Structures built by animals
Encyclopedia
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
and bee
Bee
Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...
hive
Hive
A hive may refer to a beehive, an enclosed structure in which some honey bee species live and raise their young.Hive may also refer to:-Arts:* The Hives, a Swedish rock band* Hive , a DJ and producer in the drum and bass music genre...
s, burrow
Burrow
A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...
complexes of rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s, beaver dam
Beaver dam
Beaver dams are dams built by beavers as protection against predators such as coyotes, wolves, and bears, and to provide easy access to food during winter. Beavers work at night and are prolific builders, carrying mud and stones with their fore-paws and timber between their teeth...
s, elaborate nests of birds
Bird nest
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American Robin or Eurasian Blackbird, or the elaborately woven hanging nest of the...
, web
Spider web
A spider web, spiderweb, spider's web or cobweb is a device built by a spider out of proteinaceous spider silk extruded from its spinnerets....
s of spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
s and many more.
Often, these structures incorporate sophisticated features such as ventilation
Ventilation
Ventilation is movement of air in and out of an enclosed space, including a body. It is used in the following contexts:* Ventilation * Ventilation * Ventilation * Ventilation * Ventilation...
, temperature regulation, structural strength
Strength of materials
In materials science, the strength of a material is its ability to withstand an applied stress without failure. The applied stress may be tensile, compressive, or shear. Strength of materials is a subject which deals with loads, deformations and the forces acting on a material. A load applied to a...
, multiple escape routes, trap
Trap (tactic)
A trap is a device intended to catch an intruder or prey. "Trap" may also refer to the tactic of catching or harming an adversary. Conversely it may also mean a hindrance for change, being caught in a trap.-Device:*Animal trapping*Bird trapping...
s, bait
Bait (luring substance)
Bait is any substance used to attract prey, e.g. in a mousetrap.-In Australia:Baiting in Australia refers to specific campaigns to control foxes, wild dogs and dingos by poisoning in areas where they are a problem...
, special-purpose chamber
Chamber
Chamber may refer to:*Chamber , a Marvel Comics superhero associated with the X-Men*Chamber , the portion of the barrel or firing cylinder in which the cartridge is inserted prior to being fired...
s and many other features. They may be created by individuals or complex societies of social animals
Eusociality
Eusociality is a term used for the highest level of social organization in a hierarchical classification....
with different forms carrying out specialised roles. These constructions may arise from complex building behaviour of animals
Ethology
Ethology is the scientific study of animal behavior, and a sub-topic of zoology....
such as in the case of night-time nests for chimpanzee
Chimpanzee
Chimpanzee, sometimes colloquially chimp, is the common name for the two extant species of ape in the genus Pan. The Congo River forms the boundary between the native habitat of the two species:...
s, from inbuilt neural responses
Neuroethology
Neuroethology is the evolutionary and comparative approach to the study of animal behavior and its underlying mechanistic control by the nervous system...
as in the case of birds, or triggered by hormone
Hormone
A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...
release as in the case of domestic sow
Domestic pig
The domestic pig is a domesticated animal that traces its ancestry to the wild boar, and is considered a subspecies of the wild boar or a distinct species in its own right. It is likely the wild boar was domesticated as early as 13,000 BC in the Tigris River basin...
s, or as emergent properties from simple instinct
Instinct
Instinct or innate behavior is the inherent inclination of a living organism toward a particular behavior.The simplest example of an instinctive behavior is a fixed action pattern, in which a very short to medium length sequence of actions, without variation, are carried out in response to a...
ive responses and interactions, as exhibited by termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, or combinations of these. The process of building such structures may involve learning
Learning
Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...
and communication
Communication
Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...
, and in some cases, even aesthetics
Aesthetics
Aesthetics is a branch of philosophy dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty. It is more scientifically defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste...
. Tool use may also be involved in building structures by animals.
Animals which build
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
s (other than man), bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s, insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and arachnid
Arachnid
Arachnids are a class of joint-legged invertebrate animals in the subphylum Chelicerata. All arachnids have eight legs, although in some species the front pair may convert to a sensory function. The term is derived from the Greek words , meaning "spider".Almost all extant arachnids are terrestrial...
s. It is also seen in a few species of fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
, reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
s, amphibian
Amphibian
Amphibians , are a class of vertebrate animals including animals such as toads, frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods...
s, molluscs, urochordates, crustaceans, annelids and some other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s. It is virtually absent from all the other animal phyla.
Functions
Animals create structures primarily for three reasons:- to create protected habitats, i.e. homes.
- to catch prey and for foraging, i.e. traps.
- for communication between members of the species (intra-specific communication), i.e. display.
Animals primarily build habitat for protection from extreme temperatures and from predation. Constructed structures raise physical problems which the need to be resolved, such as humidity control or ventilation, which increases the complexity of the structure. Over time, through evolution, animals use shelters for other purposes such as reproduction, food storage, etc.
Protection from predators
Predators are attracted to animal-built structures either by the prey or its offspring, or the stored caches of food. Structures built by animals may provide protection from predators through avoiding detection, by means such as camouflage and concealment, or through prevention of invasion, once predators have located the hideout or prey, or a combination of both. As a last resort, structures may provide means of escape.Animals use the techniques of crypsis
Crypsis
In ecology, crypsis is the ability of an organism to avoid observation or detection by other organisms. It may be either a predation strategy or an antipredator adaptation, and methods include camouflage, nocturnality, subterranean lifestyle, transparency, and mimicry...
or camouflage
Camouflage
Camouflage is a method of concealment that allows an otherwise visible animal, military vehicle, or other object to remain unnoticed, by blending with its environment. Examples include a leopard's spotted coat, the battledress of a modern soldier and a leaf-mimic butterfly...
, concealment
Concealment
Hiding is obscuring something from view or rendering it inconspicuous.Concealment is obscuring something from view or rendering it inconspicuous, the opposite of exposure...
, and mimicry
Batesian mimicry
Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator...
, for avoiding detection. Crypsis works by blending the structure with its background. The use of lichen flakes as an outer covering of nests by birds, as in the case of the Paradise Flycatcher (Terpsiphone paradisei) have been considered by some authors to be a case of crypsis through "branch-matching" and as a case of disruptive camouflage by the British ethologist, M. Hansell, where the lichen flakes are thought to resemble small patches of light seen through as in the case of insubstantial objects of insufficient importance to receive a predator's interest.
Ground-nesting birds which rely on crypsis for concealment have nests made from local materials which blend in with the background, the eggs and young too are cryptic; whereas birds which do not use crypsis for hiding their nests may not have cryptic eggs or young.
In a case apparently of masquerade, the Red-faced Spinetail
Red-faced Spinetail
The Red-faced Spinetail is a species of bird in the Furnariidae family.It is found in Colombia, Costa Rica, Ecuador, and Panama.Its natural habitat is subtropical or tropical moist montanes....
Cranioleuca erythrops places bits of grass and other material loosely streaming both above and below the nest chamber to break the shape of the nest and to cause it to resemble random debris without any underlying structure.
Thermo-regulation
Endotherm
An endotherm is an organism that produces heat through internal means, such as muscle shivering or increasing its metabolism...
ic or ectotherm
Ectotherm
An ectotherm, from the Greek εκτός "outside" and θερμός "hot", refers to organisms that control body temperature through external means. As a result, organisms are dependent on environmental heat sources and have relatively low metabolic rates. For example, many reptiles regulate their body...
ic. In endothermic animals, construction of shelters, coupled with behavioural patterns, reduces the quantity and energy cost of thermoregulation
Thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different...
, as in the case of the arctic ground squirrel
Arctic Ground Squirrel
The Arctic ground squirrel is a species of ground squirrel native to the Arctic.-Subspecies:Listed alphabetically.*S. p. ablusus Osgood, 1903...
s.
In ectothermic animals, moderation of temperature, along with architectural modifications to absorb, trap or dissipate energy, maximises the rate of development, as in the case of the communal silk nests of the Small Eggar moth Eriogaster lanestris
Eriogaster lanestris
The Small Eggar is a moth of the family Lasiocampidae. It is found in most of Europe ranging to the Amur River.The wingspan is 30–40 mm. The moth flies from March to April depending on the location....
. The primary sources of energy for an animal are the sun and its metabolism. The dynamics of heat in animal shelters is influenced by the construction material which may act as a barrier, as a heat sink or to dissipate heat. The cocoons of insect are a case in point.
An interesting example is the case of silk caps which cover the pupal cells of the Oriental hornet Vespa orientalis. Firstly, the silk insulates the pupa from the air outside the cell, and secondly, it acts as a thermostatic regulator. By virtue of its thermoelectric properties, the silk stores excess daytime heat in the form of electric charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
which it releases in the form of an electric current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
when the temperature falls resulting in heating. Cooling is aided by evaporation of excess water from the pupal cells. When the ambient temperature drops, the silk absorbs moisture and restores the moisture content by spreading water through all parts of its cocoon.
Internal architectural devices, such as walls may block convection or the construction of air flow systems may cool the nest or habitat.
Building materials
Materials used by animals in building structures need to not only be suitable for the kind of structure to built but also to be manipulable by the animals. These materials may be organic in nature or mineral. They may also be categorised as "collected material" and "self-secreted material".Collected materials
Some animals collect materials with plastic properties which are used to construct and shape the nest. These include resinResin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
collected by stingless bee
Stingless bee
Stingless bees, sometimes called stingless honey bees or simply meliponines, are a large group of bees, comprising the tribe Meliponini . They belong in the family Apidae, and are closely related to common honey bees, carpenter bees, orchid bees and bumblebees...
s, mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
collected by swallow
Swallow
The swallows and martins are a group of passerine birds in the family Hirundinidae which are characterised by their adaptation to aerial feeding...
s and silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
collected by hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...
s.
Some materials in nature act as ready made "building blocks" to the animals in question, such as feathers and leaf petioles for some birds and animal hair
Hair
Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class....
for the chaffinch
Chaffinch
The Chaffinch , also called by a wide variety of other names, is a small passerine bird in the finch family Fringillidae.- Description :...
. Other materials need to be "processed". Caddisfly larvae use stone pieces and also cut sections from green leaves for use in construction. The stone pieces are selected as per their size and shape from a large variety. In the case of leaf sections, these are cut and shaped to required size. Similarly bagworms cut and shape thorns or twigs to form their case. Some sphecid wasps collect mud and blend them with water to construct free standing nests of mud. Paper wasp
Paper wasp
Paper wasps are -long wasps that gather fibers from dead wood and plant stems, which they mix with saliva, and use to construct water-resistant nests made of gray or brown papery material...
queens build with paper pulp which they prepare by rasping wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
with their jaws and mixing with saliva
Saliva
Saliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...
, a case of collecting, processing and blending raw materials.
An animal builder may collect a variety of materials and use them in complex ways to form useful habitat. The nest of the Long-tailed Tit
Long-tailed Tit
The Long-tailed Tit or Long-tailed Bushtit is a common bird found throughout Europe and Asia. There are several extensive accounts of this species, most notably Cramp and Perrins, 1993; Gaston, 1973; and Harrap and Quinn, 1996...
, Aegithalos caudatus, is constructed from four materials – lichen
Lichen
Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...
, feather
Feather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s, spider egg cocoons
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
and moss
Moss
Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
, over 6000 pieces in all for a typical nest. The nest is a flexible sac with a small, round entrance on top, suspended low in a gorse
Gorse
Gorse, furze, furse or whin is a genus of about 20 plant species of thorny evergreen shrubs in the subfamily Faboideae of the pea family Fabaceae, native to western Europe and northwest Africa, with the majority of species in Iberia.Gorse is closely related to the brooms, and like them, has green...
or bramble
Bramble
Brambles are thorny plants of the genus Rubus, in the rose family . Bramble fruit is the fruit of any such plant, including the blackberry and raspberry. The word comes from Germanic *bram-bezi, whence also German Brombeere , Dutch Braam and French framboise...
bush. The structural stability of the nest is provided by a mesh of moss and spider silk. The tiny leaves of the moss act as hooks and the spider silk of egg cocoons provides the loops; thus forming a natural form of velcro
Velcro
Velcro is the brand name of the first commercially marketed fabric hook-and-loop fastener, invented in 1948 by the Swiss electrical engineer George de Mestral...
. The tit lines the outside with hundreds of flakes of pale lichens – this provides camouflage. Inside, it lines the nest with more than 2000 feathers to insulate the nest.
About the construction of nest by the Long-tailed tit
Long-tailed Tit
The Long-tailed Tit or Long-tailed Bushtit is a common bird found throughout Europe and Asia. There are several extensive accounts of this species, most notably Cramp and Perrins, 1993; Gaston, 1973; and Harrap and Quinn, 1996...
, it has been written:
Material of animal origin
Birds form the majority of the group of animals which collect building material of animal origin. They collect animal furFur
Fur is a synonym for hair, used more in reference to non-human animals, usually mammals; particularly those with extensives body hair coverage. The term is sometimes used to refer to the body hair of an animal as a complete coat, also known as the "pelage". Fur is also used to refer to animal...
and feathers of other species of birds to line their nests. Almost 56% of all families of passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
birds have species which utilise spider silk. Most birds use spider silk as in the case of the Long-tailed Tit, previously discussed; however the Little Spiderhunter
Little Spiderhunter
The Little Spiderhunter is a species of long-billed nectar feeding bird in the Nectariniidae family found in the moist forests of South and Southeast Asia. Unlike typical sunbirds, males and females are very similar in plumage...
Arachnothera longirostra of Asian tropical forests uses spider silk differently. It constructs a nest of plant strips which it suspends below a large leaf using spider silk for about a 150 or so of "pop-rivets".
Plant material
Cantilever
A cantilever is a beam anchored at only one end. The beam carries the load to the support where it is resisted by moment and shear stress. Cantilever construction allows for overhanging structures without external bracing. Cantilevers can also be constructed with trusses or slabs.This is in...
ed beam
Beam
Beam may refer to:*Beam , a construction element*Beam , the most extreme width of a nautical vessel, or a point alongside the ship at the mid-point of its length*A narrow, propagating stream of particles or energy:...
s while leaves and green twigs provide flexible but strong supports.
Mud and stones
Mud is used by a few species of a wide variety of families including wasps and birds. Mud is plasticPlasticity (physics)
In physics and materials science, plasticity describes the deformation of a material undergoing non-reversible changes of shape in response to applied forces. For example, a solid piece of metal being bent or pounded into a new shape displays plasticity as permanent changes occur within the...
when wet and provides compressive strength when dried. Amongst birds, 5% of all birds use mud and stones in their nest for toughness
Toughness
In materials science and metallurgy, toughness is the ability of a material to absorb energy and plastically deform without fracturing; Material toughness is defined as the amount of energy per volume that a material can absorb before rupturing...
and compressive strength.
Self-secreted materials
The majority of self-secreted materials are produced by insects and selection acts on this characteristic of production of self-secreting materials and increases the fitness of the animal. In some cases, the self-secreted material is directly applied, as in the case of ecribellate silk, spun by ecribellate spiders, to form sticky traps for prey, or it may be processed, as in the case of salivary excretion used for creation of paper by paper wasps, by blending it with directly with wood pulp. Self-secreted materials may be processed in some cases. In cribellate spiders, silk produced by the spider are reworked in the cribellumCribellum
The cribellum is a silk spinning organ found in certain spiders. Unlike normal spinnerets, the cribellum consists of one or more plates covered in thousands of tiny spigots. These spigots produce extremely fine fibers which are combed out by the spider's calamistrum, producing silk with a wooly...
to form fine sticky strands used for capturing prey. In other cases, the scale wax, produced on the bodies of honey bees, is gathered and blended with saliva, to form comb wax, the building material. All self-secreted materials are not developed specifically for that purpose, bird feathers are used for lining and insulation; a typical example being that of the female Common Eider
Common Eider
The Common Eider, Somateria mollissima, is a large sea-duck that is distributed over the northern coasts of Europe, North America and eastern Siberia. It breeds in Arctic and some northern temperate regions, but winters somewhat farther south in temperate zones, when it can form large flocks on...
duck (Somateria mollissima), which produces down feathers for lining its nest.