Nest Is Reinforced

a branch holds a magpie lark nest, one mudlark sits facing forward in the nest, the other stands on the branch facing the opposite way, both birds are black and white and the nest appears reinforced with mud

Biological Strategy

Magpie lark

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Physically Assemble Structure

Living systems use physical materials to create structures to serve as protection, insulation, and other purposes. These structures can be internal (within or attached to the system itself), such as cell membranes, shells, and fur. They can also be external (detached), such as nests, burrows, cocoons, or webs. Because physical materials are limited and the energy required to gather and create new structures is costly, living systems must use both conservatively. Therefore, they optimize the structures’ size, weight, and density. For example, weaver birds use two types of vegetation to create their nests: strong, a few stiff fibers and numerous thin fibers. Combined, they make a strong, yet flexible, nest. An example of an internal structure is a bird’s bone. The bone is comprised of a mineral matrix assembled to create strong cross-supports and a tubular outer surface filled with air to minimize weight.

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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.

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The nest of the magpie lark provides a sturdy home on a branch because it is a bowl-shape, made of mud and reinforced with sticks, feathers, fur, and grass.

Introduction

“The magpie lark of Australia constructs a bowl of mud strengthened not only with grass but with small sticks, feathers, and fur. This creation is placed atop a branch, so it must be well secured. Not only is there less surface area between nest and substrate than the swallows and martins have to work with, but the branch can move abruptly, whereas cliff faces do not. One behavioral response to this greater challenge is that the birds seem to vibrate the mud more intensely, apparently to forge a better bond as it liquefies and runs between the straw and other reinforcing material. The birds also wrap the mud almost completely around the supporting branch, enlarging the area of contact…the individual mud pellets cannot be distinguished, so complete has been the flow of liquefied mud.” (Gould and Gould 2007:184)

Last Updated August 18, 2016

References

Book

Animal Architects: Building and the Evolution of Intelligence

Basic Books | 06/03/2012 | James L. Gould

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