“What time are the birds due?” asked the woman beside me. The curtains would open on the starlings of the show – a cast of thousands – at 5:50pm on a chilly February day in Lilliput on the shores of Lough Ennell, Co Westmeath.
All through the winter there is a chance of seeing a starling murmuration at several locations around the country. But, by the end of March our visiting performers have all departed back to Russia, Scandinavia and Baltics, leaving the much smaller resident population of Irish starlings to start their breeding season.
Over the past few years starling murmurations have been amassing all kinds of fans. Philomena Brady is a regular at Lough Ennell and posts her photographs and videos to Facebook with tips for where to see them.
However, there are no guarantees that the starlings will perform at the same time and place each evening. Regardless of the uncertainty, crowds of adults and children, birdwatchers and photographers wait in the cold for hours in the hope of seeing the birds make swirling shapes in the sky at dusk before settling down to roost for the night.
‘It is so expensive in Dublin we decided to rent’: Swedish embassy returns to capital
Tenants who were ‘full of hatred’ followed and video-recorded neighbours, tribunal hears
‘I was 34 and all my friends were having kids... I was like: what am I waiting for?’
Consumers could face €1,000 increase in bills across energy, broadband and other areas from this week
A few birds flew overhead, then a bigger group, with the fluttering sound of hundreds of wings beating in the evening air. Groups came from different directions, converging together and flowing through an aerial ballet. Birds of prey swooped in, disrupting the group, which, like a shoal of fish pursued by a shark, split and peeled off before merging once more. The hungry predators, confused by the swirl, circled and tried again to isolate a vulnerable group member.
Just as we see pictures in the clouds, our unconscious ability to discern meaning from patterns interprets the murmuration shapes as peacocks, pigs or fish. The co-ordinated swirling looks incredibly intricate, appearing to be choreographed by some higher power, but relatively simple movement rules for individual birds lie behind the complexity.
To make a murmuration, a starling needs to be attracted to other starlings at dusk, to move in the same direction as around six of its neighbours, and avoid predators and collision with the birds immediately around it. Computer simulations with these simple rules can produce dynamic three-dimensional murmuration-type patterns.
An understanding of bird flocking behaviour has inspired the design of flocks of automated vehicles in two dimensions (think roads) and three dimensions (think drones). Avoiding collisions, with other vehicles, and with fixed or moving obstacles is an important problem to solve for safe and effective self-driving cars. Understanding how schools of fish or murmurations of starlings self-organise gives important insight into the kinds of rules that need to be built into collective groups of human-designed vehicles.
The shapes we see in starling murmurations are an example of “emergent behaviour” of a complex system, a type of behaviour that is not designed, but emerges from relatively simple underlying rules. If an individual in a flock of birds or school of fish perceives a threat from a predator the rule is to move towards the centre of the group, the safest place to be.
This creates a compact ball, no individual wants to be caught on the outside. As a predator swoops through the ball of prey, it splits and then comes back together as individuals seek safety in having neighbours all around them.
Ecosystems are complex systems with many interacting parts. By recognising relatively simple rules about how individual plants or animals interact with each other and their environment, ecologists can understand and explain the behaviours of much more complicated systems of many species.
It has taken decades to adequately understand the movement patterns in a single species; the starling. Now imagine hundreds of species, sometimes working together, sometimes competing with or eating each other. The complexity of ecology is both deeply attractive and maddeningly frustrating.
At the side of Lough Ennell the excitement among the children was electric as nature came alive in front of their eyes. The cameras clicked and whirred and Philomena Brady spent her 100th day waiting for starling murmurations, a winter-long vigil. One hundred days of anticipation, cold, rain, sun and sometimes, starlings.
- Prof Yvonne Buckley is co-director of the Co-Centre for Climate + Biodiversity + Water in Trinity College Dublin
