bluuebunny/crossref_metadata_2025 huggingface dataset:
The Social Systems of Gregarious Lemurs: Lack of Convergence with Anthropoids due to Evolutionary Disequilibrium?
Authors: van Schaik Carel P. , Kappeler Peter M.
Published: May 2010

The gregarious lemurs of Madagascar show a lack of convergence with anthropoid primates in several social, demographic, morphological and ecological features. They lack sexual dimorphism in canine and body size, and live in groups with equal adult sex ratios that can vary in composition from pairs to larger units. In most species, females dominate males, and have brief and often synchronized estruses. Finally, lemurs are often active during both day and night (i.e. cathemeral). Three hypotheses for this lack of convergence are discussed. The traditional explanation is that Madagascar's unique ecological pressures have forced females to exclude males from access to limiting resources, selecting for the other unique features as means to maintain female dominance over males. This idea is not logically consistent and is also poorly supported empirically. The second hypothesis claims that cathemerality imposes unique constraints on lemur social organization. The social behavior of cathemeral taxa is largely consistent with this idea. However, the social organization of the diurnal species is not. The third hypothesis claims that recent ecological changes, in particular the demise of large diurnal raptors, have produced a mismatch between current activity periods and adaptations to activity period. This idea is supported by a review of morphological adaptations to light conditions among lemurs, and, more generally, by a comparative analysis of cathemerality among tropical forest mammals. We conclude that the social systems of non‐nocturnal lemurs are best considered as groups formed by species adapted to live in pairs. However, we cannot conclusively exclude the possibility that cathemeral activity is an old and stable activity pattern among lemurs. We indicate which data would decide the issue, and discuss the implications for views of social evolution of lemurs and other animals.
Territorial Dominance of Male Laboratory Mice
Authors: Hayashi Susumu
Published: May 2010

Social interaction and spatial distribution among male mice (Mus musculus) were observed. The enclosure was divided into three compartments, left, right and center. Each side compartment contained two males for 3 d and then the doors that led to the center compartment were opened for 7 d. The dominant male was removed 3 d after the opening day. The results indicate that the dominant male monopolized its own territory including the compartment where it had dwelt before opening the doors. The other subordinates huddled together in the opposite compartment. The dominant male patrolled more frequendy than subordinates and sometimes attacked subordinates. One of the subordinates rapidly became dominant after the removal of the dominant male. The secondary dominant male monopolized the familiar area and attacked subordinates, as the dominant male had done.
Life History Dependent Behavioural Variation in Water Striders, Aquarius remigis
Authors: Blanckenhorn Wolf U. , Perner Dirk
Published: May 2010

We investigated behavioural consequences of life history states in Aquarius (Gerris) remigis, a hemipteran surface predator and scavenger of small North American streams. A repeated‐measures field study comparing reproductive and non‐reproductive first summer generation females and males during the same time in summer showed that non‐reproductive males and females, which were foraging to survive the winter, behaved essentially alike, often being territorial. In contrast, reproductives of both sexes were more mobile than non‐reproductives, reproductive males being much more mobile than reproductive females, always in search of and attacking potential mates. This resulted in reproductive males showing litde territoriality and having lower foraging success than all other categories, while reproductive females had higher foraging success than non‐reproductive females or males, thus likely increasing their fecundity. Many behavioural variables did not change with time. Exceptions were a decrease in the mating activity of reproductives of both sexes, the number of mating attempts, mobility, and the stride rate of reproductive males, and an increase in overall foraging activity of all individuals. This indicates that the behaviour of reproductive males converged towards that of non‐reproductive males as the season progressed. Individuals were assigned to either state post‐hoc according to whether they had been seen mating at least once during the study period (July and August). Females were further tested to ascertain if they laid eggs. These results support the hypothesis that diapause and reproductive state to some degree predetermine behaviour, thus constraining behavioural flexibility. Attributing behavioural variation to various proximate causes can be central to the interpretation of alternative strategies and tactics.
Ontogeny of Dominance in Free‐living Red Foxes
Authors: Meyer Sandrine , Weber Jean‐Marc
Published: May 2010

We established the ethogram of fox pups of free‐living foxes after emergence from the den. We recorded the reactions of the pups during encounters to determine their social status and documented the relationship between social status and social play. The ethogram comprised 12 behavioural classes including 64 behavioural acts. ‘Moving’ and ‘exploration’ were the most observed classes with a frequency of occurrence higher than 20%. Most behavioural acts occurred at frequencies ranging from 0.5% to 5%. The intra‐litter hierarchy was linear. Social play was the predominant type of social activity among pups, and induced the maintenance of dominance relationships among them. Adult—juvenile interactions (‘relation with an adult’ and ‘suckling’) could depend on the social rank of the juveniles. Juvenile‐juvenile contacts allowing strong social bonds to develop between littermates (‘tactile communication’ and ‘comfort social behaviour licking and nibbling fur’) were not correlated with the social rank of the juveniles.
Inhibition of Host Queen Reproductive Capacity by the Obligate Social Parasite Polistes atrimandibularis (Hymenoptera, Vespidae)
Authors: Cervo Rita , Lorenzi M. Cristina
Published: May 2010

Polistes atrimandibularis is the obligate and permanent parasite of the social paper wasp Polistes biglumis bimaculatus. This parasite lives together with the host foundress for a considerable period on the invaded nest. Ovarian development was measured in females of the host species (foundresses and, when present, workers) from 18 parasitized and 14 non‐parasitized colonies. The reproductive capacity of foundresses from parasitized nests decreased faster than that of foundresses from non‐parasitized nests. These results indicate that the presence of the parasite lowers reproductive capacity of the host queen. Simultaneously, the fertility of the host worker is inhibited.
Correlates of Territoriality in Rutting Red Deer
Authors: Carranza Juan , Fernandez‐Llario Pedro , Gomendio Montserrat
Published: May 2010

The mating strategy most commonly reported for male red deer, Cervus elaphus, is the defence of females (harems), territoriality having been described only in Doñana, Spain. We observed rutting males at five different populations in Spain and during 4 consecutive yr in Doñana. Female defence was the only strategy observed in two of the populations, whereas territorial defence coexisted with female defence in the remaining three populations. Territorial defence appeared to be more costly than female defence, in terms of rates of aggressive interaction, and territorial males tended to gather more females per d than non‐territorial ones. Both mating strategies seemed to respond to local variations in habitat, which in turn affected female distribution. Females concentrated in areas with high‐quality forage, and most territories contained patches of high‐quality food (i.e. greater quality within boundaries) or were located along main routes used by females. The results are interpreted in the light of environmental conditions in southern Europe, where the rut coincides with the less favourable season for herbivores (in terms of food resources) after the hot and dry summer. Under such conditions of food scarcity coupled with patchy distribution, females tend to concentrate on the remaining patches of green swards, and males benefit from defending the food resources that attract females.
Individual Odours in Two Chromosomal Species of Blind, Subterranean Mole Rat (Spalax ehrenbergi): Conspecific and Cross‐species Discrimination
Authors: Todrank Josephine , Heth Giora
Published: May 2010

Mole rats from two chromosomal species (2n = 58 and 2n = 60) of the Spalax ehrenbergi superspecies of Israel were tested to determine whether they were able to discriminate differences in the odour of urine from same‐sex individuals of their own and of the other chromosomal species. An habituation‐discrimination apparatus was designed for use with these solitary and blind subterranean rodents. Animals habituated to the odour of urine from one individual presented for 10 min at a centre sniffing area in the roof of a 50 cm long Perspex tunnel. The odour of urine from the original donor and from a second individual were presented at two other sniffing areas in the tunnel roof during a 5 min discrimination phase. Significant differences in the time spent investigating the two odours demonstrated successful discrimination between them. The results indicate that male and female mole rats of both species can discriminate between the individual‐specific odour cues in urine from pairs of conspecifics and pairs of heterospecific mole rats.
Determinants of Dominance in the Tree Lizard Urosaurus ornatus: the Relative Importance of Mass, Previous Experience and Coloration
Authors: Zucker Naida , Murray Leigh
Published: May 2010

A determination of some of the factors that predict the outcome of contests between male tree lizards, Urosaurus ornatus, was made using logistic regression modelling on matched‐pair data. Two‐day‐long encounters were staged between pairs of males differing in size (snout‐vent length and mass), previous contest status (previous winners and previous losers), and coloration (dorsal coloration during their previous contest and throat coloration, a fixed trait). Mass proved to be the best single predictor of contest outcome, resulting in an 80% correct classification rate for predicting winners and losers, far better than the less than 57% correct classification rate for snout‐vent length. Previous social status (winner or loser) also was a powerful single predictor of contest outcome with a 793% correct classification rate, as was previous dorsal coloration (76.7%). When combined, mass and previous status produced the strongest combination of predictors with a better than 86% correct classification rate. Contrary to several previous studies, which implicated throat coloration as an important status signal of dominance, our results failed to show that throat coloration is a strong predictor of contest outcome. Possible reasons for this discrepancy with earlier findings are discussed. The logistic regression models also allow prediction of the magnitude of difference in mass between two contestants for there to be an equal chance of winning, given a second asymmetry in contest predictors.
The Huh Vocalization of White‐faced Capuchins: a Spacing Call Disguised as a Food Call?
Authors: Boinski Sue , Campbell Aimee F.
Published: May 2010

White‐faced capuchins, (thus capuchins, predictably emit huh vocalizations at high rates within dense fruit patches. We sought to determine why white‐faced capuchins at the La Selva Biological Station, Costa Rica produce these food‐associated calls. Here we analyze the contexts in which this intra‐group vocalization was emitted, including the spatial responses elicited from other troop members. A cumulative 26.6 h of continuous focal samples and 3314 spectrograms (including 1643 huhs) were analyzed from a study troop with 16 focal subjects. The mean individual rate of huhs was greater (1) during foraging versus nonforaging activities; (2) during fruit foraging compared to both visual searching for foraging sites and foraging for arthropod prey; and (3) when the nearest neighbor was within a 10 m radius of the focal animal compared to when the nearest neighbor was at greater distances. A huh also predicted a significant increase in nearest‐neighbour distance; on average, mean nearest‐neighbor distance increased 3 m within 2 min following a huh vocalization. Null models of change in mean nearest‐neighbor distance over time were generated from the original data set by treating predetermined time points (140 s intervals) in the focal recordings as if those points marked instances at which huhs were produced by the focal subject. No significant alterations in nearest‐neighbor distance were detected within time lags up to 100 s in these null models, supporting the conclusion that huhs are causally linked with subsequent increases in nearest‐neighbor distances. Huhs were most evident when capuchins were within dense fruit patches, but these calls were produced across all foraging contexts. Our results suggest that huhs may not be food calls in the usual sense (i.e. informing others of the location of food sources to be shared), but may be more appropriately described as spacing calls. Huhs probably act to increase foraging efficiency by reducing overlap in foraging areas with other troop members.
Probing, Assessment and Management during Interactions between Ground Squirrels (Rodentia: Sciuridae) and Rattlesnakes (Squamata: Viperidae). 2: Cues Afforded by Rattlesnake Rattling
Authors: Rowe Matthew P. , Owings Donald H.
Published: May 2010

The predator‐prey relationship between California ground squirrels (Spermophilus beecheyi) and northern Pacific rattlesnakes (Crotalus riridis oreganus) is a useful system in which to explore risk assessment and management. Rattlesnakes are major predators of ground‐squirrel pups, but pose only a sublethal threat to adult squirrels. Adults approach, harass, and even attack rattlesnakes when confronted with them. A rattlesnake's response to such harassment can include rattling and striking.

Not all rattlesnakes pose the same risk to an adult squirrel. Larger, warmer rattlesnakes strike in ways that may be more effective at overwhelming the defensive leaps of squirrels, and larger snakes can inject more venom if they are successful in landing a bite. It would therefore benefit squirrels to assess and respond appropriately to rattlesnakes of different body size and temperature. We looked for cues in rattling upon which such assessments might be based.

We recorded and digitally analyzed the rattling sounds of snakes of different sizes, each tested at four different body temperatures — 10, 18, 27, and 35°C. Results indicate that warmer snakes rattle with faster click rates, higher amplitudes, and shorter latencies. Similarly, larger snakes produce rattling sounds of higher amplitude and lower dominant frequencies. Thus, rattling provides reliable cues about rattlesnake dangerousness. Nevertheless, this highly ‘informative’ characteristic of rattling has its origins in physical and physiological constraints, not in specialization for communication.

Ground squirrels appear to probe for the information extractable from rattling, for example by pushing loose substrate at the snake and thus inducing it to rattle. Future reports will discuss the degree to which ground squirrels actually exploit these cues.
Call Variation in the Bufo microscaphus Complex: Implications for Species Boundaries and the Evolution of Mate Recognition
Authors: Gergus Erik W. A. , Sullivan Brian K. , Malmos Keith B.
Published: May 2010

Since the Modern Synthesis, many species concepts have considered characters mediating mate recognition essential to both the identification and definition of species. To explore divergence in mate recognition systems, calls were recorded and toads measured from all three species of the monophyletic Bufo microscaphus species complex including five populations of Bufo californicus, three populations of B. microscaphus, and one population of B. mexicanus. Call duration, dominant frequency, and pulse rate were significantly related to temperature, but not snout‐vent length. When adjusted for temperature, calls of B. californicus had a significantly longer call duration, higher dominant frequency, and slower pulse rate than B. mexicanus and B. microscaphus, which did not differ from one another. However, the magnitude of variation among populations of B. californicus was similar to that between species. Discriminant analysis using call variables provided some separation of B. californicus and B. mexicanus from B. microscaphus, and cross‐validation analysis correctly classified approximately 75% of B. californicus and B. mexicanus. Given only slight divergence in mate recognition systems between B. californicus and the other two taxa, the biological significance of this difference remains ambiguous. Comparisons among B. americanus group members indicate that hybridizing taxa may or may not exhibit divergence in advertisement calls. Maintenance of independently evolving lineages may be driven by other evolutionary mechanisms. These results support the notion that species recognition is best viewed as an effect of mate recognition.
Escape Behavior and Predation Risk of Mainland and Island Spiny‐tailed Iguanas (Ctenosaura hemilopha)
Authors: Blázquez M. Carmen , Rodríguez‐Estrella Ricardo , Delibes Miguel
Published: May 2010

We investigated the relationships between predator avoidance behavior and predation risk by comparing the wariness of iguanas (Ctenosaura hemilopha) belonging to an island population with few predators with that of iguanas belonging to a mainland population under high predation pressure. We predicted that island iguanas would be less wary than mainland ones. Island iguanas allowed the closer approach of potential predators before their first reaction and fleeing. The responses of both sexes did not differ statistically, except for the frequent displays shown by males as the first reaction. These results suggest that island iguanas, which were probably introduced onto the island by man, have modified their behavior in response to a decline in predation risk, supporting the hypothesis that predation pressure can contribute to intraspecific variation in antipredator behavior. The results also quantify the tameness of prey on islands without terrestrial predators, and their consequent vulnerability if foraneous predators are introduced. No significant difference was found between the populations in the time needed by frightened iguanas to resume their normal activity, suggesting that the island iguanas could learn to recognize predators and develop a suitable antipredator behavior.
Evolution of Female Egg Care in Haremic Triggerfish, Rhinecanthus aculeatus
Authors: Kuwamura Tetsuo
Published: May 2010

Paternal care is predominant among telcost fishes with external fertilization. This study describes maternal care in a haremic coral‐reef fish and discusses the possible factors leading to its evolution. Both sexes of the triggerfish Rhinecanthus aculeatus (Balistidae) maintained territories; some individuals for more than 8 years. Each male's territory overlapped 2‐3 female territories. Pair‐spawning occurred around sunrise. Only females cared for the demersal eggs until hatching, which occurred just after sunset on the day of the spawning. No predation was observed on eggs under the maternal care, but experimental removal of parental females decreased the hatching rate to nearly zero. Egg‐guarding females foraged as frequently as males, but less than half of non‐spawning days. Spawning occurred only in the periods of about 1 wk around the new or full moon, and individual females spawned up to three times in each period. Thus, the maternal care did not significantly affect the duration of the females' spawning intervals, while males would suffer mate loss if they performed parental care. In this situation, maternal care should be the evolutionarily stable strategy. Evolutionary transition from no care to maternal care and then to biparental care is suggested in the Balistidae.
Convenience Stores: Repeated Use of Some Cache Sites by Clark's Nutcrackers (Nucifraga columbiana)
Authors: Balda Russell P. , Kamil Alan C. , Carder Justin P. , Racz Christy L.
Published: May 2010

Field studies reveal that Clark's nutcrackers (Nucifraga columbiana) cache thousands of seeds in subterranean caches during the autumn in some years, and laboratory studies have shown that these caches can be recovered with high levels of accuracy. Over the life of a bird, numerous cache recovery cycles may be experienced and many of these may be in the same area. Birds may thus develop strong individual preferences for certain sites. These sites may become more memorable and used preferentially. These sites might also be more vulnerable to theft because of continual reuse. In this study, birds were allowed to cache and recover four times from the same set of potential cache sites in a large experimental room. Three of five birds used some cache sites more often than would be expected by chance. However, these birds did not place more seeds per cache, have higher recovery accuracy, or make more revisits to cache sites previously used. Birds did not create caches earlier in previously used holes until cycle 4, when birds actually cached in used sites significantly sooner than in previously unused ones. Birds neither recovered caches earlier from previously used sites nor made error probes earlier at them. Sites that were repeatedly used for caching were holes that were significantly closer to a centrally located feeder than less frequently used sites. Thus, some birds may develop slight preferences for some locations but these sites are not treated preferentially. Birds appear not to gain the advantages, nor suffer the consequences associated with repeated use of the same sites.
Temporal Pattern of Agonistic Interaction in Two Gerbil Species (Rhombomys opimus and Gerbillus perpallidus) Differing in Resistance to Social Pressure
Authors: Goltsman Michael E. , Volodin Ilya A.
Published: May 2010

This study compares temporal patterns of intraspecific agonistic interactions in two gerbil species in order to indicate interspecific differences in levels of social resistance. Both cross‐sex and same‐sex pairs of great gerbils (Rhombomys opimus Licht., 1823), and only same‐sex male pairs of pallid gerbils (Gerbillus perpallidus Setzer 1958) were observed during staged encounters on a neutral arena. Analysis of three latency measures—latency to first agonistic interaction; latency to overt aggression (attack and/or ‘arrested’ fight); and latency to establishment of a stable winner‐loser asymmetry among opponents—revealed both similarities and differences among the species. Latencies to first agonistic interaction were similar (did not differ significantly) among species and sexes. However, great gerbil males showed significantly more long latencies to establishment of a stable asymmetry among opponents, than great gerbil females or pallid gerbil males. So, the periods of symmetrical struggle in agonistic conflict last longer in great gerbil males, than in great gerbil females or pallid gerbil males. These differences in temporal pattern of agonistic interaction may reflect sex and species differences in resistance to social stress.
Food‐anticipatory Activity as a Cue for Local Enhancement in Golden Shiners (Pisces: Cyprinidae, Notemigonus crysoleucas)
Authors: Reebs Stephan G. , Gallant Bruno Y.
Published: May 2010

The goal of this study was to test whether food‐anticipatory activity, which is more subtle than feeding activity, can be used as a cue for local enhancement by fish. Golden shiners, Notemigonus crysoleucas, were offered a choice between spending time near a shoal of conspecifics normally fed at that time of day or a shoal normally fed at another time. Despite the fact that no food was delivered during the tests, the shoal that was normally fed at that time had more fish moving and more fish close to the surface, where food usually appeared, than the other shoal. This is evidence of food‐anticipatory activity. The choosing shiners, after being deprived of food for 24‐48 h, preferred to stay near the anticipating shoal rather than near the other one. When satiated, the shiners chose both shoals at random, indicating that hunger promotes the use of food‐anticipatory cues in shoal choice and local enhancement. The results also support the idea that food‐anticipatory activity can attract competitors for food and may therefore be costly. Food‐anticipatory activity might also attract predators, but the fact that satiated shiners did not actively avoid anticipating shoals indicates that the potential cost of predator attraction would be either low or mitigated by other factors.
Reproductive Benefits from Female Promiscuous Mating in a Small Mammal
Authors: Keil Anja , Sachser Norbert
Published: May 2010

Promiscuous systems where both males and females mate several times with different individuals are widespread among mammalian species. As a consequence, females obtain sperm from more than one male and paternity is decided by sperm competition. In theory, females might gain ‘genetic benefits’ for their offspring from this mechanism. In a mating experiment we now demonstrate in the promiscuous rodent Galea musteloides that females which were paired with four males, and became pregnant, weaned more surviving offspring than females which were paired with a single male. Litter sizes did not differ between the two groups. The data support the hypothesis that promiscuous females copulate with several males to induce sperm competition and/or to enforce cryptic female choice and thereby increase the viability of their offspring.
The Direction of Celestial Rotation Affects the Development of Migratory Orientation in Pied Flycatchers, Ficedula hypoleuca
Authors: Weindler Peter , Liepa Varis , Wiltschko Wolfgang
Published: May 2010

The migratory direction in young passerine migrants is based on innate information, with the geomagnetic field and celestial rotation as references. To test whether the direction of celestial rotation is of importance, hand‐raised pied flycatchers in Latvia were exposed during the premigratory period to a planetarium rotating in different directions. During autumn migration, when their orientation behavior was recorded in the local geomagnetic field in the absence of celestial cues, birds that had been exposed to a sky rotating in the natural direction showed a unimodal preference of their south‐westerly migratory direction. Birds that had been exposed to a sky rotating in the reversed direction, in contrast, showed a bimodal preference of an axis south‐west‐north‐east. Their behavior was similar to that of pied flycatchers that had been raised without access to celestial cues. In Latvia, the magnetic field alone allows only orientation along the migratory axis, and celestial rotation enables birds to select the correct end of this axis. Our findings show that the direction of rotation is of crucial importance: celestial rotation is effective only if the stars move in the natural direction.
Anal Gland Secretion Codes for Relatedness in the Beaver, Castor canadensis
Authors: Sun Lixing , Müller‐Schwarze Dietland
Published: May 2010

We investigated how information about relatedness is coded in the anal gland secretion (AGS) of the beaver (Castor canadensis). Using gas chromatography, we found that individual secretion profiles did not change over time and location of the beaver and the variation in the AGS profile was smaller within an individual than between individuals. Therefore, the AGS is suituable for characterising individuality. We also found that related individuals shared more features in the AGS profile than did unrelated individuals. Hence, information about kinship can be coded in the AGS profile. These findings substantiate the behavioural kin recognition system using the mechanism of phenotype matching in the beaver.
Nest and Nestmate Recognition by a Fungus‐growing Ant, Apterostigma collare Emery (Hymenoptera: Formicidae)
Authors: Singer T. L. , Espelie Karl E.
Published: May 2010

The ability of Apterostigma collare workers to differentiate their nest from other nests and their nestmates from non‐nestmates was examined. In field tests, workers that were removed from their nest were accepted back into their own nests, but were rejected when they were placed onto a nearby (≤ 1 m) nest or a distant (≥ 100 m) nest. In the laboratory, when given a choice between a fragment of their own nest and a fragment of a second nest (near or distant), workers selected their own nest material rather than the material of the second nest. For the nestmate recognition bioassay, two workers from one nest were placed together in an arena with a worker from a second nest. In most bioassays, the nestmates were tolerant of each other, but they were intolerant of the non‐nestmate. The results demonstrate that A. collare workers have the ability to recognize nestmates and their nests. The results also suggest that each nest of A. collare is an independent colony.
The Protector Species Hypothesis: Do Black Skimmers Find Refuge from Predators in Gull‐billed Tern Colonies?
Authors: Pius Sandra M. , Leberg Paul L.
Published: May 2010

The protector‐species hypothesis explains mixed‐species coloniality on the basis of benefits individuals of a species may receive by nesting with another species, the ‘protector’ species, that responds aggressively to potential threats. The reactions of nesting individuals to both natural and model predators were observed to determine whether black skimmers (Rhynchops niger) gain an antipredator advantage by nesting with gull‐billed terns (Sterna nilotica). Observations of natural predators were gathered from three mixed‐species and three single‐species (black skimmers) subcolonies. Natural predators most commonly encountered by the colonies were herring gulls (Larus argentatus), laughing gulls (Larus atricilla), and ruddy turnstones (Arenaria interpres). Gull‐billed terns responded to the gulls, but not to the turnstones, in higher proportions than did black skimmers. Two decoys, a mink and a gull, were used to simulate predatory encounters, and a duck decoy was used as a control at two mixed‐species and one single‐species subcolonies. Gull‐billed terns responded in significantly higher proportions than did skimmers to all decoy treatments in the mixed‐species subcolonies. Mobbing of both natural and model predators by the terns suggests that skimmers may gain a reproductive advantage by nesting with these terns. However, the response of black skimmers to both natural and simulated predators was independent of the presence of gull‐billed terns in the colony, indicating that black skimmers may not perceive these objects as threats, or may react differently to predators than do gull‐billed terns.
Parameters of Mating Effort and Success in Male European Ground Squirrels, Spermophilus citellus
Authors: Millesi Eva , Huber Susanne , Dittami John , Hoffmann Ilse , Daan Serge
Published: May 2010

Behavioural and physiological changes during the reproductive period were documented in male European ground squirrels including: initiated conflict, scent marking, locomotion and range size, as well as testis size, scrotal pigmentation, testosterone levels and changes in body mass. Spring emergence dates in adult males varied but preceded those of females. Gonadal maturation was complete in adult males at emergence. Most yearlings did not mature and emerged with females. After a quiescent premating phase, male range, range overlap, conflict rates and locomotion increased at female emergence. The synchrony of females, their small ranges and short latencies to ovulation produced a highly male‐biased operational sex ratio (OSR) and potential for scramble competition polygyny. In contrast to other ground squirrel species, each female apparently mated with only a single male. Scramble competition did appear to occur, in that males tried to contact as many females as often as possible before copulation. Females placed high temporal prerequisites on males. Costs of scrambling were documented by body mass loss during mating, which covaried with the number of ‘acquired’ females. Testicular regression occurred earlier, and fattening, moult and onset of next hibernation were delayed in successful males. The determinant factor in these costs was found to be mass loss intensity during the main mating period. Surprisingly, this factor was best related to feeding changes and not to locomotion or aggression. Time budget constraints perhaps imposed by the female, with compounding influences of exercise and stress effects of conflict, then negatively affected ensuing seasonal activities. The individual changes may adversely affect individual survivability and/or future reproductive success.
Morphological and Behavioural Traits Affecting the Intensity and Outcome of Male Contests inGallotia galloti galloti(Family Lacertidae)
Authors: Molina‐Borja Miguel , Padron‐Fumero Monica , Alfonso‐Martin Teresa
Published: May 2010

This study describes the sequence of behaviour during aggressive encounters between male ‘tizón’ lizards (G. galloti galloti) and assesses the effect of morphological and behavioural traits on the outcome and intensity of staged aggressive encounters between males. Aggressive encounters ranged from only throat extension to escalated fights with biting and rolling over. Winners were heavier, had longer heads, and performed tongue‐flicking, throat extension and biting at a higher rate than losers. The rate of aggressive behaviour increased with decreasing difference in snout‐to‐vent length, head length and head width of the contestants. The results are in agreement with some predictions of the sequential assessment game model in that probability of victory increased with the difference in fighting ability and that the rate of aggressive behaviour was higher in contests between animals of similar size.
Flight Directions in the Migratory Butterfly Pieris brassicae: Results from Semi‐natural Experiments
Authors: Spieth Hubert R. , Cordes Ralf‐Gerd , Dorka Martin
Published: May 2010

A recently developed experimental set‐up has been used to test the constancy of flight direction in the large white butterfly Pieris brassicae, originally collected in Northern Germany. The flight direction, tested with virgin females, depends on the developmental mode. Butterflies from diapause pupae fly north, those from subitan pupae fly south.

The constancy of the flight direction has been examined in detail with the spring generation over a period of 14d. The preferred direction does not change with advancing age and is essentially not influenced by temperature or by the sun's azimuth. The flight activity, however, increases with temperature, but this is concealed by an intrinsic response resulting in a diurnal peak of flight activity at 10.00–11.00 hours, long before the maximum temperature of the day is reached.

Whether the observed direction can be considered as a parameter of migration behaviour is discussed. It is shown that migration in Pieris brassicae does not end with reproductive maturity but lasts throughout the entire imaginal stage.
Social and Demographic Influences on Mothering Style in Pigtail Macaques
Authors: Maestripieri Dario
Published: May 2010

This study represents the first investigation of variability in mothering styles in pigtail macaques, Macaca nemestrina nemestrina. Fifteen group‐living mother‐infant pairs were focally observed during the first 12 wk of infant life and several measures of maternal and infant behavior were recorded. Variability in mothering styles occurred along the three dimensions of maternal protectivencss, rejection, and warmth. Maternal parity and aggression received by mothers were the best predictors of variability in protectiveness and warmth, whereas variability in rejection was not predicted by any of the variables considered. This study provides clear evidence that aggression towards mothers and previous maternal experience have an important influence on mothering styles in pigtail macaques.
Release Factors of Breeding Activities in Capercaillie (Tetrao urogallus) Hens
Authors: Catusse Michel
Published: May 2010

The present 7‐year study was conducted on a capercaillie (Tetrao urogallus) lek. The study included four years of continuous monitoring of reproductive behaviour of capercaillie in spring and a 3‐year study of hen‐cock relationships. We used a factorial Correspondence Analysis (CA) to assess the relationship between variables such as weather, release activity and cock display behaviour, as well as the presence and activity of hens. The statistical correlations between these factors were also summarized, showing that: there is no direct relationship between daily activity of hens on the lek and photoperiod; the behavioural interactions between cocks, their spatial and territorial organization, on the one hand, and hen activity and receptivity on the other, are reinforced by reciprocal interactions between the sexes.
Influence of the Queen on Worker Behaviour and Queen Recognition Behaviour in Ants
Authors: Vienne Catherine , Errard Christine , Lenoir Alain
Published: May 2010

We investigated the influence of the queen on worker behaviour in ants and their queen recognition behaviour. Queenless and queenright homo‐ and hetero‐specific groups were created using three Myr‐micinae species (Manica rubida, Myrmica rubra and Myrmica ruginodis). In homospecific groups, the presence of a queen contributed to an increase in the brood care, which had an effect on all other tasks of the group. In heterospecific groups, the presence of a queen led workers to care more for the conspecific brood. The queen appears to be a factor in the maintenance of both behavioural characteristics of the workers and the organization of the colony. The absence of the queen revealed some behavioural differences between species compared and populations that did not occur in queenright groups. Attractiveness tests were also conducted on these colonies. In homospecific queenright groups, workers were attracted both by unfamiliar conspecific and allospecific queens, but they were attracted more by the former. Therefore, queens appear to emit volatile pheromones which have a non‐species‐specific and a species‐specific attractant effect. In heterospecific groups, workers were attracted more by an unfamiliar queen of the familiar species (even if allospecific) than by an unfamiliar conspecific queen, suggesting the importance of early social experience for the discrimination behaviour of adults.
Age and Behavior of Honey Bees, Apis mellifera (Hymenoptera: Apidae), that Perform Vibration Signals on Queens and Queen Cells
Authors: Painter‐Kurt S. , Schneider S. S.
Published: May 2010

The vibration signal of the honey bee (Apis mellifera) may play a central role in the regulation of queen behavior during reproductive swarming and supersedure. We examined honey bee workers that performed vibration signals on queens and developing queen cells in three observation hives, each containing a population of marked bees of known age. In all three colonies, workers of all ages greater than 2 d old could perform vibration signals on queens and queen cells. However, most signals were performed by a small proportion of the bees of greater than 10 d of age. Relatively few workers less than 10 d old vibrated queens and queen cells, even though this age‐group is typically associated with queen care. Thus, the regulation of queen behavior by the vibration signal may occur primarily through a relatively small subset of older workers that, under most circumstances, have only limited involvement with queens. It is unclear what triggers the vibrating of queens. Workers producing vibration signals did not differ from same‐age non‐vibrating controls in rate of locomotion in the hive or in task performance, and they rarely engaged in foraging, even though the majority of observed bees were of foraging age; vibrators also did not spend more time with queens and queen cells compared with controls. Vibration signals performed on queens and queen cells therefore do not appear to be influenced by task performance or increased contact with queens.
Sound Characteristics and Outcome of Contests in Male Croaking Gouramis (Teleostei)
Authors: Ladich Friedrich
Published: May 2010

A correlative study using similar‐sized males of the croaking gourami Trichopsis vittata was carried out to investigate whether sound characteristics influenced winning and if relative fighting ability was assessed by acoustic signals. Pair‐wise contests between males were decided using lateral displays (LD) and vocalization in 26 cases, whereas 66 fights escalated to the frontal display (FD) phase. Physical fighting (mouth wrestling) and injuries were rarely observed in this species. Winners were generally larger than their opponents, and this effect was more pronounced in non‐escalated than in escalated contests. Sounds of fight winners had a higher sound pressure level and also a lower dominant frequency. Neither number of acoustic signals nor duration of lateral and frontal displays were predictors of contest outcome. Acoustic measures were highly correlated to body weight. These results indicate that traits correlated with RHP (such as sound pressure level and dominant frequency) were predictors of the outcome, while traits not correlated with size (such as number and duration of displays) did not influence winning. In accordance with the main prediction of assessment models, the contest duration (cost) increased with the decrease in asymmetry of body length as well as sound pressure level. No such relationships were found for weight and dominant frequencies in LD‐ and FD‐contests.

The present study indicates that morphological and sound characteristics influence winning in fish. Moreover, the results suggest that croaking gouramis settle conflicts without damaging combats by assessing asymmetries in different components of RHP such as body weight and length, which may reliably be signalled by acoustic and visual assessment signals.
Embryonic Calls as Care‐soliciting Signals in Budgerigars, Melopsittacus undulatus
Authors: Berlin Kim E. , Clark Anne B.
Published: May 2010

Embryonic calls occur 1–3 d before hatching among precocial and some altricial birds. In precocial species, calls may synchronize hatching among siblings or, in semi‐precocial species, elicit parental attention to, and often thermoregulation of, the hatching egg. Much less is known about the functional significance of calls in fully altricial species. In this study, naturalistic observations and laboratory experiments were used to document factors affecting calling and the parental responses to calls in one altricial species, the budgerigar Melopsittacus undulatus. Budgerigar chicks hatch asynchronously and vocalize 24–48 h before hatching. Embryonic calling rates increase at higher egg temperatures, and also as embryos near hatching. Parents easily locate a calling egg in their clutch, even among a large brood of much older, vocalizing nestlings. Furthermore, they actively assist in the last stages of hatching by helping to break the shell along the crack in the egg. Both observational and experimental evidence suggests that embryonic vocalizations are distinctive signals that increase parental attention and care, and may stimulate hatching assistance to a calling egg.
The ‘Widow Effect’ and its Consequences for Reproduction in Burying Beetles, Nicrophorus vespilloides (Coleoptera: Silphidae)
Authors: Sakaluk Scott K. , Eggert Anne‐Katrin , Müller Josef K.
Published: May 2010

Burying beetles tend their young on small vertebrate carcasses, which serve as the sole source of food for the developing larvae. Single females are as proficient at rearing offspring as male‐female pairs, yet males opt to remain with their broods throughout most of the larval development. One potential benefit of a male's extended residency is that it affords him the opportunity of additional copulations with the female, which could ensure his paternity in a replacement brood should the female's first egg clutch fail to hatch. We tested this hypothesis by manipulating males' access to their mates during the production of replacement clutches, using genetic colour markers to determine the paternity of offspring. Females were induced to produce a replacement brood by removing their first clutch of eggs. In one experimental treatment, we removed the female's mate upon the removal of her first egg clutch (‘widowed’ females); in a second treatment, the female was permitted to retain her mate up until she produced a replacement clutch. There was no significant difference in paternity between males removed from females before the initiation of replacement clutches and those permitted to remain with their mates. However, widowed females produced fewer offspring in replacement broods than did females permitted to retain their mates. This difference occurred primarily because a significantly greater proportion of widowed females opted not to produce a replacement clutch, a result we refer to as the ‘widow effect’. This widow effect was further shown in those replicates in which females of both treatments produced replacement clutches: widowed females took significantly longer to produce a replacement clutch than did females permitted to retain their mates. The loss of her mate could be a signal to a female that a take‐over of the carcass is imminent. Her reluctance to produce a replacement clutch under these circumstances might constitute a strategy by which she conserves carrion for a subsequent reproductive attempt with an intruding male successful at ousting her previous mate. Regardless of its functional significance, the widow effect favours the extended residency of males and therefore contributes to the selective maintenance of male parental care.
Behavioural Responses to Scent Marks of Increasing Age in Klipspringer Oreotragus oreotragus
Authors: Roberts S. C.
Published: May 2010

Klipspringers Oreotragus oreotragus are small antelopes which use scent marks to demarcate and defend their territory. The strength of behavioural response to the introduction of unfamiliar scent was measured in order to estimate the effective lifespan of scent secretion. The total number of scent marks deposited during the experiment was higher than control levels when fresh scent was introduced, but not when older scent was introduced. However, the proportion of marks deposited on introduced twigs remained higher than control levels until scent was aged at least 7d. The probability of licking twigs immediately before scent‐marking was much higher than control levels when scent aged up to 3d was introduced, but not when scent was aged 7d or more. These results indicate that preorbital gland scent retains at least some degree of efficacy for up to 7d. The decreasing level of response to scent aged 0‐7d is most likely to be due to decay of the scent signal. However, in contrast to the total number of marks deposited and the probability of licking before scent‐marking, which both consistently decreased in response to older scent, the proportion of marks deposited on scent aged 3d was higher than over fresh scent. It is suggested that, in view of the role that scent‐marking plays in territory defence, this difference in the timing of peak response between the three variables may represent an adaptive response to the perceived threat of encounter with an adversary, which is mediated by the age of the scent marks.