bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hilltopping Behavior of Polistes commanchus navajoe (Hymenoptera: Vespidae)
Authors: Matthes‐Sears William , Alcock John 
Published: May 2010

AbstractMales of the paper wasp Polistes commanchus aggregate in large numbers on hilltops in central and southeastern Arizona where individual males defend perch sites on shrubs, trees or rocks. Residents chase intruders away quickly and exhibit strong site fidelity at their perches. Takeovers are rare as are prolonged battles for possession of a site. Males have only weak preferences for peaktop perch sites as opposed to those lower on hillsides, and a similarly weak preference for perches in shrubs as opposed to those on rocks. Receptive females appear occasionally at the male aggregation sites to mate with perch holders. The relatively weak territoriality exhibited by P. commanchus may stem in part from the high density of males at peaktops and the correspondingly high rate of interactions. The evolution of hilltopping in a species whose reproductive females are clumped spatially at nest sites poses a puzzle for the ecological analysis of mating systems.
Sexual Monomorphism in Spotted Hyenas, Crocuta crocuta
Authors: III William J. Hamilton , Tilson Ronald L. , Frank Lawrence G. 
Published: May 2010

AbstractIntersexual and intrasexual interactions by female spotted hyenas, (Crocuta crocuta), are correlated with the ability of the heavier and more aggressive females to dominate males at large carcasses, the principal food of spotted hyenas.Female spotted hyenas have a modified clitoris closely resembling a penis. A slightly bilobed scrotum containing fat and connective tissue contributes to the male‐like appearance of the female sexual facies. Penile and pseudopenis erection by spotted hyenas occurs primarily during social encounters at carcasses and elsewhere.Analyses here, based on interspecies comparisons of spotted hyena, brown hyena (Hyaena brunnea) and striped hyena (H. hyaena) morphology, behavior and ecology and interpopulation comparisons of spotted hyenas suggest possible gradualistic evolutionary interpretations of the pseudopenis.
Cumulative Effect of Male's Displays in the Sexual Behaviour of the Smooth Newt Triturus vulgaris (Urodela, Salamandridae)1
Authors: Teyssedre Claudine , Halliday Tim 
Published: May 2010

AbstractThe relevance of the temporal spacing of signals to the timing and nature of the receiver's response during a communicative process was studied in the sexual behaviour of the smooth newt Triturus vulgaris. The possibility that a high rate of stimulation allows an accumulation of the effects of successive signals was investigated by comparing sexual interactions leading and not leading to spermatophore deposition.Results showed that the difference between the two types of interactions lay only in temporal features of the stimulation provided by the male to the female. Females, although in a comparable initial state of receptivity and exposed to comparable amounts of stimulation, performed the act triggering spermatophore deposition by the male only in some interactions. Display bouts, in which the male displayed at short intervals (less than 4 s), were longer in interactions where spermatophore deposition took place than in the others. This suggests that courtship was effective if accumulation of the effects of male displays could occur. This proposition was supported by the observation of a progressive change in the immediate female response to a given male display in the group where courtship bouts were longer.Our results indicate the existence of a system of tonic communication (see Schleidt 1973) during the sexual behaviour of the smooth newt, in which the effects of the male displays accumulate over time until some critical threshold is reached in the female.
Territorial Advertisement and Mate Attraction in the Bat Pipistrellus pipistrellus
Authors: Lundberg Karin , Gerell Rune 
Published: May 2010

AbstractA South Swedish population of the vespertilionid bat Pipistrellus pipistrellus was studied by means of bat boxes from April to the beginning of October in 1984. The mating system of the pipistrelle bat is a “resource defence polygyny”. Three territorial males were studied to determine the relative importance of two potential resources, food and roost sites, for male reproductive success. The day roost was found to be the crucial resource for the male's chances to get access to females. A territorial male advertises the location of his day roost to the females by a songflight display. The male who spent most time in songflight display was visited by the greatest number of females.
Species Recognition by Song in the Veery (Catharus fuscescens: Aves)
Authors: Nally Ralph C. Mac , Weary Daniel M. , Lemon Robert E. , Lefebvre Louis 
Published: May 2010

AbstractTerritorial male veeries (Catharus fuscescens) were presented with three series of reorganised songs to determine the functional properties of song structure. Songs consist of three parts: a low frequency initial phrase, a higher frequency middle phrase, and again a lower frequency end phrase. The latter two consist of vibrato syllables. Three series of experiments were performed, using various combinations of song syllables. In Series I, songs consisted of repetitions of a single syllable, one from each part of the song. Veeries responded to syllables from the middle and end phrases as to normal songs, both in localisation and in vocal responses. However, they showed little localisation and vocalisation responses to the introductory syllables. In Series II and III, veeries responded significantly more to songs in which syllables from the middle and end phrases were presented in proper sequence, rather than not. The minimum requirements for intraspecific recognition were determined in relation to the number and order of syllables in the song.
Avian Helpers at the Nest: Are they Psychologically Castrated?
Authors: Reyer Heinz‐Ulrich , Dittami John P. , Hall Michael R. 
Published: May 2010

AbstractIn cooperatively breeding pied kingfishers (Ceryle rudis) blood plasma levels of LH and testosterone (T) were compared among three types of males: breeders, primary (= related) helpers and secondary (= unrelated) helpers. These categories did not differ in LH, but primary helpers had significantly lower T titers than breeders and secondary helpers. The low levels were paralleled by small gonad sizes and no sperm production, suggesting that primary helpers were not able to fertilize eggs.The differences in T levels could neither be attributed to stochastic variation nor to differences in age, stress, molt, or reproductive activities. The most likely explanation arises from the observation that primary helpers are behaviorally dominated by breeders, whereas secondary helpers are not.The adaptive significance of low T titers and reduced fertility as a result from being dominated is discussed on the basis of empirical data and theoretical models. We argue that primary helpers in the pied kingfisher, and subordinate helpers in many other cooperative breeders, apparently are not “unwillingly” suppressed in their sexual development; they rather “choose” delayed reproduction when the costs from sexual competition with breeders exceed the benefits from cooperative breeding. In contrast, helpers that benefit more from competition than from cooperation, as secondary helpers do, cannot be expected to show reduced fertility.
Social Organization of the Bat,Carollia perspicillata(Chiroptera: Phyllostomidae)
Authors: Williams Charles F. 
Published: May 2010

AbstractThe social organization of the frugivorous bat,Carollia perspicillata, was studied by frequent visual censuses of a population in northwestern Costa Rica. A pattern of resource defense polygyny was found, based on male defense of roosting sites in caves and hollow trees. Protected roost sites were apparently limited. Harem compositions were relatively labile and female groups did not appear to be cooperative. Harem males were among the oldest and heaviest members of the population and these attributes were also correlated with the size of the harems they defended.
Cultural Diffusion of a Novel Food‐finding Behaviour in Urban Pigeons: an Experimental Field Test
Authors: Lefebvre Louis 
Published: May 2010

AbstractThe cultural diffusion of a novel food‐finding behaviour, piercing the paper cover of a box containing seed, was experimentally provoked in two flocks of pigeons (Columba livia): a closed aviary flock and an open urban flock. In the urban flock, piercing behaviour spread to 24 previously naive individuals. The rate of cultural diffusion was more rapid in the urban flock than in the aviary. In both situations, many individuals simply fed from the discoveries of birds that pierced, but this effect slowed diffusion less in the open urban flock because experienced piercers left the flock and naive birds entered it. Individual trial‐and‐error learning and natural shaping can be ruled out as mechanisms of diffusion in the present case.
The Feeding Behaviour of a Sit‐and‐Wait Predator, Ranatra dispar (Heteroptera: Nepidae): The Combined Effect of Food Deprivation and Prey Size on the Behavioural Components of Prey Capture
Authors: Bailey Paul C. E. 
Published: May 2010

AbstractPrevious work has shown a significant effect of hunger on the predatory behaviour in a sit‐and‐wait predator Ranatra dispar, the water stick insect (Bailey 1986 a). The experiments reported here were designed to investigate the combined effect of prey size and hunger on the predatory behaviour in order to identify which behavioural components are effected. It was found that the hunger level determines whether R. dispar will initially be aroused or not but the distance at which the arousal takes place is influenced by the size of the prey. This is believed to reflect the capacity and interrelation between visual and mechanoreceptor, sensory organs. The decision to strike at a prey is, although again influenced by hunger, significantly affected by prey size. The distance of the prey when the strike takes place is affected by hunger not the size of the prey. The outcome of the strike is determined by the size of the prey, not the hunger level of the predator. This is believed to reflect the relationship between strike trajectory, leg morphology and prey size. Food deprivation affects all components of predatory behaviour of R. dispar leading up to prey capture, by increasing not only distance of response but also the number of strikes, hits, and captures per unit presentation of prey. It does not affect capture efficiency which remains at about 70 to 80 %. Food deprivation also increases the range of prey sizes that R. dispar responds to and attempts to capture. The effect of food deprivation is considered to reflect a motivational change in responsiveness to particular prey stimuli usually described as a sensitization of particular stimulus‐response relations rather than the food deprivation affecting the sensory mechanisms. The predatory success in relation to size of model prey suggested a hypothetical size that could be captured, irrespective of predator motivational level, which is based primarily on the relationship between the shape of the grasping leg and size of prey.
Seasonality of Mobbing Intensity in the Pinyon Jay
Authors: Cully Jack F. , Ligon J. David 
Published: May 2010

AbstractIn the wild, pinyon jays (Gymnorhinus cyanocephalus) mob owls at all times of year, but our observations of wild birds suggested that the mobbing response was strongest during the breeding season. To test this, we placed four groups of five wild caught adult pinyon jays in environmental chambers during late autumn when their testes were regressed. These birds received photoperiods of 12, 12, 13 and 14 h for 30 days prior to being exposed singly to a live great horned owl (Bubo virginianus). Three groups of five birds were maintained under natural photoperiods in outdoor aviaries and were tested with the owl in Aug., Sep. and Nov. Birds on long artificial photoperiods mobbed more strongly than birds exposed to shorter photoperiods. The jays under natural photoperiods showed the opposite response: those tested in November mobbed significantly more strongly than birds tested in August. Jays with the weakest mobbing responses were molting, and those with the strongest responses seemed to be closest to reproductive readiness. There was no correlation between gonad size and mobbing intensity, but our results suggest a strong relationship between reproductive readiness and mobbing intensity in pinyon jays.
Mallard Duckling Response to Distress Calls with Reduced Variability: a Constraint on Stereotypy in a “Fixed Action Pattern”
Authors: Gaioni Stephen J. , Evans Christopher S. 
Published: May 2010

AbstractMallard duckling distress calls consist of a series of stereotyped notes and are usually given in calling bouts. When two or more ducklings are separated from their brood and begin to distress call, they alternate their calls, with each bird inhibiting its own vocalizations during those of another bird. In two playback experiments we reduced the acoustic variability found in distress calls and examined the effect this had on the alternation response of ducklings. In Exp. 1, one treatment involved an unedited tape‐recording of a natural bout of 8 distress calls. Three other treatments involved edited tapes in which (a) the original 8 calls were presented, but at a constant intercall period, or (b) a single call was repeated 8 times at the natural (variable) intercall periods, or (c) a single call was repeated 8 times at a constant intercall period. The two tapes on which the same call was repeated 8 times elicited significantly weaker alternation responses from ducklings than the two tapes on which the original 8 calls were presented; the manipulation of the intercall period had no significant effect on the alternation response. In Exp. 2, analogous manipulations were performed to remove the variability between the notes within a single distress call or between the internote periods within that call. Ducklings alternated significantly better with the unedited distress call than with the distress calls in which variability had been removed. These results suggest that the variability found within many “Fixed Action Patterns” may serve an important antihabituation function.
Rate of Supply of Sugar Solution and Behaviour of Collector Wasps (Paravespula germanica)
Authors: Pflumm Walter 
Published: May 2010

AbstractThe rate of supply of sucrose solution at an artificial food source was varied by means of a pump, while the concentration of the solution and the temperature at the food source were kept constant. The behaviour of the collector wasps was found to change in correlation with the supply rate, in several respects.As rate of supply increases

the duration of sojourn at the food source decreases;
the volume of solution removed per h increases;
the number of single visits during a sojourn and per h decreases;
the duration of single visits increases, except that at extremely high supply rates the single visits become shorter.

The waiting time (Saugwartezeit) does not depend on supply rate.Comparison of these wasp data with related observations of honeybees (Apis mellifera) supports inferences regarding the motivation of collector wasps and, in view of the frequency of their single visits, about their suitability as potential pollinators of the flowers from which they collect.
Rattlesnake Rattles and Burrowing Owl Hisses: A Case of Acoustic Batesian Mimicry
Authors: Rowe Matthew P. , Coss Richard G. , Owings Donald H. 
Published: May 2010

AbstractBurrowing owls nest and roost in ground squirrel burrows, a refuge frequently used by rattlesnakes. When cornered, burrowing owls produce a vocal hiss that has been suggested to mimic a rattlesnake's rattle. To test this hypothesis, we conducted an experiment using two populations of Douglas ground squirrels that differ in their evolutionary histories with rattlesnakes. Both squirrel populations were sympatric with burrowing owls. Squirrels from a population subjected to natural selection by rattlesnakes treated the owl hiss as cautiously as they did the rattle, and responded with greater caution to the rattle and hiss than to two control sounds. Squirrels from a rattlesnake‐free area, however, were less systematic in differentiating among the rattle, the hiss, and the control treatments. Such variation between ground‐squirrel populations provides evidence that the burrowing owl's defensive hiss currently functions as an acoustic Batesian mimic of a rattlesnake's rattle.
Female Cowbird Song Perception: Evidence for Different Developmental Programs within the same Subspecies
Authors: King Andrew P. , West Meredith J. , Eastzer David H. 
Published: May 2010

AbstractFemale Molothrus ater from Oklahoma at the subspecies border with M.a. obscurus were tested for their discrimination of songs from their native area and from Austin, Texas. This 400‐km distance is characterized by a structural shift in the male cowbird's inclusion of the mid‐song element, a structure found in the songs of Austin and the more southern M.a. obscurus populations but not in the songs of Oklahoma or the more northern and eastern M.a. ater populations. Females captured in Oklahoma showed a strong preference for their native song variants. In contrast, captive females from Oklahoma who were housed with Austin males showed no preference, responding equally to Oklahoma and Austin song. The songs of the Austin males housed with the Oklahoma females did not differ acoustically from those of wild Austin males. Thus, a different developmental pattern may operate in this region than in eastern populations of M.a. ater: here, the female may be more open to social influence.
Functional Aspects of Singing in Male and Female Uraeginthus bengalus (Estrildidae)
Authors: Gahr Manfred , Güttingery Hans‐Rudole 
Published: May 2010

AbstractBoth sexes of the African estrildid species Uraeginthus bengalus sing regularly. Song structure and the context of singing were studied in males and females under aviary conditions. It was found that:

Males and females have a similar song differing merely in strophe length, medial length being 1.38 ± 0.47 s in females and 2.58 ± 0.63 s in males.
Males sing during nesting, laying, incubation and broodcare, but also long before, with a remarkable activity peak at the beginning of incubation, whereas females hardly sing at all during the egg‐laying and incubating phases, and their singing peak is long before laying starts.
In 52 % of all cases the male responds to his female's song during the pre‐incubation period. His reaction includes singing, courtship display and elements introducing copulation.
Reproductive Behaviour and Parental Care of Helobdella striata (Hirudinea, Glossiphoniidae): a Leech that Feeds its Young
Authors: Kutschera Ulrich , Wirtz Peter 
Published: May 2010

AbstractThe leech Helobdella striata Kutschera (1985) is a protandrous hermaphrodite. It copulates by hypodermic injection: a spermatophore is attached to the skin of the partner and sperm injected through it. During their male phase, the leeches copulate repeatedly and with different partners.In the female phase, 3 to 7 cocoons, each containing 2 to 20 eggs, are produced from the female gonopore and attached to the ventral side of the parent. The larvae which hatch from these eggs cling to the ventral side of the parent. After they have used up their yolk supply and have developed into juvenile leeches they remain attached to the parent for a further three weeks. Helobdella striata capture Tubifex worms and give them to the young they carry. This access to food allows the juveniles to grow from a size of 1 mm to 6 mm length while being carried and protected by the parent.H. striata reared in isolation produce young; at present it is not known whether they reproduce by parthenogenesis or by self‐fertilization.The probable phylogenetic development of parental care patterns in the Hirudinea is reviewed.
Constant Proportions of Mixed Singers in Tree Creeper Populations (Certhia familiaris)
Authors: Thielcke Gerhard 
Published: May 2010

AbstractOf 205 tree creeper males in 7 syntopic populations 69 (34%) were mixed singers. Of these, 17 sang complete short‐toed tree creeper song, six sang incomplete and 46 sang only one element thereof. In three populations (Neuenburg, Wendhausen, Kenzingen) there was a dominance of mixed singers, in another population (Lorettowald) a large proportion was present. Only one mixed singer was found in each of the last three populations (Freiburg, Bodanrück, Seerücken).Three populations had high proportions of mixed singers between 1960 and 1970 and later in 1983 and/or 1984. Two other populations had only one mixed singer in both periods. A small isolated population of 4 to 5 tree creeper pairs (Lorettowald) with many mixed singers was surrounded by populations with low proportions of mixed singers (Bodanrück, Seerücken).The proportions of different forms of mixed songs in Neuenburg in 1983 and 1984 were almost identical to those in the 1960′s whereas highly significant changes occurred in Kenzingen.The pronounced differences in the songs of tree creepers and short‐toed tree creepers probably do not result from contrast reinforcement. Mixed song is also probably not caused by character (vocal) convergence according to Cody (1969) and Dobkin (1979). Instead, it seems more probable that mixed song results from errors in copying, which are passed on to the next offspring by cultural transmission.
Adaptation of Amplitude Structure of Songs to Propagation in Field Habitat in Song Sparrows
Authors: Shy Eyal , Morton Eugene S. 
Published: May 2010

AbstractWe examined the influence of two habitats, old field and small islands on a river, on the propagation of amplitude and frequency characteristics of song sparrow songs.At 27 m from the source, songs originally recorded in the field degraded significantly less there than over water in the river. At that distance, songs recorded on the river also degraded less in the field than over water, but the differences were not significant. At 54 m from the source, songs recorded at both sites also tended to degrade more on the river than in the field, but the differences were not significant. Songs from the two habitats differed significantly in the total number of amplitude peaks in a song, in song duration, in maximum frequency, and frequency range. They did not differ significantly in the fraction of peaks in the upper amplitude range, and in the width of the amplitude range.The results suggest that, in fields, a more typical habitat, songs are locally adapted to communication at about 30 m but poorly so at 60 m from the source. We suggest that this is related to the territory size of birds in the field. The results are discussed in relation to the ranging hypothesis (Morton 1982) that predicts that the least degraded song types would be selected for, and that listeners use degradation to estimate their distance from singers.
Preference for Vertical‐striped Backgrounds by the Oyanirami Coreoperca kawamebari, a Freshwater Serranid
Authors: Kohda Yasutoshi , Watanabe Munetaka 
Published: May 2010

AbstractThe oyanirami Coreoperca kawamebari displays cross‐stripes on its body when afraid; this pattern is also used as a signal to conspecifics. The fish preferred to rest at vertically‐ rather than horizontally‐striped sites, and transparent stripes were more attractive than opaque ones, but no inclination was shown for any particular stripe widths. It is hypothesized that the cross‐stripes first evolved as a pattern furthering crypticity among the vertical aquatic habitat plants, secondarily as a signal to conspecifics.