2023-06-20 by Shakunthala Natarajan

Why Do Some Birds Fly In Groups? Science Blog

The sky is tinted with shades of orange and yellow coming from the golden coloured Sun. The dusk is here. As you walk home, you gaze up to watch a ticket-free flight show by a group of birds!😊 You are fascinated by the excellent coordination and beautiful flying patterns of our winged friends! As the group flies away from your sight, you start wondering why birds fly together in groups, right? Utsuka and Jigyasa too have the same question in their minds and want to know more about the winged performers. Are you ready to take a quick flight along with the duo and find more about why birds fly in groups?

Flying in groups and coordinating with all the members of the flock is a difficult task. So, what’s the benefit? Simple. It is ‘survival’. To begin with, the chance of a predator targeting a particular bird in a group is less. The groups of birds can collectively watch out for predators and escape from a predator when they encounter one. Studies on the ‘European starling’ bird groups reveal these nice bird tactics! When a member of the group spots a predator, it makes slight movements. These movements are noticed and imitated by other closer members of the group. This can be understood by visualizing the ripples that form and travel throughout a water puddle when a tiny raindrop falls. Similarly, this warning signal travels through the entire flock, causing the group to move away from the danger. This interesting behaviour in the bird group is explained by the ‘chorus-line hypothesis’.

Having been awe-struck by the wonderful bird groups, Utsuka and Jigyasa are now curious to know why the bird groups fly in a specific wave pattern seen in the sky. Birds fly in the V formation mostly to save energy and sustain long flights. When the leader bird flaps its wings, it creates an updraft or lift for the bird behind it, making the follower’s flight easier and reducing its effort to flap its wings. V formation saves the energy of the entire troupe and lessens the burden of flight through large distances. Wait there… You must now be asking ‘will the leader bird not get too tired if it continues to flap its wings hard throughout the journey?’. When the leader bird gets tired, it exchanges its position with another bird in the group, who now starts to lead the bird flight.

But do you think birds remain in groups only when they fly? The answer is ‘no’. Some birds like the pink footed geese and common passenger pigeons search for food in groups as well. While some others make their nests next to each other and live together as nice neighbours. There are still other birds, who choose to just sit together in tree branches and enjoy the warmth radiating from each other’s bodies. This helps them overcome the spine-chilling winters and maintain their body temperatures. Team spirit and caring for others are two valuable lessons we can learn from our bird friends!

Utsuka and Jigyasa, after having understood the secret behind the flying pattern of birds, now want to get a broad scientific insight on aspects that could influence grouping behaviours in animals. They call upon Dr Vishwesha Guttal, a theoretical ecologist, who provides a detailed explanation on grouping behaviours that must be enlightening for you too! As Dr Guttal puts it, the bodily and environmental constraints of organisms tend to affect their grouping patterns. Further, organisms choose to stay together when the associated benefits are greater than the demerits. So, grouping is a behaviour that is highly dependent on the associated cost-benefit ratio.

Hence, survival needs, risk factors and contexts like the life cycle stage, tend to heavily impact grouping behaviours in animals.

I bet you must now be flying imaginarily along with Utsuka and Jigyasa, in awe of the inspirational flyers. Wouldn’t it be nice to hear a live commentary of Utsuka and Jigyasa’s narrations as you fly? It is now time to gear up your headphones and listen to the duo in the podcast!

References

1. Why birds fly together: How birds fly (no date) The RSPB. Available at: https://www.rspb.org.uk/birds-and-wildlife/natures-home-magazine/birds-and-wildlife-articles/features/why-birds-flock-together/ (Accessed: 07 May 2023).
2. Team, H.I.W. (2019) Why do birds flock together?, How It Works. Available at: https://www.howitworksdaily.com/why-do-birds-flock-together/ (Accessed: 07 May 2023).
3. Tom Langen, Professor of Biology (2022) Why do flocks of birds swoop and swirl together in the Sky? A biologist explains the science of Murmurations, The Conversation. Available at: https://theconversation.com/why-do-flocks-of-birds-swoop-and-swirl-together-in-the-sky-a-biologist-explains-the-science-of-murmurations-176194 (Accessed: 06 May 2023).
4. Marvellous Murmurations: Why do birds flock together? (no date) WWT. Available at: https://www.wwt.org.uk/news-and-stories/blog/marvellous-murmurations-why-do-birds-flock-together/ (Accessed: 08 May 2023).
5. Nature curiosity: Why do some birds fly in a V formation? (no date) Accelerator. Available at: https://www.reconnectwithnature.org/news-events/the-buzz/nature-curiosity-why-do-birds-fly-in-v-formation/ (Accessed: 09 May 2023).
6. Friederici, P. (2023) How A flock of birds can fly and move together, Audubon. Available at: https://www.audubon.org/magazine/march-april-2009/how-flock-birds-can-fly-and-move-together (Accessed: 09 May 2023).