bluuebunny/crossref_metadata_2025 huggingface dataset:
Individual Distinctiveness and Possible Function of Song Parts of Short‐toed Treecreepers (Certhia brachydactyla). Evidence from Multivariate Song Analysis
Authors: Bauer Hans‐Günther , Nagl Willy
Published: May 2010

Sonagram analyses of short‐toed treecreeper (= STT) song by use of discriminant analysis revealed consistent individuality in the songs predominantly sung by each male (P‐songs).

The P‐songs had been digitized and over 30 song variables were used in the analysis to separate different individuals. In the end, 7 of these variables were needed for a correct classification of 100% of the 203 P‐songs recorded of 39 individuals in 1986. Most of these variables were derived from the first part of the song. A similar analysis with data from 1987 showed that by use of all variables with unskewed distribution complete discrimination of all 271 P‐songs of 47 individuals ensued. The reduction of variables to the 10 most important led to the correct classifications of 99.5%. Using the 7 best discriminators of the 1986 data set 94.2% of the 1987 data were correctly classified, thus confirming the 1986 results. Wrong assignments were mainly due to P‐songs from second or third recording dates which in some cases could not be separated from other P‐songs of the same males by the analysis.

Further analysis of the data showed that although the most important discriminators were found in the first part of the song, the combination of all characters of the end part would also allow for a virtually complete discrimination of individuals.

The song features of STT P‐song are so distinctive that territory holders should have no difficulties in separating individuals (e.g. neighbours from strangers). Corresponding playback experiments have yet to be carried out on STT.
Competitive Mating Success and Attractiveness of Sterile and Fertile Males of Drosophila montana
Authors: Hoikkala Anneli , Liimatainen Jaana
Published: May 2010

The attractiveness and the mating success of fertile (normal and brownie, br) and sterile (rudimentary testis, rt) Drosophila montana males were studied in female‐choice experiments (one female + two males). The normal males courted the sterile rt males nearly as much as they courted the females, while they courted other males less frequently. The females required a long courtship with the rt males and accepted them as their mating partner less often than normal males.

The courtship behaviour of normal, br and rt males was recorded in single pair situations with a normal female. The courtships of the males of all types proceeded in a similar manner, but the successful courtships of the rt males included more licking and touching than those of the normal and br males. The licking and touching periods are probably the critical phases at which the females are able to detect differences in male fertility.
Femme Fatale — the Case of the Threespine Stickleback
Authors: de Fraipont Michelle , Fitzgerald Gerard J. , Guderley Helga
Published: May 2010

In addition to courting females, male threespine sticklebacks must guard their nests from attacks on the eggs by female cannibals. We hypothesized that the presence of females in high densities in tide pools adversely affects a male's health and reproductive success. In the laboratory males housed with conspecific females during the breeding season were in poorer physical condition and died sooner than solitary males and males housed with conspecific males or with heterospecific females.
Syntactical Organization of the Gargle Vocalization of the Black‐capped Chickadee, Parus atricapillus
Authors: Ficken Millicent Sigler , Popp James W.
Published: May 2010

The gargle is a complex call of the black‐capped chickadee Parus atricapillus associated with agonistic interactions. A large sample of calls was recorded from five sites in southeastern Wisconsin. Three sites were near one another and the other two with a different dialect pattern were more distant (all sites were within 15 km of each other). A typical call consists of about 6 notes selected from an array of about 15 different note‐types that are shared among individuals in the same population. Note‐types are given in many combinations, and any individual may deliver many different variations. Analysis of two‐ and three‐note sequences shows a syntactical organization with certain note‐types much more likely to precede or follow than others. In some cases linkage between note‐types was nearly complete. Some differences occurred among individuals and sites, but general organizational rules were similar. One effect on ordering was acoustical structure of the notes. Higher pitched, shorter duration notes were more likely at the beginning than the end of the call which often consisted of trills. Organization of the gargle was compared to that of the chick‐a‐dee call of the same species. Similarities include recombinant properties, general acoustic rules and syntax. A major difference may be that in chick‐a‐dee calls various note combinations constituting a call have different meanings, while the various note combinations comprising an individual's repertoire of gargles may be functionally equivalent.
The Dynamics of Colony Organization in the Primitively Eusocial Wasp Polistes dominulus Christ
Authors: Theraulaz Guy , Gervet Jacques , Thon Bernard , Pratte Michel , Semenoff‐Tian‐Chanski Sophie
Published: May 2010

In colonies of Polistes dominulus Christ, the behaviour of each wasp was recorded individually. We investigated first the relationships between the wasps' hierarchical ranks and their behavioural profiles; secondly, successive α individuals were removed to examine the effects of rank change, particularly accession to α rank, on the behavioural profiles. Four main types of behavioural profiles were observed. Although an individual's rank tended to determine its behavioural profile, the effects of the hierarchy were found to be based on a stepwise arrangement into large hierarchical groups.
Attempts to Determine the Roles of Visual and Olfactory Inputs in Initial Orientation and Homing of Pigeons over Familiar Terrain
Authors: Streng Andrea , Wallraff Hans G.
Published: May 2010

The role of familiar visual landmarks in pigeon homing is still unsettled. If they are involved, they must be thought to be utilized in parallel with olfactory signals. In order to recognize the effectiveness of either one of the input channels separately, vision and olfaction, it is therefore necessary to interfere with both of them.

Pigeons were temporarily deprived of image vision by spectacles made of translucent white paper, producing a condition called V‐ as compared with the largely unimpaired condition V+. Access to olfactory signals was temporarily prohibited by charcoal filters before release and nasal anaesthesia upon release, resulting in condition O‐ versus unimpaired smelling of natural air in O+. Prior to the test releases, all the participating pigeons had been made familiar with the two or four test sites (and with other sites in the area) by training flights.

According to decreasing levels of initial homeward orientation and homing performance, the four combinations of treatments are to be arranged in the following order: V+O+, V+O‐, V‐O+, V‐O‐. In the last type, no trace of initial homeward orientation remained, indicating that at least one of the two input channels need be functional to enable home‐related orientation. Over well known terrain, either alone seems to be more or less sufficient.

The results are indicative but not definitely conclusive. Effects of visual impairment on behavioural activities in general cannot clearly be separated from orientation‐specific effects. Therefore, and because many pigeons refuse to fly in V‐ condition or fail to provide useful data, we stopped applying this method.
“Laughter” and “Smile” in Barbary Macaques (Macaca sylvanus)
Authors: Preuschoft Signe
Published: May 2010

In an observational study on semi‐free Barbary macaques it was investigated whether the phylogenetic roots of human laughter and smile can be traced back to the genus Macaca. On the basis of morphological similarity a ‘relaxed open‐mouth display’ as the phylogenetic precursor of the laughter, and a ‘silent bared‐teeth display’ as the possible ancestor of the smile can be distinguished in the repertory of the Barbary macaque. Behavioural sequences from focal animal protocols were analyzed in order to establish message and meaning of both displays. Relaxed open‐mouth display is regularly observed in the play interactions of juveniles. It is associated with partner‐directed behaviour, it is frequently answered by a relaxed open‐mouth display of the receiver, and accompanied by a special vocalization. Although up to 50% of the juvenile's play partners were higher ranking than themselves voluntary participation was the rule. Most characteristically, the behaviour patterns shown by both play partners are highly symmetrical and synchronized.

Silent bared‐teeth display is typically accompanied by evasive or submissive body movements, and occurs primarily in dyadic interactions, mainly by the lower ranking individual. It is not an unidirectional sign of a linear dominance hierarchy, though. Silent bared‐teeth display is a frequent answer to aggressive behaviour shown by the receiver. After its performance, an increase of body contact between sender and receiver was observed. Behavioural sequences of senders and receivers are complementary, but lose their asymmetry after occurrence of the display.

It is concluded that these results further support Van Hooff's (1972) view that human laughter and smile have different phylogenetic roots: while silent bared‐teeth display is a signal of submission and appeasement, relaxed open‐mouth display is rightly called the ‘play face’, and is an expression of fun.
Inter‐male Spacing and Aggression in African Painted Reed Frogs, Hyperolius marmoratus
Authors: Dyson Miranda L. , Passmore Neville I.
Published: May 2010

Inter‐male spacing and the role of aggression in the maintenance of spatial organization was examined in choruses of Hyperolius marmoratus males housed in a semi‐natural enclosure. The effects of chorus size on spacing patterns, nearest neighbour distances and male aggressive behaviour were examined. Males were found to reduce nearest neighbour distances as chorus size increased. This was accompanied by a shift in spacing pattern from even in small choruses (5–9 males) to random in choruses of 10 to 13 males. In choruses of 14, spacing patterns were once again even. The reason for these shifts is unclear but may reflect a sudden, rather than gradual increased tolerance by individuals to high neighbour call intensity as space to call from becomes more limited. The level of male aggression was influenced by chorus size and the time of night. In general, more aggressive interactions occurred in high density choruses. However, this did not translate into higher levels of individual male aggression as density increased. Individual male aggression was high in early evening choruses and declined to a minimum at peak chorusing time. High levels of aggression during early evening may reflect the establishment of calling sites by males, while the drop in aggression at peak chorusing time may occur in response to the presence of females in the chorus at this time or as a consequence of masking of neighbours calls.
The Flying Behavior of Homing Pigeons, Columba livia, Immediately after Release
Authors: Wiltschko Roswitha
Published: May 2010

After release, homing pigeons are often observed to fly around at the release site before they depart. To assess the significance of this behavior, the bearings of pigeons were taken 1,2,3 and 4 min after release and analysed with respect to the mean vanishing direction of the group (Table 1) and the individual vanishing bearing of each bird (Fig. 3, Table 2). The data come from a series of experiments involving young untrained pigeons that were shown to orient using information obtained on the outward journey, older untrained pigeons (older than 12 weeks) and trained pigeons using local information (see R. Wiltschko & Wiltschko 1985).

Analysis of behavior at the release site revealed that most groups of pigeons headed into the direction in which they finally departed almost immediately after release. Their flight directions showed a highly significant relationship to the vanishing bearing from the first min onward. Noteworthy exceptions were the young untrained control birds that seemed to fly around erratically, their bearings after one minute still unrelated to the individual vanishing bearing. Because these birds were shown to use information obtained during the outward journey, this finding indicates that flying around at the release site has nothing to do with determining the current home direction. Instead it might possibly serve to collect local release site information and match it with the home course as determined by information collected en route, thus to integrate it into the navigational ‘map’ of the spatial distribution of navigational factors.
Social Interactions and Familiarity in a Communal Halictine Bee Lasioglossum (Chilalictus) hemichalceum
Authors: Kukuk Penelope F.
Published: May 2010

Social organization in Hymenoptera is quite variable, but most group‐living species have a reproductive division of labor. Communal species, by definition, do not; all individuals work and all are reproductive. In order to understand the evolution and maintenance of such cooperative societies the essential first step is characterization of the behavioral interactions between individuals. In particular, it is important to investigate the influence of common group membership (familiarity) on these interactions.

Circle‐tube arenas were used to observe the interactions between 42 pairs of field‐collected Lasioglossum (Chilalictus) hemichalceum females either from the same nest, from different nests but the same nest aggregation, or from different aggregations. Identical procedures were applied to 24 pairs of females from laboratory colonies. There was a striking lack of agonistic behavior with Lunging occurring in only 0.03% of all bouts, and C‐Postures (threat behavior) in only 19% of bouts using field bees and 27 % of bouts using females held in the laboratory. Passing was virtually ubiquitous, occurring in 98 % of all bouts. None of these behavior patterns is significantly associated with the level of familiarity between females. The lack of agonistic behavior and the indiscriminate cooperative behavior (Passing) suggest that all conspecifics are accepted and are treated similarly. This is in contrast to previous studies of L. (Dialictus) zephyrum that demonstrated both kin recognition and nepotism.

While Avoidance behavior was rare, significantly more was seen between bees taken from different nest aggregations. Trophallaxis Solicitation occurred in 13 bouts between field bees. While the proportion of bouts in which this occurred is not associated with familiarity, the number of solicitations per bout is greater between females from different nest aggregations. These minor but statistically significant differences suggest that L. hemichalceum females can discriminate between familiar and unfamiliar individuals.

Therefore the proximate mechanism underlying universal acceptance of all conspecifics cannot be a lack of recognition cue expression or recognition cue perception. Rather, it is due to a lack of clearly preferential treatment toward familiar individuals. This suggests that some component of fitness is positively associated with group membership per se, or group size.

The high levels of mutual tolerance suggest, as do other lines of evidence (Kukuk & Schwarz 1987), that communal societies are not intermediate between solitary and eusocial species.
Electrolocation of Capacitive Objects in Four Species of Pulse‐type Weakly Electric Fish I. Discrimination Performance
Authors: von der Emde Gerhard , Ringer Thomas
Published: May 2010

The great variety of species‐typical electric signals (electric organ discharges, EOD) emitted by weakly electric mormyrid fish might be the result of evolutionary pressures stemming from the two main functions of the electro‐sensory‐motor system: electrocommunication and electrolocation. Employing a conditioned discrimination task we tested four species of mormyrids, emitting EODs differing in waveform, for their ability to detect capacitive properties of objects during electrolocation. Each fish could discriminate capacitive objects within a certain range of capacitive values, which was species specific. The upper and lower limits (upper and lower thresholds) of this detectable range were determined for each fish. In fish species emitting long duration EODs composed of mainly low spectral frequencies both the lower and the upper thresholds were shifted to larger capacitive values compared to fish species emitting shorter EODs. The upper limit of the detectable range was much more variable between species than the lower limit, which was relatively low in all fish. We interpret this as an adaptation of mormyrids to detect small capacitive objects, for example food items. All mormyrids could discriminate between a resistive object and a capacitive object even if the complex impedances of the two objects were identical. This implies that the fish are highly sensitive to small waveform distortions of their self produced EODs.
Post‐bite Elevation in Tongue‐flick Rate by Neonatal Garter Snakes (Thamnophis radix)
Authors: Cooper William E.
Published: May 2010

A post‐biting elevation in tongue‐flicking rate was demonstrated experimentally in neonatal, ingestively naive garter snakes (Thamnophis radix). That the snakes also exhibited apparent searching movements suggests that strike‐induced chemosensory searching occurs in nonvenomous snakes lacking previous experience with food or prey chemicals. Two litters of neonates differed in numbers of tongue‐flicks emitted, but had similar relative magnitudes of response across experimental conditions. The existence of post‐bite elevation in tongue‐flick rate (and presumably strike‐induced chemosensory searching) argues for a genetic basis for these chemosensory behaviors in a nonvenomous species of snake, extending the recent finding that strike‐induced chemosensory searching is fully developed in ingestively naive neonatal rattlesnakes. Possible patterns of evolution of post‐bite elevation in tongue‐flick rate, and the strike‐release‐trail strategy of highly venomous snakes are discussed.
Do Female Red‐winged Blackbirds Engage in a Mixed Mating Strategy?
Authors: Westneat David F.
Published: May 2010

Parentage analyses of broods of nestling red‐winged blackbirds (Agelaius phoeniceus) revealed that extra‐pair fertilizations (EPFs) accounted for 24% of the offspring. 8% of attempted copulations and 13% of male courtship displays during observations of focal females were by extra‐pair males. In addition, mates and non‐mates often chased and occasionally made physical contact with females; 34% of those chases in which contact was made were extra‐pair chases. Females behaved variably during both within‐pair and extra‐pair events; females crouched less and resisted more frequently during extra‐pair courtship than during within‐pair courtship. All extra‐pair events, whether natural or induced by male removal, were either resisted or accepted by the female. In 318 focal female‐hours of observation during the fertilizable period, no female was ever seen in another male's territory soliciting a copulation. In addition, removal of females' mates resulted in frequent extra‐pair courtship and copulation; all of these occurred on the removed male's territory. Some females left their mates' territories on occasion — these forays were nearly always off the study area, no female was ever seen copulating with an extra‐pair male while on these forays, and neither the frequency nor the duration of female forays correlated with the frequency of extra‐pair fertilizations within broods. There were no associations between extra‐pair fertilizations and female age, settlement order, nest order, or clutch size. The number of fledglings produced from a nest was significantly positively associated with the number of sires of the brood. Fewer offspring apparently starved in broods that were multiply sired, yet males did not provide courtship feedings during either within‐pair or extra‐pair copulations, nor was any paternal care provided to young sired through extra‐pair matings. The frequency of infertile eggs was low (< 1%); in those instances of infertile eggs the territory owner sired some young in the same nest or another nest on his territory. Fewer broods were a mixture of within‐pair and extra‐pair paternity than expected by chance. Clear evidence implicating a mixed strategy on the part of females could not be gathered. Because females behaved variably and because not all costs and benefits to females of extra‐pair copulations could be measured, it remains possible that female behavior patterns are either (1) part of a mixed strategy, or (2) part of a strategy minimizing the costs of copulation.
Variability of Forage Pecking in Pigeons
Authors: Siemann Martina , Delius Juan D.
Published: May 2010

The pecking of birds has been classically considered a fixed action pattern that is little modified by varying internal and external circumstances. Although recent research has documented several instances of variability, the stereotypy of pecking by pigeons continues to be stressed. The present study illustrates the adaptability of the response employing an accelerometric/videographic technique. It is demonstrated that it is influenced by several experimental conditions mimicking natural contexts. The effects of admixture of non‐nourishing grit, non‐removability of food items, degree of deprivation, application of head loads and grain size, on the detailed course of pecking are described. A number of different, recurring types of pecking patterns were recognized but even within these the frequency, timing, extent, speed, and/or vigour of several component movements varied specifically in response to the various experimental treatments. Appreciable inter‐ and intraindividual variations still occur under identical conditions. In conjunction with additional evidence it is concluded that the pecking of pigeons exhibits a remarkable flexibility that conforms poorly with a fixed action pattern characterization. Accelerometry promises to be an efficient and economic aid in the analysis of the sensory, neural and motor mechanisms of avian pecking.
Courtship Activity of Wandering and Burrow‐holding Male Uca arcuata
Authors: Murai Minoru
Published: May 2010

The male of Uca (Deltuca) arcuata, a vertical claw‐waving fiddler in the Indo‐Pacific, is used to court females by approaching them from his burrow or while wandering. Differences in the rate of encounters with females between burrow‐holding males and burrowless wandering males are found not to be significant. Burrow‐holding males less often cause displacement of wandering by females than wandering males do. Wandering of females caused by wandering males occurs as often as wandering of males caused by other males. Thus, burrow‐holding males tend not to reduce the number of their potential mates in the neighborhood.

Burrow dwelling males are apt to start wandering after decreased encounters with females. Wandering males experience more interactions with other males than burrow‐holding males do. Most wandering males that displace burrow owners descend the burrows one or more times after displacing the owners. The extra fighting for temporary burrows is responsible for no increase of the encounter rate with females during wandering.
Experimental Evidence that a Desert Parasitoid Keeps its Host Cool
Authors: Ward David , Henschel Joh R.
Published: May 2010

The wasp parasitoid Pseudopompilus humboldti (Hymenoptera; Pompilidae) in the Negev desert of Israel stores its paralyzed host, the spider Stegodyphus lineatus (Araneae; Eresidae), at the entrance of the spider's nest. The spider is moved by the wasp from the depth of the nest to the entrance in spite of increased exposure to visually‐searching predators, such as birds. We examined the hypothesis that this behaviour has evolved to prevent the wasp's host from overheating in this hot desert. Experimental manipulations of the position of the parasitized spiders demonstrated that spiders and wasp larvae could not survive the heat experienced deep in the spider's nest during summer. By contrast, in the cooler nest entrance, spiders and larvae survived, if they were overlooked by predators. This host‐storing behaviour is an adaptive trade‐off between thermoregulatory requirements and predation risk. This appears to be the first evidence that a parasitoid manipulates the temperature of its host, albeit for its own ultimate gain.
Basking and Antipredator Behaviour in a High Altitude Lizard: Implications of Heat‐exchange Rate
Authors: Carrascal Luis M. , López Pilar , Martín José , Salvador Alfredo
Published: May 2010

This paper presents an observational and experimental study of the basking behaviour and heat exchange rate of the montane lizard Lacerta monticola. The results obtained by these procedures were coupled in order to understand behavioural mechanims promoting effective thermoregulation at high altitudes. Heating rate was higher when body size was smaller, and substrate temperature and sun rays incidence angle were higher. The lizards cooled faster when body size and substrate temperature were lower, and when the body temperature of the lizard going into shadow was higher. Time exposed to sun and mean duration of basking periods were longer early in the morning, while bask frequency increased through the morning. Our results suggest that time devoted to basking is mainly obtained by regulating bask duration. Lizards obtained the necessary time for heating by means of long basking periods. Mean travel distance per minute and distance to the nearest refuge increased from early morning to midday. These behavioural variables were tightly correlated with the expected heating rate of individuals. Body size affects thermoregulatory behaviour as well as locomotor activity. Juvenile lizards, with small body mass and high surface‐to‐volume ratios, were subjected to faster heating and cooling rates, basked more frequently than adults (but during shorter periods), and devoted more time to locomotion than adults. The thermoregulatory behaviour of L. monticola is the result of the combination of shuttling heliothermy by basking and the exploitation of thermal opportunities offered by patches in shade through thermal exchange with the substrate.
Signalling of Nutritional Need by Magpie Nestlings
Authors: Redondo Tomás , Castro Francisca
Published: May 2010

The relationship between begging behaviour, chick nutritional state, and parental distribution of food within broods was studied in 4‐ and 5‐chick magpie Pica pica broods under natural conditions. Three components of the begging display (duration, latency, and posture) were highly correlated with each other and also with the emission and duration of begging calls. Begging performance was strongly influenced by the food intake of nestlings during the preceding 1‐h interval, indicating that begging may reliably reflect the nutritional need of nestlings. Daily growth during the preceding day, as well as average cumulative food intake by the brood during the preceding 24 h, seemed not to affect begging in a similar way. Begging signals employed by hungrier nestlings involved a higher degree of muscular activity, thus supporting the prediction that nestlings in greater need should employ more costly signals. Overall, those nestlings who begged more tended to obtain more food, but the relationship between feeding success and begging behaviour was weak due to a high variation between broods in the way that parents seemed to respond to variations in begging behaviour. Possible causes for this variation, and its implications for the evolution of reliable begging displays, are discussed.
Influence of Unrewarded Stimuli on the Classification of Visual Patterns by Honey Bees
Authors: Ronacher Bernhard
Published: May 2010

Bees were trained to discriminate visual patterns in five experiments. The rewarded pattern (S+), was a 50‐mm black disc in all experiments; the unrewarded pattern (S–) was varied. Subsequently bees were given a choice between different stimuli in order to discover what bees learnt about five attributes of the training stimuli. The attributes tested were size, contrast, color, ‘compactness’ vs. ‘dissectedness’ (tests with ring‐patterns), and presence or absence of acute points (tests with discs, squares, triangles and stars). The significance of these attributes varied with the particular unrewarded pattern (S–) used in training (Figs. 1, 2). This is interpreted as a modification of the bee's selective attention to certain features during training. The results also indicate a difference in the salience of attributes. Differences in size or outline (presence of acute points) only influenced the bee's preference after a training that specifically required this distinction, while differences in contrast, colour and dissectedness were also significant when the training stimuli did not differ in that respect.
Power to Hold Sheltering Burrows by Juveniles of the Signal Crayfish, Pasifastacus leniusculus
Authors: Ranta Esa , Lindström Kai
Published: May 2010

Juveniles of the signal crayfish reside during daylight hours in shelters. At twilight they leave for food, at daybreak they either return or find another shelter. We examined conflicts over burrow ownership. At low densities with equal numbers of shelters and crayfish 1/5 of the burrows were occupied. Increasing both the number of crayfish and shelters improved the occupancy close to 50%. Doubling the number of crayfish in relation to the number of shelters increased the occupancy up to 75%. In an experiment with 30 randomly selected crayfish and 15 sheltering holes available the burrow holders were about 1–2 mm longer in carapace length than those found freely moving in the aquarium. Shelter owners were rarely newly moulted individuals.

Size asymmetry (2 mm difference in carapace length) between owner and intruder affected the outcome of the contest over burrow ownership. When intruders were larger than owners, takeovers occurred in about 80% of the cases tested. If the owner was large and the intruder small the takeover frequency was about 20%. When the owner and the intruder were of matching size takeovers were still observed in about 45% of the cases. The outcome of the ownership contest has a true meaning. In a nursery‐pond experiment, where low‐protein food was randomly scattered all around, no size differences were found in carapace lengths of crayfish juveniles residing in different shelters. However, when high‐protein food was introduced in a single spot, owners of burrows were significantly larger and more numerous in the nearby shelters than in the shelters furthest away from the food source. Therefore, when food is unevenly distributed the burrow ownership contests may potentially lead to size asymmetries between individuals. This may lead to large individuals nearby the food growing faster than small individuals further away from the food source, a process likely to further enhance size differences.
Calling Behaviour Influences Mating Success in Male Painted Reed Frogs, Hyperolius marmoratus
Authors: Passmore Neville I. , Bishop Phillip J. , Caithness Neil
Published: May 2010

A detailed study was made of the natural calling behaviour of male painted reed frogs in the wild. Comprehensive minute by minute records of the vocal activity of males calling simultaneously in the breeding chorus were generated over a 19‐night period using a multi‐channel event recorder. With few exceptions, the period over which males called either spanned or extended beyond the time window when females sought mates in the chorus. Males varied little in calling persistence and the majority produced advertisement calls during each minute of the calling period. Aggressive interactions between males curtailed advertisement call production but fights were short‐lived, seldom repeated and limited to a small proportion (12.6%) of males. Call rate was independent of body size and varied widely among males active in the chorus at the same time and under the same environmental conditions. The relative call rate ranks of individuals were sustained over time. The call rates of mated males were high in relation to the rates of other males monitored in the chorus at, and prior to, the time of mating. Females usually preferred the higher of two call rate alternatives presented in a range of two‐choice phonotaxis experiments.
Absence of Mate Guarding in the Yellowhammer (Emberiza citrinella)?
Authors: Sundberg Jan
Published: May 2010

The mate guarding behaviour of male yellowhammer (Emberiza citrinella) was studied with special reference to the effects of age, body size (tarsus length) and coloration of males. Measurements of intra‐pair distance do at the most provide evidence for relatively lax mate guarding. On the other hand, patterns of male song activity and inter‐male aggression were more in agreement with the predictions of the mate guarding hypothesis. The reasons for the comparatively low mate guarding intensity in the yellowhammer may be that males do not need to guard their mates intensely. Age differences were found in song and aggressive activity, older males singing and fighting the most. Size had no effect on guarding behaviour. Coloration was correlated with inter‐male aggressiveness and conflict initiation propensity. Less colourful males fought the most in the pre‐fertile period of their mates, whereas colourful and old males fought the most during the fertile period. This suggests that coloration may be an indicator of individual fighting and guarding ability.
Cooperative Territorial Defense in the Australian Magpie, Gymnorhina tibicen (Passeriformes, Cracticidae), a Group‐living Songbird
Authors: Farabaugh Susan M. , Brown Eleanor D. , Hughes Jane M.
Published: May 2010

Comparison of populations that vary in cooperative behavior can point to factors that influence the evolution of cooperative breeding. In this paper we study cooperative territorial defense in two populations of the Australian magpie. These populations differed in social organization; in New Zealand group breeding was the norm and in Queensland simple pair breeding was the norm. We used caged territorial intruders to examine experimentally the participation of males, females, and juveniles in synchronous territorial defense. Within a population in Queensland and a population in New Zealand, adult males and females participated in cooperative defense significantly (p < 0.05 at least) more often together than alone. Between populations, Queensland pairs differed significantly (p < 0.01 at least) from New Zealand pairs in the level of response. As group size increased, percapita input in defense decreased in both populations. We discuss the importance of synchronous defense as a cooperative behavior in this species.
Mother‐Offspring Relationship in the Vicuña, Vicugna vicugna (Mammalia: Camelidae)
Authors: Vilá Bibiana L.
Published: May 2010

The vicuña mother‐offspring bond was studied during the calves' first and third months of life. Pairs kept in field and corral conditions allowed to compare mother‐offspring relationships between animals with and without management. Vicuñas belong to the “follower type” in the classic distinction among ungulate species between “followers” and “hiders”. In the field, mother‐offspring distances were small during the first month then increased. In the corral, mother‐offspring distance was greater than in the field in the first month and did not vary with age. In the third month, in both “conditions” mothers tended to avoid their calves more than in the first month. Although calves initiated approximately 90% of nursing bouts during both periods, the percent terminated by the mother was significantly higher in the third month than in the first (96% to 59%). The calves increased their grazing time from a few scans per h in the first month to half the sample period in the third month. The mother‐offspring bonds showed some quantitative differences between field and corral, but in both “conditions” the mothers nursed their calves successfully.
Colony Member Discrimination by Juvenile Columbian Ground Squirrels (Spermophilus columbianus)
Authors: Hare James F.
Published: May 2010

Kin discrimination mechanisms allow the maximization of inclusive fitness via kin‐differential behaviour. Previous studies of kin discrimination in ground squirrels (Spermophilus spp.) have concentrated on the proximate mechanisms by which kin are discriminated from non‐kin. Few studies have examined the extent to which kin discrimination is expressed among free‐living squirrels, and none have examined the relative strength of potential alternative levels of social discrimination (i.e. kin, neighbour, group member).

To elucidate the level at which juvenile Columbian ground squirrels (Spermophilus columbianus) discriminate among conspecifics, dyadic interactions between otherwise free‐living littermates, neighbours, non‐neighbouring members of the same colony, and individuals from two different colonies were staged in a neutral arena. Similar levels of cohesive and agonistic behaviour, and similar inter‐individual distances were recorded for all intra‐colony dyads while interactions between non‐colony members were characterized by decreased cohesion, increased agonism, and greater inter‐individual distances. The results suggest that siblings are not discriminated from nonsiblings, but that colony members are discriminated from members of other colonies.

Although the functional significance of colony member discrimination is unclear, such discrimination produces amicable relationships among local group members and ensures xenophobic responses to non‐group members. Colony member discrimination may reduce costs of intra‐colony aggression, ensure the appropriate distribution of cooperation and reciprocal altruism to enhance direct fitness benefits that accrue via social grouping, and ultimately promote outbreeding among sexually mature individuals. Finally, the discrimination of colony members from non‐colony members could appear as an incidental byproduct of the operation of a mechanism promoting species recognition.
Ecological and Social Factors Affecting the Vocal Behavior of Adult Female Squirrel Monkeys
Authors: Boinski Sue , Mitchell Carol L.
Published: May 2010

Focal recordings of the vocalizations of squirrel monkeys, Saimiri sciureus, occupying an undisturbed Peruvian habitat were collected to evaluate the importance of both the ecological and social functions of female vocal behavior. The rates and sequences of six call types were examined by context: single, double, and multiple chuck, peep, tweet, and tweet‐chuck. In contrast to laboratory studies, our findings emphasize the primacy of ecological functions in the wild, where calling permits females to operate as a convoy of spatially separated individuals in an arboreal habitat where visual contact is limited. Chuck calls are probably best interpreted as contact calls. The rate of chucks and tweet‐chucks increased when the nearest adult female was > 5 m away. However, call production did not predict a change in the spatial separation between a female and her nearest adult female. During travel, the rate of single and double chucks was greater and the rate of multiple chucks was reduced. No direct relationship was found between foraging activities and vocal behavior. Although secondary, social factors did have a subtle effect on vocal behavior: the larger the social alliance of a female, the lower the rate and repetitiveness of her chuck vocalizations. We also consider the role of variations in vocalization rates among primates and the differing conclusions of field and captive studies of squirrel monkey vocal behavior.
Territoriality and Male Mating Success in the Dart‐poison Frog,Epipedobates femoralis(Dendrobatidae, Anura)
Authors: Roithmair Margarete E.
Published: May 2010

The social and reproductive behaviour of the dart‐poison frog,Epipedobates femoralis, was studied in Amazonian Peru for 14 months. Males defended territories with advertisement calls and, ultimately, fighting. Territory size ranged from 0.25 to 26 m2and was positively correlated with duration of residence and calling activity of the owner. Females were not territorial and were never attacked when approaching calling males. Males and females only mated once and females sampled calling males before mating. Male mating success was closely correlated with territory size and calling activity. No correlation was found between male body size and mating success. Territories provide residents with sufficient space for mate attraction and reproduction without interference from rivals. Since territory size is dependent on calling activity which involves high energetic costs, it is suggested that territory size reveals male quality.
A Comparison of Living Singly and in Male‐female Pairs in the Prairie Vole, Microtus ochrogaster
Authors: Getz Lowell L. , McGuire Betty
Published: May 2010

We measured potential advantages of living singly as contrasted to in male‐female pairs in a free‐living population of the prairie vole (Microtus ochrogaster) in a high food habitat. Whereas adult females survived longer when living in a pair than when living singly, adult males survived longer when single and wandering throughout the study site than when paired. Estimated total number of offspring produced that survived to adulthood and became reproductive was similar for paired females (0.32 female and 0.36 male offspring/female) and females living singly (0.34 female and 0.25 male offspring/female). There was no correlation between the proportion of unpaired adult males in the population and either adult population density, adult sex ratio, or proportion of females that were living singly. These results support the hypothesis that living in pairs evolved in the original low food habitat of the prairie vole and represents a basic behavioral trait that is retained regardless of food resources in the habitats now occupied.
Individuality in the Voice of the Emperor Penguin Aptenodytes forsteri: Adaptation to a Noisy Environment
Authors: Robisson Patrice , Aubin Thierry , Bremond Jean‐Claude
Published: May 2010

The extreme coloniality in emperor penguins (Aptenodytes forsteri) demands that (1) individual recognition by the mutual display call must be supremely adapted to the total absence of nest sites — landmarks that would facilitate partner reunion, and (2) birds must transmit a precise message through an obstructed and noisy environment. A computerized sound analysis and subsequent data were submitted to univariate and multivariate statistics to determine individual‐specific cues of the call. Temporal patterning of syllables, variables of the power spectrum (frequency and timbre features) and variables of a beat generated by two acoustic sources were analyzed (58 calls from 7 animals). Number and duration of syllables, fundamental frequencies and period of the beat were highly individual, with inter‐ significantly greater then intra‐individual variation, enabling correct classification of the 58 calls. The respective relevance of temporal and spectral cues for individual recognition is discussed. In the acoustically hostile and noisy environment, beat was peculiarly emphasized, as it allowed great precision in the production of an amplitude modulation that was unlikely to be degraded by the environment.
Social Interactions in Isard Kids Rupicapra pyrenaica pyrenaica (Artiodactyla: Bovidae): Possible Influence on Development of Social Bonding
Authors: Richard‐Hansen Cecile
Published: May 2010

Assuming that social experiences at an early age may be a determinant factor in the process of formation of social network and attachments, we studied the social interactions of isard, or Pyrenean chamois, kids (Rupicapra pyrenaica pyrenaica) during their first year, to understand “how” sociality arises in isards rather than “why”. Interactions with the mother were affiliative, and approaches of kid to mother or vice versa were generally followed by another “positive” interaction. Interactions between kids were also frequent and playful. Interactions with both mother and peers provided positive reinforcement which may strengthen bonds. However, early interactions of kids with yearlings and other adults provided negative experience, no attachment thus developing from them. Social affinities of adults as well as the social and spatial organization of groups may be understood when ontogenetical history and immediate causality are highlighted.
The Effect of Habitat Structure and Density of Nests on Territory Size and Territorial Behaviour in the Black‐headed Gull (Larus ridibundus L.)
Authors: Bukacińska Monika , Bukaciński Dariusz
Published: May 2010

We studied the effects of vegetation structure and nest density on territory size and aggression in the black‐headed gull (Larus ridibundus). Vegetation structure influenced the types of aggressive behaviour, but not territory size. The proportion of overt aggression (attacks, fights) was highest in barren areas or those with short, sparse vegetation, and lowest in plots covered with dense, tall grass. We explain this by decreased visibility of conspecifics in habitats isolated by vegetation. In such areas, total aggression did not decrease, because the low proportion of attacks and fights was offset by an increase of more moderate (“upright”) displays. Only when nest density was high did the vegetation reduce the frequency of agonistic behaviour — but then it comprised almost exclusively attacks and fights. As expected, greater nest density was related to reduced territory size and an increased proportion of overt aggression. A high proportion of attacks and fights occurred in the plot with the lowest nest density, where at the same time there were also numerous first‐year breeders. We conclude that, when analyzing the effects of habitat conditions on aggressive behaviour, it is important to consider the structure of behaviour, and not only the total frequency of all types of agonistic interactions.
Cross‐species Discrimination of Individual Odors by Hamsters (Muridae: Mesocricetus auratus, Phodopus campbelli)
Authors: Johnston Robert E. , Robinson Tara A.
Published: May 2010

Golden hamsters, Mesocricetus auratus, and Djungarian hamsters, Phodopus campbelli, Muridae, were tested for the ability to discriminate between individual odors from both their own species and the other species. Hamsters were tested using an habituation technique, in which differences in time spent investigating familiar and novel scents indicate discrimination of individual differences. Both species showed similar patterns of results when tested with flank gland scents from golden hamsters and ventral gland scents from Djungarian hamsters: The duration of investigation of samples from the same indivídual scent donor declined over trials, indicating recognition of this scent, but then increased when a scent from a novel individual was presented, indicating discrimination of individual differences. Thus, the capacity and tendency to respond differentially to signals from different individuals is not confined to a single species, suggesting the lack of species‐specificity in the signals and perceptual mechanisms involved in individual recognition by scent. This capacity may be common in mammals, and if so suggests the possibility for considerable knowledge of heterospecific individuals.