bluuebunny/crossref_metadata_2025 huggingface dataset:
Stimulus Movement, Hen Behaviour and Filial Imprinting in Japanese Quail (Coturnix coturnix japonica)
Authors: ten Cate Carel
Published: May 2010

A living hen is a very attractive imprinting stimulus compared to artificial stimuli. The present study examined to what extent this attractiveness is influenced by the behaviour of the hen. The effectiveness of a living quail hen as an imprinting stimulus was compared with that of a moving stuffed hen, a non‐moving stuffed hen and an empty cage. Naive quail chicks were exposed to one of these stimuli for 2 h. Both during and after this period chicks exposed to the living hen showed the strongest attachment to the stimulus, next came chicks exposed to a moving stuffed hen, while chicks exposed to a non‐moving stuffed hen showed no indication of any attachment, i.e. they behaved in the same way as chicks exposed to an empty cage. Also, among chicks exposed to the living hen a correlation was present between the strength of the attachment to the hen and the behaviour of this hen during the exposure. In particular pecking and behaviour directed at the chick seemed to stimulate the development of a filial bond. Together, these findings indicate that a living hen is attractive not just because she moved, but also because of specific qualities of this movement. The behaviour of the living hen differed in various ways from the movement of the moving stuffed hen. The influence of these differences on the filial imprinting process is discussed and compared with similar findings for sexual imprinting and song learning.
Migratory Orientation of Blackcaps (Sylvia atricapilla): Population‐specific Shifts of Direction during the Autumn
Authors: Helbig Andreas J. , Berthold Peter , Wiltschko Wolfgang
Published: May 2010

The population‐specific orientation of two groups of blackcaps (Sylvia atricapilla), one from southwest Germany, the other from easternmost Austria, was studied outdoors in Emlen funnels. We investigated whether a seasonal shift in the migratory direction — as expected for the Austrian birds from ringing recoveries — occurs under experimental conditions and in a seasonally constant magnetic field. The West German birds, for which no shift was expected, oriented southwest during the entire season. The Austrian birds oriented southeast in October and southsouthwest in November. The clockwise shift by about 60° occurred within a 10‐day period.

The results indicate that in this species seasonal changes of migratory direction are probably based on an endogenous program, occur without the birds actually migrating and are independent of changes in the magnetic field. Our results provide further evidence that directional shifts in Sylvia warblers may be controlled by a different mechanism than in pied flycatchers (Ficedula hypoleuca).
The Influence of Alarm Substance on Feeding in Zebra Danio Fish (Brachydanio rerio)
Authors: Jakobsen Johan , Johnsen Geir Helge
Published: May 2010

The effects of alarm substance on feeding behaviour of zebra danio fish (Brachydanio rerio) were tested by offering them high and low densities of enclosed waterfleas (Daphnia magna). Normally the fish attacked high densities of prey, but when exposed to alarm substance they preferred lower and presumably less confusing prey densities — also lowering their feeding rate.
A Model of Search Behaviour for the Northern Wheatear Oenanthe oenanthe (Aves, Turdidae) and Other Pause‐travel Predators
Authors: Tye Alan
Published: May 2010

Many animals hunt by pausing to scan a particular locality then moving rapidly to the next pausing position. Prey are spotted from pausing positions. I develop a descriptive and analytical model which relates the distance moved between pauses (move‐length) to the area scanned at each pause, and which relates search rate to these two variables, and to pause time and running speed. The northern wheatear uses pause‐travel to hunt invertebrates on short grassland. Wheatears used a search pattern which reduced the distance moved to the minimum consistent with avoiding previously‐searched ground. The chosen move‐length maximized search rate at any given pause duration and running speed. When movement accounted for a small proportion of search time, search rate was little affected by variations in running speed. Incubating females searched faster, with shorter pauses, than males and non‐incubating females, but captured prey at a faster rate which implied reduced selectivity. The model showed that wheatears do not exhibit area‐restricted search by searching an area more than once, while plovers (Charadriidae) sometimes do, although previous assumptions about the search patterns which lead to area‐restricted search need to be modified. Examples from plovers, chats and thrushes (Turdidae) and tyrant‐flycatchers (Tyrannidae) show that pause duration is affected by prey visibility and density, and that search radius is affected by prey visibility.
Predator‐recognition Behaviour in Two Species of Gobiid Fishes, Asterropteryx semipunctatus and Gnatholepis anjerensis
Authors: Smith R. J. F. , Smith M. J.
Published: May 2010

When Asterropteryx semipunctatus and Gnatholepis anjerensis detect a predator they bob rhythmically, raising and lowering the body. Bobbing and reduced movement was transmitted visually between fish in adjacent tanks, both within and between species. Fish isolated from other fish for at least 5 days still bobbed when they encountered a predator model. G. anjerensis remained resident in one location for an average of 61 days from marking to disappearance or the end of the study. They could, therefore, benefit if bobbing reduced predator hunting success. Three general categories of hypotheses have been proposed to account for predator‐recognition behaviour: assessment of the predator, informing the predator that it is detected, and warning the sender's conspecifics. Two of these, informing the predator and warning, seem most likely to account for goby bobbing. These hypotheses are not mutually exclusive.
Mating System Variation in Woodhouse's Toad (Bufo woodhousii)
Authors: Sullivan Brian K.
Published: May 2010

Sexual selection and mating‐system variation was studied in two disjunct populations of Woodhouse's toad (Bufo woodhousii) with dissimilar breeding‐period durations. In spite of the differences in breeding‐period duration, nightly operational sex ratios were roughly equivalent and strongly male biased in both populations, ranging from 0 to 0.5 in the population with a prolonged breeding period, and from 0 to 0.2 in the explosively breeding form. Although operational sex ratios were similar, some males mated with up to three females in the population with an extended breeding period, whereas none of the males mated polygynously in the population with a short breeding season. Two alternative reproductive tactics, satellite and active‐searching behavior, were only exhibited by males under high densities in the population with a short breeding period. In the population with an extended breeding period, male mating success was positively related to call rate, but independent of size or number of nights of participation in chorus activity. Although operational sex ratios were equally low, mating was random by size, number of nights of participation in chorus activity, and call rate for males in the explosively breeding population.
Associations between Langur Monkeys (Presbytis entellus) and Chital Deer (Axis axis): Chance Encounters or a Mutualism?
Authors: Newton Paul N.
Published: May 2010

The relationship between a troop of hanuman langur monkeys (Presbytis entellus) and chital deer (Axis axis) was examined in Kanha Tiger Reserve, Central Indian Highlands. The frequency distribution of closest approaches between the two species suggested that associations (defined as proximity < 25 m) were not chance encounters; 70.1% of all those herds observed within 200 m came within 25 m of the troop. Associations were more frequent and lasted longer during the hot and cold weather than in the monsoon. Chital initiated and terminated the majority of associations, whilst langurs terminated them more frequently than they initiated.

The langur troop dropped a mean of 4.0 kg vegetation fresh weight/day and chital were seen to scavenge or glean this forage in 38.2% of associations; more frequently in the hot and cold weather than in the monsoon. Chital gleaned items from 19 species of tree, with Shorea robusta the most frequently utilized.

Responses to potential predators suggested that chital and langur responded to each other's alarm behaviour. Chital alerted to langur alarm more frequently than vice versa. Antagonistic interactions between the two species were observed in 5.8% of associations, predominantly directed from langurs to chital.

The study suggests that chital‐langur associations are asymmetrical mutualisms. Chital gained by opportunistically taking advantage of vegetation dropped by langurs, and by responding to langur alarm behaviour. The benefit, if any, to langurs was probably slight; they may have gained from responding to chital alarms but incurred costs of antagonism and feeding competition with chital.
The Sexual Behaviour of the Great Crested Newt, Triturus cristatus (Amphibia: Salamandridae)
Authors: Green Andy J.
Published: May 2010

The sexual behaviour of Triturus cristatus is described. The first stage of sexual behaviour consists of an orientation phase in which the male approaches the female, sniffs her and moves in front of and perpendicular to her. The second stage is a prolonged period of static display with two different tail movements, called Fan and Lash, in 13.8 ± 1.3 bouts (x̄ ± SE) with intervals of 10.5 ± 0.3 s between bouts. Each bout contains 6.7 ± 0.3 regular Fan beats at a frequency of 0.5–0.8 Hz. This Fanning provides olfactory and mechanical stimulation to the female. 15% of bouts also contain a violent Lash, in which the male rapidly slaps the female's flank. Some Lashes are used to stop the female when she tries to move away. In the third stage of the sexual sequence, the male turns away, Creeps for 6.7 ± 0.3 s (x̄ ± SE) and then Quivers his tail. A receptive female follows and touches his tail, and the male deposits a spermatophore and then turns to one side with his tail folded along his flank in a position called Brake. The female now approaches again and the male steps away sideways in a movement called Rebrake. After several Rebrakes the male stops, the female touches his tail and the spermatophore may now be picked up in her cloaca. This sequence can be repeated several times during one encounter. This behaviour is discussed in relation to previous studies of courtship in this genus.
Orientation and Communication in the Neotropical Ant Odontomachus bauri Emery (Hymenoptera, Formicidae, Ponerinae)
Authors: Oliveira Paulo S. , Hölldobler Bert
Published: May 2010

The Neotropical species Odontomachus bauri employs canopy orientation during foraging and homing. An artificial canopy pattern above the ants is much more effective as an orientation cue than horizontal landmarks or chemical marks. However, both horizontal visual cues and chemical marks on the ground can serve in localizing the nest entrance. Successful O. bauri foragers recruit nestmates to leave the nest and search for food. However, the recruitment signals do not contain directional information. Antennation bouts and pheromones from the pygidial gland most likely serve as stimulating recruitment signals. Secretions from the mandibular and poison gland elicit alarm and attack behavior.
Aggression, Dominance, and Social Organization in Evening Grosbeaks
Authors: Bekoff Marc , Scott Abby C.
Published: May 2010

Relationships between social behavior and ecology are of great interest to ethologists and behavioral ecologists. For example, limited comparative data have already resulted in the development of broad explanations for possible interrelationships between patterns of social interaction and food supply in diverse species. Here, we analyzed agonistic behavior, dominance relationships, and social organization in evening grosbeaks (Coccothraustes vespertinus) living near Boulder, Colorado U.S.A. We found marked seasonal variations in mean rates of agonistic behavior, mean sex ratios, and mean flock sizes. Rates of agonistic encounters were positively correlated with group size and the number of adult males present. Generally, adult males dominated (>>) adult females, young males, and young females; young males >> adult and young females; and young females >> adult females. Adult males were most aggressive during the beginning of the breeding season.

The formation of large flocks of grosbeaks most likely facilitates locating the dispersed and locally irruptive food on which these birds depend, and may also confer protection against predators. We suggest that flocks of grosbeaks composed of mainly transient birds are maintained by (1) low rates of noncontact aggressive encounters and (2) the rare occurrence of potentially disruptive fights, both of which appear to result from birds' being able to assess the likely outcome of an encounter with another animal using phenotypic cues such as wing length, weight, and especially plumage. The ability to predict the outcome of an aggressive encounter may also be important in the integration of young birds into flocks.
Plural Breeding in the Splendid Fairy‐wren, Malurus splendens (Aves: Maluridae), a Cooperative Breeder
Authors: Rowley Ian , Russell Eleanor , Payne Robert B. , Payne Laura L.
Published: May 2010

Groups of the cooperatively breeding splendid fairy‐wren Malurus splendens may include more than one female. Previously this species has been described as singular breeding (only one female breeds). This paper describes the occurrence of plural breeding (PB) groups in 10% of group years, in which two females had separate nests. In all cases, the secondary female (Y) was related to the primary breeding female (X) and was generally a 2‐year old female which had helped in the group during the previous breeding season. Plural breeding was correlated with an increase in population density and in the number of female helpers; PB groups were larger than singular‐breeding groups. In most cases, the X female was occupied with her own nest or offspring when the Y female began to nest, and there was no aggression between them. Which birds helped the Y female to feed at her nest depended on the time between the hatching of the two nests. If the interval was small, some group members helped at each nest; with longer intervals, the group members began to feed at the earlier nest, and the other female was left to raise her brood alone. Female helpers were very active in feeding at single nestings, and the cost to an X female of a Y female breeding was mainly a loss of this assistance. The success of individual X nests was not affected. Effects on productivity were slight, but fewer X females in PB groups raised second broods than did experienced singular breeding females. Y females were less productive than X females, but no less productive than singular breeding novice females without helpers. It is not known whether Y females copulated with primary or secondary males within their group, or with males from outside the group. Certainly, they did not form an observable pairing with any male in the group. Plural breeding occurred in a minority of group years in response to extrinsic conditions and the current demographic situation, and shows the extreme plasticity of the mating system in M. splendens.
Time‐Place Learning by Garden Warblers (Sylvia borin): Route or Map?
Authors: Krebs John R. , Biebach Herbert
Published: May 2010

Garden warblers are able to learn to go to four different feeding places at different times of day (time‐place learning). We investigated whether or not the birds rely on a fixed route by preventing them from entering one of the places at the normal time (blocking experiments). At the end of the blocking period the birds were allowed to visit any of the four feeding places.

In two such blocking experiments, one in which the blocking period was first thing in the morning (from 06.00–10.00 h), the other in which it was later in the day (from 12.00–16.00 h), there was no subsequent shift in the phase of visiting the places during the rest of the day, apart from a tendency to go to the first place of the day after the morning block. These results suggest that the birds do not rely on following a fixed route, but instead use a time‐place map.
Sexual Selection and Assortative Mating in Subdivided Populations of the Thrips Elaphrothrips tuberculatus (Insecta: Thysanoptera)
Authors: Crespi Bernard J.
Published: May 2010

This study presents four years of data on size‐related mating patterns in Elaphrothrips tuberculatus, a subsocial thrips inhabiting subdivided populations (clusters of hanging dead oak leaves) that vary in sex ratio, operational sex ratio (ratio of males to females guarding eggs), and number of adults. Laboratory observations, experimental removals of guarding males, and field collections showed that: (1) males guard mates after copulation, (2) guarding males are larger than non‐guarding males, and (3) large male mating advantage is caused by male fighting. The populationwide intensity of sexual selection for large male body size varied substantially among years, reflecting yearly differences in the sex ratio and operational sex ratio. Among local populations (leaf clusters), the sexual selection intensity was correlated with the operational sex ratio in each year, and with the sex ratio in three of four years. Males and females mated assortively for size (fore‐femora length) in 1986, but not in 1983, 1984, or 1985. Assortative mating in 1986 was attributed to Darwin's (1871) mechanism for sexual selection in monogamous species: in this year alone, there was a highly significant tendency for large females to initiate breeding earlier than smaller females and strong directional selection for large male body size. Population subdivision affects mating patterns of E. tuberculatus by: (1) creating single‐male populations where male size does not affect mating success, (2) promoting high sexual selection intensities, relative to a continuous population, when the population‐wide sex ratio is female biased, and (3) constraining the size covariation between paired males and females.
Laughing, Smiling, and Talking: Relation to Sleeping and Social Context in Humans
Authors: Provine Robert R. , Fischer Kenneth R.
Published: May 2010

The propabilities of laughing, smiling, or talking during a given hour and in various social environments were investigated by having undergraduate college students record their performance of these activitics in a log book during a one‐week period. All three activities were least likely to occur during the hours immediately before bedtime and after waking and were most frequent in social situations. Smiles and laughs, like talking, were performed primarily during social encounters and were often part of verbal and nonverbal conversations. Because laughing and smiling are phasic social acts, they are of limited value as indices of ongoing (tonic) emotional state. The role of laughing, smiling, and talking in communication, the production of mood, and social bonding is considered.
Pattern of Dispersion of Young Wild Rabbits, Oryctolagus cuniculus L., in Relation to Burrows
Authors: Vitale Augusto F.
Published: May 2010

The development of dispersion in relation to burrows of young rabbits, Oryctolagus cuniculus L., was studied in a sand dune habitat between May and September 1984–1985. Generally, young rabbits did not show a close association with their original burrow. From the first week of life on the surface they used different burrows as well as the original one. No significant age‐related changes in the mean distance from different kinds of burrows were observed. The mean distance from the nearest burrow remained always under 3 m, but this distance may have been due largely to the high density of burrows. The apparent freedom of movements of young rabbits around different burrows may be related to the social system of the adults in a sand dune habitat.
Age‐dependent Discrimination of Unfamiliar Pups in Galea musteloides (Mammalia, Caviidae)
Authors: Künkele Joachim , Hoeck Hendrik N.
Published: May 2010

In this study we tested whether polygynously paired G. musteloides females discriminate between pups of the own and of unfamiliar groups. The transfer experiments showed that without exception unfamiliar pups older than 8 d were attacked immediately after introduction. If the resident females had no offspring or their offspring were older than 20 d the introduced strange pup was treated aggressively irrespective of its age. Transferred pups younger than 8 d were not treated aggressively, as long as the resident young were present and of an age below 20 d. The adaptivity of the observed behaviour is discussed.
Effects of Removal of Successful Males in a Fallow Deer Lek
Authors: Apollonio Marco , Festa‐Bianchet Marco , Mari Franco
Published: May 2010

Removal of 5 of the 8 most successful males in a fallow deer lek between breeding seasons led to an increase in fighting rate of males and a decrease in mating rate of both sexes. The increase in fighting was likely due to disruption of the social hierarchy. The lower mating rate of females was not due to disruption of copulations by territorial males, nor did it appear to result from disturbance from fights. We suggest that difficulties in mate choice related to an unstable male hierarchy resulted in females either increasing their length of stay in the lek, visiting the lek more than once before mating, or leaving the lek without mating.
Male Mate Preferences in the Mosquitofish Gambusia holbrooki
Authors: Bisazza Angelo , Marconato Andrea , Marin Guglielmo
Published: May 2010

Although male mosquitofish invest little in their progeny, the simultaneous availability of many potential mates and the large variance in their quality are expected to favour the evolution of mechanisms of male mate choice. Males of Gambusia holbrooki were shown to exhibit sexual preferences when presented simultaneously with two potential mates. When females differed in size, males showed more sexual activity directed at the larger of the two and the time spent with this female increased with the difference between the two females. This preference, however, was lower than expected if males spent time in direct proportion to the difference in fertility between females. In the second part of the study, females which had just delivered were found to be clearly preferred over gravid females. Attractiveness of females dropped after the third day, and disappeared in the sixth day after parturition. The results are discussed in relation to the probable occurrence of sperm competition and sperm displacement in this species.
Neighbor Recognition and Context‐dependent Aggression in a Solitary Wasp, Sphecius speciosus (Hymenoptera: Sphecidae)
Authors: Pfennig David W. , Reeve Hudson K.
Published: May 2010

Female cicada‐killer wasps (Sphecius speciosus) nest underground and provision one brood chamber at a time with cicadas upon which they lay a single egg. Females commonly nest in dense aggregations of several dozen burrows. Although there is usually only one female per nest, occasionally two females encounter each other in the same burrow. Burrow owners exhibit variable tolerance of intruders (i. e. conspecific females who enter their nest), ranging from apparent indifference to intense aggression (biting and stinging). Field observations and experimental manipulations show that a nest owner's behavior toward intruders is influenced by 1) the presence of an exposed cicada in the owner's burrow, 2) whether or not the intruder is nesting near the nest owner, and 3) the intruder's size. A nest owner was most aggressive when an exposed cicada was present in its burrow and the intruder was a large nonneighbor (i.e. a female who was not nesting within 1 m of the nest owner in the same nest aggregation). Owners were markedly less aggressive when there was no exposed cicada and the intruder was a large nonneighbor or a small neighbor (i.e. a female who was nesting within 1 m of the nest owner in the same nest aggregation). Owners displayed little or no aggression when there was no exposed cicada and the intruder was a large neighbor. Owners apparently modulate their aggression according to their susceptibility to usurpation and/or perhaps cleptoparasitism. The ability of S. speciosus females to vary their aggression in different contexts suggests that selection can favor plasticity in social responses even in solitary Hymenoptera. Such flexibility may have been a forerunner of the elaborate social assessment mechanisms of eusocial insects.
The Parental Response to Brood Size Manipulation in Smallmouth Bass (Micropterus dolomieui)
Authors: Ridgway Mark S.
Published: May 2010

In this field study, the broods of male smallmouth bass (Micropterus dolomieui) were manipulated to determine if males adjust their level of defense in response to changes in brood size. Conspecific models of equal size were used to elicit defense before and after manipulations, prior to swim‐up of offspring from the nest. Males with augmented broods increased their defense and males with reduced broods decreased their defense, both relative to a control. These results were in the predicted directions; however, the risky tactic, biting, was more independent of brood size changes relative to a less risky threat behaviour, the jaw display. These results demonstrate that parents adjust their level of investment in response to changes in brood size relative to their own expected future reproduction, and that risks of injury or mortality associated with the parent's different defense tactics can explain why some measures of brood defense are relatively independent of brood size.
Lekking Behaviour in Crested Newts, Triturus cristatus
Authors: Hedlund Linda , Robertson Jeremy G. M.
Published: May 2010

We describe the distribution of males and females in a natural population of crested newts, Triturus cristatus, during the breeding season and show that the mating system is a lek. Males arrived earlier than females at breeding sites, and throughout the breeding season there was a male‐biased operational sex ratio. Males aggregated for most of the breeding season, and did not cluster over any resources essential for females. The male aggregations were not correlated with environmental factors, nor with female distribution. The males display to females prior to mating, but contribute nothing apart from sperm, and they cannot force females to mate. Females also aggregated, though less than males, and their aggregations were separate from those of males.
The Behavioral Ecology of Libellula luctuosa (Burmeister) (Odonata: Libellulidae)
Authors: Moore Allen J.
Published: May 2010

In a pond dragonfly, Libellula luctuosa, the number of males at the mating site increased linearly during mating seasons. The number of fertilizable females in the population did not increase. An increasingly male biased operational sex ratio (OSR) therefore correlated with the increasing density of males. I predicted that this would cause increased male‐male competition and alter female mate choice.

Competition for territories influenced mating success in L. luctuosa. Two different mating strategies were adopted by males of L. luctuosa: some flew and defended lengths of shoreline (territorial males), and some perched and avoided male‐male interactions (satellite males). Satellite males increased later in the season when all territories were occupied. However, no satellite ever switched to the territorial strategy and no territorial male ever became a satellite. At high male density, two males occasionally defended the same territory. The occupation of territories was nonrandom. The probability of any male mating depended on the time of year. Territory owners did most of the mating; satellite males rarely mated. Postmating guarding of females by males depended on the number of conspecific males present.

Mating success of males was also influenced by female mating behavior, and female mating behavior was influenced by the number of males present. Females visited several males prior to mating. When fewer males were present females were more likely to reject male mating attempts. The length of copulation did not change during the mating season. At high male density, females spent less time ovipositing immediately after mating. Postcopulatory mate guarding by males increased the length of time the female spent ovipositing. These behavioral patterns may represent different strategies of mate choice, precopulatory mate choice at low male density and postcopulatory mate choice at high male density.
Temporal Patterns of Division of Labor among Workers in the Primitively Eusocial Bumble Bee, Bombus griseocollis (Hymenoptera: Apidae)1)
Authors: Cameron Sydney A.
Published: May 2010

The primitively eusocial bee, Bombus (Fraternobombus) griseocollis, possesses a complex temporal division of labor based on shifting patterns of principal tasks rather than on discrete age castes. Workers within a given age range perform ensembles of tasks which change quantitatively as the workers age. Functional classes of behavior, such as nursing or guarding, are not limited to a given age class of workers; all tasks are performed by workers of all ages. Colony ontogeny also influences worker behavioral ontogeny; significant differences in task performance exist among workers born in different phases of colony development. As the colony aged, young bees foraged with increasing probability. In the absence of foraging mortality, foragers shifted to nursing tasks, and were replaced by younger bees.
Sexual Harassment in Langur Monkeys (Presbytis entellus): Competition for Ova, Sperm, and Nurture?
Authors: Sommer Volker
Published: May 2010

Interference of nonmating individuals in copulations was studied for 14 months in a harem troop of free‐ranging Hanuman langurs living in Rajasthan/India. 80.6% of 346 sexual interactions were harassed by members of all age‐sex classes except infant‐I. A mean of 1.6 (range 1–7) harassers cooperated entailing a mean of 1.9 (range 1–7) successive copulatory attempts of the disturbed couples. Rank did not influence the direction of male‐male harassment. However, higher‐ranking adult females harassed lower‐ranking twice as often (67.2%) as vice versa (32.8%). Moreover, only 58.8% of copulations of the 3 top‐ranking females were disturbed against 96.4% in the 3 lowest‐ranking.

Harassment by adult males seems to reflect intrasexual competition for insemination of females. Harassing females possibly try to limit births and reduce future resource competition. Since insemination of one female may reduce the probability of another female's impregnation, harassment might also express sperm competition. The latter hypothesis is supported by the fact that 75.0% of all copulatory attempts of pregnant females were likewise disturbed. Since interference in nonfertile matings cannot reflect resource competition, it is assumed that copulating pregnant females try to deplete the sperm available to competing fertile females. Immatures harassing maternal copulations obviously try to delay the births of siblings who are rivals for nurture.
The Display of the Blue‐black Grassquit: The Acoustic Advantage of Getting High
Authors: Wilczynski Walter , Ryan Michael J. , Brenowitz Eliot A.
Published: May 2010

Male blue‐black grassquits (Volatinia jacarina) display by leaping vertically above the top of the dense grass in which they perch and emitting a high pitched call. Acoustic‐transmission experiments demonstrated that calls broadcast from above the high grass typical of grassquit habitat attenuated less over distance than identical calls broadcast from typical perch heights within the grass. By leaping when they call, grassquits might enhance the distance over which their call can be detected.
Infant Killing and Infant Adoption Following the Introduction of New Males to an All‐Female Colony of Baboons
Authors: Gomendio Montserrat , Colmenares Fernando
Published: May 2010

A novel group of Hamadryas baboons (Papio hamadryas) containing three adult males was introduced into an already established colony of Hamadryas and hybrid baboons, with no adult males. All the unfamiliar males attacked the unweaned infants in their newly established harems. However, only one of them actually killed infants. All females in the colony who were not cycling when the union took place, including the lactating females, resumed cycling soon after the new males' arrival. In most cases lactating females had already started cycling when their infants were killed. The infants interfered with the interactions between the males and their mothers. In this way, infants initiated conflict with originally friendly males, who then started attacking the infants. Unrelated infants born shortly after the introduction developed friendly relationships with the males, in marked contrast to those born before. It was suggested that if a mother starts to develop a relationship with a new male while her infant is still dependent, the latter will respond to the male in a fearful and interfering way, possibly as a result of the decrease in maternal investment which accompanies the process of male‐female bonding. On the other hand, if this bonding process is over by the time the infant is born, no infant‐male conflict will arise. Young and/or subordinate males might be less capable of dealing in other ways with this kind of conflict, and therefore more prone to kill infants. Immatures followed different strategies. Oldest infants and juveniles who were not dependent on maternal care stayed away from their mothers and the new males. Younger infants who could not survive on their own actively tried to associate with other caretakers.
Temporal Progression of the Giant Petrel Courtship
Authors: Bretagnolle Vincent
Published: May 2010

The courtship behaviour of the giant petrel Macronectes giganteus is described after a 15‐months field study in Adélie Land, Antarctica. The five sexual displays are briefly summarized. Sequences of these displays given by both partners form the courtship. Analysis of 1122 sequences shows that their structure varies during the two months before laying. The biological function of this temporal evolution is discussed, focusing on two particular aspects: the synchronization of partners and the diminution of aggressivity leading to copulation.
Nestmate Recognition in Fire Ants (Solenopsis invicta Buren). Do Queens Label Workers?
Authors: Obin Martin S. , van der Meer Robert K.
Published: May 2010

In studies with large, laboratory colonies containing fertile (physogastric) queens, the intensity of worker aggression directed at nonnestmate kin and nonnestmate nonkin was independent of queen‐derived olfactory cues. Workers were also confined for 24 h with a physogastric queen. Those workers selected for testing while tending queens were attacked during subsequent introductions to nestmates. Queen‐derived cues are thus sufficient for nestmate recognition in the laboratory. Aggression elicited by queen‐tending workers was not significantly associated with queen fecundity (weight). The fire‐ant queen attractant/recognition pheromone was transferred from queens to queen‐tending workers in these small groups. Data are consistent with the hypothesis that workers detect both qualitative and quantitative differences in queen pheromones. While queen‐derived cues do not appear to play a significant role in colony‐level recognition, they could function as caste‐recognition cues within fire‐ant nests.
An Experimental Study of the Behavioral Basis of Sexual Isolation between Two Sympatric Plethodontid Salamanders, Desmognathus imitator and D. ochrophaeus
Authors: Verrell Paul A.
Published: May 2010

Sexual isolation between two species of North American plethodontid salamanders (Desmognathus imitator and D. ochrophaeus) from a locality where they are sympatric was investigated by staging a series of 40 intraspecific and 40 interspecific sexual encounters. Only 5% of interspecific encounters resulted in insemination of the female, indicating a high degree of sexual isolation between these species (Stalker's index of sexual isolation = + 0.88). Behavioral observation revealed that, in 80% of interspecific sexual encounters, males apparently ignored heterospecific females and failed to initiate even the preliminary stage of courtship, during which the male actively pursues the female. Evidence of a role for chemical stimuli in maintaining sexual isolation was obtained in experiments in which males were exposed to different types of odors in a Y‐maze olfactometer. Males of both D. imitator and D. ochrophaeus preferred conspecific over heterospecific female odor. This result supports the hypothesis that interspecific courtships fail because heterospecific females produce inappropriate chemical cues.
Kin Association in Japanese Quail Chicks
Authors: Waldman Bruce , Bateson Patrick
Published: May 2010

Japanese quail (Coturnix coturnix japonica) have finely‐tuned kin‐recognition abilities that may serve a role in mate choice. To investigate whether these abilities are expressed in other life stages, we examined patterns of association among quail chicks in the laboratory four days after hatching. Hatchlings were reared either in mixed‐family groups, consisting of siblings and nonsiblings, or in pure‐family groups, consisting just of siblings. Chicks were highly social in testing sessions, as reflected in their clumped spatial distributions, and interacted more with their siblings than with nonsiblings. Siblings in each of four mixed‐family groups preferentially associated with one another over nonsiblings. No discrimination was evident among differently marked siblings in four purefamily groups. Thus, at an early age, quail discriminate between siblings and nonsiblings despite social experience of both. Recognition abilities that develop prior to or soon after hatching may facilitate cooperation among chicks, may enable siblings to track each others' traits as they mature, or both.
The Pattern of Helping in the Bell Miner (Manorina melanophrys)
Authors: Clarke Michael F.
Published: May 2010

The amount of aid a helper gave a single brood varied significantly according to the helper's age, sex and breeding status. The rate at which non‐breeding helpers fed a brood increased as the helpers aged. Male helpers and unmated breeding‐age helpers gave aid at higher rates and to a greater number of different breeding pairs than did female helpers and mated helpers.

Breeding pairs which were assisted by six or more helpers during the fledgling period produced more independent offspring per attempt than did pairs assisted by fewer helpers. It is suggested that the helpers reduced the provisioning burden of the breeding pair.

Individual helpers fed nondescendant kin at significantly higher rates than they fed recipients of no known genetic relationship. However, most helpers also aided broods to which they had no known genetic relationship. Their pattern of aid distribution amongst such recipients was neither random nor related to the proximity of the recipients. Naturally ‘widowed’ female breeders paired preferentially with the unrelated, unmated, breeding‐age male which had provided the most aid to their previous broods.

The pattern of aid distribution by bell miners was most accurately predicted by the hypotheses that helpers gain indirect fitness benefits by aiding kin (whenever appropriate kin were present, which was predominantly when an individual was young), and direct fitness benefits through aiding breeders as the helpers approached sexual maturity, thereby increasing the likelihood of being accepted to fill a breeding vacancy.
Measuring Pair Relationships in Jackdaws
Authors: Wechsler Beat
Published: May 2010

The pair relationships of 8 pairs of jackdaws (Corvus monedula), living in a captive flock of 28 jackdaws, were characterized by 12 quantitative measures in three observation periods. The 12 measures represent different aspects of jackdaw social relationships like spatial proximity, exclusiveness, interactional frequencies, asymmetry and behavioural meshing. They were analysed with respect to their consistency in measuring the quality of jackdaw pair‐bonds. The amount of time the pair mates spent in mutual proximity was significantly correlated with the behavioural meshing of the mates and the exclusiveness of the pair relationship. The frequencies of feeding and preening the mate as well as the asymmetry in each partner's contribution to the maintenance of mutual proximity were not significantly correlated with any other pair‐relationship measure. A factor analysis distributed the 12 measures on five orthogonal factors.
Strike‐induced Chemosensory Searching in the Colubrid Snakes Elaphe g. guttata and Thamnophis sirtalis
Authors: Cooper William E. , McDowell Susan G. , Ruffer Jay
Published: May 2010

Strike‐induced chemosensory searching (SICS) occurs in numerous venomous snakes. SICS also occurs in the nonvenomous snakes Elaphe g. guttata and Thamnophis sirtalis. These species elevated tongue‐flicking rates more after striking than after exposure to experimental control conditions. Controlled effects were disturbance, visual cues (and possibly noncontact chemical cues), and handling. In another experiment with T. sirtalis, degree of disturbance was controlled. Some snakes received tactile stimulation of the oral mucosa and others similar tactile stimulation plus chemical prey cues. The much greater tongue‐flick rate in the condition including prey odors indicates that 1) disturbance alone cannot account for SICS, 2) tactile stimulation of the mouth is unlikely to elicit the full SICS response, and 3) chemical cues may be of paramount importance. SICS may be widespread in nonvenomous snakes and was presumably a preadaptation favoring the strike‐release‐trail strategy used by many venomous species. The highest tongue‐flicking rates in both species occurred after striking. In E. g. guttata an equally high rate followed swallowing. Tongue‐flicking rate in T. s. sirtalis decreased after swallowing. Interspecific differences in post‐swallowing response by snakes may be related to feeding mode and prey aggregation.
Buffalo Herd Structure and its Repercussions for Condition of Individual African Buffalo Cows
Authors: Prins H. H. T.
Published: May 2010

The African buffalo Syncerus caffer was studied in Lake Manyara National Park, Tanzania. Emphasis was placed on the study of (individual) buffalo cows, which live in mixed herds. Buffalo herds are discrete social units and females were never observed in another herd than their own. The herd showed a structure with respect to the distribution of sex‐age classes. Individual cows generally kept the same location within the herd. The location in the herd appeared to be coupled to food intake and was strongly related to physical condition. The best location (highest intake and best condition) was between the front and the centre of the herd, the worst location was the rear of the herd (when moving or grazing). Females with calves appeared to have the highest position in the hierarchy as determined from the rate of displacement over food; adult bulls did not interact with cows. Few births were observed during the late dry season and it appears that there is a calving peak at the end of the long rains. Conception rate increased when cows increased in condition and dropped when cows lost condition. Cows showed a strong seasonality in condition but bulls on average hardly changed in condition, except for a loss in condition during the inferred conception peak. Buffalo herds in Manyara showed a fusion‐fission pattern independent of season but strongly influenced by the size of the herd: large herds split more often than smaller ones. In large herds, buffalo grazed closer together than in small herds and it appeared likely that competition was more severe in large herds. Animals in the rear of a large herd lost condition faster during the dry season than animals in the best location in the herd, and especially cows in the rear split off most frequently from the herd to graze in a smaller fragment. From the literature on cattle, it is inferred that the reproductive success of cows in the rear of the herd will be lower than of cows in the best location, and this differential is confirmed by the behaviour of adult bulls. It is as yet unclear what the advantage is for adult cows in the rear of a large herd to stay in that herd but the sharing of information with more successful individuals seems a good candidate.
Visiting Behaviour by Females of the Sexually Dichromatic Damselfish, Chrysiptera cyanea (Teleostei: Pomacentridae): a Probable Method of Assessing Male Quality
Authors: Gronell Ann M.
Published: May 2010

The process of female choice of mates was examined in the damselfish Chrysiptera cyanea. Females make their choices during courtship periods termed “visiting” which are performed the day prior to spawning. Each female spawns once every four days; the eggs take four days to hatch. Female spawning is asynchronous. Males may therefore have eggs in all stages of development in their nests simultaneously. Females were shown to rely on apparent male reproductive status (whether or not there were eggs in the nest at the time of visits) when choosing spawning partners. Secondarily, courtship levels, male size, and the colour pattern of males appeared to influence choice. Among successful males, estimates of male reproductive success were correlated with the operative sex ratio (females to successful males) and the percentage of the eggs received which remained on day 4, just prior to hatching (estimated parental care ability). The first factor contributes in a direct manner to male reproductive success. The second is probably a result of differential reproductive success and not a cause of it. Eggs in nests with a large number of eggs had a higher hatching success than those in nests with fewer. Females therefore pursue a copying strategy, preferentially laying their eggs with those of other females. Thus eggs appear to be a valuable commodity from the viewpoint of the males. Unsuccessful males readily foster eggs, regardless of their source, in what is effectively a “cheating” strategy.
Neighbor Recognition in a Solitary Desert Rodent (Dipodomys merriami)
Authors: Randall Jan A.
Published: May 2010

Neighbor recognition in the Merriam's kangaroo rat (Dipodomys merriami) was tested in neighbor and nonneighbor pairs of the same and opposite sex in a large enclosure in the field. Mutual tolerance, rather than aggression, occurred in the encounters, and neighbor recognition was more apparent in females than in males. Females tolerated and engaged in nonagonistic contact with familiar males and females; males approached and attempted to contact neighbors and nonneighbors alike. Neighbor recognition is important to both spacing and mating in females. Males' persistent attempts to interact with any conspecific may be important to their mating success.
Courtship, Fighting and Sexual Dimorphism of the Banded Newt, Triturus vittatus ophryticus
Authors: Raxworthy C. J.
Published: May 2010

A study was made of the courtship and fighting behaviour of banded newt Triturus vittatus ophryticus in both the laboratory and field. Sexual dimorphism is more pronounced in this species than in any other urodele but up to now there has been no detailed description of the courtship behaviour. Functional explanations are proposed for the extreme secondary sexual characters based on the nature of courtship and fighting behaviour. T. vittatus appears to have a type of lek mating system similar to T. marmoratus and T. cristatus. Behavioural features of the courtship display indicate that T. vittatus is taxonomically closely related to T. marmoratus and T. cristatus.