Ant Foraging Research Articles

Spatial patterns of seed removal by harvester ants in a seed tray experiment.

Using a selection of native grass and forb seeds commonly seeded in local restoration projects, we conducted a field experiment to evaluate the effects of seed species, distance of seed patches from nests, and distance between patches on patterns of seed removal by Owyhee harvester ants, Pogonomyrmex salinus (Olsen) (Hymenoptera: Formicidae). To provide context for ants' seed preferences, we evaluated differences in handling time among seed species. In addition, we assessed the influences of cheatgrass, Bromus tectorum (L.) (Poales: Poaceae), and Sandberg bluegrass, Poa secunda (J. Presl) (Poales: Poaceae), cover on seed removal. We found significant differences in removal rates among seed species. In general, seeds placed closer to nests were more vulnerable to predation than those placed farther away, and seeds in closely spaced patches were more vulnerable than seeds in widely spaced patches. However, the strength of these effects differed by seed species. Differences in handling time among seed species may help to explain these findings; the protective effect of from-nest distance was weaker for species that required less time to transport. For 2 of the seed species, there was an interaction between the distance of seed patches from nests and the distance between patches such that the protective effect of distance between patches decreased as the distance from nests increased. Cheatgrass and bluegrass cover both had small protective effects on seeds. Taken together, these results offer insight into the spatial ecology of harvester ant foraging and may provide context for the successful implementation of restoration efforts where harvester ants are present.

Insects in temperate urban parks face stronger selection pressure from the cold than the heat.

Urban areas experience higher temperatures compared to rural areas and as such, are increasingly considered places of acclimatization and adaptation to warming. Small ectotherms, such as insects, whose body temperature rises with habitat temperature, are directly affected by temperature changes. Thus, warming could have a profound effect on insect behavior and physiology. To test if the urban heat island effect drives higher thermal tolerance and activity changes, we used globally distributed and abundant insects-ants. We measured the heat and cold tolerance of 14 ant species distributed across urban and peri-urban areas. As thermal traits are often correlated with ant foraging, we measured foraging activity during three consecutive years across eight sites. Contrary to our prediction, ants exposed to the urban heat island effect did not have a higher heat tolerance than peri-urban ants. Instead, cold tolerance varied across habitats, with ants from the cooler, peri-urban habitats being able to tolerate lower temperatures. We recorded the same pattern of invariant heat and higher cold tolerance for ants in the canopy, compared to ground nesting ants. Ant activity was almost 10 times higher in urban sites and best predicted by cold, not heat tolerance. These unexpected results suggest that we need to rethink predictions about urban heat islands increasing insect heat tolerance in urban habitats, as cold tolerance might be a more plastic or adaptable trait, particularly in the temperate zone.

Impact of temperature and season on ant foraging activity of two invasive species in a Mediterranean urban area

Abstract Invasive species often have harmful effects on human activities and biodiversity. The Tapinoma nigerrimum complex includes three species that exhibit invasive traits and the ability to form supercolonies, including Tapinoma magnum and Tapinoma darioi. While these species are native to the Mediterranean basin, they have recently been reported as invasive in more northern regions of Europe. However, T. magnum and T. darioi show different invasion patterns in Europe, suggesting differences in thermal preferences between these species. We aimed to determine whether there was any difference in activity pattern depending on temperature or season between the two Tapinoma species and between Tapinoma and co‐occurring native Mediterranean ants. We measured ambient temperature and ant foraging activity around the nest entrances of T. darioi and T. magnum in urbanised sites around Montpellier, southern France, over almost 1 year. We did not detect differences in activity between the two species according to temperature, but T. magnum was more active than T. darioi in winter. Compared to the co‐occurring native species, the two Tapinoma species were more active at low temperatures and earlier in the year. These results suggest that the difference in invasion success between T. magnum and T. darioi may not be explained by temperature preference. The difference in activity between native Mediterranean species and invasive Tapinoma suggests a coexistence through niche partitioning. In addition, our results suggest that control measures against invasive Tapinoma species would be more effective if applied at the end of winter.

A stochastic model of ant trail formation and maintenance in static and dynamic environments

Colonies of ants can complete complex tasks without the need for centralised control as a result of interactions between individuals and their environment. Particularly remarkable is the process of path selection between the nest and food sources that is essential for successful foraging. We have designed a stochastic model of ant foraging in the absence of direct communication. The motion of ants is governed by two components - a random change in direction of motion that improves ability to explore the environment, and a non-random global indirect interaction component based on pheromone signalling. Our model couples individual-based off-lattice ant simulations with an on-lattice characterisation of the pheromone diffusion. Using numerical simulations we have tested three pheromone-based model alternatives: (1) a single pheromone laid on the way toward the food source and on the way back to the nest; (2) single pheromone laid on the way toward the food source and an internal imperfect compass to navigate toward the nest; (3) two different pheromones, each used for one direction. We have studied the model behaviour in different parameter regimes and tested the ability of our simulated ants to form trails and adapt to environmental changes. The simulated ants behaviour reproduced the behaviours observed experimentally. Furthermore we tested two biological hypotheses on the impact of the quality of the food source on the dynamics. We found that increasing pheromone deposition for the richer food sources has a larger impact on the dynamics than elevation of the ant recruitment level for the richer food sources.

Vegetation structure and relative humidity drive the diurnal foraging activity of Malaysian giant ant workers in urban fragmented forests

Abstract The impacts of urban forest fragmentation on tropical ant foraging activity are poorly understood. The Malaysian giant ant (Dinomyrmex gigas) is among the largest ant species worldwide. Colonies of this species contribute to important ecosystem processes such as predation and nutrient cycling in the tropical forests of Southeast Asia. Here, we compared the diurnal foraging activity of D. gigas workers in urban‐fragmented and contiguous forests, and investigated how this was shaped by key environmental factors such as vegetation structure and microclimate. Specifically, we sampled ground‐foraging D. gigas workers in four urban/semi‐urban forest patches and two contiguous forests in Peninsular Malaysia across the wet and dry seasons. Surprisingly, we found that some urban forest patches, irrespective of area, supported greater foraging activity of D. gigas workers than contiguous forests. These differences in foraging activity were explained by differences in multiple stand‐level variables between urban forests patches and contiguous forests. Specifically, the abundance of foraging D. gigas workers increased with number of trees with Diamater at breast height (DBH) 5–30 cm, but it decreased with relative humidity, canopy cover, number of palms, number of shrubs and trees with DBH <5 cm. Our study highlights the importance of urban forest patches, microclimate and vegetation structure for driving the diurnal foraging activity of Malaysian giant ant. Small and relatively large forest patches were of comparable importance for the maintenance of biodiversity in urban landscapes. In the absence of landscape connectivity, reforestation is the most feasible option to restore the natural habitat of D. gigas in urban forest patches and mitigate microclimatic edge effects.

Unbalanced visual cues do not affect search precision at the nest in desert ants (Cataglyphis nodus)

Desert ant foragers are well known for their visual navigation abilities, relying on visual cues in the environment to find their way along routes back to the nest. If the inconspicuous nest entrance is missed, ants engage in a highly structured systematic search until it is discovered. Searching ants continue to be guided by visual cues surrounding the nest, from which they derive a location estimate. The precision level of this estimate depends on the information content of the nest panorama. This study examines whether search precision is also affected by the directional distribution of visual information. The systematic searching behavior of ants is examined under laboratory settings. Two different visual scenarios are compared – a balanced one where visual information is evenly distributed, and an unbalanced one where all visual information is located on one side of an experimental arena. The identity and number of visual objects is similar over both conditions. The ants search with comparable precision in both conditions. Even in the visually unbalanced condition, searches are characterized by balanced precision on both sides of the arena. This finding lends support to the idea that ants memorize the visual scenery at the nest as panoramic views from different locations. A searching ant is thus able to estimate its location with equal precision in all directions, leading to symmetrical search paths.

Dynamics, statistics, and task allocation of foraging ants.

Ant foraging is one of the most fascinating examples of cooperative behavior observed in nature. It is well studied from an entomology viewpoint, but there is currently a lack of mathematical synthesis of this phenomenon. We address this by constructing an ant foraging model that incorporates simple behavioral rules within three task groups of the ant colony during foraging (foragers, transporters, and followers), pheromone trails, and memory effects. The motion of an ant is modeled as a discrete correlated random walk, with a characteristic zigzag path that is congruent with experimental data. We simulate the foraging cycle, which consists of ants searching for food, transporting food, and depositing chemical trails to recruit and orient more ants (en masse) to the food source. This allows us to gain insights into the basic mechanism of the cooperative interactions between ants and the dynamical division of labor within an ant colony during foraging to achieve optimal efficiency. We observe a disorder-order phase transition from the start to the end of a foraging process, signaling collective motion at the population level. Finally, we present a set of time delay ODEs that corroborates with numerical simulations.

Role of trisaccharides in larval secretion of Lycaeides argyrognomon butterfly on ant attendance

Several myrmecophilous insects participate in symbiotic relationships with ants that receive sugar-rich food rewards. For instance, certain aphid species secrete honeydew containing high concentration of melezitose, which acts as a potent feeding-stimulant and attractant for ants. Lycaenid butterfly larvae possess dorsal nectary glands that secrete sugar-rich droplets for tending ants. However, the roles of sugar components in ant foraging and larva-tending activities are unknown. Lycaeides (Plebejus) argyrognomon are larvae that are frequently and facultatively attended by various ant species, including Formica japonica, on the host plant Indigofera pseudotinctoria. The larval secretions of this insect contained small amounts of trisaccharides, melezitose and maltotriose, which were not detected in the host plant’s flower nectar, and larval secretions of two sympatric and myrmecophilous lycaenids, Zizeeria maha and Everes argiades. Melezitose and maltotriose, along with sucrose, were preferred by the worker ants. Of the four sugar mixture samples that mimicked I. pseudotinctoria floral nectar and the larval secretions of three lycaenids, respectively, the L. argyrognomon mimic was the most preferred by F. japonica ants. Moreover, the removal of trisaccharides from this mimic significantly reduced its stimulatory activity to ant feedings. These results indicated that the sugar composition of L. argyrognomon larval secretions is suited to the feeding preference of F. japonica ants, and that the trisaccharide components play a key role in increasing their preference. However, only half of the ants responded to the L. argyrognomon mimic even at the concentration corresponding to the maximum total sugar concentration in the collected larval secretions. The fact that the secretions of all L. argyrognomon larvae did not have sufficient sugar levels to stimulate ant feedings suggests that the production of sugar-rich secretions and trisaccharide components is metabolically costly for the larvae and that components other than sugars may be involved in ant attendance.

Movement during the acquisition of a visual landmark may be necessary for rapid learning in ants.

We conducted laboratory experiments using Japanese carpenter ants (Camponotus japonicus) to investigate whether movement during visual learning can influence the learning performance of ant foragers. We performed three different experiments. In the first experiment, the ants could move freely in a straight maze during the visual learning. The ants in the experiments two and three were fixed to a certain position during the visual learning training. A distinct difference between these two experiments was that the ants in one experiment could perceive an approaching visual stimulus during the training, although they were fixed. After training phases, a Y-maze test was performed. One arm of the Y-maze had a visual stimulus presented to the ants during the training. We found that the ants in the first experiment showed rapid learning and correctly selected the landmark arm. However, the ants in the experiments two and three did not exhibit any preference for the chosen arm. Interestingly, we found differences in the time spent around a certain location in the Y-maze between the experiments two and three. These results suggest that movement during visual learning may influence the rapid learning of ant foragers.

Elucidating the trophic role of Tapinoma ibericum (Hymenoptera: Formicidae) as a potential predator of olive pests

AbstractAnts play a key role in improving the structure and function of local communities. They interact with plants, herbivores, predators and parasitoids and are able to change their trophic role in space and time. These features, however, make it difficult to establish the net trophic role of ants in agroecosystems. Here we aim to determine the isotopic enrichment and tissue incorporation rates in ants of the Tapinoma nigerrimum complex, which are found abundantly in olive orchards (i.e. T. ibericum), to determine their trophic role through stable isotopes analysis. We compared the isotopic signature of ants feeding on (1) natural diets, (2) experimental diets and (3) contrasting diets of ants inhabiting natural habitats and olive orchards with different management systems. Then, we contrasted our isotopic results on natural diets with the prey of ant foragers in olive orchards. Our results showed that (1) ants from olive orchards had an isotopic signature different from that of a hyper‐predator; (2) the isotopic signature did not vary significantly amongst different management practices and (3) the diet of ants in nature varies greatly on preys according to resource availability, which may be reflected in isotopic signatures. Therefore, T. ibericum is a species that can potentially contribute to control olive pests without posing a risk to other natural enemies because commonly it is not a hyper‐predator. The information presented here could be used by farmers and technicians to enhance local biological control planning and/or strategies in olive orchards.

Diacamma ants adjust liquid foraging strategies in response to biophysical constraints.

Ant foragers provide food to the rest of the colony, often requiring transport over long distances. Foraging for liquid is challenging because it is difficult to transport and share. Many social insects store liquids inside the crop to transport them to the nest, and then regurgitate to distribute to nest-mates through a behaviour called trophallaxis. Some ants instead transport fluids with a riskier behaviour called pseudotrophallaxis-holding a drop of liquid between the mandibles through surface tension. Ants share this droplet with nest-mates without ingestion or regurgitation. We hypothesised that ants optimize their liquid-collection approach depending on viscosity. Using an ant that employs both trophallaxis and pseudotrophallaxis, we investigated the conditions where each liquid-collection behaviour is favoured by measuring biophysical properties, collection time and reaction to food quality for typical and viscosity-altered sucrose solutions. We found that ants collected more liquid per unit time by mandibular grabbing than by drinking. At high viscosities ants switched liquid collection method to mandibular grabbing in response to viscosity and not to sweetness. Our results demonstrate that ants change transport and sharing methods according to viscosity-a natural proxy for sugar concentration-thus increasing the mass of sugar returned to the nest per trip.

The Geomagnetic Field (GMF) Is Necessary for Black Garden Ant (Lasius niger L.) Foraging and Modulates Orientation Potentially through Aminergic Regulation and MagR Expression.

The geomagnetic field (GMF) can affect a wide range of animal behaviors in various habitats, primarily providing orientation cues for homing or migratory events. Foraging patterns, such as those implemented by Lasius niger, are excellent models to delve into the effects of GMF on orientation abilities. In this work, we assessed the role of GMF by comparing the L. niger foraging and orientation performance, brain biogenic amine (BA) contents, and the expression of genes related to the magnetosensory complex and reactive oxygen species (ROS) of workers exposed to near-null magnetic fields (NNMF, ~40 nT) and GMF (~42 µT). NNMF affected workers' orientation by increasing the time needed to find the food source and return to the nest. Moreover, under NNMF conditions, a general drop in BAs, but not melatonin, suggested that the lower foraging performance might be correlated to a decrease in locomotory and chemical perception abilities, potentially driven by dopaminergic and serotoninergic regulations, respectively. The variation in the regulation of genes related to the magnetosensory complex in NNMF shed light on the mechanism of ant GMF perception. Overall, our work provides evidence that the GMF, along with chemical and visual cues, is necessary for the L. niger orientation process.

Biocontrol and Circadian Rhythms of Medfly larvae emergence and Monomorium subopacum ant foraging along the fruiting season in the Argan forest (Morocco)

To illuminate biocontrol traits between the Medfly pest and its predator Monomorium subopacum ant, we assessed the daily rhythm of ant foraging and Medfly larva emergence from host fruits in the argan forest. M. subopacum foraging activity and Ceratitis capitata larvae emergence were monitored in Essaouira argan forest during the fruiting season. Behavioral activities were quantified, and the circadian rhythms of the two species were determined. M. subopacum diel foraging was exhibited in a circadian bimodal rhythm with a principal morning peak and a secondary crepuscular one. Larvae’s emergence showed unimodal rhythmicity with a single morning peak with 86.42% of daily emergences. The studied behaviors of the two species showed a clear synchronization during their principal activity peaks, which suggests the importance of circadian timing in the temporal partitioning, and chance of encounters between the two species. Besides their adaptive and fundamental ecological values, the understanding of biological rhythms that govern the time of behavioral interactions and predict encounter schedules between pests and their natural enemies may provide a novel efficient tool in sustainable pest management.

Wind disrupts trail pheromone communication in the leaf-cutting ant Acromyrmexlobicornis

Although wind is a ubiquitous component of ecological systems and might affect pheromone communication, its effects have not been studied in depth. To test whether wind impacts trail pheromone behaviour, we studied the behaviour of the leaf-cutting ant Acromyrmex lobicornis in natural nests. We conducted observations under (1) unaltered scenarios with different wind intensities and (2) manipulative experiments aimed at altering trail-marking pheromone volatilization rates. In our manipulative experiments, we placed filter paper on ant trails, then removed the pheromone-marked paper 24 h later and either exposed or did not expose the marked paper to artificial wind (2 km/h) for 1 or 3 h. We then put the marked paper back on the trail and filmed ants' responses for 1 min. As controls, we filmed ants’ responses to filter paper immediately before it was removed as well as their responses to new unmarked filter paper. We measured ant flux, speed and walking sinuosity of ants over trails and filter paper, the number of ants tapping their gaster against the substrate (an indication of pheromone-marking frequency), the number of head-on encounters among workers (as alternative modes of communication) and ant body size. Wind negatively affected ant traffic by decreasing ant flux and speed. Colonies increased the number of U-turns and head-on encounters among workers, with a higher response as wind exposure time increased, but trail pheromone deposition was constant among treatments. The size frequency distribution of foragers over the treatment area was skewed towards larger ants on trails with unmarked paper and on trails with paper that had been exposed to wind for 1 or 3 h or not exposed to wind but removed for 3 h. This could be the result of small ants focusing on pheromone trail maintenance, while larger ones focused on foraging on the filter paper irrespective of whether it had been marked. Our results suggest that division of labour and behavioural plasticity might allow leaf-cutting ants to mitigate the effects of wind on pheromone communication and continue foraging. • Wind negatively affected ant traffic on trails by decreasing ant flux and speed. • Ants performed more U-turns and head-on encounters on trails exposed to wind. • Wind exposure did not affect trail pheromone deposition. • Wind exposure influenced the size frequency distribution of forager ants.

The Evolution and Ecology of Interactions Between Ants and Honeydew-Producing Hemipteran Insects

The interactions between ants and certain sap-feeding insects in the order Hemiptera are classic examples of food-for-protection mutualisms. In these associations, herbivorous hemipterans use a highly specialized, straw-like mouthpart to consume sap directly from plant phloem and xylem and, as a result, excrete a sugar-rich waste product called honeydew. Ant foragers use specialized adaptations to collect and share honeydew with nestmates and, in exchange, protect hemipterans against predators. The two key innovations underlying this interaction—hemipteran sap feeding and ant harvesting of honeydew—have driven the evolutionary success and ecological dominance of ants. These interactions also carry unique costs and benefits for each partner and are highly context dependent. Understanding the factors mediating this mutualism is critical, as these interactions have broader ecological consequences for the natural and agricultural ecosystems in which they are embedded.

Perception and recognition of a visual landmark on ant foraging

Perception and recognition of a visual landmark on ant foraging

Floral and Bird Excreta Semiochemicals Attract Western Carpenter Ants

Ant colonies have vast and diverse nutritional needs but forager ants have limited mobility to meet these needs. Forager ants would accrue significant energy savings if they were able to sense and orient toward odor plumes of both carbohydrate and protein food sources. Moreover, if worker ants, like other flightless insects, had reduced olfactory acuity, they would not recognize the specific odor signatures of diverse carbohydrate and protein sources, but they may be able to orient toward those odorants that are shared between (macronutrient) food sources. Using the Western carpenter ant, Camponotus modoc, as a model species, we tested the hypotheses that (1) food sources rich in carbohydrates (aphid honeydew, floral nectar) and rich in proteins (bird excreta, house mouse carrion, cow liver infested or not with fly maggots) all prompt long-distance, anemotactic attraction of worker ants, and (2) attraction of ants to plant inflorescences (fireweed, Chamaenerion angustifolium; thimbleberry, Rubus parviflorus; and hardhack, Spiraea douglasii) is mediated by shared floral odorants. In moving-air Y-tube olfactometer bioassays, ants were attracted to two of four carbohydrate sources (thimbleberry and fireweed), and one of four protein sources (bird excreta). Headspace volatiles of these three attractive sources were analyzed by gas chromatography-mass spectrometry, and synthetic odor blends of thimbleberry (7 components), fireweed (23 components), and bird excreta (38 components) were prepared. In Y-tube olfactometer bioassays, synthetic blends of thimbleberry and fireweed but not of bird excreta attracted ants, indicating that only the two floral blends contained all essential attractants. A blend of components shared between thimbleberry and fireweed was not attractive to ants. Our data support the conclusion that C. modoc worker ants can sense and orient toward both carbohydrate and protein food sources. As ants were selective in their responses to carbohydrate and protein resources, it seems that they can discern between specific food odor profiles and that they have good, rather than poor, olfactory acuity.

Prey–predator dynamics with adaptive protection mutualism

Prey can ease the burden of exploitation by attracting a third party that interferes with their predators. Such is the case for plant-ant or aphid-ant mutualisms, where the victim supplies food to the ants, while the ants attack or drive away the offenders. Since ants are adaptive foragers, defense services can be altered by alternative food sources (e.g., other plants, or human-supplied resource). This article explores the prey-predator-ant system, using a model that combines predator-prey population dynamics with ant optimal foraging, where ants consume prey-supplied resources or alternative resources. Feedbacks between prey-predator dynamics and adaptive ant foraging leads to complex dynamics. For a given ant colony size and supply rate of alternative resources, prey can coexist with predators at alternative stable states, or along alternative limit cycles. Limit cycles extend the scope of defensive mutualism beyond the point where ants would abandon prey in favor of alternative resources under equilibrium conditions. These results highlight the importance of trait-mediated indirect interactions for natural mutualistic–antagonistic systems, and potential outcomes of manipulating ant defense services using baits in the case of agriculture.

Are seed-dispersing ants elaiosome-limited? An experimental test in a Connecticut forest dominated by myrmecochorous plants

Food-for-dispersal mutualisms are critical sources of energy flow in ecological networks. By providing a nutrient-rich reward in the form of a fruit or seed to an animal mutualist, plants gain directed dispersal. Myrmecochory is one form of animal-mediated seed dispersal in which ants are recruited to plant seeds by providing a nutrient rich appendage called an elaiosome. It is unclear to what impact nutrients provided by elaiosomes have on ants, and whether the mutualism can tolerate disruptions to this food source. In the Northeastern U.S. mixed deciduous forest ecoregion, a diverse assemblage of herbaceous plants are dispersed by Aphaenogaster ants. Since Aphaenogaster ants gain a significant nutrient subsidy from this mutualism, it is predicted that loss of these seeds could cause reductions in their population size. To test this hypothesis, I performed a long-term removal of elaiosome food sources for ants. All seeds were removed by hand from three 50m2 plots, each paired with control plots with no removal, and a supplementation plot from April to May, from 2010 to 2012. Five years following removal treatments, I collected data on coverage of ant-dispersed plants and the abundance of seed-dispersing Aphaenogaster ants. Removal of all sources of elaiosomes resulted in modest reductions in the proportional coverage of ant-dispersed plants relative to control plots. Ant forager abundance was not impacted by the treatments five years after the removal of elaiosomes. In sum, Aphaenogaster populations may not always be limited by the availability of elaiosomes or myrmecochorous plants produce can recover quickly (<5 years) to provide enough food for these ants. As long as surrounding populations of understory forest plants are maintained, it appears that both mutualistic ants may rebound from a short-term reduction in the production of elaiosomes.

Role of vegetation structure and abiotic factors affecting the temporal dynamics of ant foraging

The study of foraging dynamics is essential to understanding the way organisms arrange themselves to reduce the effects of competition in the most diverse natural systems. The analysis of temporal foraging patterns is an important tool for understanding how ant communities respond to different environmental conditions. Thus, to verify how complexity of the vegetation and abiotic factors can influence ground-dwelling ants communities, we evaluated the foraging temporal patterns in three types of landscapes (Grassland, Arboreal Caatinga, Shrub Caatinga) in an área of dry seasonal rainforest. These environments were characterized by abundance of plant life forms. The ants were collected by pitfall trap, arranged in six rows each with five traps. The pitfalls were inspected every hour from 7:00 am to 6:00 pm, and temperature and humidity data were taken at the same time. The foraging structure of ant communities presented a nested pattern between the phytophysiognomies, but with variation in the observed metric values. For less complex environments, foraging activity was restricted to preferential times, demonstrating a temporal niche partition. Despite more complex environments have a greater richness of species foraging throughout the day, we found greater diversity in environment with intermediate complexity. Temperature influences the richness of foraging ants throughout the day, but we found no effect on diversity. Our results indicate that, although temperature may influence the temporal dynamics of ground-dwelling ant communities, changes in the structural complexity of the environment affect the foraging activity among species, influencing ant-mediated ecological processes.