Ant colony - WikiHQ

thumb|[[Walter R. Tschinkel next to a plaster cast of a Pogonomyrmex badius nest]]

thumb|Ant hill and ant tracks, [[Oxley Wild Rivers National Park, New South Wales]]

An ant colony is a population of ants, typically from a single species, capable of maintaining their complete lifecycle. Ant colonies are eusocial, communal, and efficiently organized and are very much like those found in other social Hymenoptera, though the various groups of these developed sociality independently through convergent evolution. The typical colony consists of one or more egg-laying queens, numerous sterile females (workers, soldiers) and, seasonally, many winged sexual males and females. In order to establish new colonies, ants undertake flights that occur at species-characteristic times of the day. Swarms of the winged sexuals (known as alates) depart the nest in search of other nests. The males die shortly thereafter, along with most of the females. A small percentage of the females survive to initiate new nests. Another name is "formicary", which derives from the Medieval Latin word formīcārium. The word also derives from formica. "Ant nests" are the physical spaces in which the ants live. These can be underground, in trees, under rocks, or even inside a single acorn.

Colony size

Colony size (the number of individuals that make up the colony) is very important to ants: it can affect how they forage, how they defend their nests, how they mate, and even their physical appearances. Body size is often seen as the most important factor in shaping the natural history of non-colonial organisms; similarly, colony size is key in influencing how colonial organisms are collectively organized. Genetics and environmental factors can cause the variation among different colonies of a single species to be even bigger. Different ant species, even those in the same genus, may have enormous colony size disparities: Formica yessensis has colony sizes that are reported to be 306 million workers while Formica fusca colonies sometimes comprise only 500 workers. Until 2000, the largest known ant supercolony was on the Ishikari coast of Hokkaidō, Japan. The colony was estimated to contain 306 million worker ants and one million queen ants living in 45,000 nests interconnected by underground passages over an area of . In 2000, an enormous supercolony of Argentine ants was found in Southern Europe (report published in 2002). Of 33 ant populations nested along the stretch along the Mediterranean and Atlantic coasts in Southern Europe, 30 belonged to one supercolony with estimated millions of nests and billions of workers, interspersed with three populations of another supercolony. The researchers claim that this case of unicoloniality cannot be explained by loss of their genetic diversity due to the genetic bottleneck of the imported ants. Because of this there is little doubt that the Argentine intercontinental super colony represents the most populous known animal society.

Another supercolony, measuring approximately wide, was found beneath Melbourne, Australia in 2004.

Organizational terminology

The following terminology is commonly used among myrmecologists to describe the behaviors demonstrated by ants when founding and organizing colonies: Despite the title of queen, she does not delegate the tasks to the worker ants; however, the ants choose their tasks based on individual preference.

Communication

Ant colonies can range from a few dozen to millions of ants so communication is very important. Because of this, ants have been known to communicate through something called odor trails or pheromone trails. These pheromone or odor trails are secreted by certain glands on an ants body though these glands and where they are located differ for each ant species. In general these animals are able to provide a positive and negative feedback with these pheromone trails, this is why ants are typically seen in a single file line going from point A to B. When a foraging ant is successful in finding food they will deposit their pheromone trail on the way back to their nest, the pheromone trail will get stronger as more ants tread it signaling there is still food to be had in that area and this is known as the positive feedback. These forms of communication allow for the ants to be able to stay organized no matter how large their colony grows.

Aggression between colonies

Aggression between ants can vary depending on the relationship between their colonies. The aggression levels in ants can increase when colonies are in close proximity to each other due to limited resources.

It is common for ants to engage in battle with ants from different colonies, but uncommon for conflict to arise between ants in the same colony. Cardiocondyla ants are an exception because of their ability to produce wingless males, creating the opportunity for these males to mate with the queen ants that inhabit the nest without having to leave the nest like other ant species. Because of this these ants have been known to form mutualistic interaction with different species like the mutualistic interaction between ants and hemipterans. Ants protect the hemipterans, a tree bug from predators and in turn the hemipterans provide honeydew which is rich in carbohydrates and have been seen to increase an ants activity, aggressiveness, population size, and dominance of ants within a community. Fungal hyphae like chaetothyriales and capnodiales are also often used in the structural construction of ant colonies because as these fungi age they leave behind resistant tube-shaped cell walls ensuring these colonies will have sturdy walls even long after these fungi have died. In some cases, this involves a great deal of digging.

The casts are often used for research and education purposes, but many are simply given or sold to natural history museums, or sold as folk art or as souvenirs. Walter R. Tschinkel notes in Ant Architecture: The Wonder, Beauty, and Science of Underground Nests that many commercial operations seem to use a casting procedure he developed and published based on the work of Brazilian myrmecologists Meinhard Jacoby and Luiz Forti. Usually, the hills are chosen after the ants have abandoned so as to not kill any ants; however in the Southeast United States, pouring casting into an active colony of invasive fire ants is a novel way to eliminate them.

Ant-beds

thumb|Nest construction of ants

An ant-bed, in its simplest form, is a pile of soil, sand, pine needles, or clay or a composite of these and other materials that build up at the entrances of the subterranean dwellings of ant colonies as they are excavated. A colony is built and maintained by legions of worker ants, who carry tiny bits of dirt and pebbles in their mandibles and deposit them near the exit of the colony. They normally deposit the dirt or vegetation at the top of the hill to prevent it from sliding back into the colony, but in some species, they actively sculpt the materials into specific shapes and may create nest chambers within the mound.

References

External links

Journal of Insect Science: The nest architecture of the Florida harvester ant
Myrmedrome, a realistic ant colony simulator
Winged Ants, The Male, Dichotomous key to genera of winged male ants in the World, Behavioral ecology of mating flight

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