Group Organization Protects From the Cold

penguins huddled together on snow with a mountain in the background

Biological Strategy

Emperor penguin

Shanley Lynne

Image: Ian Duffy / Flickr / CC BY NC - Creative Commons Attribution + Noncommercial

Cooperate Within the Same Species

A species is a group of organisms capable of breeding to produce fertile offspring. When individuals within a species undertake activities that benefit one another, that cooperation benefits not just the individuals, but also local and wider populations of that species. Collaborating in activities such as finding food, controlling parasites, and protecting from predators enhances overall survival. To cooperate, there must be enough benefit to an individual, and especially to a population, to justify any risk taken by individuals. Through cooperation, risk is distributed among individuals and the benefits to the community are greater than the sum of the benefits to individuals. An example is birds that gather in flocks, a cooperative activity more beneficial than acting alone. While some birds forage, others watch for predators. When one finds food, others also feed on it. Despite potential short-term competition for an individual that finds food, over the long-term, that same individual benefits when others find different food sources.

Search this Function

Coordinate by Self-Organization

To create and maintain a healthy community of individuals and ecosystems requires that living systems coordinate their activities. Coordination doesn’t necessarily mean that there’s a leader orchestrating what happens. In nature, coordination is usually achieved through self-organization. In a flock of geese flying in a V-formation, for example, there’s no lead goose controlling where all of the others fly. The flock uses this formation because each goose gains energy from air vortices created by the goose in front of it. The lead goose doesn’t gain that benefit, so when it tires, it moves back and another goose takes the front position.

Search this Function

Protect From Temperature

Many living systems function best within specific temperature ranges. Temperatures higher or lower than that range can negatively impact a living system’s physiological or chemical processes, and damage its exterior or interior. Living systems must manage high or low temperatures using minimal energy, which often requires controlling responses along incremental temperature changes. To do so, living systems use a variety of strategies, such as avoiding high or low temperatures, removing excess heat, and holding heat in. Insulation is a well-known example of managing low temperatures by retaining heat using thick layers of hair, fur, or feathers to hold warm air next to the skin.

Search this Function

Birds

Class Aves (“bird”): Eagles, hawks, sparrows, parrots

Birds are evolutionary engineering marvels. They are descended from dinosaurs, but are far from our idea of heavy, scaly reptiles. Of the specific adaptions that set them apart, most notable is flight—although some mammals can fly, birds take the prize for abundance in the skies. Many birds have hollow, lightweight skeletons and specially-designed wings to help them stay aloft. They also have feathers made of keratin that help them stay warm, attract mates, and improve navigation and aerodynamics in flight. In contrast to their dinosaur ancestors, they lack true teeth and have replaced them with specialized beaks and bills.

Search this Living System

Groups of emperor penguins use social huddling to protect themselves from the cold.

Introduction

Emperor penguins breed during the cold Antarctic winter, where temperatures can reach -30C and below. To conserve energy and protect themselves from the cold, they adopt a behavioral strategy of huddling close together in large groups. Huddling is considered key to their ability to live in such a cold place. They have different huddling patterns across different breeding stages, with the largest number of penguins huddling during the egg incubation period, when the males must survive fasting while also trying to keep their eggs warm.

The Strategy

Within a huddle, emperor penguins shift their position in a wavelike movement. Every 30-60 seconds a penguin will move, triggering neighboring penguins to also move. These actions/reactions result in a wave of movements across the huddle, which over time leads to large scale movement of the huddle. This can increase the size of the huddle, by allowing smaller huddles to eventually join together. These small movements also affect the organization of the huddle by increasing the density, from creating a more orderly arrangement as each penguin finds their ideal position.

Image: Caroline Gilbert, Stéphane Blanc, Yvon Le Maho, André Ancel / CC BY SA - Creative Commons Attribution + ShareAlike

Male emperor penguins huddle to stay warm while females spend months foraging for food.

Over time, huddles grow larger as individual penguins join or other huddles join together, causing the penguins to be more tightly packed together, which can sometimes cause the penguins to get too hot. When they need to get rid of the excess heat, the penguins leave the huddle in an abrupt breakup. This relatively slow increase in huddle size followed by rapid separation is a behavior that further allows them to regulate their exposure to unwanted temperature.

Lens of Time: Huddle Masters | bioGraphic

Emperor penguins just may be the best huddlers on Earth—and scientists are finally revealing the secrets to their success.

Body Heat Melts Wax to Form Hexagons

Honeybees

Honeybees generate heat to mold cylindrical wax cells, then surface tension pulls the cooling wax into hexagons.

Biological Strategy

Baboons Stay Together by Making Compromises As a Group

Baboons

Baboons stay together through distributed decision-making and compromise

Biological Strategy

Flamingos Form Friendships

Flamingos

Long-term social bonds help flamingos survive by providing mutual support.

Biological Strategy

Hermit Crabs Use Social Networking to Find New Homes

Caribbean hermit crab

Crabs use “synchronous vacancy chain” behavior to find new shells fast and avoid risky homelessness.

Last Updated August 20, 2018

References

“For Emperor penguins (Aptenodytes forsteri), huddling is the key to survival during the Antarctic winter. Penguins in a huddle are packed so tightly that individual movements become impossible, reminiscent of a jamming transition in compacted colloids. It is crucial, however, that the huddle structure is continuously reorganized to give each penguin a chance to spend sufficient time inside the huddle, compared with time spent on the periphery. Here we show that Emperor penguins move collectively in a highly coordinated manner to ensure mobility while at the same time keeping the huddle packed. Every 30–60 seconds, all penguins make small steps that travel as a wave through the entire huddle. Over time, these small movements lead to large-scale reorganization of the huddle. Our data show that the dynamics of penguin huddling is governed by intermittency and approach to kinetic arrest in striking analogy with inert non-equilibrium systems, including soft glasses and colloids.” (Zitterbart et al. 2011:e20260)

Journal article

Coordinated movements prevent jamming in an emperor penguin huddle

PLoS ONE 6(6): e20260 | 01/06/2011 | Zitterbart DP, Wienecke B, Butler JP, Fabry B

embedly preview

Reference

“Social thermoregulation is a cooperative strategy in which animals actively aggregate to benefit from the warmth of conspecifics in response to low ambient temperatures. Emperor penguins, Aptenodytes forsteri, use this behaviour to ensure their survival and reproduction during the Antarctic winter. An emperor penguin colony consists of a dynamic mosaic of compact zones, the so-called huddles, included in a looser network of individuals. To maximize energy savings, birds should adjust their huddling behaviour according to environmental conditions. Here, we examined the dynamics of emperor penguin aggregations, based on photo and video records, in relation to climatic factors. Environmental temperature, wind and solar radiation were the main factors contributing to huddle formation. The analysis of individual movements showed that birds originating from loose aggregations continually joined huddles. Sometimes, a small number of birds induced a movement that propagated to the entire huddle, causing its breakup within 2 min and releasing birds, which then integrated into looser aggregations. Different parts of the colony therefore appeared to continually exchange individuals in response to environmental conditions. A likely explanation is that individuals in need of warmth join huddles, whereas individuals seeking to dissipate heat break huddles apart. The regular growth and decay of huddles operates as pulses through which birds gain, conserve or lose heat. Originally proposed to account for reducing energy expenditure, the concept of social thermoregulation appears to cover a highly dynamic phenomenon that fulfils a genuine regulatory function in emperor penguins.” (Ancel et al. 2015: 91)

Journal article

New insights into the huddling dynamics of emperor penguins

Animal Behaviour | 01/12/2015 | André Ancel, Caroline Gilbert, Nicolas Poulin, Michaël Beaulieu, Bernard Thierry

embedly preview

Reference

Journal article

Huddling behavior in emperor penguins: Dynamics of huddling

Physiology & Behavior | 30/07/2006 | C GILBERT, G ROBERTSON, Y LEMAHO, Y NAITO, A ANCEL

embedly preview

Reference

Journal article

The origin of traveling waves in an emperor penguin huddle

New Journal of Physics | 16/12/2013 | R C Gerum, B Fabry, C Metzner, M Beaulieu, A Ancel, and D P Zitterbart

embedly preview

AskNature