Food patch use of Japanese quail (Coturnix japonica) varies with personality traits.

BACKGROUND: The classic optimal foraging theory (OFT) predicts animals' food patch use assuming that individuals in a population use the same strategy while foraging. However, due to the existence of animal personality, i.e. repeatable inter-individual differences and intra-individual consistency in behaviours over time and/or across contexts, individuals often exhibit different behavioural strategies, challenging the basic assumptions of the OFT. Here, we tested whether personality traits (boldness and exploration in open arena) of Japanese quail (Coturnix japonica, 38 females and 34 males) influenced their patch use in two foraging experiments with different inter-patch distances (i.e. 2 m in Experiment 1 and 3 m in Experiment 2). RESULTS: The total feeding time and food intake of individuals did not differ between Experiment 1 and 2, but in both experiments, proactive (i.e. bolder and more explorative) individuals had longer feeding time and higher food intake than reactive individuals. In Experiment 1, proactive quails changed patches more frequently and had shorter mean patch residence time than reactive individuals, while the effects were not significant in Experiment 2. The quails reduced patch residence time along with feeding, and this trend was weakened in Experiment 2 which had longer inter-patch distance. CONCLUSIONS: The above results suggest that personality traits affect animals' patch use, while the effects might be weakened with longer inter-patch distance. Our study highlights that animal personality should be considered when investigating animals' foraging behaviours because individuals may not adopt the same strategy as previously assumed. Furthermore, the interaction between personality traits and inter-patch distances, which is related to movement cost and capacity of information gathering, should also be considered.

Competition for light induces metal accumulation in a metal hyperaccumulating plant.

Plants can respond to competition with a myriad of physiological or morphological changes. Competition has also been shown to affect the foraging decisions of plants belowground. However, a completely unexplored idea is that competition might also affect plants' foraging for specific elements required to inhibit the growth of their competitors. In this study, we examined the effect of simulated competition on root foraging and accumulation of heavy metals in the metal hyperaccumulating perennial plant Arabidopsis halleri, whose metal accumulation has been shown to provide allelopathic ability. A. halleri plants originating from both metalliferous and non-metalliferous soils were grown in a "split-root" setup with one root in a high-metal pot and the other in a low-metal one. The plants were then assigned to either simulated light competition or no-competition (control) treatments, using vertical green or clear plastic filters, respectively. While simulated light competition did not induce greater root allocation into the high-metal pots, it did result in enhanced metal accumulation by A. halleri, particularly in the less metal-tolerant plants, originating from non-metalliferous soils. Interestingly, this accumulation response was particularly enhanced for zinc rather than cadmium. These results provide support to the idea that the accumulation of metals by hyperaccumulating plants can be facultative and change according to their demand following competition.

A comparative analysis of colour preferences in temperate and tropical social bees.

The spontaneous occurrence of colour preferences without learning has been demonstrated in several insect species; however, the underlying mechanisms are still not understood. Here, we use a comparative approach to investigate spontaneous and learned colour preferences in foraging bees of two tropical and one temperate species. We hypothesised that tropical bees utilise different sets of plants and therefore might differ in their spontaneous colour preferences. We tested colour-naive bees and foragers from colonies that had been enclosed in large flight cages for a long time. Bees were shortly trained with triplets of neutral, UV-grey stimuli placed randomly at eight locations on a black training disk to induce foraging motivation. During unrewarded tests, the bees' responses to eight colours were video-recorded. Bees explored all colours and displayed an overall preference for colours dominated by long or short wavelengths, rather than a single colour stimulus. Naive Apis cerana and Bombus terrestris showed similar choices. Both inspected long-wavelength stimuli more than short-wavelength stimuli, whilst responses of the tropical stingless bee Tetragonula iridipennis differed, suggesting that resource partitioning could be a determinant of spontaneous colour preferences. Reward on an unsaturated yellow colour shifted the bees' preference curves as predicted, which is in line with previous findings that brief colour experience overrides the expression of spontaneous preferences. We conclude that rather than determining foraging behaviour in inflexible ways, spontaneous colour preferences vary depending on experimental settings and reflect potential biases in mechanisms of learning and decision-making in pollinating insects.

Do Common Marmosets (Callithrix jacchus) Use Scent to Communicate Information about Food Resources?

Many animals use olfactory cues to signal information about food resources; however, this particular use of scent has received little attention in primates. Common marmosets (Callithrix jacchus) are exudativores that gouge bark to elicit exudate production and frequently deposit scent marks at gouge holes. We conducted preliminary tests of the hypothesis that common marmosets use olfactory cues to communicate information about exudate value, with more desirable resources targeted for marking. We performed choice experiments on two captive male marmosets. The animals were presented with: (1) a urine scent-marked and unmarked food resource, and (2) a high and low value food resource (i.e., greater/lesser food volumes). Marmosets placed more scent marks on high, compared to low, value food resources. Animals also spent more time gouging, removed more bark and more frequently revisited high versus low value food resources. Lastly, scent-marked foods were gouged more often than unmarked foods. Our findings support the hypothesis that marmosets use scent marking and olfaction to convey information about food resources, although verification in a larger sample is needed. Nonetheless, the demonstrated link between food value and scent marking suggests that olfactory signals may aid marmoset foraging decisions.

Stingless bees (Melipona scutellaris) learn to associate footprint cues at food sources with a specific reward context.

Foraging insects leave chemical footprints on flowers that subsequent foragers may use as indicators for recent flower visits and, thus, potential resource depletion. Accordingly, foragers should reject food sources presenting these chemical cues. Contrasting this assumption, experimental studies in stingless bees (Apidae, Meliponini), so far, demonstrated an attractive effect of footprints. These findings lead to doubts about the meaning of these chemical cues in natural foraging contexts. Here, we asked whether foragers of stingless bees (Melipona scutellaris) use footprints according to the previously experienced reward level of visited food sources. Bees were trained to artificial flower patches, at which the reward of a flower either decreased or, alternatively, increased after a visit by a forager. Individuals were allowed a total of nine foraging bouts to the patch, after which their preference for visited or unvisited flowers was tested. In the choice tests, bees trained under the decreasing reward context preferred unvisited flowers, whereas individuals trained under the increasing reward context preferred visited flowers. Foragers without experience chose randomly between visited and unvisited flowers. These results demonstrate that M. scutellaris learns to associate unspecific footprint cues at food sources with differential, specific reward contexts, and uses these chemical cues accordingly for their foraging decisions.

Contrasting patterns of short-term indirect seed-seed interactions mediated by scatter-hoarding rodents.

It is well known that direct effects of seed predators or dispersers can have strong effects on seedling establishment. However, we have limited knowledge about the indirect species interactions between seeds of different species that are mediated by shared seed predators and/or dispersers and their consequences for plant demography and diversity. Because scatter-hoarding rodents as seed dispersers may leave some hoarded seeds uneaten, scatter hoarding may serve to increase seed survival and dispersal. Consequently, the presence of heterospecific seeds could alter whether the indirect interactions mediated by scatter-hoarding rodents have a net positive effect, creating apparent mutualism between seed species, or a net negative effect, creating apparent competition between seed species. We present a testable framework to measure short-term indirect effects between co-occurring plant species mediated by seed scatter-hoarding rodents. We tested this framework in a subtropical forest in south-west China using a replacement design and tracked the fate of individually tagged seeds in experimental patches. We manipulated the benefits to rodents by using low-tannin dormant chestnuts as palatable food and high-tannin non-dormant acorns as unpalatable food. We found that seed palatability changed the amount of scatter hoarding that occurred when seeds co-occurred either among or within patches. Consistent with our predictions, scatter-hoarding rodents created apparent mutualism through increasing seed removal and seed caching, and enhancing survival, of both plant species in mixed patches compared with monospecific patches. However, if we ignore scatter hoarding and treat all seed harvest as seed predation (and not dispersal), then apparent competition between palatable chestnuts and unpalatable acorns was also observed. This study is the first to demonstrate that foraging decisions by scatter-hoarding animals to scatter hoard seeds for later consumption (or loss) or consume them can influence indirect effects among co-occurring seeds, and rodent-mediated indirect effects vary depending on whether the harvested seeds are hoarded or eaten.

Ecological factors predictive of wild spider monkey (Ateles belzebuth) foraging decisions in Yasuní, Ecuador.

Because fruiting trees are uncommon in tropical forests, frugivorous primates experience selective pressure to incorporate knowledge of where to find feeding trees, what to expect when they arrive there, and when they can return after depleting a tree. I investigated these abilities in wild spider monkeys (Ateles belzebuth) in Yasuní, Ecuador, by analyzing the characteristics of feeding trees that drive foraging decisions. Foraging data were derived from four 2-week follows of focal adult females, conducted between May and December 1999, during which I measured and mapped all trees in which the focal subject fed, feeding bout duration, and the number of conspecifics feeding simultaneously with the focal. Taking into account the order in which feeding trees were visited across each follow, I analyzed each foraging decision from the second week of a follow, treating all previously visited trees as options for visits. I scored each option tree in terms of nine ecological variables, including the distance from the decision to each location tree, DBH, recent feeding time and mean feeding times for the focal and other monkeys present, and the interval in hours between the foraging decision and the most recent visit to each option tree. I then examined the predictive strength of the model using logistic regression analysis, comparing characteristics of selected trees to those not selected. The overall model successfully predicted trees selected by focal monkeys (r(2) = 0.27). Monkeys preferentially moved to nearby, large canopy trees, in which previous feeding success was high, and which were visited after an interval of 3.5 days. Interval mattered most for medium and large trees, but did not predict selection for trees <10 cm DBH. Despite the large home range and large numbers of trees, Yasuní spider monkeys appeared to integrate spatial, value, and temporal information when deciding where to feed.

Do primates flexibly use spatio-temporal cues when foraging?

Foraging in seasonal environments can be cognitively demanding. Comparative studies have associated large brain size with a frugivorous diet. We investigated the ability of three semi-free-ranging primate species with different degrees of frugivory (Ntrials: Macaca tonkeana = 419, Macaca fascicularis = 197, Sapajus apella = 346) in developing a mental representation of the spatio-temporal distribution of food using foraging experiments. Forty-two boxes were fixed on trees, and each week ("season"), some of them were filled with fruits which were either highly preferred, or less preferred. Spatial (geometrical panels) and temporal (peel skin of the available fruit) cues were present at each season to indicate where (food location), what (which food) was available, and when. To test the flexible use of the cues in primate foraging behaviour, we first removed the spatial and temporal cues one at a time, and then, we manipulated the "seasonal" order of the available fruit. We compared the foraging performances in the absence and the presence of the cues and during the usual and unusual seasonal order. The average proportion of baited boxes chosen by the subjects in presence of both cues was high (between 73% and 98%) for all species. The primates seemed to remember the spatio-temporal food availability (or used other cues) because no difference was found between trials with or without our spatial and temporal cues. When the usual seasonal pattern was changed, they flexibly adjusted the feeding choice by using the provided temporal cues. We discuss these results also in view of a possible experimental bias.

Wild common marmosets (Callithrix jacchus) employ spatial cognitive abilities to improve their food search and consumption: an experimental approach in small-scale space.

The ability of an animal to integrate and retain spatial information of resources often depends on the spatial memory and the speed at which this memory crystallizes. These become especially important once foragers reach their target area. However, very little is known about how wild common marmosets encode spatial information when feeding rewards are near to each other in a small-scale space. With this in mind, we performed field experiments to test foraging decisions related to a small-scale space setting. Specifically, we tested the (i) short- and (ii) long-term spatial memory, as well as (iii) the ability to remember the spatial location of resources after a single visit (one-trial spatial learning). The study was conducted with four groups of wild common marmosets (Callithrix jacchus) living in a semiarid Caatinga environment. We observed that individuals were able to retain spatial information of food sources on both a short- and long-term basis and to learn the spatial location of these resources after a single visit. We suggest that such abilities during foraging can improve the search for scattered resources with fluctuations of food availability. Presumably, this would be particularly advantageous in Caatinga, with its vegetation exhibiting asynchronous phenological patterns. Altogether, our results demonstrate that common marmosets employ all three studied spatial cognitive abilities to improve their food search and consumption.

Where and what? Frugivory is associated with more efficient foraging in three semi-free ranging primate species.

Foraging in seasonal environments can be cognitively challenging. Comparative studies have associated brain size with a frugivorous diet. We investigated how fruit distribution (where) and preference (what) affect foraging decisions in three semi-free ranging primate species with different degrees of frugivory: Macaca tonkeana (N indiv = 5; N trials = 430), M. fascicularis (N indiv = 3; N trials = 168) and Sapajus apella (N indiv = 6; N trials = 288). We used 36 boxes fixed on trees and filled with highly and less preferred fruits with different (weekly) spatio-temporal distributions. Individuals were tested in two conditions: (1) same fruit provided concurrently in the same quantity but in a scattered and in a clumped distribution, (2) highly preferred fruit was scattered while the less preferred was clumped. Generally, primates preferred feeding first on the boxes of the clumped distribution in both conditions, with the more frugivorous species at a higher degree than the less frugivorous species in condition (1), but not (2). Therefore, what fruit was available changed the foraging decisions of the more frugivorous species who also engaged more in goal-directed travel. When feeding on preferred fruit, primates probably maximized foraging efficiency regardless of their degree of frugivory. Our findings emphasize that the food type and distribution may be a preponderant driver in cognitive evolution.

Taking a trip to the shelf: Behavioral decisions are mediated by the proximity to foraging habitats in the black-legged kittiwake.

For marine top predators like seabirds, the oceans represent a multitude of habitats regarding oceanographic conditions and food availability. Worldwide, these marine habitats are being altered by changes in climate and increased anthropogenic impact. This is causing a growing concern on how seabird populations might adapt to these changes. Understanding how seabird populations respond to fluctuating environmental conditions and to what extent behavioral flexibility can buffer variations in food availability can help predict how seabirds may cope with changes in the marine environment. Such knowledge is important to implement proper long-term conservation measures intended to protect marine predators. We explored behavioral flexibility in choice of foraging habitat of chick-rearing black-legged kittiwakes Rissa tridactyla during multiple years. By comparing foraging behavior of individuals from two colonies with large differences in oceanographic conditions and distances to predictable feeding areas at the Norwegian shelf break, we investigated how foraging decisions are related to intrinsic and extrinsic factors. We found that proximity to the shelf break determined which factors drove the decision to forage there. At the colony near the shelf break, time of departure from the colony and wind speed were most important in driving the choice of habitat. At the colony farther from the shelf break, the decision to forage there was driven by adult body condition. Birds furthermore adjusted foraging behavior metrics according to time of the day, weather conditions, body condition, and the age of the chicks. The study shows that kittiwakes have high degree of flexibility in their behavioral response to a variable marine environment, which might help them buffer changes in prey distribution around the colonies. The flexibility is, however, dependent on the availability of foraging habitats near the colony.

Appetitive and aversive learning of plants odors inside different nest compartments by foraging leaf-cutting ants.

Cues inside the nest provide social insect foragers with information about resources currently exploited that may influence their decisions outside. Leaf-cutting ants harvest leaf fragments that are either further processed as substrate for their symbiotic fungus, or disposed of if unsuitable. We investigated whether Acromyrmex ambiguus foragers develop learned preferences for olfactory cues they experienced either in the fungus or in the waste chamber of the nest. Foragers' olfactory preferences were quantified as a choice between sugared papers disks scented with a novel odor and with the odor experienced in one of the nest compartments, before and after odor addition. Odors incorporated in the fungus chamber led to preferences towards paper disks smelling of them. Conversely, odors experienced in the waste chambers led to avoidance of similarly-scented disks. To investigate context-specificity of responses, we quantified learned preferences towards an odor that occurred first in the fungus chamber, and 14 h later in the waste chamber. Foragers initially developed a preference for the odor added in the fungus chamber that turned into avoidance when the same odor solely occurred later in the waste chamber. Avoidance of plants could also be induced in a more natural context, when fresh leaf disks of novel plants, privet or firethorn, were presented in the waste chamber. We conclude that learned acceptance or rejection of suitable plants by foragers depend on the learning context: smells can lead to appetitive learning when present in the fungus garden, or to avoidance learning when they occur at the dump.

Behavioral responses to encounter of fishing boats in wandering albatrosses.

Animals are attracted to human food subsidies worldwide. The behavioral response of individuals to these resources is rarely described in detail, beyond chances of encounters. Seabirds for instance scavenge in large numbers at fishing boats, triggering crucial conservation issues, but how the response to boats varies across encounters is poorly known. Here we examine the behavioral response of wandering albatrosses (Diomedea exulans), equipped with GPS tags, to longline fishing boats operating near their colony for which we had access to vessel monitoring system data. We distinguish between encounters (flying within 30 km of a boat) and attendance behavior (sitting on the sea within 3 km of a boat), and examine factors affecting each. In particular, we test hypotheses that the response to encountered boats should vary with sex and age in this long-lived dimorphic species. Among the 60% trips that encountered boats at least once, 80% of them contained attendance (but attendance followed only 60% of each single encounter). Birds were more attracted and remained attending longer when boats were hauling lines, despite the measures enforced by this fleet to limit food availability during operations. Sex and age of birds had low influence on the response to boats, except the year when fewer boats came fishing in the area, and younger birds were attending further from boats compared to older birds. Net mass gain of birds was similar across sex and not affected by time spent attending boats. Our results indicate albatrosses extensively attend this fishery, with no clear advantages, questioning impacts on foraging time budgets. Factors responsible for sex foraging segregation at larger scale seem not to operate at this fleet near the colony and are not consistent with predictions of optimal foraging theory on potential individual dominance asymmetries. This approach complements studies of large-scale overlap of animals with human subsidies.

Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits (Poecile montanus) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

Caching for where and what: evidence for a mnemonic strategy in a scatter-hoarder.

Scatter-hoarding animals face the task of maximizing retrieval of their scattered food caches while minimizing loss to pilferers. This demand should select for mnemonics, such as chunking, i.e. a hierarchical cognitive representation that is known to improve recall. Spatial chunking, where caches with the same type of content are related to each other in physical location and memory, would be one such mechanism. Here we tested the hypothesis that scatter-hoarding eastern fox squirrels (Sciurus niger) are organizing their caches in spatial patterns consistent with a chunking strategy. We presented 45 individual wild fox squirrels with a series of 16 nuts of four different species, either in runs of four of the same species or 16 nuts offered in a pseudorandom order. Squirrels either collected each nut from a different location or collected all nuts from a single location; we then mapped their subsequent cache distributions using GPS. The chunking hypothesis predicted that squirrels would spatially organize caches by nut species, regardless of presentation order. Our results instead demonstrated that squirrels spatially chunked their caches by nut species but only when caching food that was foraged from a single location. This first demonstration of spatial chunking in a scatter hoarder underscores the cognitive demand of scatter hoarding.

Multiple-stage decisions in a marine central-place forager.

Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator-prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.

Brainless but Multi-Headed: Decision Making by the Acellular Slime Mould Physarum polycephalum.

Because of its peculiar biology and the ease with which it can be cultured, the acellular slime mould Physarum polycephalum has long been a model organism in a range of disciplines. Due to its macroscopic, syncytial nature, it is no surprise that it has been a favourite amongst cell biologists. Its inclusion in the experimental tool kit of behavioural ecologists is much more recent. These recent studies have certainly paid off. They have shown that, for an organism that lacks a brain or central nervous system, P. polycephalum shows rather complex behaviour. For example, it is capable of finding the shortest path through a maze, it can construct networks as efficient as those designed by humans, it can solve computationally difficult puzzles, it makes multi-objective foraging decisions, it balances its nutrient intake and it even behaves irrationally. Are the slime mould's achievements simply "cute", worthy of mentioning in passing but nothing to take too seriously? Or do they hint at the fundamental processes underlying all decision making? We will address this question after reviewing the decision-making abilities of the slime mould.

Influence of the amount of food resources in the foraging behavior of Nasutitermes corniger (Motschulsky) / Influência da quantidade de madeira no comportamento de forrageamento de Nasutitermes corniger (Motschulsky)

Food scarcity or abundance are factors regulating termites' foraging behavior in general. The aim of the present study is to evaluate the influence of four amounts of Eucalyptus grandis on foraging behavior events shown by worker and soldier of Nasutitermes corniger during laboratory tests. The tests were carried out with adult and active N. corniger colonies found in nests collected in the field, which were stored in glass cubes connected to the test arenas. Four different amounts of wood blocks were used in the tests and each amount concerned a treatment and defined a different experimental group: 1, 2, 3 and 4 blocks/arenas, with 5 repetitions. Each test lasted 60 minutes and consisted in observing, or not, the occurrence of behavioral events shown by foragers when they had contact with the treatment. The duration of each event was recorded, whenever it was observed. The number of recruited foragers and the number of workers consuming the blocks were recorded at the end of each test applied to each treatment. Nasutitermes corniger presented the three behavioral events in all treatments; however, there was not significant difference between treatments in the occurrence of the two first events, in the time taken from test start to the occurrence of a new event, in the number of recruited termites and in the number of gnawing workers. Only workers' mass recruiting was influenced by the amount of wood available. The occurrence of this event was significantly higher in treatments with greater amounts of wood. Thus, N. corniger adjusts its mass recruitment behavior in response to available food amount, which should be considered when developing baiting system for its control. (AU)

A escassez ou abundância de alimento são fatores que regulam o forrageamento do térmitas em geral. No presente estudo, avaliou-se a influência de quatro quantidades de madeira de Eucalyptus grandis em eventos comportamentais do forrageamento exibidos por operárias e soldados de Nasutitermes corniger em testes de laboratório. Os testes foram realizados com colônias maduras e ativas de N. cornigerpresentes em ninhos coletados a campo, os quais foram acondicionados em cubas de vidro conectadas a arenas testes. Blocos de madeira de mesma dimensão foram ofertados aos térmitas em quatro quantidades: 1, 2, 3 e 4 blocos/arena, com 5 repetições. Cada teste durou 60 minutos e consistiu na observação ou não da ocorrência de eventos comportamentais exibidos pelos forrageadores quando foi dado acesso a cada tratamento. Quando cada evento foi observado, o tempo de sua duração foi registrado. Ao final de cada teste registrou-se, em cada tratamento, o número de térmitas forrageadores recrutados e o número de operários consumindo os blocos. Observou-se que N. corniger exibiu os três eventos comportamentais em todos os tratamentos. Todavia, não houve diferença significativa entre os tratamentos com relação à ocorrência dos dois primeiros eventos, aos tempos transcorridos desde o início do teste até a ocorrência de cada evento, aos números de térmitas recrutados e ao número de operários em roedura. Apenas a ocorrência de recrutamento em massa dos operários foi influenciada pela quantidade de madeira ofertada, sendo que foi significativamente superior quando se ofertou os blocos de madeira na maior quantidade. Dessa forma, N. corniger ajusta seu comportamento de recrutamento em massa em resposta a quantidade de alimento disponível, o que deve ser considerado ao se desenvolver um sistema de isca para seu controle. (AU)