A place for natural history in the 21st century

Natural history provides an important basis for observing interactions between organisms in their environments. Biotropica recently inaugurated a new paper category called "Natural History Field Notes" to provide an outlet for such studies. Depicted here are drawings and observations by the author from research trips. Natural history, which has been defined in different ways (Schmidly, 2005) but at its core involves observing and understanding organisms in their natural environments (Travis, 2020), in many ways once provided a foundation for the study of biodiversity. The scientific literature is now replete with studies highlighting the causes, severity, and urgency of the global extinction crisis (Ceballos et al., 2015; Janzen, 1994; Jaureguiberry et al., 2022). Increasingly, biodiversity loss is linked to both land-use change (Foley et al., 2005) and climate change (Bellard et al., 2012), and there are calls for policy makers to address these multiple crises in an integrated and comprehensive manner (Pereira et al., 2024; Pettorelli et al., 2021). In parallel to these developments in the scientific literature, in the popular media there is abundant evidence of people feeling disconnected to nature and anxiety over the alarming state of the environment (Ojala et al., 2021). Academics have even given these feelings various names: nature deficit disorder, eco-anxiety, climate change worry, and ecological grief (Louv, 2008; Ojala et al., 2021). Indeed, the success of books in the popular press like "Green Sketching" (Foxon, 2022) and "Slow Birding" (Strassmann, 2022) is a testament to attempts to reestablish connections with nature in an increasingly digital world. Natural history may thus help uncover important aspects of species' biology that are essential components of biodiversity and also has the potential to inspire biologists and non-biologists alike (Tewksbury et al., 2014). Recording observations about the natural world has been a part of human experience since people first took pigments to the walls of caves tens of thousands of years ago. Records became more formalized as explorers such as Oviedo made extensive botanical collections on overseas voyages (Villamil-Montero & Ming, 2016). Observations from these and other expeditions such as those of José Celestino Mutis, Alexander Von Humboldt, Charles Darwin, and Alfred Russell Wallace later became the foundation for fields including ecology, biogeography, evolution, and meteorology (Funk, 2018). I contend that while many fields of scientific enquiry developed from early natural history observations, few continue to be so intimately tied to natural history as the place-based sciences of tropical field ecology and biology (Raby, 2017). Throughout the 20th and 21st centuries, natural history has been deemphasized in universities and academic journals (Barrows et al., 2016; Bartholomew, 1986; Schmidly, 2005) in parallel with the increasing focus on prediction and mathematical, theoretical, and molecular approaches to biology. This is unfortunate, as natural history provides a foundation for understanding how organisms interact with each other and the environment—information not easily gleaned from DNA sequences and 'omics approaches (see Greene, 2005 for a thought-provoking discussion of apparent distinctions between empiricists and theoretical biologists vis-à-vis their approaches to natural history and education). Simply put, it is very hard to interpret big data in ecology in meaningful ways if you do not know anything about who the organisms are and what they do in the environment. Moreover, new tools and technological advances are bringing innovative ways to observe nature (Hartig et al., 2024), and many of these methods are noninvasive and unobtrusive. For example, passive acoustic monitoring coupled with data analysis pipelines now provides ways to collect community-level data for multiple vocalizing taxa including birds, insects, and frogs without introducing "observer bias", that is, altered animal behavior due to the presence of humans (Deichmann et al., 2018; LeBien et al., 2020). Similar to soundscape ecology, camera trapping can provide visual observations of animal presence and behavior (Delisle et al., 2021). Trail cameras or camera traps are now relatively reasonably priced and widely available, and online repositories of images are increasingly available. Environmental DNA metabarcoding (eDNA) is another new technology that is proving useful in detecting community-level presences of animals in aquatic and terrestrial environments and may assist in monitoring biodiversity (Polanco F. et al., 2021). In addition to these methods that are usually applied or used by researchers, citizen or community science is helping to develop global, geospatial databases of observations including organismal presences and ecological processes such as phenology (Bison et al., 2019; Dickinson et al., 2010). This nonexclusive list of emerging new tools highlights the discrepancy between our growing ability to make natural history observations in novel ways, at the same time that outlets to publish such observations have decreased over the 20th and 21st centuries. In an attempt to "get back to the basics," in 2021 Biotropica inaugurated a new manuscript category called "Natural History Field Notes (NHFN)" (Powers et al., 2021), as other journals have done (Jenkins et al., 2022). Our goal was to provide a platform for biologically rich observations about species and their inter-connections withing the context of their environments, that is, observations that do not easily fit within the confines of a standard research paper. The instructions to authors of NHFN state that: "Submissions to NHFN must tell a compelling story that generates a novel hypothesis or that can be placed in a larger context of tropical ecology, biology, and evolution. While we recognize that these may be rare events and thus inferences may be based on a single event or handful of observations, the manuscript as a whole must be robust enough to be of broad interest to our international readership." (Powers et al., 2021). Now that Biotropica has published NHFN for 2 years, it is fair to ask: what have we learned from these contributions? In an attempt to answer this question, I reviewed all Field Notes published from March, 2021 to November, 2023 and extracted the focal taxa, methods, key findings and further hypotheses (Table 1). (Carvalho et al., 2021) (Carrillo & Fuller, 2022) (Sundar et al., 2022) (Rubin, 2022) (Gadek et al., 2022) Collectively, these papers address a remarkably diverse range of taxa and include marine, aquatic, and terrestrial habitats. The focal taxa include birds, frogs, fish, jaguars, ocelots, sengis, insects, bats, snakes, and trees. Researchers themselves were not spared as subjects of NHFN, as one paper reported evidence of an ocelot attacking people in a remote field station (Champagne et al., 2023). Four of the 17 papers used camera traps to document animal presence and behavior, while many relied on the "tried and true" methods of careful field observations. In other words, nobody should retire their binoculars just yet. Importantly, several of these papers grew out of rare, chance encounters, and speak to the ubiquity of cell phone cameras as a means to record these serendipitous sightings. The topics that these papers engage are as diverse as the taxa and include community ecology, basic biology, behavior, and some amazing things that are difficult to categorize. They reveal many novel interactions among species, such as commensal African ground-foraging ant birds that follow ground-foraging sengi (Cordeiro et al., 2022) and cases that blur the lines between competition and predation, such as evidence of a jaguar killing an ocelot at a waterhole during a drought in a water-limited ecosystem (Perera-Romero et al., 2021). Papers that increase our knowledge of the basic biology of species include a study of a frugivorous fish that swallows seeds whole and then regurgitates them prior to careful chewing and digestion (Carvalho et al., 2021). Other surprising findings include a tree species with medicinal properties that apparently functions as a pharmacy for at least 10 species of mammals as diverse as bats, deer, and primates (Kaisin et al., 2022). These field notes have not only enhanced scientists' knowledge of the natural world, they have also captured the popular imagination. Who knew that there were hawkmoths that keep predatory bats away by using sound to jam their sonar systems (Rubin, 2022) and snakes that avoid predation by cartwheeling away (Quah et al., 2023)? These papers made splashes on social media and traditional news outlets. For example, the NHFN on cartwheeling snakes was covered by 75 news organizations across the globe. This underscores the ability of natural history to move out of the "ivory tower" and connect people back to nature through a common sense of wonder. I argue that this is an essential step if we are to convince people that we all need to do more to ensure the future of biodiversity on this planet. It is heartening but perhaps not surprising that there are still so many fascinating things that we do not yet know about the natural world, particularly in tropical latitudes, which harbor the bulk of the planet's biodiversity. Careful observations of the natural world are typically the starting point for the development of ecological theory and further hypothesis tests, and not the other way around. The papers highlighted in Table 1 suggest what makes a successful Natural History Field Note: a set of novel observations that links something specific from one locality to general phenomena that may occur elsewhere and suggests further research directions. For example, the observation in the Atlantic Forest of Brazil that many animal species use the same tree species prophylactically or therapeutically (Kaisin et al., 2022) may not be limited to this particular region, as recent reports of a Sumatran orangutan in Indonesia suggest self-medication with a plant species to treat a facial wound (Laumer et al., 2024). Collectively, these two studies beg the question of how many other tree species out there have been used as local pharmacies by animal communities. They also have applied significance as they imply a possible route for drug discovery. Besides serving as fodder for future studies, there are other benefits that accompany making a space for natural history observations. Natural history was typically construed as a realm where explorers with names like "Squamish P. Wigglesworth III" read out reports of their travels to the adventurers' club. Promoting natural history, especially in the tropics, allows people living in those ecosystems to record their observations; for example, a group of high school students in Panama (along with a biologist coauthor) published their observations of mutualistic ants repairing damage to their Cecropia host plants (Wcislo et al., 2021). In summary, in this age of looming twin crises of biodiversity decline and climate change, our need for natural history is greater than ever before. I am proud that the journal Biotropica can play a role in promoting natural history observations by providing an outlet for such studies. I thank Catherine Hulshof, Peter Tiffin, Jeff Klemens, and an anonymous reviewer for feedback that improved this Commentary. In particular, thanks go out to Jeff Klemens for inventing the fictitious explorer Squamish P. Wigglesworth III. No data were used in this Commentary.