Attraction of the sexes inFormica lugubris Zett (Hymenoptera: Formicidae)

Summary Sexuals ofFormica lugubris fly to mating places, where females attract males by using a sex pheromone. Females collected on the nest surface before departing on a mating flight are much less attractive than those collected on the mating place after the mating flight, suggesting that the mating flight triggers the release of the sex pheromone. Olfactory cues are essential for males to locate females while they patrol. Males probably use visual cues to locate females once they have alighted nearby them. Males are also attracted by aggregations of other males on the ground, probably because one or several females are likely to be close to male aggregations.     

The mating system of a bee fly (Diptera: Bombyliidae). I. Non-resource-based hilltop territoriality and a resource-based alternative

The mating system of an undescribed Australian bee fly (Comptosiasp. near lateralisNewman) was studied in Southeast Queensland. Males perched in clearings on a wooded hilltop and darted toward nearby flying insects. On sunny days males interacted with other insects about once per minute. A minority of these interactions was with conspecific males. They had the effect of determining ownership of the perching area. Most conspecific interactions occurred withtin 90 min of the first male's arrival each day, although territories were occupied for an average of 4.6 h per day. The same territories were used by different generations of flies for at least 4 years, while other apparently similar clearings on the hilltop remained unoccupied. Following removal of resident males, replacement males occupied the sites in 12.5 min on average. Females were not observed on the hilltop except when mating at territories. No interactive courtship behavior was detectable prior to midair coupling. Copulations lasted for 118 min on average. We interpret this as a landmark-based mating system and discuss it in relation to the concept of lek polygyny. Observations of Comptosiasp. near lateralismatings at a nonhilltop, resource-based encounter site suggest that the mating system of this species varies in response to the distribution of resources.     

Lekking and the small-scale distribution of the sexes in the Caribbean fruit fly,Anastrepha suspensa (Loew)

Male and female Anastrepha suspensa(Loew) had a clumped distribution in the foliage of their guava host plants. Males were no closer to other males than they were to females or than females were to other females. Flies were often found in roughly the same locations over time. However, contemporaries (flies present at the same time) were closer to each other than subsequent flies were to their predecessors. Males were more likely to be found near spots previously occupied by males than they were to spots used previously by females. Some trees had more flies than others, but there was no regional (northwest, etc.) preference within trees. Females were no more likely to be found in the vicinity of clumped (lekking) males than they were by isolated males. About a third of the females taken from inside leks had sperm in their spermathecae, and it is not clear if their motive for being in these areas was sexual. In pairs of males (within 15 cm of each other), the larger fly tends to be in a position farther up the branch, suggesting that larger males may control preferred territories. It seems possible that males attempting to intercept females accumulate in favorable microhabitats where females are likely to be concentrated and that leks have evolved from such clumping.     

The Hilltopping Mating System of Leschenaultia adusta (Loew) (Diptera: Tachinidae)

Males of the tachinid fly Leschenaultia adusta perch on small trees and shrubs on the highest parts of Usery Peak in central Arizona. Individuals select twig perches on the downwind side of these plants and fly out spontaneously from time to time or in response to another passing insect. Conspecific males elicit chases that on occasion escalate into elaborate, high-speed pursuit flights that go back and forth near the plant for several minutes. Although several males sometimes perch together briefly in the same plant, typically only one individual remains at a site for more than an hour on any given day. These site-faithful males can be considered territorial residents; they constituted about one-quarter of the males marked during the study. More than half of these residents returned to the same perch plant for two or more days. Perch plants varied in their attractiveness to male flies; male preferences were largely consistent across two years of study. Given that females were occasionally observed mating at male-occupied plants, we place the mating system of L. adusta within the hilltopping territorial category in which males compete for landmark perching sites attractive to receptive females. As is true for other hilltopping insects, receptive females of L. adusta appear to be rare and widely distributed.     

Overlapping territories ofPseudosimochromis curvifrons males and other herbivorous cichlid fishes in Lake Tanganyika

Males of the herbivorous cichlid fishPseudosimochromis curvifrons established mating territories 3–10 m in diameter, which included both spawning and feeding sites. Territorial males attacked conspecific males and also other species. Only conspecific males were chased out of the territories. Territorial males attacked other species at the spawning sites while courting or waiting for females and at other sites in their territories while patrolling and foraging. Attacks against herbivorous species were more frequent than against non-herbivores since herbivores were much more abundant. Territories of four abundant herbivorous cichlids largely overlapped the territories ofP. curvifrons males. Symbiotic relationships were not detected between the species. Instead, they were aggressive towards each other but coexisted by segregating feeding sites in the overlapping areas. The aggressive coexistence ofP. curvifrons males with other herbivores may have resulted from the energetic costs of defending their relatively large territories against all food competitors. Interspecific food-resource partitioning may also have facilitated the coexistence.     

Mate retention, harassment, and the evolution of ungulate leks

Current models of lek breeding mostly suggest that males defendclustered mating territories because females show a preferencefor mating on leks. Here we argue that, in lek-breeding ungulates,males may also gain benefits from holding clustered mating territoriesbecause clusters retain does in estrus. We show that in fallowdeer (Dama dama) harems are commonly disrupted by young males.Bucks that hold territories on the lek that lose their haremsquickly regain does as other harems are disrupted, whereas bucksdefending isolated, single territories rarely regain does thesame day. The risk of harassment may also help to explain whydoes in estrus leave the large, unstable herds that they usuallylive in. Does in estrus are frequently chased by young maleswhen outside male mating territories. Benefits of moving tothe lek (versus moving to single territories) include reducedrisks of long chases. Though intrusions by young bucks are thecommonest cause of does leaving male territories in our studypopulation, other factors that cause does to move between neighboringharems (including disturbance by predators and persistent courtshipby males) may generate benefits to males holding clustered matingterritories. Once clustered mating territories have developed,the additional costs of mate choice are likely to be low, andfemale preferences for particular male characteristics may belikely to develop.     

Male mating success,sexual size dimorphism,and site fidelity in two species of Malacoctenus (Labrisomidae)

Synopsis In both Malacoctenus hubbsi and Malacoctenus macropus, males defended preferred oviposition sites from both other males and potential egg predators. In M. hubbsi, adult females were larger than adult males. Larger M. hubbsi males were not associated with territory parameters that were correlated with higher mating success, and male size was not correlated with mating success. Male size did affect mating success when territory parameters were statistically controlled for, but the failure of large males to associate with better territories eliminated any mating advantage for larger males. In M. macropus, males are larger than females. Larger males defended preferred oviposition sites, and had higher mating success than did smaller males. Male M. macropus also had much higher site fidelity than male M. hubbsi. These results suggest that the evolution of the differences in site fidelity and sexual size dimorphism between these two species may be due to sexual selection acting differentially in these two species.     

The influence of age and experience with conspecifics on territorial behavior inDrosophila melanogaster

Drosophila melanogastermales initiated aggressive behavior toward other males and defended territories several hours after they were able to court and mate females. Males that were 3 days or more posteclosion were more successful at holding territories than younger males. Three-day-old males established territories more readily and escalated more often against territory residents than males that were 1 day old. Residents did not usually force young males from territories until they were a few hours posteclosion. The development of territorial behavior was not affected by familiarity or prior exposure to females. Males held in isolation established territories more quickly and behaved more aggressively than males held in groups. Males that previously held territories were more likely to reestablish them after a disturbance.     

Pursuit of Heterospecific Targets by Territorial Amberwing Dragonflies (Perithemis tenera Say): A Case of Mistaken Identity

Although they are defending mating territories, territory residents of a wide variety of insect species have been observed to pursue heterospecifics in addition to the conspecifics that intrude on their territories. One species that has such heterospecific pursuits is the Eastern amberwing dragonfly (Perithemis tenera Say) (Anisoptera: Libellulidae). In this study, we tested five alternative hypotheses for the function of heterospecific pursuits in amberwings: competition for resources, prevention of interference while mating, predator deterrence, foraging, and mistaken identity. Resident males pursued both male and female conspecifics, as well as a species of horse fly (Tabanus spp.) and butterfly (Ancyloxypha numitor). Other intruding odonates, including Epitheca princeps, Erythemis simplicicollis, Libellula luctuosa, Pachydiplax longipennis, and Plathemis lydia, were relatively ignored. Because the horse fly and butterfly were similar to amberwings in body size, color, and flight height, and because they are not predators or prey of amberwings, we concluded that the pursuit of these heterospecifics was due to mistaken identity. The characteristics of the horsefly and butterfly likely correspond to the cues that the male amberwings use to identify conspecifics, and the relative rarity of intrusions by these two species (as well as by female amberwings) probably made it more costly to discriminate and pursue only conspecifics than to make some mistaken pursuits.     

Non-resource based territoriality in males of the butterflyXamia xami (Lepidoptera: Lycaenidae)

In the Pedregal de San Angel reserve, in Mexico City, males of the butterfly Xamia xamiperch in and defend areas with well-defined topographic limits. These areas lack concentrations of receptive females and of larvae and adult resources. One individual defends the same territory an average of 5 h/day, up to a maximum of 23 days. The same areas are used as territories by different males during the year. These areas share some characteristic features which are described. Evidence is presented in support of the hypothesis that the territories function as mating stations. A possible scenario for the evolution of this territorial mating system is advanced.     

Competition for territories does not explain allopaternal care in the tessellated darter

Extensive research has focused on understanding the evolution of parental care, with fishes providing important model systems for understanding patterns of variation within and between species. Classic theory predicts that individuals will care for offspring when the fitness benefits through increased offspring survival and growth outweigh the cost to the parents through decreased future reproductive opportunities. Yet, a puzzling observation not explained by this basic theory is the fact that in some species individuals defend and provision unrelated offspring and thus exhibit alloparental care. The tessellated darter, Etheostoma olmstedi, represents one of the first known examples of allopaternal care in fishes. In this species, males often clean and guard eggs fertilized but deserted by other males. Allopaternal care has been argued to occur in the tessellated darter because of competition for a limited number of mating sites where less dominant males accept territories with eggs when other breeding sites are not available. Here, we test this hypothesis using male territory choice experiments. When allowed to choose between two otherwise identical territories either containing eggs fertilized by another male or with no eggs, males spent significantly more time at territories with eggs. This demonstrates that competition for mating territories is not the primary factor explaining the existence of allopaternal care in the tessellated darter. Instead, males of this species may exhibit allopaternal care to dilute predator pressure on their own eggs or because females prefer to mate with males whose territories contain eggs.     

Mating system of the lefteye flounder,Engyprosopon grandisquama

Underwater observations were conducted on the reproductive behavior and mating system of the lefteye flounder,Engyprosopon grandisquama, off Nagashima, southwest of Kyushu Island, Japan. Two types of males were found: large males, which defended territories against other large males, and small males, which did likewise but only against smaller males. Large males established territories which encompassed or ovelapped the home ranges of 1 or 2 cohabitant females. Territories of the small males, in which a smaller female often maintained a home range, overlapped those of large males. Pair spawning occurred around sunset. Mating of large males with cohabitant females was observed 36 times and that of a small male with a smaller female once. Pair formation was assorted by body size, paired males being larger than females in most cases. Thus, inE. grandisquama, gigamous large males were common, small males occurring within the former's erritorial boundaries mating with smaller females.     

Mating behavior and male mating success in wildAnastrepha Ludens (Diptera: Tephritidae) on a field-caged host tree

Mating behavior and factors affecting mating success of males were studied using wild Anastrepha ludens on a fieldcaged host tree. The most common courtship sequence had five components: (1) male calls from the underside of a leaf, (2) female arrives to the maleoccupied leaf, (3) male orients to female and stops calling, (4) one or both approach to a face-to-face position 1–3 cm apart, and (5) male mounts female after 1–2 s. Courtship behavior was almost identical to that of laboratoryculture flies observed previously under laboratory conditions. Most malefemale encounters occurred at a height of 1–2m, well inside the outer canopy of the tree. Differential mating success by males occurred. No male mated more than once per day, owing possibly to a very short sexual activity period. Factors favoring mating success of males were survival ability and tendency to join male aggregations and to fight other males. Thorax length and age (9–11 days difference) had no effects on male copulatory success. Overall win/loss percentage was not related to mating success because the males that were most successful at mating fought mostly among themselves, driving their win/loss percentage down. However, these successful males (at mating) won most of their fights against less successful males. Results confirmed a lek mating system: males aggregated, called, and defended territories; territories did not contain femalerequired resources; and females exercised mate choice, apparently through selection of sites within leks.     

Male territoriality and mating tactics in the wool-carder bee,Anthidium septemspinosum Lepeletier (Hymenoptera: Megachilidae)

Mate-seeking behaviours in males ofAnthidium septemspinosum are described. Mating occurred at the females' food plant patches, as in other congeneric species previously studied. Males were behaviourally classified either as territorial or non-territorial. Territorial males were generally larger, and superior in mating. Smaller males were forced to be non-territorial, adopting a different mating tactic of creeping into the territories to intercept females. This compensated for their physical inferiority in mating competition. The adaptive significance of this tactic is discussed.     

Resource Defence or Exploded Lek? – A Question of Perspective

It becomes increasingly obvious that animal mating systems cannot be classified into distinct categories, but transitions between mating system classes are continuous. Positioning a certain mating system at this continuum is often not straightforward, however. Depending on which characteristic is considered, a mating system may end up at very different positions on this gradient. Here, we explore the potential conflict between mating system classifications that may arise when they are based on different criteria by investigating the mating system of the cichlid fish Simochromis pleurospilus in which males defend small patches of homogeneously distributed food resources (turf algae) vigorously against food competitors, but they allow specific females to use them. We hypothesized that male defence may generate high‐quality feeding patches serving to attract females, and hence male territoriality constitutes a form of courtship. Our field data show that males selectively allow approximately one‐third of the visiting females to feed on their territory and that females preferentially feed in male territories and usually sample several territories successively. As males protect food patches against other algae grazers and guard females from harassment by food competitors, females gain nutritional benefits from visiting male territories. Hence, males appear to generate essential resources for females, which is the key feature of resource‐defence mating systems, although the distributions of resources and of males and females are characteristics of an exploded lek.     

Spawning behavior and haremic mating system in the corallivorous butterflyfish,Chaetodon trifascialis, at Kuroshima Island, Okinawa

Territorial and spawning behavior ofChaetodon trifascialis were investigated on a small patch of reef at Kuroshima Island, Okinawa, Japan. Three males and 8 females inhabited the reef, each individual defending a territory against conspecifics of the same sex. Each male territory included 2 or 3 female territories. In the daytime, each male frequently visited the females living in its territory. At dusk in the full or new moon periods, courtship began within the female territories, pair spawning subsequently occurring within or near those territories. When a male actively courted a female in the territory of a second male, the latter male immediately chased off the intruder. Thus, mating occurred only between a male and females living in former's territory. This is the first report of a haremic mating system among butterflyfishes (Chaetodontidae).     

Chorus organization and male mating behavior in the Japanese pond frog,Rana porosa brevipoda

Male mating behavior of a Japanese pond frog,Rana porosa brevipoda, was observed in an enclosed pond. Males organized chorus aggregation during the night. Within the chorus, most males defended “floating” territories. Territorial males exhibited 2 types of calls: advertisement and encounter. Mating occurred primarily in male territories with female initiation, while most spawning occurred outside of the territories. After spawning, males returned to their territories and resumed display behavior. The mating system of this frog is analogous to the typical lek system. Alternative male mating tactics, including satellite and ambush behavior, were also observed. Satellite and ambush males mated with females through forced clasping.     

The social organization of feral peafowl

Peafowl are usually reported to have a mating system based on harem defence by adult males. In a small feral population near Oxford, males defended small (<1 ha) territories while females remained in one flock that ignored male territory boundaries. After mating, females become solitary. At no time did a female associate selectively with one male or remain within his territory, nor did males attempt to follow or guard female groups. Two out of four males were seen to mate. These differed from the other two in being neither very old nor very young; they held territories smaller than that of the young male and were no larger or longer-tailed. However, they spent more time displaying. We suggest that peafowl have a mating system similar to a lek: males defending small, clumped territories visited by females for mating.     

Familiarity and flexible mating strategies of a solitary rodent, Dipodomys ingens

Because mating is a product of individual reproductive strategies that may vary with changing conditions, we predicted variable mating behaviour in an arid-adapted, territorial rodent, the giant kangaroo rat, Dipodomys ingens. We also predicted that familiarity would facilitate nonaggressive courtship and mating in this solitary rodent. Through direct observations in the field, we found that mating varied from exclusive to multiple partners. Where densities were low, and on nights when multiple females were in oestrus, each animal mated with one member of the opposite sex. In conditions where the operational sex ratio was skewed towards multiple males, males footdrummed and competed for females. Males were able to mate with one or two females in adjacent territories, and they successfully competed for these same females throughout the breeding season. Females that mated exclusively with one male had more pups emerge from the burrow compared with females that experienced male competition. Females allowed nearest neighbour males to enter their burrows, and they engaged in more nonaggressive contact with close neighbours than with other males. Paired encounters in the field showed less aggression towards neighbours than strangers. In laboratory tests, females were less aggressive towards and allowed more contact with familiar than unfamiliar males. These results show that D. ingens can alter mating strategies as conditions change. Familiarity is an important factor in nonaggressive interactions between males and females and may be important to mate preferences in females during reproduction. The less aggressive behaviour to neighbours than to strangers (‘dear enemy’ phenomenon) is consistent with other solitary animals that defend multipurpose territories. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

The effects of male body size on territorial and mating success in the landmark-defending fly Hermetia comstocki (Stratiomyidae)

Abstract.

• 1 Males of Hermetia comstocki Williston compete for territorial control of certain agaves and yuccas. Winners copulate with females that visit these plants solely to acquire a mate.
• 2 Males vary in body weight by more than an order of magnitude and larger flies almost always defeat smaller ones in aerial contests for control of landmark territories.
• 3 The mean body size (as measured by wing-length) was significantly greater for males retaining residency at a site for at least one hour compared to males unable to do so. Likewise, males able to return to a perch site in the study area on more than one day were larger on average than males unable to do so.
• 4 Male preferences for landmark territories remained similar across years. Large males dominated the perch landmarks most likely to be occupied by males and most likely to be visited by females.
• 5 Despite the fighting and territorial advantages enjoyed by large males, the mean size of males found mating with females was not significantly larger than that of the general population.
• 6 The apparent failure of large males to secure a statistically significant mating advantage may be a statistical consequence of the small sample size of males observed mating. On the other hand, any mating advantage of large males may be reduced because (a) receptive females visit many different landmarks, (b) females mate with the first male they encounter at a landmark, regardless of his size, (c) there are usually many vacant landmarks available for smaller males, and (d) even popular territories are often open to small males, thanks to the low site-tenacity of territory owners.