Introduction

It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing in the bushes, with various insects flitting about, and with worms crawling through the damp earth.

Charles Darwin, On the Origin of Species

Darwin’s dreamy words speak to the immense power of the natural world to please us. What did the author have in mind? I imagine a long, grassy slope near his home in the south of England. It is early summer, and the cowslips are in flower, a glorious lemon yellow, along with some purple dog violets. You can hear the buzz of bumblebees and the scratchy song of a white-throat singing from a nearby hawthorn bush, which is ablaze with clusters of pure white flowers. Swallows are flying low across the bank, and a song thrush takes off, its beak full of worms for its nestlings.

It is easy to change the scene at this entangled bank. Take it to a different season, perhaps to August when armies of small bees are visiting the delicate, pale blue harebells, and meadow brown butterflies are sipping nectar from the pink brushlike flowers of thistles. Change the players again by traveling to a grassy slope on a different continent. Perhaps our entangled bank can shape-shift altogether to a sphagnum bog in a conifer forest or the Arctic tundra; to an exposed rocky seashore where limpets and barnacles flourish, despite the onslaught of battering waves; to a coral reef resplendent with fish of every color; or to the cold, dark world of the deep sea where lanternfish make their own light of yellow, green, or blue, and giant squid capture their prey (including lanternfish) with thirty-foot-long feeding tentacles. An entangled bank is anywhere that is teeming with life in all its splendid diversity. Even the totality of animals, plants, and other organisms that make up the biosphere of this planet can be considered as one great entangled bank.

I am confident that I am not extending the meaning of Darwin’s words beyond his intention. Charles Darwin did not invite readers to imagine an entangled bank as a rhetorical flourish about the diversity and beauty of the natural world in his local area. The epigraph at the beginning of this introduction is the opening of the final paragraph of On the Origin of Species (Darwin [1859] 1985), one of the most consequential books ever written.

For better or worse, the fame of On the Origin of Species does not relate primarily to the diversity of life but to its central thesis that no organism is here by design. All the animals, plants, and microbes alive today are the descendants of organisms that happened to produce the most offspring, a process that Darwin called natural selection. This carefully argued conclusion is still disputed, despite the overwhelming evidence that Darwin’s ideas are fundamentally correct. The enduring controversy is the probable reason why subsequent parts of his argument that concern the complexity of the natural world tend to be neglected.

In principle, Darwinian natural selection could be a recipe for “winner takes all.” The creature that produces the most offspring will eliminate the entire opposition and become the sole surviving species, a so-called Darwinian Demon. This line of reasoning is much beloved by certain politicians and some traditional economists, but it does not apply to the natural world. The difficulty for any budding Darwinian Demon is that there is never quite enough of what an organism needs (e.g., food) and too much of what it could do without (e.g., extreme temperatures, predators, deadly pathogens). What’s more, many organisms have come to depend on partnerships with other organisms. For example, insects pollinate flowering plants in exchange for sugar-rich nectar, and pilot fish promote the health of sharks when they feed on the parasites infesting the sharks’ skin. As Darwin recognized, the struggle for survival generates complex networks of interacting organisms or, in his words, the players on his entangled bank.

There is one more step in Darwin’s long argument. Namely, the participants and interactions in the entangled bank are endlessly changing both in ecological time because of shifts in the conditions (e.g., weather, seasons) and interactions with other organisms (e.g., prey, pathogens, mutualists) and in evolutionary time because, down the generations, organisms with slightly different inherited traits produce more or fewer offspring. The consequence is elegantly summed up in the closing words of On the Origin of Species: “. . . endless forms most beautiful and most wonderful have been, and are being, evolved” (Darwin [1859] 1985, 460).

The words “most beautiful and most wonderful” reveal something more: Darwin’s profound awe of the natural world. This emotional response is shared by many who spend time in nature (with cell phone off and earplugs removed). Some people experience heightened spiritual awareness or a sense of union with a greater power. The natural world can be a gateway to religious insight. In his poem “The Windhover,” Gerard Manley Hopkins used the kestrel “rung upon the rein of a wimpling wing” as a symbol of Christ “a billion times told lovelier, more dangerous” (Hopkins 1888). Olivier Messiaen, who composed the monumental musical cycle of Catalogue d’oiseaux in 1956–58, combined an unswerving commitment to an authentic representation of the song of birds in their natural habitat with a conviction that birds are truly God’s angels on earth. Darwin’s awe of the natural world took him in a different direction. Darwin harnessed his deep knowledge of animals and plants to inform his scientific endeavors, revealing that the natural world can function without divine intervention.

A knowledge and appreciation of the natural world, as expressed so eloquently by Charles Darwin, are the central concerns of the discipline of natural history, the focus of the essays in this book.

Natural History

Natural history, sometimes referred to as nature study, is a descriptive activity that delights in the details. We observe creatures in their natural habitats, we may identify them, and we note details about their life cycle stage and, especially for animals, their behavior. Natural history is all about the particular and the personal. Put differently, natural history does not seek an understanding in terms of mechanism or process, which is the purview of science, an activity whose ultimate goals are not focused on either the particular or the personal. Nevertheless, natural history is closely related to science because observations about the natural world can play an important role in supporting or refuting scientific hypotheses. After all, Charles Darwin used his extensive knowledge of natural history to validate his scientific theory of evolution by natural selection.

Fortunately, natural history is an activity in which anyone can engage. Formal training is not needed, although we can all learn from an accomplished naturalist who, over the years, has become skilled in species identification and knowledgeable about the habits of animals and plants. By contrast, a scientist is a highly trained professional who has studied over many years. This difference between natural history and science may be blurred by the very welcome development of citizen science, enabling nonprofessionals to participate in the scientific process, especially with data collection and analysis. Nevertheless, citizen science programs are most productive when they are designed and run by professional scientists.

Charles Darwin was both a superb naturalist and a premier scientist. He was also very interested in humans, primarily from an evolutionary perspective. The Descent of Man, and Selection in Relation to Sex (Darwin [1871] 1981) provides thoughtful deliberations on the evolution of human anatomy and on the human mind and morality. (The book is, however, marred by references to race and gender in terms that are totally unacceptable today.) However, Darwin did not give any extended consideration to the place of humans in his entangled bank.

How times have changed! Today, humans figure prominently in any discussion of the natural world, including from the perspective of natural history.

Humans and the Natural World

There is a version of human life that is disengaged from the natural world. The habitat is made of climate-controlled buildings of perfectly vertical and horizontal surfaces and ninety-degree angles, connected by fast-moving metal boxes, such as cars and airplanes. To meet material needs, products are selected from images on a computer screen and delivered to the door. In this dystopian but not necessarily unfamiliar existence, we can be totally ignorant of where our food, clothing, and possessions come from and how they were made. A moment’s thought reveals that such disengagement is an illusion. The raw materials for everything that humans consume or manufacture come from other living organisms and inanimate resources, including water, minerals, and the atmosphere. This is basic economics. It is a mystery to me why some professional economists treat our planetary resources as infinite and, consequently, worthless.

There is more to the human relationship with the natural world than economic transactions. We also benefit from direct contact with nature. The intuition that the natural world can make us feel healthier and happier is backed up by hard data obtained by academic researchers in many disciplines, from biomedical science to psychology, epidemiology, and the social sciences. Even after confounding factors, such as access to clean air, the opportunity to exercise, and disparities in wealth, are accounted for, access to nature gives a small but statistically significant boost to our physical and mental health and to life expectancy (Hartig et al. 2014; Jimenez et al. 2021).

We have reached a contradiction. Humans have a deep affinity for the natural world, but, as societies and individuals, we tend to adopt lifestyles that distance ourselves from nature. A useful way to think about how this has happened is to consider our origins. The trouble probably started at the time of the earliest complex societies in which individuals specialized in different tasks and took up writing to supplement communication by the spoken word. People embedded in a complex, “civilized” society have weakened day-to-day contact with the natural world. Archaeological records place the earliest human civilizations at six thousand years ago, meaning that humans have been semidetached from the natural world for no more than 2 to 6 percent of the time since our species, Homo sapiens, first evolved (one hundred to three hundred thousand years ago). Fast-forward to today. More than half of the eight billion humans alive today live in cities, and some cities are very large. At least five hundred cities have more than one million inhabitants, and the population in nine cities exceeds twenty million inhabitants (Gillespie et al. n.d.). Billions of people adapted to their ancestors’ world of nature are today living in urban habitats where nature is mostly squeezed out.

Furthermore, humans are not passive recipients of the goods and services of nature on which we depend for our survival and well-being. Rather, we have profoundly altered the natural world. The scale of our interventions is so great that it can be difficult to comprehend. Half of the world’s habitable land has been requisitioned by humans for agriculture (Ritchie 2024), and an additional 35 percent of the remaining land is not actively managed but has been changed sufficiently to qualify as “novel ecosystems” (Marris 2011). The artifacts (e.g., buildings, bridges, dams) constructed by humans weigh more than all living organisms on the planet, including the world’s forests, the entire human population, and all other animals (Elhacham et al. 2020).

Many of the anthropogenic changes (changes caused by human activities) can be attributed to self-interest. Forests are felled for timber and to create agricultural land; waterways are dammed to enhance human water supplies and for hydroelectric energy; and animals are hunted and plants collected for food and other valued products (e.g., traditional medicines, furs, feathers), bringing many species to the brink of extinction—and sending some over the brink.

Other anthropogenic changes are incidental. “Exhibit A” must be our vast global experiment in anthropogenic climate change caused primarily by burning fossil fuels. For a century, the consequences of this activity were not appreciated. However, over the last thirty years, scientists have been issuing increasingly urgent warnings about increases in global temperatures and regional changes in climate caused by the uncontrolled emission of greenhouse gases (United Nations 2023a). The responses to these warnings are generally inadequate. For example, an analysis issued in late 2023 concluded that the goal of restricting the global temperature increase to less than 1.5°C above preindustrial levels could not be met by the climate action plans of most nations (United Nations 2023b). At a societal level, we cannot say that we don’t know what we are doing.

The ramifications of climate change for the world’s fauna and flora are incalculable. The winners will be those that can tolerate shifts in conditions (e.g., temperature, precipitation) or can disperse to different locations with more suitable conditions. The players in all the interconnected tangled banks of the world are changing, and they increasingly include novel combinations of species, often with unpredictable ecological consequences.

A different motivation for human modification of the natural world has become increasingly prominent in recent decades: to protect habitats and species that we value. We recognize the ecological importance, for example, of the forests and wetlands that serve as carbon sinks and of the insects that pollinate our crops; environmental economists refer to these activities as ecosystem services, giving them monetary value. We perceive certain landscapes, such as high mountains and forest-lined lakes, as beautiful and awe-inspiring, and we know that many species are endangered. A few are magnificent, such as tigers, or are endearing, such as pandas, but don’t we all have a sense of loss, even if only fleetingly felt, when unremarkable species, such as a small frog or straggly shrub, goes extinct as a direct result of human greed and thoughtlessness?

Self-interest, ignorance, or a desire to make good the previous environmental insults: whatever the reason, humans are mighty meddlers of the natural world.

Humans as Mighty Meddlers

Humans are not the only meddlers of the natural world. American beavers fell trees, which they use to dam a stream, creating a pond. This suits the beavers, which often construct their dens with sticks and mud in the pool, well-protected from predators, and store branches underwater in the pool, as food through the winter. Inadvertently, beavers can drastically alter their environment by slowing water flow, raising the water table, and creating wetlands. Other ecosystem engineers are biochemists. The cyanobacteria are an ancient group of microbes that hit upon the chemical trick of photosynthesis to make sugars with oxygen as the waste product. This trait evolved about 1.6–1.9 billion years ago and, slowly but surely, the waste oxygen accumulated, profoundly changing the atmosphere of the planet. Chemical engineering of the planet’s ecology by cyanobacteria created the opportunity for the evolution of organisms that can use oxygen as a fuel in respiration. Oxygen-respiring organisms, including humans, now dominate the planet. Beavers, cyanobacteria, and other meddlers are known as ecosystem engineers (Jones et al. 1994).

Nevertheless, human meddling is different from other ecosystem engineers in two respects. First, we meddle in many different ways. For example, we alter water courses (like a beaver), make a myriad of other structural changes to the environment, and modify the chemistry of the planet by pumping carbon dioxide and other greenhouse gases into the atmosphere, by interfering in the global nitrogen cycle, and various other interventions. Second, we have the capacity to reason. A beaver cannot reflect on whether it is good for the ecosystem to build a dam in a particular location, or at all, but we can weigh the economic, environmental, and public health effects of building a highway through a pristine habitat or polluting the land and waters with toxic chemicals and plastic waste. We can also debate the pros and cons of different strategies to reduce the ecological footprint of cities and agriculture, to restore a degraded habitat, or to protect an endangered species.

Decision-making about environmental issues is complex and often difficult. The challenges are not limited to habit and the vested interests that tend to favor the status quo. Even the best decisions founded on scientific information involve value judgments that balance financial feasibility, public health priorities, aesthetics, ethics, and what members of society value about the natural world. These considerations raise the question: How can we, as individuals, identify what is important to us in the natural world?

This brings me to the purpose of the essays in this book: to celebrate our engagement with the natural world through the discipline of natural history not only because this activity is fun but also because natural history helps us understand what we value about the natural world.

To summarize, science gives us concepts and explanations, and natural history—which, as explained above, is particular and personal—reveals the value of the natural world to us as individuals.

A Map and Compass for the Essays

This collection of forty-eight natural history essays focuses on the natural world in my local area around the city of Ithaca in upstate New York. In my explorations of local nature, I am usually accompanied by my husband, Jeremy Searle—hence the “we” in many of the essays.

Three themes permeate the essays, but first, I want to alert readers to a theme that is conspicuously absent: a temporal baseline. As Darwin appreciated, the natural world is always changing, and it is doing so now at an unprecedented rate because of anthropogenic climate change and environmental degradation. Many people see the natural world through the lens of alterations since their childhood, which is their baseline for what they perceive as natural. I lack this perspective because I spent the first half century of my life in Britain, meaning that I tend to compare between “here and there,” not “now and then.” I witness the natural world in my new home without any personal remembrance of times past.

Now for the three recurring themes, which some readers may find useful as a map and compass for the essays.

I value the predictability of seasons and the chaotic fluctuations in weather. This is true most of the time, although I admit to doubts when I am scraping ice off the car windshield on a bitterly cold February morning or when I am drowning in sweat after a five-minute walk up the road at midday in early August. The joy of a world dominated by season and unpredictable weather is that life does not stand still, and it is impossible to get bored. This month is different from last month; at some times of year, the natural world has noticeably changed since last week, occasionally since yesterday or even this morning. Nevertheless, the perpetual flux has a reassuring predictability. What has gone will come around again. You could say that time is an arrow that, every year, bends into a circle. Reflecting this value, my essays are arranged by month, from January to December.

I value the human factor. From the time when I arrived in Ithaca in 2008, I knew that I valued the role of ice and water in creating the landscapes that dominate the local area: the glaciers that gouged out riverbeds to form Cayuga Lake and the other Finger Lakes and the creeks that eroded soft sedimentary rocks to create the gorges and waterfalls. It took me longer to understand and appreciate the human meddling. The landscape has been modified for millennia by Indigenous people who used fire extensively to optimize the environment for their lifestyle as hunter-gatherers with shifting agriculture (Jordan 2022). The settlement of the local area by people of European descent in the late 1700s was followed by large-scale forest clearance for timber and agriculture, and most of the forest today is secondary growth on agricultural land abandoned in the nineteenth and twentieth centuries.

Humans are also responsible for alien plants, mostly of European and Asian provenance, in the local flora. Many of the plants brought to North America, either by design, for culinary or medicinal use or as garden ornamentals, or by accident, for example as contaminants of imported seeds, have thrived, self-propagating in the wild. Laws that regulate the import and purchase of certain invasive plants and the welcome recommendations that gardeners “plant native” are reducing the influx, but various aliens have become an integral part of our local world. Clumps of Japanese day lilies in woodland areas and swathes of West European purple loosestrife in wetlands are common summertime sights. As I have already considered, further change is inevitable, particularly in response to anthropogenic perturbations to the climate. The bottom line is that human activities, past and present, play a large role in shaping the natural world we enjoy and value.

I value the diversity of the natural world. Local nature is immensely varied. It includes a diversity of habitats, from hemlock groves and maple-beech woodlands to sedge-grass wetlands, grassy meadows, creeks, beaver ponds, lakes, and deep-plunge pools at the base of waterfalls. These habitats support diverse communities of animals and plants, including many species that are seasonal. Our local bird fauna is composed of both year-round residents and many winter visitors, summer visitors, and spring/fall migrants passing through. Some mammals and most amphibians and insects “disappear” into dormancy during the winter. Plant and butterfly species vary from early spring through high summer to late fall. What’s more, the total diversity of my local natural world is a tiny portion of the great diversity of nature on this planet.

These three themes bind my essays and have given me insight into what I truly value about nature. The myriad of entangled banks and the endless forms of the natural world are truly awesome and have an immense power to please.

A final map-and-compass issue is that the essays can be read in any order. There is no linear plot that requires the earlier months of the year to be read before the later, and I cross-reference between linked topics covered in different essays. I conclude with a brief postscript that revisits the central theme of this book, the importance of the natural world in our lives.