Behavioral seasonality in Mahale chimpanzees

To analyze how the chimpanzees in the Mahale Mountains National Park, Tanzania, change their grouping pattern, activity budget, travel speed, and travel distance within an annual cycle, I divided 1-year data into four periods. The Mahale chimpanzees have the behavioral flexibility to adapt to various climates and exhibited at least three behavioral seasons. In the early wet season, chimpanzees formed a few, large parties, and spent much time feeding on insects and animal meat. In the early and late dry seasons, chimpanzees maintained party sizes as large as in the early wet season, and traveled distances similar to the early wet season, but spent the most time feeding and traveling within the year. By contrast, in the late wet season chimpanzee parties broke up into more numerous, small groups, and traveled slowly over shorter distances. Although time spent feeding and traveling were the same as that in the early wet season, time spent feeding on terrestrial herbaceous vegetation (THV) was the highest in the year. The results suggest that chimpanzees travel longer, faster, and farther in seasons when they form large parties.     

Time Budgets and Territory Size: Some Simultaneous Optimization Models for Energy Maximizers

A set of optimization models in two variables of choice, territorysize and time spent patrolling for intruders, is presented forenergy maximizers. Models vary in the curvilinearity of therelationship between territory circumference and both intrusionrate and cost of expelling a single intruder. Models are analyzedboth with and without constraints; constraints are on processingrate and on the time spent patrolling, feeding and activelydefending. The models all include the concept of "intruder equilibrium,"an equilibrial density of intruders in a territory resultingfrom a balance between intrusion rate and expulsion by the defender.This equilibrial density can be considered a measure of territorialexclusiveness. The two-variable models predict effects on territory size andpatrol time of variation in food density, intrusion rate, costsof expelling a single intruder in energy and time, food-consumptionrate of an intruder, area of detection while patrolling, totaltime available for territorial and feeding activities, timeto eat a unit of food energy, energy cost of patrol per time,and processing-rate capacity. With increasing intruder rate,optimal territory size usually decreases, whereas optimal patroltime behaves much more irregularly. With increasing food density,optimal patrol time usually decreases, whereas optimal territorysize behaves irregularly. In particular, when intrusion rateand expulsion costs accelerate sufficiently with increasingterritory size and no constraints exist, the higher the fooddensity the smaller the optimal territory size. When food densityis large enough for a constraint to be effective, the oppositerelation can hold and will always hold for a processing constraint. When a particular parameter changes, optimal territory sizeand optimal patrol time may covary or one may increase whilethe other decreases, depending on the parameter and model. A new set of one-variable models is suggested by the two-variablemodels; models optimizing patrol time while holding territorysize constant could correspond to a tightly packed system ofterritories initially determined by settlement patterns. A unifiedonevariable analysis suggests that how food density affectsterritory size when patrol time is constant depends upon whethera constraint is operating: Provided that invasion rate doesnot vary with density of intruders on the territory, time minimizersand constrained energy maximizers decrease territory size withincreasing food density; unconstrained energy maximizers dothe opposite. The addition of a second optimization variable to a one-variablemodel can change qualitative predictions about variation inparticular parameters (e.g., food density) and can increasethe number of parameters predicted to affect optimal territorysize and patrol time.     

Mate-locating behavior of the butterfly Lethe diana (Lepidoptera: Satyridae): do males diurnally or seasonally change their mating strategy?

The mate-locating behavior of male butterflies has been classified into two major types, territorial and patrolling. Territorial males defend a specific site, whereas patrolling males fly around a wider area without having to defend a site. In this study, I investigated the use of these tactics by males of the satyrine butterfly, Lethe diana. A previous study suggested that the males of L. diana change their mate-locating behavior during the day (they patrol in the morning and defend territories in the afternoon) and that patrolling is the primary mating strategy, whereas defending territories is a supplementary one. In the present study, I found that the daily activity pattern of the males of L. diana was similar to that described in the previous study: males often flew around in the morning and competed for territories in the afternoon. However, contrary to the previous study, all courtships and copulations were performed within male territories during their territorial activity. Closer observations revealed that copulations found in male territories were achieved by the owner of the territory. Males tended to feed in the morning, suggesting that the males flying in the morning searched for food rather than females. I conclude that territory holding is the primary male matelocating tactic in L. diana. I further found that, in summer, males exhibited territorial behavior later than in spring or autumn, which may be a strategy for preventing heat stress.     

The effects of lactation and infant care on adult energy budgets in wild siamangs (Symphalangus syndactylus)

In mammals with biparental care of offspring, males and females may bear substantial energetic costs of reproduction. Adult strategies to reduce energetic stress include changes in activity patterns, reduced basal metabolic rates, and storage of energy prior to a reproductive attempt. I quantified patterns of behavior in five groups of wild siamangs (Symphalangus syndactylus) to detect periods of high energetic investment by adults and to examine the relationships between infant care and adult activity patterns. For females, the estimated costs of lactation peaked at around infant age 4–6 months and were low by infant age 1 year, whereas the estimated costs of infant‐carrying peaked between ages 7 and 12 months, and approached zero by age 16 months. There was a transition from primarily female to male care in the second year of life in some groups. Females spent significantly less time feeding during lactation than during the later stages of infant care, suggesting that female siamangs do not use increased food intake to offset the costs of lactation. Female feeding time was highest between infant ages 16 and 21 months, a period of relatively low female investment in the current offspring that coincided with the period of highest male investment in infant care. This suggests that male care may reduce the costs of infant care for females in the later stages of a reproductive attempt. The female energy gain resulting from male care was likely invested in somatic maintenance and future reproduction, rather than the current offspring. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Mating Tactics in Response to Costs Incurred by Mating with Multiple Males in Wild Female Japanese Macaques

We investigated the costs of mating with multiple males in terms of feeding time, traveling distances, sexual proceptivity, and male aggression, for wild female (Macaca fuscata yakui) on Yakushima Island, Japan. We analyzed all-day focal sampling data from 7 females during the mating season (Sept.-Nov. 1996). On days when estrous females copulated with multiple males, they decreased their feeding time to half that of anestrous days, traveled longer distances, showed more proceptive sexual behaviors and received more aggression from subordinate males than on days when they copulated with only the 1st-ranking male. On days when females copulated with only the 1st-ranking male, they showed no difference in feeding time with that of anestrous days, and expended less effort than the above mating pattern because of short traveling distances, diminished sexual proceptivity and a lower frequency of aggression received. The results suggest that the costs of estrous vary according to female sexual proceptivity and the number and social status of mating partners. Female Japanese macaques exhibit a mixed mating strategy over prolonged estrous periods, which may provide females with opportunities to maximize the benefits of copulating with multiple males and to minimize the costs of estrus by mating with only the 1st-ranking male. During an estrous cycle, females may be adjusting efforts for reproduction and survival; i.e., mating vs. feeding.     

Contrasting Alternative Hypotheses to Explain Rut‐Induced Hypophagia in Territorial Male Chamois

Male ungulates in temperate environments often show a severe reduction in time spent foraging during the mating season. Several hypotheses have been put forward to explain this phenomenon but, so far, no study investigated the proximate mechanisms underlying rut‐induced hypophagia in ungulates using alternative mating tactics (AMTs). Between the pre‐rut and post‐rut of 2011 and 2012, we collected data on activity budgets, parasite burden and androgen levels of territorial and non‐territorial male Alpine chamois Rupicapra r. rupicapra in the Gran Paradiso National Park (Italy). We aimed to investigate whether AMTs showed similar reduction in time spent foraging during the mating period and to test the predictions underlying alternative hypotheses that may explain rut‐induced hypophagia. Only territorial males showed a significant reduction in time spent foraging during the rut; the lack of correlation between proportion of time spent foraging and androgen metabolites or parasite burden did not fully support the physiological and the parasite hypotheses, while the foraging constraint, the energy‐saving and the physical rest hypotheses could not be discounted. Territorial males decreased the time spent lying down from the pre‐rut to the rut, but not their foraging‐to‐lying‐down ratio. During the mating period, we found negative correlations between time spent foraging or lying down and time spent rutting. Our data suggest that territorial males’ behaviour is more consistent with the foraging constraint hypothesis than with the energy‐saving hypothesis previously suggested. Yet, during the rut territorial males did not maximise their foraging time, and the optimisation of their energy balance could rather depend upon feeding on relatively high‐quality plants. This suggestion – possibly named ‘forage quality hypothesis’ – now requires further investigations. This work showed that alternative mating behaviours may underlie different patterns of foraging strategies: we suggest that tests of alternative hypotheses to explain rut‐induced hypophagia within ungulate populations should not ignore the occurrence of AMTs.     

The Foraging Costs of Mating Effort in Male Chimpanzees (Pan troglodytes schweinfurthii)

Costs of mating effort can affect the reproductive strategies and lifetime fitness of male primates, but interspecific and interindividual variation in the magnitude and distribution of costs is poorly understood. Male costs have primarily been recognized in seasonally breeding species that experience concentrated periods of mating competition. Here, we examine foraging costs associated with male mating effort in chimpanzees (Pan troglodytes schweinfurthii), a polygynandrous species, in which mating opportunities occur intermittently throughout the year. To quantify male feeding, aggression, and mating, we conducted focal follows on 12 males in a wild community (Kanyawara, Kibale National Park, Uganda) for 11 mo. Males fed less on days when high-value mating opportunities (estrous parous females) were available than on days without any mating opportunities. Reductions in feeding time were related to increased rates of aggression and copulation, indicating that the proximate cause of changes in male foraging was mating effort. Surprisingly, however, there was no relationship between dominance rank and the extent to which feeding time was reduced. High costs of mating effort may reduce the degree of reproductive skew and limit the use of possessive tactics in chimpanzees. We suggest that male bonding in chimpanzees may be favored not only for its benefits but because intragroup competition is so costly. Our results complement the available data on mammals, and primates in particular, by showing that mating effort can have measurable foraging costs even in species, in which breeding is aseasonal and only moderately skewed.     

Feeding Consequences of Hand and Foot Disability in Wild Adult Chimpanzees (<Emphasis Type="Italic">Pan troglodytes schweinfurthii</Emphasis>)

Many wild primates experience long-term limb disability, and their ability to cope with disability has implications for survival and fitness. We quantified the arboreal feeding and postural behaviors of adult chimpanzees to study the consequences of physical limb disabilities. We collected behavioral data for a total of 8 mo on chimpanzees at Sebitoli, Kibale National Park, Uganda, focusing on the time spent feeding, common feeding tree species, body postures, and substrate use. Of the 51 chimpanzees we observed, 16 (31%) exhibited limb anomalies, which varied in form and severity. Disabled chimpanzees climbed as high as chimpanzees without disabilities and did not differ from nondisabled chimpanzees in the amount they used feeding tree species. Adult chimpanzees with severe hand disability spent significantly more time feeding than nondisabled individuals. In addition, manually disabled adults did not suspend themselves from branches during feeding as frequently as nondisabled adults and used larger substrates for gripping and sitting than nondisabled adults. These results indicate that disabled individuals compensate to carry out feeding activities in trees.     

What drives patrolling behaviour by nasute termites? A model and an empirical assessment

Animals have evolved a number of antipredator strategies, which can reflect both intrinsic and extrinsic factors related to predation risk. In many termite species, a chemically armed soldier caste known as “nasute” engages in patrols upon breaching of foraging galleries, suggesting an adaptive response to imminent risk of mortality. However, the drivers of this collective behaviour are poorly understood. Here, I describe and test a qualitative model of patrolling behaviour upon gallery breaching by the arboreal termite Nasutitermes corniger (Termitidae: Nasutitermitinae). Patrolling behaviour is postulated to change throughout colony ontogeny, thus scaling with colony size. Further, this pattern is expected to be modulated by extrinsic cues for predation risk. Accordingly, patroller number increased with tree circumference at breast height, a surrogate for colony size. However, for any tree size, more soldiers engaged in patrols after repeated breaching, suggesting sensitization to structural damage. In parallel, patrolling rate (i.e., patroller number per time unit) was higher in smaller trees due to a disproportionate increase in patrol duration with patroller number. However, this response only occurred after repeated breaching; otherwise, patrolling rate was constant across tree sizes. Overall, patrolling behaviour by N. corniger seems to reflect intrinsic risks related to colony growth, adjusted by the extrinsic risk imposed by structural damage.     

Diurnal and seasonal changes in the mate-locating behavior of the satyrine butterfly <Emphasis Type="Italic">Lethe diana</Emphasis>

The time schedule of mate-locating behavior in the male satyrine butterfly Lethe diana was studied. Males displayed territorial behavior only in the afternoon, but it was not known whether they attempted to locate mates in the morning. In order for males of most butterfly species to mate with a virgin female, it would be most effective to initiate mate-locating behavior in the morning, when synchronous eclosions occur. Males of L.diana flew patrols in the morning and displayed territorial behavior in the afternoon. The cost of territorial behavior is probably less than that of patrolling, as territorial flights are shorter than those when patrolling. The temporal switching of mate-locating behavior is theoretically favored, since the reproductive value of females decreases later in the day, when males perform the less costly mate-locating behavior. Thus, the diurnal switching of male mate-locating behavior may be an adaptive strategy in response to the rapid decline in the reproductive value of females over the course of a day.     

Challenges facing the introduction of SMART patrols in a game reserve,western Tanzania

The spatial monitoring and reporting tool (SMART) is being implemented in Tanzania's protected areas to help improve the efficiency of ranger patrols. Unfortunately, there has been no attempt to understand users' perspectives regarding site‐specific factors likely to affect its use. In this study, we investigated the perspectives of staff in Ugalla Game Reserve, a protected area in western Tanzania, to understand the challenges that affect the use of SMART in the reserve. The main challenges included a lack of motivation to use SMART, limited knowledge of SMART among game scouts, insufficient ranger capacity, difficulty collecting data during night patrols, limited resources for patrolling, and difficulty accessing some remote sections of Ugalla. The presence of trophy hunting company patrol teams has led Ugalla rangers to concentrate their effort in less‐patrolled areas. We recommend introducing incentives to encourage game rangers to use SMART alongside improving patrol coverage in wet seasons. Advanced and regular refresher trainings in SMART should be conducted to enhance data collection. Furthermore, game scouts should be trained and equipped to participate effectively in the SMART process. Although SMART is now becoming increasingly popular in Tanzania, understanding local factors that influence its implementation will be important to improve uptake.     

Landmark Territoriality in the Neotropical Paper Wasps Polistes canadensis (L.) and P. carnifex (F.) (Hymenoptera: Vespidae)

Male Polistes canadensis and P. carnifex aggregate along crests of prominent ridges in Santa Rosa National Park, Costa Rica. At these sites males of both species defend territories (trees and shrubs) by chasing conspecific rivals. Territories do not contain nests or resources that are collected by females. Chasing by territorial males reduces the amount of time spent by intruders in a territory. I describe and contrast male territorial behavior of both species. Some male P. canadensis are territorial while others in the same area exhibit patrolling behavior, flying from one occupied territory to another. Males of P. carnifex exhibit territoriality only. Patrolling in P. canadensis is an outcome of relatively high male density along the ridge, rendering territories in short supply, as shown by the observation that experimentally vacated territories are seized rapidly by formerly patrolling males. Due to a high intraspecific intrusion rate, territorial male P. canadensis spend less time perching and more time flying and chasing intruders from their territories than do male P. carnifex. Males of these two species also differ in the placement of their territories along the ridgeline; P. canadensis occupy territories in saddles while P. carnifex occupy those at peaktops. I show that this divergent spatial pattern is not maintained by competitive exclusion of either species by the other, and I discuss alternative explanations for their separate spatial distributions. Comparative data suggest that males are territorial because females restrict matings to within territories, and I discuss alternative hypotheses to explain this bias in female behavior.     

Aggressive Transition between Alternative Male Social Tactics in a Long-Lived Australian Dragon (Physignathus lesueurii) Living at High Density

Theory predicts the evolution of alternative male social tactics when intense competition coupled with the superior competitive ability of some individuals limits access to reproductive opportunities by others. How selection has shaped alternative social tactics may be especially interesting in long-lived species where size among sexually mature males varies markedly. We conducted experimental studies on long-lived eastern Australian water dragons living where competition was intense to test the hypotheses that mature males adopt alternative social tactics that are plastic, and that large size and body condition determine resource-holding potential. Approximately one-half of mature males (N = 14) defended territories using high rates of patrol and advertisement display, whereas 16 smaller mature males having lower body condition indices utilized non-territorial social tactics. Although territorial males were larger in absolute size and head dimensions, their heads were not allometrically larger. Territorial males advertised very frequently using displays involving stereotypical movements of the head and dewlap. More aggressive displays were given infrequently during baseline social conditions, but increased during periods of social instability. Female home ranges overlapped those of several territorial and non-territorial males, but females interacted more frequently with territorial males. The extreme plasticity of social tactics in this species that are dependent on body size was confirmed by two instances when relatively large non-territorial males spontaneously evicted territory owners, and by marked shifts in tactics by non-territorial males in response to temporary experimental removals of territory owners, followed (usually) by their expulsion when original owners were reinstated. The high level of social plasticity in this population where same-sex competitors are densely concentrated in preferred habitat suggests that chronic high energetic costs of defense may select for males to cycle between territorial and non-territorial social tactics depending upon their changing energetic status and their current capacity for competition with rivals.     

Adolescent male chimpanzees (Pan troglodytes) form social bonds with their brothers and others during the transition to adulthood

Social relationships play an important role in animal behavior. Bonds with kin provide indirect fitness benefits, and those with nonkin may furnish direct benefits. Adult male chimpanzees (Pan troglodytes) exhibit social bonds with maternal brothers as well as unrelated adult males, facilitating cooperative behavior, but it is unclear when these bonds develop. Prior studies suggest that social bonds emerge during adolescence. Alternatively, bonds may develop during adulthood when male chimpanzees can gain fitness benefits through alliances used to compete for dominance status. To investigate these possibilities and to determine who formed bonds, we studied the social relationships of adolescent and young adult male chimpanzees (N = 18) at Ngogo in Kibale National Park, Uganda. Adolescent male chimpanzees displayed social bonds with other males, and they did so as often as did young adult males. Adolescent and young adult males frequently joined subgroups with old males. They spent time in proximity to and grooming with old males, although they also did so with their age peers. Controlling for age and age difference, males formed strong association and proximity relationships with their maternal brothers and grooming relationships with their fathers. Grooming bonds between chimpanzee fathers and their adolescent and young adult sons have not been documented before and are unexpected because female chimpanzees mate with multiple males. How fathers recognize their sons and vice versa remains unclear but may be due to familiarity created by relationships earlier in development.     

Sexual Differences in Ranging of <Emphasis Type="Italic">Ateles belzebuth belzebuth</Emphasis> at La Macarena,Colombia

I examined sex differences in the ranging patterns of 3 female and 3 male wild spider monkeys. Each of the focal males used the home range widely, whereas each of the focal females used a distinct, restricted area of the home range. The males traveled longer distances than the females did. Although males were consistently in larger parties than females were, travel speed was affected by party composition rather than party size. All-male parties traveled faster than other party types did. Foraging manner also differed between sexes. Males spent more time feeding on fruits and less time on flowers and traveled longer distances between feeding trees. Both males and females used salados, where they ate soil and drank water. Salado location is likely to have affected the ranging pattern. Males used boundary areas more frequently than females did, often traveling along the boundary area in alliance with other males. Males also used areas that had been part of neighboring groups home ranges and were not used at all by females of the group. Greater travel distance of males is likely to be facilitated by consumption of a higher caloric diet. I compare the social structure of spider monkeys with that of chimpanzees, whose society is characterized by male-philopatry and female dispersion.     

Lipid economy,flight activity and reproductive behaviour in the speckled wood butterfly: on the energetic cost of territory holding

Insect flight is a highly energy demanding type of locomotion. In butterflies, males may locate females by different behavioural tactics. The tactics correspond to different flight types that, in turn, are assumed to reflect different energetic costs. Costs need to be considered to fully understand the pay‐offs of co‐existing alternative tactics relative to the environmental context and the phenotypes of the individuals. We addressed the issue in the speckled wood Pararge aegeria, in which males either adopt a territorial wait‐and‐fight tactic (i.e. territorial perching) in a sunlit patch on the forest floor, or a fly‐and‐search tactic to locate females in a wider area of the forest (i.e. patrolling). Perching corresponds to high frequency of take‐off flights and aerial combats with high levels of manoeuvrability and is assumed to be energetically more costly than longer, continuous flights at lower speed in patrollers. We tested the effect of different flight activity levels and of the behavioural tactics on lipid reserves and lipid use in males by laboratory and outdoor cage experiments. Low‐activity males that had access to honey water were capable of synthesizing lipids; their lipid reserves increased with age. The effect disappeared in males that actively flew in the outdoor cages. Lipid reserves decreased significantly faster in territorial perching males compared to non‐perching males, but resting metabolic rate did not differ between the alternative behavioural tactics. Territorial perching males had larger flight muscle ratio (i.e. thorax/body mass) than non‐perching males. We discuss the evidence of the physiological costs of perching relative to the co‐existence of perching and patrolling tactics.     

Effects of tail autotomy on survival,growth and territory occupation in free‐ranging juvenile geckos (Oedura lesueurii)

Abstract Many animals autotomize their tails to facilitate escape from predators. Although tail autotomy can increase the likelihood of surviving a predatory encounter, it may entail subsequent costs, including reduced growth, loss of energy stores, a reduction in reproductive output, loss of social status and a decreased probability of survival during subsequent encounters with predators. To date, few studies have investigated the potential fitness costs of tail autotomy in natural populations. I investigated whether tail loss influenced survival, growth and territory occupation of juvenile velvet geckos Oedura lesueurii in a population where predatory snakes were common. During the 3‐year mark–recapture study, 32% of juveniles voluntarily autotomized their tails when first captured. Analysis of survival using the program mark showed that voluntary tail autotomy did not influence the subsequent survival of juvenile geckos. Survival was age‐dependent and was higher in 1‐year‐old animals (0.98) than in hatchlings (0.76), whereas recapture probabilities were time‐dependent. Growth rates of tailed and tailless juveniles were very similar, but tailless geckos had slow rates of tail regeneration (0.14 mm day⁻¹). Tail autotomy did not influence rock usage by geckos, and both tailed and tailless juveniles used few rocks as diurnal retreat sites (means of 1.64 and 1.47 rocks, respectively) and spent long time periods (85 and 82 days) under the same rocks. Site fidelity may confer survival advantages to juveniles in populations sympatric with ambush foraging snakes. My results show that two potential fitness costs of tail autotomy – decreased growth rates and a lower probability of survival – did not occur in juveniles from this population. However, compared with juveniles, significantly fewer adult geckos (17%) voluntarily autotomized their tails during capture. Because adults possess large tails that are used for lipid storage, the energetic costs of tail autotomy are likely to be much higher in adult than in juvenile O. lesueurii.     

Orangutan activity budgets: Monthly variations and the effects of body size,parturition, and sociality

The activity budgets of individual orangutans were investigated at the Kutai Reserve, Indonesia. Activity profiles within and between individuals were compared to examine monthly variations in feeding patterns, potential energetic constraints imposed by large body size and parturition, and the costs of sociality. Animals showed monthly changes in travelling, feeding, and resting patterns. Monthly increases in travelling and feeding were associated with marked reductions in the time spent resting. Inter-individual variations in activity budgets did not exist among animals of the same age-sex class. Activity patterns differed, however, as a function of age and sex. Adult females and subadult males travelled and fed significantly longer than an adult male. Parturition had predictable effects on activity; one female reduced her feeding and travelling immediately following parturition. Adult male orangutan sociality appears to be limited by travel costs. Associations with females forced a male orangutan to travel significantly more compared with periods in which he was solitary. The male did not lose an appreciable amount of time feeding when accompanying a female.     

The Energetic Costs of Fighting

SYNOPSIS. Current evolutionary theory predicts that energy expenditurewill be adjusted in contest situations to the value of the disputedresource and the relative probability of winningit. Estimatesof energy expended in contest situations support this prediction.I report on theenergetic costs of display relative to othercontest costs to individual fitness (e.g., risk ofpredation,losses in feeding time, injury and mortality) in territorialdisputes of the spider Agelenopsis aperta. Cost estimates obtainedin terms of decrements to milligrams wet-weight of future eggproduction resulting from single contests indicatethat actualenergy expenditure inthese territorial disputes represent insignificantcosts. Thesecosts are, in fact, 5–6 orders of magnitudesmaller than the costs associated with injury, potential predationand even loss infood as a result of time spent in the interactions.Review of the literature indicates that in most instances, energyexpenditure may be correlated with some other factor upon whichselection is acting (e.g., short contests wherepredation riskis high, variation in levels of escalation exhibited). Two exceptionsinclude the tremendous losses of workers to reproductives inant, termite, and bee colony territorial disputes and the productionof specializedagonistic organsexhibited by some corals, seaanemones and corallimopharians when encountering neighbors within"territorial"boundaries.