bluuebunny/crossref_metadata_2025_split huggingface dataset:
Size Assortative Mating in the Yellow Dung Fly Scatophaga Stercoraria
Authors: Otronen Merja 
Published: April 2008

AbstractIn the yellow dung fly, Scatophaga stercoraria, pairs copulating in the grass or ovipositing on a dropping were size assortatively mated. However, pairs initiating copulations showed no assortative pattern: 1) Pairs formed at different times from the deposition of droppings or in different parts of the mating area showed no consistent relationship in size. 2) Successful males in copulation attempts involving several males were larger than in single male attempts but these type of copulation attempts were not more frequent with large females. 3) Female display did not result in assortative mating although displaying females copulated with a relatively larger male than other females. During copulation and oviposition, single males attempted to take-over paired females which resulted in the separation of many initial pairs. Pairs in unsuccessful take-over attempts were size assortatively mated but not in succesful take-overs. Pairs flying between droppings were also size assortatively mated suggesting that assortatively mated pairs are more likely to move long distances than other pairs. In addition, density affected pair formation. The difference from the expected female-male size ratio decreased with increasing density among copulating pairs suggesting that assortative mating is more common at high density droppings. Assortative mating in the yellow dung fly therefore results from male aggression against copulating and ovipositing pairs. During take-over attempts non-assortatively mated pairs are likely to be separated. High male density with increased level of male encounter rate is likely to contribute to this process.
Determinants of Time Allocation By Adult and Yearling Black-Tailed Prairie Dogs
Authors: Loughry W.J. 
Published: April 2008

AbstractThe time budgets of all adult and yearling black-tailed prairie dogs in a wild population were measured in 14 separate samples between late April and mid-August 1989. In general, males were more vigilant and fed less than females did. This sex difference was due largely to the behavior of males that had sired offspring; non-fathers behaved more like females. As the summer progressed, prairie dogs spent more time feeding and less time vigilant. The lone exception to this pattern was mothers, who fed less and spent more time vigilant as the summer progressed. Other influences on time allocation produced similar effects for all sex/parental groups: animals were more vigilant while in tall vegetation and in the early morning as opposed to mid-day or evening. Environmental (e.g. weather) and social (e.g. number of other adults and pups present) effects on time allocation were analyzed via multiple regression. Of all potential influences, distance from the nearest burrow seemed to have the most consistent impact on time allocation for all individuals. These results point to strong effects of sex, parental status and environmental context in determining the particular pattern of time allocation observed in an individual prairie dog.
Oviposition Behaviour of Diphagous Parasitoids (Hymenoptera, Aphelinidae): a Case of Intersexual Resource Partitioning?
Authors: Walter G.H. 
Published: April 2008

AbstractFemale diphagous parasitoids are endoparasitic as larvae, whereas their males are ectoparasitic. It is possible that males, during their development, eliminate competitors, and this has been proposed as the selective advantage to male ectoparasitism. In this way resources would be partitioned between the sexes. The hypothesis was tested experimentally by observation of whether mated females were capable of recognizing parasitized hosts, and whether they then deposited male eggs on them (because ectoparasitic larvae are supposed to be good competitors). The behaviour of individual Coccophagus bartletti ANNECKE & INSLEY (Aphelinidae) wasps did not follow prediction, and an alternative hypothesis is proposed. Selection pressures from the environment (e.g. host) need not be the same for both sexes, and if male eggs of the pre-diphagous aphelinid were treated differently at oviposition from female eggs (as is found in at least one extant species of aphelinid with otherwise conventional host relationships), a host shift at speciation could account for the divergence in host relationships of the sexes.
Effect of Familiarity With the Mother and Kinship On Infanticidal and Alloparental Behaviour in Virgin House Mice
Authors: D'Amato Francesca R. 
Published: April 2008

AbstractExperienced male and female house mice encountering a newborn pup can display indifference, parental or infanticidal behaviour. Characteristics of the pup such as sex and strain do not seem to influence the likelihood of infanticide, in contrast to attributes of the adult subjects (age, sex, strain, sexual experience, previous cohabitation with the mother, reproductive condition). This study investigated the effect of kinship and/or familiarity with the mother on male and female behaviour towards pups. The subjects were 100-day-old Swiss-Webster virgin male and female mice. After 24 hours of isolation, a 24-36 hrs old pup was introduced into their home-cage and their behaviour was recorded for 15 min. Male and female mice killed related as well as unrelated pups. Females killed fewer offspring of females with whom they had cohabited until 3 weeks before the study, in comparison with the offspring of completely unfamiliar females. When females were exposed to the offspring of females of comparable familiarity but different relatedness, they devoted more parental behaviour towards more related pups. This suggests that, even if familiarity plays a major role in determining females' behaviour, kin recognition occurs and is responsible for differences in alloparental care distribution. The behavioural strategies adopted by male and female mice are interpreted on the basis of differences in activity range of the sexes within a deme (breeding group).
Sex Recognition in Zebra Finch Males Results From Early Experience
Authors: Vos Dave R. 
Published: April 2008

AbstractThis study investigated whether sexual imprinting plays a role in the recognition of the sex of conspecifics. Subjects were zebra finch males that had been raised with either normal pairs, white pairs or pairs of both morphs. They were tested for their preferences in six two-stimuli tests covering all combinations of both morphs of either sex. Males of all groups showed a clear preference for females of their mother's morph over males of their father's morph. Moreover, a majority of the males from mixed parentage preferred a male of their mother's morph over a female of their father's morph, indicating that morphological characteristics are more important than behavioural differences for discrimination between the sexes. This was confirmed in a subsequent series of tests in which males raised by parents of the white morph, which are sexually dimorphic only in respect to the intensity of the red colour of the bill, were given a choice between a white male with his bill painted orange and a white female with her bill painted red. All males of this group preferred to court the male in this test. In addition to differential responses in a sexual context, males showed discrimination in an aggressive context; that is, most aggression was directed towards stimulus birds resembling the father. The implications of these results for the evolution of sexual dimorphism and sexual selection are considered.
Dynamic Pair Bonds in Hylobatids: Implications Regarding Monogamous Social Systems
Authors: Palombit Ryne 
Published: April 2008

AbstractDescriptions of monogamy in the gibbons (Hylobates spp., Hylobatidae) have generally emphasized features derived from inference rather than direct observation: 1) adults mate for life; 2) the genetic structure of groups corresponds with a ''nuclear family'' pattern of parents and their mutual offspring; 3) first mate acquisition is achieved when two ncwly dispersed, unaccompanied, young adults of opposite sex establish a new pair and territory together. The six-year history of mating associations of adults in three groups of sympatric, wild siamang (Hylobates syndactylus) and three groups of white-handed gibbon (Hylobates lar) at the Ketambe Research Station (Sumatra, Indonesia) challenge the generality of these assumptions. These longitudinal sociodemographic data suggest that gibbon pair bonds are not necessarily life-long and that adults may leave mates permanently or temporarily, sometimes in order to exploit new reproductive opportunities. Of 11 heterosexual pair bonds that existed at some time during the study, only two were terminated by death of one adult, whereas five were terminated when one adult left its current mate. In some cases, the ''deserting'' individual left its mate and joined a neighboring adult of opposite sex who had recently lost its own mate through death or desertion. This turnover in pair bond membership generated stable, ''non-nuclear'' family groups in which the replacement mate was not the parent of the resident nonadults. Mechanisms of mate acquistion observed at Ketambe included two processes that may also promote non-nuclear families. A young adult may obtain its first mate by: 1) replacing an adult of the same sex in a neighboring group or in the group in which it resides; 2) establishing a new pair bond (and territory) with another unmated young adult of opposite sex who is, however, accompanied in dispersal by juvenile conspecifics from its group. Finally, observed extra-pair copulations (in siamang) suggested an additional, but as yet unspecified potential for variable relatedness between adult males and resident nonadults. Review of other long-term histories of pair bonds in wild gibbons and of studies of socio-sexual behavior in captivity reinforce the conclusion that the apparent temporal stability and underlying behavioral inflexibility of pair bonds has been over-emphasized. Although data on behavior and reproduction are limited, they nevertheless suggest strongly that the mating and social systems of these monogamous primates are considerably more dynamic and complex than previously appreciated.
Exchange of Grooming for Allomothering in Female Patas Monkeys
Authors: Muroyama Yasuyuki 
Published: April 2008

AbstractThe question is asked whether grooming is exchanged for allomothering in patas monkeys (Erythrocebus patas). Six adult females in one group were observed during the non-birth season (no infants) and the birth season when three females had given birth to an infant. During the non-birth season the exchange of grooming and soliciting for it indicated reciprocity between non-kin. During the birth season, however, non-mothers groomed mothers much more than vice versa, and soliciting was shown more by mothers. This is in accord with the hypothesis that grooming is offered in order to be permitted to allomother. In addition, allomothering was often preceded and followed by grooming. Investment and reciprocity by unaffiliated (rarely grooming) non-kin females tended to occur most promptly. This is in accord with the hypothesis that fairness of reciprocity can be easier assessed if reciprocal acts occur immediately. Effects were less in affiliated non-kin pairs (frequently grooming), and least between kin.
Seahorses Exhibit Conventional Sex Roles in Mating Competition, Despite Male Pregnancy
Authors: Vincent Amanda C.J. 
Published: April 2008

AbstractIn seahorses, only males undergo a pregnancy. It had been tacitly and explicitly assumed that seahorses were sex role reversed (that females competed more intensely than males for access to mates), on the basis that male pregnancy so limited male reproduction as to produce a female-biased operational sex ratio (OSR). However, this supposition had never been investigated. The laboratory experiments in this paper demonstrate that, contrary to expectations, seahorses exhibit conventional sex roles: male seahorses compete more intensely than females for access to mates, on both the first and final days of courtship. Competing males are more active than competing females in those courtship and competitive behaviours common to both sexes, and only males exhibit uniquely competitive behaviours (wrestling and snapping). Males which succeeded in copulating are heavier than their rivals and copulating seahorses of both sexes generally are more active in courtship and competition than are their unsuccessful rivals. The finding that seahorses maintain conventional sex roles requires us to reconsider the impact of male pregnancy on the OSR.
The Process of Syllable Acquisition in Adult Indigo Buntings (Passerina Cyanea)
Authors: Margoliash Daniel , Staicer Cynthia , Inoue Sue A. 
Published: April 2008

Abstract
Vocal learning in adult indigo buntings was studied by monitoring socially paired males housed together in sound isolation boxes. Two of three yearlings socially paired with older birds in early spring acquired new syllables and reorganized their stereotyped and plastic songs, while eleven yearlings socially paired later in the year largely failed to acquire new material, as did the older adults socially paired at various times of year. Yearlings changed their stereotyped songs to more closely match their tutors' by replacing syllables or by inserting new syllables. This song matching involved two processes in which adult plastic song played a role: (1) new syllables were developed in plastic song, and (2) newly mastered or pre-existing syllables were transferred from plastic song into stereotyped song. Morphological similarity between yearlings' and tutors' syllables strongly influenced which syllables yearlings retained. After social pairing, matching syllables tended to be delivered more frequently by yearlings and become incorporated into their stereotyped songs, while non-matching syllables tended to decline in use or be discarded altogether. New syllables were formed from existing syllables most morphologically similar to the "target" syllable, through transformation and combination of existing syllables. As new forms became more common, old forms declined and eventually were discarded. Our data suggest that adult indigo buntings maintain the ability to sing stereotyped songs while new material is mastered, and held in reserve, in plastic song. Acquisition of new syllables in yearling indigo buntings requires trial-and-error learning, but proceeds without overproduction and subsequent attrition of distinct syllable types, and does not substantially rely on improvisation and invention. Rather, syllable acquisition and changes to stereotyped songs are strongly influenced by the pre-existing syllable repertoire.
Effects of Parent and Offspring Food Rations On Parental Care in the Convict Cichlid Fish (Pisces, Cichlidae)
Authors: Lavery Robert J. , Kieffer James D. 
Published: April 2008

Abstract
Animals may provide more care for their young under certain environmental conditions. For instance, if food is plentiful parents may invest more in the current brood than if food is scarce, assuming that food abundance is correlated with parent and offspring condition. In this experiment, we manipulated food levels (low vs high) for both parents and offspring to determine if parental care is influenced by parental and/or offspring condition in the convict cichlid, Cichlasoma nigrofasciatum. Parents which were fed a higher ration gained weight, whereas parents fed a lower ration lost weight. Similarly, young which were fed a higher ration were significantly larger than young fed a lower ration. Parents which were fed a higher ration defended their brood more vigorously than parents fed a lower ration. Offspring condition had little effect on parental care. Furthermore, females consistently invested more than males. The results show that parental convict cichlids adjust care in response to their own food supply rather than that of their offspring.
Are Chemical Cues as Effective as Pup Contact for Inducing Paternal Behaviour in Meadow Voles?
Authors: Storey Anne E. , Walsh Carolyn J. 
Published: April 2008

AbstractWe tested what social cues mediate the transition from non-parental to parental behavior in male meadow voles, based on our previous findings that postpartum interaction with mate and pups was the most effective social experience for making males paternal. Males housed with their mates and pups for a day were more paternal and less aggressive to unrelated pups than males removed from their mates before parturition. Males housed with their mates, but with the litter removed, interacted with pups but were initially as likely to be aggressive as males with no exposure to mates and pups. These results suggest that the mate facilitates interaction with pups, but exposure to pups accelerates the sensitization process. Twenty-four hours of exposure to chemical cues from the mate and pups (mother and litter in cage with wire mesh floor suspended above male's cage) eliminated male aggression towards pups, but physical contact was necessary to enhance positive interactions with pups. Exposure to chemical cues from parturient mates reduced aggression, whereas cues from non-mates were not effective. These results may explain our previous findings that females keep sires removed during pregnancy out of the nest for about a day after reintroduction (while males become sensitized via chemosignals), and continue repelling unfamiliar males (that would not be sensitized by chemical cues from non-mates).
Prior Residence Effect in the Dart-Poison Frog, Dendrobates Pumilio
Authors: Baugh Julia R. , Forester Don C. 
Published: April 2008

AbstractEach of 32 male, Dendrobates pumilio (red phase) were allowed to establish a territory in one half of a 40 liter aquarium. Each enclosure contained a substrate of Sphagnum, a potted plant, and a water dish. Males occupying the same aquarium were prevented from seeing one another by an opaque barrier. In the first experiment, residents were presented with a conspecific intruder matched for size and color. Based on a numerical index of aggression, residents were consistently dominant over intruders. When reciprocal trials were conducted, the results were reversed (i.e. residents were dominant over males to which they previously had been subordinate). The success of resident males was not influenced by the size of conspecific intruders. In addition, residents consistently dominated a sympatric confamilial intruder (Phyllobates lugubris). Removal experiments revealed that resident males recognize and defend their enclosures after 3, and to a lesser degree, 6 days of isolation. We also examined the effect of territorial markers on the prior residence effect by stepwise removal of the plant and Sphagnum. Residents aggressively defended enclosures in both experiments. When Sphagnum was removed from the resident's enclosures and placed in a previously unused aquaria, 7 of 10 males exhibited dominance over conspecific intruders.
Migration Alliances and Coalitions Among Adult Male South American Squirrel Monkeys (Saimiri Sciureus)
Authors: Mitchell Carol L. 
Published: April 2008

Abstract1. Male South American squirrel monkeys form groups whose composition remains stable over migrations between troops. These groups are called 'migration alliances'. 2. Members of migration alliances support one another against other males through coalitions in genital display bouts both during immigration and throughout the year. Male alliances do not function to overcome female dominance. 3. Seasonal reproduction in squirrel monkeys may influence male alliances by a) intensification of within-group competition during the mating season, and b) production of temporally and spatially fluctuating mating opportunities between groups.
Affiliative Behaviour Between Adult Males of the Genus Macaca
Authors: Hill David A. 
Published: April 2008

Abstract1. Relations between sexually mature males in multi-male groups of macaques have been characterised as largely antagonistic, with bonnet macaques being the only frequently cited exception. A survey of the literature indicated that affiliative behaviour between males is more widespread than has been supposed. 2. Factors were examined which may influence the nature of relations between adult males. In all macaque species for which there are adequate data, males commonly move between groups, making it unlikely that kinship between adult males is an important factor in natural groups. 3. Affiliative behaviour between adult males is more frequently observed in small groups, with sex ratios closer to parity, than in large groups with more uneven sex ratios. Two factors are thought to influence this association. First, most large groups with highly skewed sex ratios were provisioned. Provisioning results in increased levels of aggression and tension, which may preclude the formation of affiliative relationships. Second, in groups with highly skewed sex ratios males can find many potential grooming partners among the females and their offspring. Where the sex ratio is more even there may be a shortage of potential partners among the natal animals, and males may form relationships with other males as an alternative. 4. Much of our knowledge of macaque societies has come from provisioned populations. Findings made under such conditions must be verified with data from natural populations, wherever possible, especially where competition may have an influence on the patterns of behaviours observed.
Alternative Reproductive Tactics and Reproductive Success in Male Rhesus Macaques
Authors: Berard John D. , Nurnberg Peter , Epplen Jorg T. , Schmidtke Jorg 
Published: April 2008

Abstract
Male rhesus macaques on Cayo Santiago use rank-dependent alternative reproductive tactics. High-ranking males can form long-term consorts and guard female mates while low-ranking males frequently resort to quick copulations under the cover of vegetation. No single reproductive tactic provided the Group S males with a definitive reproductive advantage during the one-year study. Males using the long-term tactic and the quick, stealth tactic sired five offspring each, but fewer males used the long-term consort tactic. Males using the long-term reproductive tactic have significantly greater mating success than males using the quick, sneaky tactic, and may have greater reproductive success. The highest-ranking males who form long-term consorts had the greatest degree of reproductive success. This indicates that for the highest-ranking males, forming long-term consorts is the most effective reproductive tactic. The effectiveness of alternative tactics for high-ranking males (i.e. consort disruption and possessive following) was equivocal. Consort disruption had no immediate effect on reproductive success. Possessive following may have resulted in the siring of two offspring by the alpha male, but was ineffective in other cases, where the females were inseminated by subordinate males. The effectiveness of the quick, furtive tactic was demonstrated by the siring of 45% of the infants by males who used this tactic.