The night is full of animal life, but scientists know very little about it

 

Naturalists and life scientists have long debated how insect-eating bats navigate their dark world.
Sarun T/Shutterstock

Human disturbance is rapidly changing the nature of the nocturnal world. Intensive farming, suburban spread, artificially lit cities, and continuously busy road systems mean daytime species are becoming increasingly active throughout the night. Ecologists suggest that the majority of land animals are either nocturnal or active across both the day and night.

Recent research has also shown that the night is warming considerably faster than the day. The stifling night-time heat experienced across Europe this summer is indicative of this, placing nocturnal animals under even greater stress.

The transforming night adds new sensory pressures concerning finding food, a mate, and navigating a world permeated by artificial illumination. Environmental change is severely threatening the ability of nocturnal animals to coexist with humans. The conservation of nocturnal species has therefore become urgent.

Despite the abundance of night-time life, the understanding of nocturnal species has evaded science throughout history. Physical restraints on human navigation in the dark are partially responsible for this. This scientific blind spot is referred to as the “nocturnal problem”.

The legacy of this inaccessibility remains a barrier to our understanding of nocturnal life today. However, given the environmental threat now facing the nocturnal world, this will have profound consequences should it remain unaddressed. A better understanding of nocturnal life is critical to ensure its effective protection.

The origins of the ‘nocturnal problem’

So how did the nocturnal problem arise and why does it still impede science?

Constrained by their own reliance on vision, early scientists struggled to imagine the different ways in which animals might navigate in the dark. The myths that built up around familiar nocturnal creatures, such as hedgehogs, are evidence of historical attempts to fill the scientific gap.

The Greek philosopher Aristotle suggested that hedgehogs poached apples and carried them off on their spines. Such mythology was commonly included within Victorian natural history texts as an introduction to more factual descriptions of hedgehog anatomy, such as their capacity for smell and other bodily adaptations.

A hedgehog passing a road with a car light illuminating the background.
Even the experiences of hedgehogs remain to some degree unknown.
Lukasz Walas/Shutterstock

But even artificial illumination afforded very limited access. Illumination fundamentally changes the nature of the nocturnal world, with impacts on animal behaviour. A good example is the attraction of moths to street lights.

The historical debate surrounding how insect-eating bats navigate their dark world illustrates the problem. Numerous attempts have been made to understand bat senses. However, it was not until the late 1930s, more than 150 years after experimentation on bats had begun, that the scientists Donald R. Griffin and Robert Galambos identified echolocation – the ability to navigate via the emission and detection of sound signals.

Griffin would later describe the secrets of bat senses as a “magic well”, acknowledging the fundamental challenge of comprehending senses so different from our own.

But efforts to understand nocturnal senses could only take scientists so far. In 1940, American naturalist Orlando Park declared that the biological sciences suffered from a “nocturnal problem”, in reference to the continued inability to understand the nocturnal world. This was reflected in the more recent philosophical text of Thomas Nagel, which posed the question what it like is to like to be a bat?

Persistence of the nocturnal problem

Despite technological developments, including the introduction of infrared photography, aspects of nocturnal life continue to elude modern science.

While technology has afforded scientists a much better understanding of echolocation in bats, our way of thinking about bat senses remains limited by our own dependence on vision. When describing echolocation, scientists still suggest that bats “see” using echoes.

The elusive Australian Night Parrot was presumed extinct for much of the 20th century. Although they have been recently rediscovered, scientists remain unable to estimate their population size accurately while questions over the threats facing the species persist.

Despite an improvement in scientific research, nocturnal life remains understudied. In 2019, life scientist Kevin J. Gaston called for an expansion of research into nocturnal life. History shows us that when there are scientific gaps in knowledge about the night, cultures create their own truths to fill those gaps. The consequences of doing so may be significant.

The night is ecologically rich and efforts to fill these gaps in scientific understanding should be prioritised. The nocturnal world is threatened by environmental change, and its future depends on our commitment to getting to know the darkness.The Conversation

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This blog is written by Cabot Institute for the Environment members, Dr Andy Flack, Senior Lecturer in Modern and Environmental History, University of Bristol and Dr Alice Would, Lecturer in Imperial and Environmental History, University of BristolThis article is republished from The Conversation under a Creative Commons license. Read the original article.

Telling the story of temperature

 

Image credit: Brigstow Institute

 

What is the most extreme temperature you have experienced?

Take your time and have a moment to think about it.

What was happening that day? Where were you? Which of your senses feature in the memory? Do any emotions come back to you?

While you’re thinking about it, I’ll tell you a little bit about the Temperature Life Stories project that I brought to COP26 on 1st November 2021.

We all experience temperature differently. The hottest day I remember might be very different from the hottest day you remember. Where we have been, when we were there and our specific circumstances at a given moment all affect the physical temperatures we have lived through. We have lived different temperature life stories.

Why does this matter? Even in the UK, in Glasgow where world leaders will be meeting for COP26, which we often think of as being cold and driech, some people will be at risk from extreme temperatures. Meanwhile, for some of us that have always lived in and become acclimatised to temperate climate zones, we may never appreciate the searing strength of heat experienced by others on a daily basis. What does “1.5 °C or 2 °C of global warming above pre-industrial temperatures” even mean for ourselves or individuals like us elsewhere in the world? Expressing our differences in circumstances in creative ways can help build new understandings and narratives of how we will live with temperature extremes in a warming world.

The Temperature Life Stories project explored these questions. By digging into global temperature data, the same data that informs global temperature targets, we produced temperature life story graphs for both individuals and our collective of research participants. As individuals we may never ‘feel’ the global average temperature, but our experience is part of that bigger picture. Memories and experiences of temperature were explored through poetry, with exercises designed by Caleb Parkin (Bristol City Poet, 2020-2022), and a host of other creative methods from the wonderful (and hidden) talents of our research participants.

Of course, there were and will be contradictions too. The temperature that the data says we lived through might not match what we remember as being the most extreme of days. But that’s okay: unreliable narrators are part of storytelling, aren’t they?

So back to COP26, what was Temperature Life Stories doing there? Of course, I would have loved to have run a series of poetry workshops with international COP26 delegates to take the temperature of the conference, but unfortunately for them, time is more of the essence. For that reason, I settled for a providing a tiny morsel of the project as a taster at the COP26 Green Zone.

I asked attendees to spare just one key memory from their temperature life story. Something that stood out for them. I asked for them to describe it in just a few lines, which could be as poetic or as factual as they pleased. I asked them where and when the memory occurred (being as specific as they could or wanted to be).

Often, relative warmth appears in the memories: perhaps not extreme in a global sense, but enough to seem unusual to locals and visitors alike in Yorkshire, the Hebridies, alpine and polar environments. Sometimes a lack of snow says as much as burnt brown grass. Travel appears regularly, making up a key part of temperature life stories – both the biting cold of northern climates after a lifetime spent nearer the tropics and vice versa. Even a momentary blast of air changing connecting flights in Qatar can give a glimpse of what temperatures are possible. We don’t expect similar blasts of heat to hit us getting off the train in Birmingham, but recent summer heatwaves featured regularly in memories too, and in with them that same wall of heat. Finally, there are emotions too: nostalgia about climates of home or childhood not being the same when people return after time spent away, sadness for places of significance lost in wildfires, weeks of unbroken heat and sunshine “both amazing and terrifying”.

Using this collection of memories, a bespoke map of experience, emotions and stories in space and time will be produced for the COP26 conference. An alternative story of a warming world. Keep an eye on Brigstow channels in the coming weeks for this.

So what about you? Have you been thinking of your memory of temperature? Maybe it was during last summer’s heatwave. Maybe you were on holiday. Maybe you were stuck in an unairconditioned bus in a traffic jam. Maybe the heat was emotional, not physical: passion, anger or embarrassment. There is no right or wrong answers – every story is different.

If you have a memory and want to add it to our collective COP26 story, you can add it here (https://forms.office.com/r/HnwesuwJqg). We’ll ask you for the same information as the Green Zone participants an all memories and data recorded is anonymous.

Together we can rewrite a new story of our warming world. One which shows our vulnerabilities, frailties and fears but also our lighter moments, hopes, achievements. We have a complex relationship with the weather and climate we experience. Sometimes a graph can’t say it all.

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This blog is written by Cabot Institute member Dr Alan Kennedy-Asser from Brigstow Institute funded Experimental Partnership “Temperature Life Stories: Feeling the heat”. This blog has been reposted from the Bristow Institute blog with kind permission from the Brigstow Institute. View the original blog.