bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nest Defense by Red Jungle Fowl (Gallus gallus spadiceus) Hens: The Roles of Renesting Potential, Parental Experience and Brood Reproductive Value
Authors: Thornhill Randy 
Published: May 2010

AbstractReproductive‐effort theory predicts that parents of any given age should expend more parental effort (1) as their residual reproductive value declines, and (2) as the reproductive value of offspring increases. An observational and experimental study of nest defense by captive red jungle fowl hens was used to examine these two predictions. Both young and old individuals significantly increased defense of the second nest compared to the first nest within a season; this pattern occurred for the defense of both eggs and chicks. Old hens showed significantly greater defense of both eggs and chicks in each of the nests than did young hens. Both young and old hens were significantly more defensive of chicks than eggs in each of two clutches of a season. Hens also reduced their nest defense significantly at the end of a two to three‐day period after their chicks were replaced with eggs, and increased their nest defense after eggs were exchanged for chicks. Hens given four chicks showed more vigorous defense than hens given two chicks. When the brood size of hens with four chicks was reduced to one chick, the hens responded by exhibiting less vigorous nest defense. These patterns of nest defense in jungle fowl were not confounded by parental experience of hens, or differences in offspring quality that are related to time of breeding, maternal age, sire genetic quality or vulnerability of offspring to weather.
A Comparative Study of Agonistic Behaviour in Hairy‐footed Gerbils (Genus Gerbillurus)
Authors: Dempster Edith R. , Perrin M. R. 
Published: May 2010

AbstractIntraspecific agonistic behaviour was investigated by means of staged encounters in Gerbillurus paeba paeba, G. p. exilis, G. tytonis, G. setzeri and G. vallinus.Four groups of behaviour were identified by motivational analysis: i.e. “exploratory and solitary”, “aggressive”, “submissive”, and “sexual” behaviour. Frequencies of acts and levels of interaction differed among species and sexes.Cluster analysis of behaviour data revealed three clusters which agree partially with the karyology and taxonomy of the genus. G. p. paeba and G. tytonis were very aggressive and highly active; female G. p. exilis and G. setzeri less so; while male G. p. exilis and G. vallinus were least aggressive and active, performing more contact‐promoting behaviour than other species. A range of social types is exhibited from solitary (G. p. paeba and G. tytonis) through semi‐tolerant (G. setzeri and female G. p. exilis) to tolerant (male G. p. exilis and G. vallinus).
Neighbor Call Amplitude Influences Aggressive Behavior and Intermale Spacing in Choruses of the Pacific Treefrog (Hyla regilla)
Authors: Brenowitz Eliot A. 
Published: May 2010

AbstractMale Pacific treefrogs (Hyla regilla) aggregate in choruses during the breeding season. Within these choruses frogs distribute themselves nonrandomly. This study tested the hypothesis that the amplitude of neighbors' calls serves as a proximate cue in regulating the spacing of males in choruses, and that this is mediated by the incidence of aggressive‐encounter calls by resident males. The amplitude of neighbors' calls showed little interindividual variation. Advertisement calls were played to males at three amplitudes that spanned the range of neighbor‐call amplitudes measured between pairs of frogs. At playback amplitudes corresponding to the minimum neighbor‐call amplitudes observed in choruses, frogs gave predominantly advertisement calls and few aggressive‐encounter calls in response. As the playback amplitude was increased, subjects progressively decreased the number of advertisement calls and increased the number of encounter calls that they produced in response. The total number of calls (advertisement + encounter) given in response did not vary with playback amplitude. Intruders were likely to move away when a resident male gave encounter calls. In this way neighbor‐call amplitude regulates intermale spacing in choruses.
Digging Behaviour while Foraging by the European Badger, Meles meles, in a Mediterranean Habitat
Authors: Pigozzi Giorgio 
Published: May 2010

AbstractDigging behaviour while foraging by the European badger (Meles meles) was studied in the Maremma Natural Park, central Italy, during late winter and spring of 1984 and 1985. Badgers digging for Lamellicornia larvae were successful in approximately 77% of the observed digging attempts. Digging success was similar among individuals and months and was positively correlated with the depth of the hole. A change of position while digging was associated with successful digging. Badgers always started their digging activity using only a foreleg at a constant rate and at a later stage used both forelegs alternately at a higher rate. The adoption of such technique is regarded as adaptive since it maximizes the chance of capturing the prey while reducing the energy expenditure due to digging. The reduced availability of those resources to be collected on the ground surface during late winter and spring is suggested as the possible cause of the energetically expensive digging behaviour.
Variation in Mating Systems of Fallow Deer (Dama dama) in Relation to Ecology
Authors: Langbein Jochen , Thirgood Simon J. 
Published: May 2010

AbstractVariation in mating systems of fallow deer (Dama damaL.) was studied in wild and park populations and could be broadly distinguished into 7 categories: following, harems, dominance groups, stands, temporary stands, multiple stands, and leks. The ecological factors which exerted the greatest influence on mating systems were buck density, doe density, and habitat structure and tree cover, resulting in pronounced changes in the degree and type of territoriality observed. Individual male reproductive success was highly skewed in all systems. A greater range of concurrent mating strategies was observed in wild populations than in parks.
Orientation Cues Used by Hatchling Loggerhead Sea Turtles (Caretta caretta L.) During their Offshore Migration
Authors: Salmon Michael , Lohmann Kenneth J. 
Published: May 2010

AbstractSea turtle hatchlings ernerge from underground nests, crawl to the ocean and swim out to sea. The orientation cues used to maintain offshore headings are unknown. Our field experiments suggest loggerhead hatchlings on the Atlantic coast of Florida continue on offshore headings by swimming into oceanic swells and wind‐generated waves. Dependence on these cues appears complete when hatchlings are 3.0 km from shore. Because waves and swells usually approach from seaward directions, they are generally reliable guideposts.
Acquisition of Breeding Space by Nonbreeders in the Anemonefish Amphiprion clarkii in Temperate Waters of Southern Japan
Authors: Ochi Haruki 
Published: May 2010

AbstractBehavior of Amphiprion clarkii, especially of nonbreeders, was investigated at the shore of boulders and rocks in Uwa Sea, southern Japan. All individuals except small ones under one year were tagged. Movements of A. clarkii between host sea anemones were usual in this study area where host anemones were abundant, unlike in the general habitat (coral reefs) of Amphiprion, where movements between hosts are restricted. Monogamous pairs established almost contiguous territories containing all hosts except small ones. Nonbreeders had home ranges on the fringes of the pairs' territories and sheltered in relatively small hosts. Breeding spaces were saturated with breeders and were available for nonbreeders only after disappearance of one or both members of an established breeding pair. Home ranges of nonbreeders of similar body size were spaced out, due perhaps to competition for breeding spaces. It is suggested that large nonbreeders refrained from becoming females to keep their gonads ambosexual, so that they could replace either sex in a territory as breeding space became available, or, in pairing with other nonbreeders, the larger fish of the pair could take the female role.
Male‐Female Interactions in Hairy‐footed Gerbils (Genus Gerbillurus)
Authors: Dempster Edith R. , Perrin M. R. 
Published: May 2010

AbstractStaged 10‐min encounters between male and female gerbils of the same species were characterized by high levels of exploratory and solitary behaviour, variable levels of agonistic behaviour, and little contact‐promoting behaviour. Female Gerbillurus paeba paeba, G. p. exilis and G. tytonis dominated males of these species, while male and female G. setzeri and G. vallinus were equally aggressive.Results of this study indicate that G. p. paeba, G. p. exilis and G. tytonis are aggressively solitary and that females behave aggressively towards unfamiliar males, while G. setzeri and G. vallinus are more tolerant. This is in partial agreement with findings for other gerbil species.
Experimental Analysis of the Symbiosis between Anemonefish and Sea Anemones
Authors: Miyagawa Kazuko 
Published: May 2010

AbstractFundamental problems of the anemonefish‐sea anemone symbiosis were experimentally analyzed, especially at the period of the first encounter of symbionts, using naive juvenile anemonefish.The results differed markedly from those of previous studies using adult fish. Naive juveniles of five Amphiprion species in the coastal region of Japan have an innate protection against their symbiotic anemones. Furthermore, juveniles of all four species examined were almost comprehensively protected from Amphiprion‐symbiotic anemone species. Naive juveniles recognize their species‐specific partner‐anemones via chemical factors released by the latter, thus leading to a species‐specific partnership. Visual cues do not play a large role in partner‐recognition at the first encounter.Possible reasons for the vast difference between the results of the present work and those of previous studies are discussed.
Functional Analysis of the Myrmecophilous Relationships between Ants (Hymenoptera: Formicidae) and Lycaenids (Lepidoptera: Lycaenidae)
Authors: Fiedler Konrad , Maschwitz Ulrich 
Published: May 2010

AbstractMyrmecophilous lycaenid larvae possessing a dorsal nectar organ release strong recruitment behavior in ants attending them. Larvae lacking a functional dorsal nectar organ are unable to release such recruitment behavior. Thus, the dorsal nectar organ with its carbohydrate secretions is responsible for the release of the recruitment behavior. The importance of the dorsal nectar organ for the evolution of mutualistic trophobiotic associations between myrmecophilous lycaenid larvae and their attending ants is discussed.
Ultrasound‐induced Parental Behaviour in House Mice is Controlled by Female Sex Hormones and Parental Experience
Authors: Ehret Günter , Koch Michael 
Published: May 2010

AbstractUltrasounds of a lost mouse pup release pup approach in adult mice and lead to pup retrieving if parental motivation is sufficient. Here, we investigate the effects of oestrogen and progesterone and parental experience on ultrasonic key‐stimulus preference and on pup retrieving. Tests with various groups of inexperienced, pup‐experienced, gonadectomized and hormone treated females and males lead to the following major results: Female sex hormones are not necessary for establishing maximum retrieving rates in mice experienced with pups, they are necessary for spontaneous retrieving to occur in inexperienced mice, they support the achievement of experience with pups and, if present during the time of formation of experience, lead to a superior and prolonged performance of retrieving and ultrasonic key‐stimulus preference. Ultrasound discrimination does not occur spontaneously but only in mice experienced with pups. It is suggested that parental motivation sensitizes selective attention for pup cues and thus makes ultrasound preference possible. Parental motivation is regarded as a state in which the salience of releasing stimuli from the pups is selectively enhanced through hormones and long‐lasting internal changes induced by experience with pups.
Intra‐pair Cooperation, Fledgling Care, and Renesting by Northern Mockingbirds (Mimus polyglottos)
Authors: Zaias Julia , Breitwisch Randall 
Published: May 2010

AbstractMale and female northern mockingbirds (Mimus polyglottos) cooperated in dividing labor between care of fledglings and renesting. This study during two breeding seasons demonstrated a temporal division of labor in this multi‐brooded passerine. Both parents fed newly fledged young. One to four days after young fledged, males reduced feeding rates and began nest‐building. Males delayed initiation of nest construction in proportion to the number of fledglings present. During nest‐building, females provided more food to fledglings. Mates then switched roles. Females finished building nests, laid the next clutches, and began incubation; males fed fledglings until they were independent. Within pairs, males fed fledglings more than did females in one of two years. Both sexes defended fledglings against potential predators, although males provided stronger and more frequent defense. This is the first detailed description of a monogamous passerine that clearly demonstrates lack of brood division while renesting. Division of broods is largely precluded by the temporal division of labor, a behavioral mechanism increasing the probability of renesting. Attempts at renesting, in turn, are favored by a high level of nest predation in this population.
Agonistic Interactions of Juvenile Savanna Baboons
Authors: Pereira Michael E. 
Published: May 2010

Abstract19 juvenile members of known genealogies in two wild baboon groups were studied over a 16‐month period. Males and females in two age classes were compared regarding third‐party aggression and support given and received during agonistic interaction. Young juvenile males and females (1–2.5 years‐old) were supported predominantly by their probable fathers. The adult males supported without regard to the family ranks of juveniles and their opponents. Old juveniles (3–5.5 years‐old) no longer had probable fathers in their groups and rarely or never received support from adult males. Females received considerable maternal support and, with age, most often received support from unrelated adult females. Males rarely received support from either their mothers or unrelated adult females. 100% of adult female support for and against 11 of the 12 females reinforced existing rank relations among matrilines. In contrast, only about half of adult female support of males reinforced matrilineal rank relations. Juvenile females exploited aggression among adult females during rank acquisition: they supported high‐ranking adults during attacks on females they had targeted for rank reversal. In contrast, males attacked adult females in support of peers or young juveniles. Females also solicited support during fights more often than males. They most often solicited adult females, whereas males directed their rare solicitations toward other males. Despite low maternal rank, one female targeted all older females for rank reversal except the adults of her group's top‐ranking family. She was the only female to receive support from adult females that contradicted existing rank relations among matrilines, and the only female ultimately to achieve stable adult rank above families outranking her own. Adult female baboons appear to structure the development of rank relations for juveniles in their groups. Juvenile females are typically limited to acquisition of familial status, while males are free to achieve rank over whichever group members they can independently intimidate.
Acoustical Entrainment of Circadian Activity Rhythms in House Sparrows: Constant Light is not Necessary
Authors: Reebs Stéphan G. 
Published: May 2010

AbstractCycles of presence/absence of social factors can sometimes entrain the circadian activity rhythms of diurnal animals kept under constant light. This might represent a special case of photic entrainment; social factors might awaken the subjects and make them see the light at times when they are normally unaware of it because of sleep. The present study attempted to falsify this hypothesis by entraining the activity rhythms of house sparrows (Passer domesticus) kept in constant darkness. The zeitgebers used were daily 2‐h playbacks of conspecific vocalizations, and daily 1.5‐h acoustical (non‐conspecific) disturbance. 7 birds were tested; four (all males) entrained to both stimuli, while the other three (all females) mostly showed relative coordination. Entrainment took place when the stimuli coincided with the late part of the birds' normal sleep time. No anticipatory activity preceded the daily stimulus presentations. In a second experiment, 8 more male sparrows in constant darkness began their free‐running activity earlier (phase‐advanced) on days that followed the presentation of a single 2‐h bout of acoustical disturbance in the last half of their normal sleep time. Stimulus presentations at other times had no effect. Opening the eyes and seeing the light are not necessary for acoustical (and social) entrainment, but other physiological consequences or correlates of sleep interruption may be involved.
Transmission Effects on Temporal Structure in the Advertisement Calls of Two Toads, Bufo woodhousii and Bufo valliceps
Authors: Ryan Michael J. , Sullivan Brian K. 
Published: May 2010

AbstractWe measured degradation of temporal structure in the advertisement calls of two species of toads (Bufo woodhousii and B. valliceps) as a function of transmission distance. Degradation, measured as the ratio of the amplitudes of pulse and interpulse interval, increased with distance and was significantly greater in B. valliceps than in B. woodhousii. These results are compared to previous reports of neural thresholds for units in the torus semicircularis that are responsive to the interaction of depth and rate of amplitude modulation in B. woodhousii and B. americanus. We suggest that the degradation of temporal structure that we measured has behavioral and neurophysiological consequences for communication.
Cultural Evolution in Song Dialects of Yellow‐rumped Caciques in Panama
Authors: Trainer Jill M. 
Published: May 2010

AbstractThe histories of five colony‐specific song dialects of yellow‐rumped caciques (Cacicus cela vitellinus) were recorded for three breeding seasons in Panama. Dialects consisted of 5 to 8 song types shared among all male members of a breeding colony. The number of song types that occurred at more than one colony decreased with distance between colonies. Color‐banded subadult and adult males frequently dispersed between years to other dialect areas where they adopted the local songs. About 78% of all song types were distinct from songs present the previous year at the same colony. During a breeding season some song types changed gradually, with all males adopting parallel changes. Gradual change in songs at colonies appeared to account for more new song types than did introduction of songs by dispersing males. Because song types changed gradually in constant directions, the cause of these changes may be cultural adaptation in which individuals benefit by adopting certain songs, rather than copy‐error or cultural drift.
Motivational Referents of Contact Calls in Japanese Monkeys
Authors: Masataka Nobuo 
Published: May 2010

AbstractVery specific vocalizations (girneys) are interchanged extensively between Japanese monkeys before they establish grooming contact. I undertook acoustic classification of vocalizations tape‐recorded in a captive group, and found that they could be divided into two broad classes according to the position of the peak of the tonal element relative to the whole call length. Sequelae analyses revealed that the two variants were linked with different probabilities of the caller's subsequent behaviour. When the peak occurred in the first third of the girneys their callers were likely to groom the signal recipients, while when the peak occurred in the final third of the calls, their vocalizers tended to receive subsequent grooming. Playback experiments showed that the animals really perceived those variants. Japanese monkey contact call variants have specific and distinctive motivational referents.
Correlations between Courtship Success, Aggressive Success, and Body Size in a Picture‐winged Fly, Drosophila silvestris
Authors: Boake Christine R. B. 
Published: May 2010

AbstractRelations between courtship success, aggressive success, and body size were examined in a laboratory study of the lekking Hawaiian fly, Drosophila silvestris. Courtship was studied by placing one male and one female in a cage together at a time, and aggression was observed with caged pairs of males. Aggressive success was positively and highly significantly correlated with body size, but uncorrelated with courtship success. Surprisingly, courtship success was negatively correlated with body size, although this relationship was not significant. Courtship success and aggressive success were not correlated. These results suggest that selection favors an intermediate optimum body size in this species.
Infanticide in Mountain Gorillas: New Cases and a Reconsideration of the Evidence
Authors: Watts David P. 
Published: May 2010

AbstractData on six cases of infanticide, one infanticide attempt, and one suspected infanticide in mountain gorillas (Gorilla gorilla beringei) are presented here for the first time. These and previously reported cases in the same population are analyzed in order to assess the circumstances and consequences of infanticide.Most infanticides occur when infants' mothers are not accompanied by their group's mature male (usually because he has died). Infants in this situation are almost certain to be killed by unfamiliar males unless they are nearly weaned. Active defense of infants by females is ineffective, and females cannot avoid unfamiliar males for prolonged periods. In contrast, infanticide is rare — yet has been observed — in encounters between mature males. It is not associated with group takeovers and male eviction by extra‐group males, unlike the case in many other mammals. Demographic constraints and reproductive competition limit the occurrence of defensive coalitions between males. These factors, plus the high risks associated with male/male aggression, inhibit the occurrence of group takeovers by male coalitions. Infanticide shortens interbirth intervals and results in a high probability that a female will mate with the infanticidal male.These findings support the sexual‐selection hypothesis for the evolution of infanticide and strongly support the argument that intersexual mutualism and intraspecific aggression have been central factors in gorillas' social evolution.
Toward a Resolution of the Paradox of Aggressive Displays: I. Optimal Deceit in the Communication of Fighting Ability
Authors: Bond Alan B. 
Published: May 2010

AbstractOne inference from game theory models of animal conflict is that adversaries should not inform one another about concealed components of their fighting ability. This poses a paradox for the customary ethological account of aggressive displays in that it is usually assumed that the primary function of such behavior is to make such information available. To resolve the paradox, I propose that the information in aggressive displays may not be strictly truthful, but may instead represent “optimal deceit,” a balance between the advantages of deceit or bluffing and the disadvantages of selecting for skepticism in the receiver. Numerical simulation of this model was performed to examine the effects of differences in fighting ability and in the risk of injury in an escalated conflict. The model converged on an equilibrium level of deceit, even when the receiver was ignorant of the average level of deception being employed.