that traces of koalas’ presence and that of its predators along with other native, domesticated, and invasive species, float in the air and can be detected through traces of DNA.
Here, we introduce a promising new tool for detecting threatened species: airborne environmental DNA (air eDNA). This innovative and promising approach affords a potentially scalable, affordable, and easy to use solution for species management and conservation. Airborne eDNA involves the collection of airborne particles, such as pollen, skin cells, or hair, that are shed into the environment by plants and animals. By gathering these particles, we can extract environmental DNA (eDNA) to discover information about the species present in a given area. eDNA has been collected from a range of substrates including water, soil, honey and even spider webs.
To test this technology in detecting a threatened species, the koala, our team at the University of Queensland deployed cloth filters to collect particles that may be floating in the air. These were deployed across four locations in Redland Bay, South-East Queensland. By sequencing eDNA collected from these filters, we were able to detect the presence of a range of different species across the landscape. These included native Australian species, the yellow-footed antechinus, ringtail and brushtail possums, and of course our main objective, the koala. We also detected some common domesticated species, like horse, cow, dog, and pig, as well as threatening invasives like the red fox, European hare, and cane toad.
Whilst our resulting detections are promising, we also acknowledge that as an idea still in its infancy, airborne eDNA may be prone to some teething problems. For example, as with other types of eDNA, such as aquatic eDNA, a large portion of the sequences produced were attributed to humans and other highly abundant species that humans rely on for food and agriculture. These detections soak up precious sequencing reads potentially masking the detection of those that may be lowly abundant, like for instance, threatened species. We also saw that our greatest limitation to detecting species from the air was the lack of genetic reference material to help us identify species.
Despite these incipient difficulties, we demonstrate airborne eDNA presents a promising method for the detection and monitoring of threatened species and their ecological communities. We discuss these results, some of the difficulties airborne eDNA faces and how we may begin to use this technology to monitor our threatened species in our research paper in Journal of Applied Ecology.
Chengjin Chu and co-authors discuss their latest research which presents a cross-trophic interaction study between the red imported fire ant and plants.
The red imported fire ant (RIFA) is one of the most invasive insects in the world. Many pest management methods have been used to control the spread and damage of RIFA, like quarantine measures and powerful pesticides. However, one may wonder: Do more eco-friendly methods exist? Elton’s ecological resistance (biotic resistance) theory probably helps: The more diverse the local community, the greater resistance it can provide.
We expanded this theory across trophic levels to explore how tree diversity, a dominant driver of community complexity, influences the RIFA invasion. We sampled data through a field survey in a subtropical plantation forest in Southeast China, finding that the plots with more tree species had lower RIFA abundance.
Tree diversity seemed to work, but how? We found that the tree species, Ilex rotunda, seemed to attract RIFA. That is because I. rotunda is attractive to aphids who can provide honeydew to RIFA to exchange for care and protection. The abundance of I. rotunda is lower in higher tree diversity areas and could be the cause of how tree diversity works.
Unexpectedly, we found more RIFA mounds in the plots with higher tree diversity. One may ask: why did tree diversity pose contrasting effects on the RIFA abundance and mound numbers? In fact, once the queen begins to breed workers, food resource (e.g. arthropod preys) will be the key factor for the mound development.
Our study showed that forests with higher tree diversity could recruit more ample food resources that, in turn, increased the number of RIFA mounds, though nearly 99% of the mounds were without living RIFA. Notably, other carnivorous ants also contributed to the resistance of RIFA, but our study did not find any significant relationships between tree diversity and other ants.
Given that previous studies reported the positive effects of tree diversity on ants, we suggested that other ants could be one of the key pathways for how tree diversity strengthens the ecological resistance to RIFA invasion. Our study revealed the complex relationships between tree diversity and RIFA and stressed that diversifying forest tree species could mitigate RIFA invasion via limiting the population size.
Víctor Martín and Joan Navarro talk us through how gulls tagged with GPS and tested for pathogens can be used as tools to detect early pathogen circulation and pollution sources in the environment. This is explored further in their new research article.
Antimicrobial resistance is a global health challenge, exacerbated by the overuse of antibiotics in both human and veterinary medicine. The emergence and spread of antibiotic-resistant bacteria not only threaten human health but can also impact agriculture, livestock, and food production. Understanding the dynamics of ARB in the environment is crucial, especially in areas where anthropogenic activities create favourable conditions to their proliferation. Can we early detect agents that impact agriculture and human health? YES!
Our study
This study investigates the role of yellow-legged gulls (Larus michahellis) as both sentinels and vectors of resistance and pathogens in an intensive agricultural landscape in northeastern Spain. The researchers focused on Ivars i Vila-sana shallow lake, a Natura 2000 site surrounded by farmland, livestock farms, and waste management facilities. By employing advanced bio-logging technology such as GPS tracking devices, the study aimed to track gull movements and assess the potential pathways for pathogen dispersal.
During the breeding seasons of 2022, 2023, and 2024, 26 adult gulls were captured, and their faecal samples were collected to analyse for the presence of pathogenic bacteria that can be harmful for humans, such as Escherichia coli, and develop resistance to antibiotics commonly used to treat human infections.
Our results
Overall, the study reveals that while yellow-legged gulls can be viewed as “evils” due to their potential role in pathogen transmission, they also serve as valuable “allies” in early monitoring pathogen dynamics. Their movements and infection status can provide critical insights into the circulation of pathogens in the environment, thereby aiding in the development of management strategies and surveillance.
Gulls as ‘evils’: In terms of pathogen risk, the analysis indicated that gulls could spread faecal matter containing bacteria up to 23 km away from their breeding colony, with a significant concentration of bacteria spread occurring within a 1 km from the colony.
Gulls as ‘allies’: The study developed a connectivity network – how easily pathogens and animals can move through the landscape – based on the GPS tracking data and identified 54 sites, including dumps, irrigation ponds, and livestock farms that can be sources and hotspots for pathogen pollution. The strong connectivity between these places underscores the role of gulls in linking several habitats, facilitating the potential transmission of pathogens and resistances within the agricultural landscape. This finding emphasizes the role of gulls not only as carriers of pathogens but also as potential early warning indicators for environmental monitoring.
The implications of this research extend beyond ecological understanding; they highlight the urgent need for integrated monitoring programs that address pathogen dissemination in human-altered ecosystems. Such programs should focus on identifying pollution sources, implementing effective waste management practices, and promoting sustainable agricultural practices to mitigate the impact of pathogen and resistance to antibiotics on public health and food safety.
In conclusion, this study demonstrates the importance of utilizing wildlife, particularly gulls, as sentinels for pathogen monitoring in agricultural landscapes. By combining GPS tracking, networks, and pathogen detection, researchers can create spatial risk maps that inform management practices aimed at reducing the spread of antibiotic resistance. This approach aligns with the One Health framework, which recognizes the interconnectedness of human, animal, and environmental health, and is essential for tackling the multifaceted challenges posed by antimicrobial resistance.
The Garden Route National Park (GRNP), in the eponym Biosphere Reserve, is one of the only truly unfenced National Parks in South Africa. The absence of fences allows wildlife to move freely between protected areas and surrounding lands, making collaboration with people essential for effective conservation.
The research project was born out of discussions between researchers from the International Research Laboratory REHABS, Nelson Mandela University, and South African National Parks scientific services. These discussions highlighted the need to combine traditional wildlife monitoring tools, like camera traps, with participatory approaches, such as interviews and surveys, to better understand mammal distribution in anthropogenic landscapes and engage with stakeholders.
The research
We deployed 75 camera traps in and around the GRNP, as a way to monitor wild mammal species and initiate conversations with the various local stakeholders. Thirty-three stakeholders (residents, farmers, foresters) engaged to the project.
We then developed an interview-based approach to gather additional data on mammal occurrences and identify the values and perceptions of local people regarding mammals. COVID-19 pandemic necessitated a shift from face-to-face interviews to an online survey, which was sent via mailing lists, Facebook, and WhatsApp groups. This approach proved effective, yielding 247 responses.
Both the camera traps and local ecological knowledge-based survey were designed using the same geographic grid (Bernard, Guerbois, Venter, et al., 2024), allowing for the integration of data from both methods. An integrated occupancy model was used to analyze species occurrence along a gradient of anthropogenic landscape transformation.
Lessons learned
In the GRBR, the protected area plays a crucial role in preserving large‐bodied species and species with a more specialist diet, although a diversity of species was detected across the landscape. Furthermore, natural habitats were highly valuable in preserving mammals with a slow demographic strategy. These findings have direct implications for land-use planning, suggesting that conservation efforts should prioritize the protection of natural habitats to prevent local biodiversity loss.
Moreover, the research demonstrated the feasibility and benefits of combining different monitoring methods. For conservation managers, this approach can enhance the spatial coverage and detection of mammal species. The integration was especially valuable to document the presence of rare and cryptic species such as the common duiker (Sylvicapra grimmia) or the African clawless otter (Aonyx capensis) in the GRBR.
Additionally, the study was valuable for practitioners as it documents people practices and knowledges about wild mammals, which can be valuable for conservation purposes. The uniqueness of the GRNR, with no fences, requires specific management approaches that are often neglected by practitioners from other protected areas who do not consider what happens beyond their own fences. For instance, Lizette Moolman and Melanie de Morney relied on local knowledge to optimize camera trap configurations inside the park (Moolman et al., 2019).
The approach used fostered participation by various stakeholders and allowed us to connect with local people and involve them in conservation research. Building trust with stakeholders is an important step for co-designing wildlife-friendly anthropogenic spaces, that are accepted by residents, and can be resilient. Aligning local ecological knowledge with camera trapping efforts, can have a variety of benefits, not just from an ecological data gathering point of view, but also in fostering long-term co-learning experiences.
The success of this project would not have been possible without the support and participation of local residents and stakeholders of the GRBR, to whom we are thankful.
