Britain's starling murmurations under pressure: are displays changing with population declines and climate change?

Author: The Conversation

Author: The Conversation

In this feature, researchers describe how Britain's autumn murmurations—thousands of starlings twisting and turning as the sun sets—captivate crowds and reveal the beauty of collective animal behavior. The piece connects the spectacle to broader ecological trends, including a dramatic decline in Britain’s breeding starling population and shifts in climate, migration and habitat. It highlights a citizen-science survey initiated 12 years ago to track murmuration size, duration, and location, and explains how predator presence can amplify displays while roosting needs may play a secondary role. The article also invites the public to participate again by recording sightings, contributing to understanding whether murmurations are changing over time.

• Predator presence tends to enlarge murmuration size and extend duration
• Population declines could alter where and when murmurations occur
• Climate change and continental migration may shift timing and locations
• Citizen-science data are essential for long-term monitoring

Overview of starling murmurations in Britain

The article discusses the autumn spectacle of starling murmurations across Britain, where thousands of birds move as a single, shapeshifting flock at dusk. This dazzling display has long attracted spectators from city centres to wetlands, yet it sits within a changing ecological landscape. Recent assessments indicate a substantial decline in the UK breeding starling population, with figures from the British Trust for Ornithology showing a 61% drop between 1995 and 2024. The text situates murmurations within broader patterns of bird declines, including farmland birds, and cautions that shifts in where birds gather, when they arrive, and how they behave could influence the displays that winter audiences enjoy.

Background and the original citizen-science project

The Conversation links murmurations to fundamental questions about why starlings engage in these spectacular formations. Over the past two decades, scientists have uncovered much about how thousands of birds coordinate their movements through neighbor-following rules, but the exact evolutionary drivers of murmurations were less clear. The article recalls a major citizen-science project begun in 2014, conducted in collaboration with the Royal Society of Biology, which collected more than 3,000 observations from observers in 23 countries between 2014 and 2016. Those observations detailed murmuration size, duration, location, and predator presence, providing a rich, unusually broad dataset to explore the phenomenon and its potential changes across time and space.

Drivers of murmurations: predators, warmth, and roosting

A central finding discussed is the predator-avoidance hypothesis: murmurations tend to be larger and longer when predators approach or attack, a pattern that offers protection through collective vigilance and confusion. The researchers also note a secondary driver—roosting in large communal groups on cold nights—though this is not the primary explanation for the displays. The article emphasizes that these displays are likely multifactorial, with predator avoidance playing a major role and environmental factors shaping when and where birds gather to roost.

Population declines and potential changes in patterns

Despite declines in breeding populations, the article suggests that murmurations are not automatically shrinking in size. Instead, shifts in spatial gathering, timing of arrival, and behavioral changes could alter the size, duration, and location of displays. Climate change, including milder winters and altered European migration patterns, could also affect murmurations by changing the wintering dynamics of UK-stationed starling populations. The piece highlights that wintering populations include large numbers arriving from continental Europe, whose migratory decisions may respond to changing winter conditions, potentially reshaping murmuration patterns over time.

Seasonal patterns and ongoing research

Seasonal records from the original study indicated a seasonal pattern in murmuration size and duration, with day length linked to display persistence. Twelve years later, researchers are re-examining whether those seasonal relationships persist and whether the interactions among murmurations, predators, and temperature remain stable in a changing climate. The article also notes that advances in understanding the coordination of thousands of birds have deepened, but questions about why exactly starlings assemble in such elaborate forms continue to intrigue scientists.

Citizen participation and how to help

In a call to public involvement, the researchers invite observers to continue contributing by tracking where and when murmurations occur, estimating the number of birds, recording display duration, and noting whether predators are present. Those data will help scientists investigate whether murmurations are evolving in response to ecological pressures and climate shifts, enabling a better understanding of one of nature's most extraordinary collective behaviours. The article closes with a reminder of the sensory and atmospheric experience of a murmuration, including the audible rush of wings and even the droppings, and invites readers to enjoy the spectacle while contributing to scientific knowledge.