Behaviour and ecology Meat ant

1 behaviour , ecology

1.1 foraging , dominance
1.2 diet
1.3 predators
1.4 life cycle , reproduction
1.5 ritualised fighting
1.6 relationship other organisms

behaviour , ecology
foraging , dominance

worker foraging on vegetation

a diurnal species (active during day), meat ant shows minimal interaction nocturnal ant species when territories overlap. meat ant , other members of i. purpureus species group regarded dominant group of diurnal species in australia, highly active, aggressive, , have enormous geographical range. during day, bulk of workers attend , feed on honeydew secreted insects live on leaves of eucalyptus trees. these trees connected foraging trails formed meat ants, connect satellite nests part of single colony; these trails visible due absence of vegetation , lead important food , water sources. other workers in smaller numbers scavenge around nest area dead insects, or other proteinaceous foods bring colony. dominance clear when meat ants capable of finding food sources more ants, capable of displacing many ants , other insects. food sources discovered more rapidly , reduces foraging efficiency of other ants, including of iridomyrmex. however, ants such green-head ant (rhytidoponera metallica) not affected presence of meat ants , still successful in finding food sources. green-head ants general predators , forage singularly , cannot recruit other nestmates, unable defend food sources dominant ants. heavily rely on food source , impossibility of defending other ants may have led peaceful coexistence dominant species, including meat ants. means green-head ants avoid conflict meat ants. myrmicines, highly competitive, capable of defending foraging workers; rapid recruitment of nestmates , use of chemicals defence allows them withstand attacks meat ants. in particular, monomorium ants have been observed occupying baits regardless of presence or absence of meat ant. not case mealworms, have moderate success honey baits. in foraging areas meat ants excluded or not present, number of other ants observed far greater , activity dramatically increases. however, presence of meats ants not affect abundant species, , of time iridomyrmex ants increase foraging rate.

foraging trail satellite nest vaguely seen (top left)

the impact of meat ants on other species varies, depending on habitat , type of food source, , ecological role ant plays. deliberate exclusion of meat ants show not can alter amount of sources available, dynamics of resource use on entire outcrops. if present, meat ants rely on rapidly discovering food sources , retain dominance other ants cannot collect them, exploitation , interference helps displace other ants. habitat meat ants live in may affect dominance among fauna. less successful in complex habitats , more successful in open areas, allowing workers forage efficiently; example, workers forage around rocks , collect food sources more in contrast in vegetation. meat ants more dominant other i. purpureus species group members in non-complex habitats. meat ants larger other iridomyrmex species , can displace or kill trying compete food sources. similar behaviours among meat ants , iridomyrmex species have increased level of conflict among each other, in open habitats.

the rate of movement of workers associated temperature, , foraging workers leave nest after sunrise when nest warmed in morning. meat ants emerge , start foraging when temperatures approximately 14 °c (57 °f), capable of withstanding extremely hot temperatures, workers have been seen foraging in 43 °c (109 °f) heat. workers may forage several minutes when soil temperature above thermal limit @ 45.8 °c (114 °f). @ 50 °c (122 °f) (soil surface temperature), foraging activity reduced further. these ants exhibit high running speeds during hot days, speed decreases after temperatures of 50 °c due physiological stress put onto them. workers can withstand such temperatures exhibiting opportunistic thermal responses adjust behaviour in order handle high trail temperatures , alter thermal biology low temperatures. deliberately expose closely thermal maxima.

the success of meat ants depends on resource dealing with. in 1 study, removal of meat ants allowed successful foraging of iridomyrmex ants @ carbohydrate sources, not protein baits. success of ants did not increase mealworm baits, suggesting competition not occur between meat ants , other species, , factors, such food preference, may involved. in contrast camponotines , myrmicines, both of success affected @ numerous food sources meat ants present. camponotines exhibit no aggression , cannot defend themselves.

diet

worker feeding on honey

like other iridomyrmex species, meat ant omnivore, retrieving food sources various insects tends, including caterpillars , various sorts of butterflies, particularly larvae of waterhouse s hairstreak (jalmenus lithochroa). meat ants feed on honeydew sap-sucking insects, flower nectar, sugar , other sweet substances. in captive colonies, workers prefer consume small pieces of grapes rather honey solutions , other sweet foods. these ants prey on various insects , animals, collecting both live , dead invertebrates , acquire meat dead vertebrates. insects meat ants prey on include giant lacewings, swarm trees kill, butterfly genoveva azure ogyris genoveva, indian mealmoths, almond moths, western australian jarrah leafminer , larvae of wasp trichogramma. large , developed larvae of cabbage butterfly (pieris rapae) attacked more meat ant workers of other iridomyrmex species. on sandy beaches, species observed preying on polychaete annelid worm, armandia intermedia, causing high mortality rates on them (rates of 30 percent). these ants feed on number of dead or alive animals, including metamorphic crucifix toads, snakes, lizards, , birds. on occasions, swarms of workers have been found on dead foxes. meat ant known ant in australia feeds on fresh guano. collection of guano nearby meat ant colony shows opportunistic nature of species. observations show trails of workers in groups of 2 4 found collecting guano under active bat roost within abandoned mine , proceeded return nest. collection of guano australian ant colony never recorded prior these observations, unknown why meat ants collect fresh guano.

meat ants cooperating devour cicada

meat ants among few native species of australia not harmed toxins of cane toad, invasive species. of time, foraging workers target metamorph toads. observations show workers forage around ponds , seize toadlet. starts single worker making contact individual , tracing movements, followed 3 or 4 workers capturing it. participating ants grab limb , sever legs, returning prey item nest. of time these tactics not work. example, toadlets able escape ants displaying aversion-like behaviour; individual may escape struggling erratically or forcing ants release grip returning water. aversion behaviour leads toadlets remaining in water or staying on objects such water lilies, pieces of bark ants cannot access, or moving around on moist substrates. unknown if meat ant predation on toadlets affected population, based on population density of toadlets within studied site , foraging time , efficiency, approximately 2,700 toadlets removed per day. toadlet population density extremely high, impact of meat ant predation minor. however, survivability of toadlets may affected if ants prevent toadlets foraging many areas of moist substrate.

water important resource colonies living in dry , arid environments, may not available. counter this, workers able extract significant amount of water sand 2%–4% water content , 4% soil. meat ants unable retrieve water soil, whereas sand able attain greater amount of water; however, soil contains wide variety of particles, including clay , coarse sand, causes water bound firmly. ants may retrieve digging or directly suck on soil @ low metabolic cost. may evolved response based on tested ants, no observations show meat ants doing this. meat ants known dig moist soil gain access water or water has been spilt, either if site nearby nest or far away.

predators

despite dominance among ants, number of animals known prey on meat ants. short-beaked echidna (tachyglossus aculeatus) prominent predator of meat ant, due high fat levels (up 47%) in virgin queens. these queens can contain 47% fat, , when no queens available after attack, echidna may stop attacking nest. however, these ants consumed either in low numbers or avoided entirely. attacking echidnas burrow down hole have made , consume them while handling bites ants, scratch on head , chest. echidna not consume meat ants throughout whole year; instead, echidnas attack meat ant nests august october, when nuptial flight (meaning virgin queens , males emerge mate) occurs. time period makes easier echidnas prey on winged females since directly above on nest. despite attacks, colony growth not affected echidnas.

nest damage feeding echidna

several birds prey on meat ants. masked woodswallow (a. personatus) , white-browed woodswallow (artamus superciliosus) gather around meat ant nests , swoop @ them, catching several ants before eating them. pieces of meat ants have been found in faeces of red-capped robin (petroica goodenovii), rufous whistler (pachycephala rufiventris), hooded robin (melanodryas cucullata) , red-browed treecreeper (climacteris erythrops). meat ants forage on ventilago viminalis trees eaten apostlebird. large ground-feeding birds, such currawongs, magpies , ravens dig out newly established colonies after queen has found suitable spot nest. small domes of excavated soil present @ such spots, revealing queens presence these birds. result, many queens consumed birds, leaving many abandoned nest chambers.

the blind snake ramphotyphlops nigrescens follow trails laid meat ants locate them, , snakes known feed on brood. various species of spiders prefer prey on meat ants, attracted alarm pheromone ants release. 1 spider, in particular, cursorial spider habronestes bradleyi, specialist predator against these ants , uses alarm pheromones released during territorial disputes locate them. these alarm signals created oscillating body along longitudinal axis, released when ant encounters nest mate.

cyclotorna monocentra moths feed on meat ant broods. larvae of these moths parasites leafhoppers , move meat ant colonies complete development, proceed consume brood; females lay many eggs near ant trails close leafhoppers tended ants. other observations show iphierga macarista larvae scavengers in meat ant nests, while sphallomorpha beetles live in burrows near nests of meat ants, larvae capture , prey on workers passing by. larvae of spitfire sawfly , pseudoperga guerini able regurgitate fluid against meat ant if getting attacked them; depending on how regurgitated, ant either walk away , clean or become fatally affected it. lizards such thorny dragon, sit , wait predator, consume meat ants, other lizards eat iridomyrmex ants reject species.

life cycle , reproduction

meat ant alates swarming nuptial flight

nuptial flight occurs during spring, in october. reproductive females mate single male , begin establishing own colonies afterwards. nuptial flight occurs after rain, males emerge nest first, followed virgin queens; groups of 20 40 females emerge after males have flown away. alates (the reproductive males , females) position on top of nest in order heat themselves, , fly @ same time once warm. process may happen multiple times unless weather had changed, otherwise, queens return nest. nuptial flight may continue days until virgin queens have withdrawn nest. of time, single queen start own colony , lay eggs take around 44 61 days develop , emerge adults, colonies can founded through multiple queens cooperating each other, adoption existing colony, or budding (also called satelliting or fractionating ), subset of colony including queens, workers , brood (eggs, larvae , pupae) leave main colony alternative nest site. around 10% of queens have @ least queen them during colony foundation. many queens killed during colony founding; major aspects include predation birds , other ants, of same species, due fact attempt establish nests near large colonies. however, queens successful, assistance of neighbouring workers, queen dig chambers. other causes of queen deaths include disease , starvation. queen s ovaries may take 4 weeks mature, , lays around 20 eggs may develop larvae in less month. workers have been observed laying eggs, presumably trophic eggs. function of these unfertilised eggs nutritional, not reproduction.

the number of individuals in colony varies. mature nest of several years old can hold between 11,000 , 64,000 ants, while other colonies can house around 300,000. in cases, enormous colonies can have many million ants. observed colonies known contain 70,000 larvae , 64,000 workers; can have 20,000 males , on 1,000 virgin queens, others may have more virgin queens males. ratio of worker ants number of larvae in colonies ranges 1 worker every 2 larvae or 2 larvae every worker. population of nest can affected or altered several factors: human interference can severely damage or destroy nests potentially devastates nest population, , overshadowing main cause of nest s demise. that, neighbouring nests may increase in population if damaged or abandoned sites taken over. meat ants rely on nests withstand climatic stress in summer , winter, foraging activity , food sources limited in summer, , in winter plant growth impossible , workers unable survive cold temperatures. result, meat ants overwinter, process organisms wait out winter season due cold conditions making everyday activity , survivability impossible; populations may affected greatly.

a queen meat ant burrowing hole after nuptial flight

most colonies monogyne, meaning colony has single queen, based on observations, nests contain more single queen. nests known contain 2 queens, having many 4 in single colony, making them polygynous; high proportion of queens living in polygynous nests unrelated 1 another. colonies oligogynous, means multiple queens present in colony, tolerated workers birthed different queens , treated equally. tolerance still occurs when new reproductive females , males born, recognition based on kin queens , workers known, hinting brood discrimination when larvae fed or groomed; queens take care of own brood , neglect after broods laid other queens. queens, on other hand, cooperate each other during nest founding, antagonistic once there workers present in colony. queens become more intolerant of each other colony grows, , separate within nest, resulting in queen laying more eggs. such cases happen when pleometrotic founding occurs, or if queen ant adopted colony, setting aggressive relationships. physical fights between queens in same colony rare.

as meat ant colonies have second queen, polydomy not associated polygyny, although 2 associated each other because polygynous colonies reproduce budding. means ecological factors promote polydomy , polygny both differ. studies show meat ants produced single, inseminated queen due high level of relatedness in 1 tested colonies. colonies not closely related result of colony fusion (meaning 2 unrelated , separate colonies form single entity). meat ants show nest fidelity: in polydomous colonies, workers different nests mingle others different nests never return nest not originate from. instead, return nest enclosed in. means colonies may homogenise through brood transfer. discussed before, nestmates different nests aggressive towards each other, due number of factors: genetic , spatial distance in nests can correlate level of aggression exhibited ants. however, exhibit more aggression ants of different species adjoining territories. aggressive conspecific ants distant colonies, suggesting environmental cues play vital role in nestmate recognition. example background odours in particular environment may impair ants identifying own nestmates, , may need make more attempts determine ant s identity.

ritualised fighting

two workers engaged in ritualised fighting

meat ants highly territorial , aggressive ants establish firm borders between neighbouring colonies. while boundaries not physical, worker ants maintain them engaging in ritualised fighting opponent ants, interaction colonies engage in. fatalities rare on both sides, fights may cause injuries several workers. fighting enables territory contested between opposing colonies without them killing each other , costing many casualties on both sides. due of this, method of avoiding casualties , promotes intercolony communication , assessment. drainage of work force occur if these boundaries acted conflict zone if ritualised fighting did not take place. lethal fighting occurs if colony under attack.

encounters between workers last 15 seconds. ritualised fighting occurs 2 worker ants come contact each other, if both ants same colony, break contact , groom themselves. afterwards walk around until make contact ant. meat ant detects foreign worker intense antennation (the act of touching antennae) , gaping of mandibles, , stretch upward appear taller , larger, suggesting meat ants in display of size-matching. workers perform behaviour known front leg boxing ; both workers have front legs sweeping , down, flex @ coxal joint in paddling motion. paddling motion aimed @ each other during fight, going on 3 5 seconds on average. point on, determine loser , winner .

the ant lost ritual fight lower body, , lean sideways victorious ant. victorious ant remain raised upward , reach down worker , open mandibles wider, grasping on opponent s mandibles, , tug , shake head few moments. however, fight may continue if neither worker backs down, , commence side side posture. both ants circle each other , present gasters directed opponent, , on occasions, either 1 or both of ants kick outward using legs @ each other. eventually, break contact , groom once appeasement has been reached , continue search ant.

relationship other organisms

worker common jassid nymph. these insects excrete sugary sap collected ants, protect valuable food resource.

meat ants have been observed blocking banded sugar ant nesting holes pebbles , soil prevent them leaving nest during hours of day. banded sugar ants counter preventing meat ants leaving nest blocking nesting holes debris, behaviour known nest-plugging. if meat ant nests encroached trees or other shade, banded sugar ants may invade , take on nest, since health of colony may deteriorate overshadowing. members of affected meat ant colony later move nearby satellite nest placed in suitable area, while invading banded sugar ants fill nest galleries black resinous material. meat ants attract cats because of chemicals secrete (dihydronepetalactone, isodihydronepetalactone , iridomyrmecin).

meat ants intolerant of myrmecophiles (which insects or other organisms share positive interspecies associations ants) living in colonies, cyclotorna larvae known dwell in colonies. although sphallomorpha larvae prey on workers discussed earlier, inquilines , live in nest commensally. unused or abandoned areas inside colonies occupied other species of ants , in cases, termites. meat ants may deliberately destroy colonies of termite amitermes laurensis if competition between 2 intensify.

meat ants play important role in seed dispersal. meat ant colony capable of dispersing 334,000 individual bellyache bush seeds per hectare, shows strong ant-seed relationship among two.