bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental and Comparative Aspects of Social Play of Mantled Howling Monkeys in Costa Rica
Authors: Zucker Evan L. , Clarke Margaret R. 
Published: April 2008

AbstractThe social play of infant and juvenile mantled howling monkeys in Costa Rica was studied via focal sampling (529.2 h) of known individuals of known age over a 22-month period. Observations of adult males (291.2 h of focal samples), done over portions of 3 calendar years, provided supplemental data for the social play of adults. Developmental patterns of play are presented, and are compared with data available for other mantled howlers, other sites, and other species of howlers. Social play by infants and juveniles occurred at the rate of .56 bouts/h, represented 5.79% of the total focal observation time, and bouts had a mean duration of 6.19 minutes. Play by an adult male occurred at the rate of .03 bouts/h (.007/h for all 4 adult males combined), represented 0.24% of his total focal time, and had a mean duration of 5.0 minutes. Ontogenetically, social play began in the 8th week of life. Infants' rates of play and percentage of time spent in play increased from the I1 stage through the I3 stage, then decreased into the juvenile period (> 1 year of age). Mean durations of play bouts increased through the 3 infant stages, then decreased slightly in the J1 stage. The occurrence ofplay groups (3 or more individuals) increased through the infant and juvenile stages. As infants aged, a larger percentage of bouts occurred further from the infants' and juveniles' mothers. With respect to social variables, no overall developmental pattern was evident for playing with an older or younger partner, or a partner that was the offspring of a mother ranked higher or lower than one's own mother; different age classes showed different patterns. When an older sibling was available as a play partner, no preference for this relative was shown. I3's had the highest number of different play partners. Immature howlers played predominantly with other immatures (93% of their interactions). The behaviours observed during play were similar to those reported for other howlers; the behaviours emitted by an adult male were similar to those of the juvenile partner, as was the style and intensity of play. The social play of these mantled howlers is viewed with respect to social, demographic, and ecological variables. The play of howlers is both facilitated and constrained by these variables.
Sexual Selection in the Leopard Toad, Bufo Pardalis
Authors: Cherry Michael I. 
Published: April 2008

AbstractSexual selection was investigated in the leopard toad, Bufo pardalis, on the Cape Peninsula in the south-western Cape Province of South Africa. Over three breeding seasons, male mating success was not dependent on either snout-urostyle length (size) or weight, when data were analysed on both a nightly and a seasonal basis. Males did not engage in active searching for females, or attempt to displace other males in amplexus. This is most unusual for an explosive breeder, in which spawning takes place at a specific site. It is suggested that the absence of patterns of behaviour normally adaptive for explosive breeders may be associated with the fact that a congeneric species with a different chromosome number, B. rangeri, overlaps in both distribution and breeding season with B. pardalis over part of its range. Active searching might therefore lead to males finding a mate of the wrong species, which would be maladaptive, as no male was successful in obtaining more than one mating over the three-year study period. Alternatively, the absence of scramble competition in this species may reflect predation pressure.
Social Dispersion and Lekking in Uganda Kob
Authors: Balmford Andrew 
Published: April 2008

AbstractLek-breeding in Uganda kob was associated with extremely high population density (c. 140 animals/km2). Kob were typically found in unstable aggregations of more than one hundred animals, including several adult males. Females occupied unusually large, overlapping home ranges, but reasons for such widespread movements were unclear. The social dispersion of Uganda kob was therefore similar to that of other lekking ungulates, and confirms predictions of several recent hypotheses of lek evolution. However, resolution of alternative models is nevertheless difficult, since in practice these make very few exclusive predictions.
Absence of Parent-Young Recognition in Kittiwakes: a Re-Examination
Authors: Storey Anne E. , Anderson Rita E. , Porter Julie M. , Maccharles Andrea M. 
Published: April 2008

Abstract
Black-legged kittiwakes (Rissa tridactyla) appear to recognize their chicks later in development than do ground-nesting gulls, an observation which has been related to the lower mobility of the chicks in nests on narrow cliff ledges. We tested whether this apparent delayed recognition was due to a failure of chicks to identify themselves (few individual cues in calls), or a failure of either participant to discriminate its relatives (differential response to calls or visual characteristics). It appears that both processes are relevant: (a) the peep calls of kittiwake chicks have fewer identifying cues in them than the peep calls from chicks of the ground-nesting herring gull (Larus argentatus), and (B) both parents and chicks show low levels of responsiveness to kittiwake calls from their own or from other nests. These results are discussed in terms of the appropriate level of responsiveness in the cliff environment, and the adaptive significance of the presence or absence of strong positive responses to one's own family members.
Intraspecific Variation in Courtship and Copulation Frequency: an Effect of Mismatch in Partner Attractiveness?
Authors: Petrie Marion , Hunter Fiona M. 
Published: April 2008

AbstractThe aim of this paper is to present a verbal theoretical model that could account for the among pair variability in courtship and copulation behaviour that occurs both during and after pair formation in socially monogamous species. We assume that copulation acts to prevent mate loss, by reducing the availability of an individual to other potential partners. Variation in copulation and courtship frequency then arises as a result of variation in the risk of mate loss. Because of the constraints on free or ideal choice, pairs will form in which it may be possible for one individual to improve upon the quality of its partner. In a mismatched pair it will pay the poorer quality mate to guard the higher quality individual and prevent it from leaving to pair with a better quality mate. The poor quality individual will therefore solicit copulations at a high frequency while it's partner may not always respond. We predict that high levels of courtship and solicitation will relate to a high risk of mate loss and that a lack of response by a partner will relate to the potential opportunities it has to improve on partner quality. Our thesis is that variation in mating behaviour arises as a result of any deviations from assortative mating that may exist in a population.
Front Individuals Lead in Shoals of Three-Spined Sticklebacks (Gasterosteus Aculeatus) and Juvenile Roach (Rutilus Rutilus)
Authors: Bumann Dirk , Krause Jens 
Published: April 2008

AbstractFish shoals are usually seen as anonymous leaderless groups in which all individuals have the same influence on swimming velocity and direction. This hypothesis was tested by investigating swimming directions of shoals of roach (Rutilus rutilus) and three-spined stickleback (Gasterosteus aculeatus). In roach, the influence of front and rear fish on the shoal's swimming direction was compared by analysing video recordings. Front fish initiated new directions significantly more often and were followed by rear fish. In a second experiment two shoals of sticklebacks were released from two channels which were positioned at an angle relative to each other. The shoals usually appeared with a short time difference at the opening of the channels and then merged. Initially the two shoals faced in different directions based on the orientation of their respective channel and it was recorded which direction prevailed after the shoals had merged. The shoal that left the channel first, and therefore formed the front part of the merged shoal, clearly dominated the direction. Thus, both experiments gave evidence for front fish having a dominant influence on the direction of the shoal. In the context of sustained position preferences of individual fish, recently observed in roach, this suggests that fish shoals may have leaders over extended time periods.
The Effect of Uncertainty On the Food Intake of the Mongolian Gerbil
Authors: Forkman B.A. 
Published: April 2008

AbstractThe effect of an unstable environment on the food intake of male adult gerbils (Meriones unguiculatus) was investigated in a laboratory set up. The main result was an increase in the intake when the environment was variable and food abundance intermediate, compared to the intake in a superabundant and stable environment. The experiment consisted of three periods. During the base-line period of the experiment all animals had superabundant food. During the next period half the animals continued in the base-line environment and the other half were presented with a variable environment with food bowls that changed places between trials. During the final period the environmental situations for the animals were reversed. Food intake was stable during the base-line period. During the second period the animals in the variable environment ate more than the animals in the base-line environment. During the third period the intake for the animals now in the variable environment increased whereas the intake in the stable environment decreased. The conclusion of the present study is that Mongolian gerbils will increase their food intake in response to variable and diminished food access. These are factors that in a natural environment could predict food scarcity.
Male Bonds: Afilliative Relationships Among Nonhuman Primate Males
Authors: Van Hooff Jan A.R.A.M. , Van Schaik Carel P. 
Published: April 2008

Abstract
A deductively obtained model concerning the factors that determine male social relationships within the framework of primate social organization is discussed in the light of existing empirical evidence. Tolerance and affiliative bonding are expected to occur less easily between male than between female primates. Whereas females compete for resources such as food, males, in addition compete to obtain fertilizations. Unlike food, fertilizations cannot easily be shared. This undoubtedly hampers the formation of male coalitions and the development of male bonds. Indeed, male tolerance tends to be low especially in species where the spatial and temporal distribution of females is such that individual males may monopolize access to such females, thus facilitating inter-male contest. Nevertheless there are a number of species in which tolerance between adult male group members is remarkable. In some cases forms of coordination and mutual attraction exist that justify the qualification of 'male bonding'. An important factor supposed to conduce to the development of male bonding is the inclusive fitness benefit that support and tolerance between male relatives may bring. This would occur especially where circumstances permit male philopatry. The latter is expected in species where the nature of female competition for basic resources does not lead to strong female-bondedness and female nepotism, allowing females to become allopatric. There is evidence from various species that related males form bonds under the mentioned conditions. A special case of this is the formation of father-son bonds, noted in species with strong intermale contest and corresponding sexual dimorphism. A remarkable alternative, by the way, is the existence of mother-son bonds which last into adulthood and which contribute to a male's position. There are indications for such bonds in two species where males stay with their mother and where sexual dimorphism is low. Still kinship clearly is not a necessary factor for the development of male tolerance and of support between males. The factor does not play a role, for instance, in the short-term coalitions found in baboons. Here opportunism based on mutual or reciprocal benefits seems to play a decisive role. The evidence presented lends support to the idea that there is an order of priorities, in which, first, socioecological factors determine the spatial, hierarchical and affiliative relationships between females. These female relationships then set the scene for the males, in that these determine the options left open for the males to organize their patterns of competition, migration and bonding.
Social and Genetic Aspects of Paternity in Wild Long-Tailed Macaques (Macaca Fascicularis)
Authors: De Ruiter Jan R. , Van Hooff Jan A.R.A.M. , Scheffrahn Wolfgang 
Published: April 2008

AbstractIn a field study of three groups of wild long-tailed macaques, Macaca fascicularis, observations on social behaviour could be related to genetically determined paternity. In contrast to what has been found in many previous studies on captive primate groups, we found a relatively strong correlation between male dominance rank and reproductive success. In a large group the high success of the alpha male compared to other males could be explained only partly by his higher copulation score. His success also resulted partly from better timing of his copulations during maximum fertility of the females, in comparison with other males. We must conclude either that the alpha-male has more access to fertile females, or that females have a preference for the alpha-male during their maximum fertility. The females clearly displayed promiscuous behaviour. This behaviour implies a risk to a female that a male other than the alpha-male with proven qualities will become the father of her offspring. One expects that there must be a social advantage related to this female strategy. In the absence of indications of any direct social advantages to the female of this sexual behaviour pattern, the ultimate explanation for this female promiscuity is most likely is aggression reduction. This could be either through the devaluating of any single copulation, or through the confusion of paternity and a resultant reduction in the risk of infanticide.
Predator Vigilance Costs of Allogrooming in Wild Blue Monkeys
Authors: Cords Marina 
Published: April 2008

AbstractAlthough allogrooming in Catarrhine primates is often interpreted as if it were a costly behavior for the groomer, such costs have not been convincingly documented. This paper presents data on rates of vigilance for aerial predators, measured as looking up toward the sky, in wild blue monkeys engaged in allogrooming, and compares these vigilance rates to those occurring when the same individuals engaged in other activities, namely feeding and resting. Grooming individuals have much lower vigilance rates than resting or feeding individuals, suggesting that grooming individuals are more likely to be at risk of being preyed upon. These results are not caused by a systematic relationship in the sample between activity and either foliage density or time of day, two factors potentially related to levels of safety from predation. Nor was there evidence that blue monkeys avoid the vigilance costs of grooming by engaging in this behavior primarily at safe times or in safe locations. Although the data suggest that vigilance costs occur, they may accrue to the recipient ofgrooming as well as the groomer, and may be compensated for both partners by long- or short-term benefits.
Individual Variation in Foraging Movements in a Lake Population of Young-of-the-Year Brook Charr (Salvelinus Fontinalis)
Authors: Biro Peter A. , Ridgway Mark S. 
Published: April 2008

Abstract
We examined the variation in foraging movements in a population of young-of-the-year (YOY) brook charr living in the near-shore littoral zone of a lake. By repeating the methodology of an earlier stream study, we made direct comparisons between data from lake and stream populations. In general, the pattern of variation in foraging movements was similar between the two sites with greater variability and activity observed in the lake population. The dichotomous nature of the proportion of time spent moving in the stream was also observed in the lake population but in a reversal of the stream pattern. Charr that moved constantly while foraging represented the largest movement category in the lake. In general, variation in foraging movements were more strongly related to the rate of prey rejection, whereas environmental factors, such as distance from shore, submerged objects, and the amount of overhead riparian cover, were more strongly related to prey ingestion. This last finding directly contrasts with that found in the stream literature for YOY charr in still water where ingestion rate, as estimated using feeding attempt rate, increases with the mobility of YOY charr.
Habituation of a Predatory Response in the Stickleback (Gasterosteus Aculeatus)
Authors: Peeke Harman V.S. 
Published: April 2008

AbstractSticklebacks presented with a clear glass tube filled with live brine shrimp will initially attempt to capture them; however, the response wanes within minutes. In the case of females, the rate of initial response is enhanced and the rate of waning is influenced by the state of the female (gravid females are more responsive) and by the density of the prey (greater density results in greater responsiveness). The predatory-response habituation differs from habituation of territorial aggression and courtship in that the pre-decremental, incremental process is absent. In common with habituation of territorial aggression but not with courtship, there is little short-term recovery of the response. The differences are consistent with different functional requirements for an experience-based inhibitory mechanism involved in the modulation of stickleback behaviour.
Conflict Outcome in Male Green Swordtail Fish Dyads (Xiphophorus Helleri): Interaction of Body Size, Prior Dominance/Subordination Experience, and Prior Residency
Authors: Beaugrand Jacques P. , Payette Daniel , Goulet Claude 
Published: April 2008

Abstract
The relative contribution of asymmetries in prior experience, size, and prior residency to the determination of dyadic dominance between unacquainted individuals was examined using pairs of green swordtail fish, Xiphophorus helleri. Four types of encounters were staged between an intruder and a smaller resident: (1) both had experienced prior vicctory; (2) both had experienced prior defeat; (3) the intruder had experienced prior victory and the resident prior defeat; and (4) the intruder had experienced prior defeat and the resident prior victory. In a fifth condition in which two intruders met, one was a prior subordinate and the other a prior dominant smaller in size than its opponent. In all these encounters, the superiority in lateral surface of one fish varied between 0 to 30% over that of its opponent. Results showed that (1) when size differences between contestants were within the range of 0-10% and there was an asymmetry in prior social experience, conflicts were essentially resolved according to prior experience with prior winners systematically defeating prior losers; (2) prior residency of 3 h was an advantage only when both opponents had experienced prior defeat before meeting and when size asymmetries were small (e.g. < 20%). It was not an advantage between prior winners or between a prior winner and a prior loser; (3) when large size asymmetries existed (e.g. 20-30%), size uniquely determined dominance outcome and nullified other advantages or disadvantages due to prior social experience and prior residency; and (4) at intermediate levels of size asymmetries (e.g. 10-20%), size partially cancelled any advantage due to a prior victory, and gradually became paramount in accounting for victories.
'Pop' Goes the Dolphin: a Vocalization Male Bottlenose Dolphins Produce During Consortships
Authors: Connor Richard C. , Smolker Rachel A. 
Published: April 2008

Abstract
Studies of dolphin communication have been hindered by the difficulty of localizing sounds underwater and thus identifying vocalizing individuals. Male bottlenose dolphins (Tursiops sp.; speckled form) in Shark Bay, Western Australia produce a vocalization we call 'pops'. Pops are narrow-band, low frequency pulses with peak energy between 300 and 3000 Hz and are typically produced in trains of 3-30 pops at rates of 6-12 pops/s. Observations on the pop vocalization and associated behavior were made as part of a long-term study of bottlenose dolphins in Shark Bay. During 1987-88 seven dolphins, including three males, frequented a shallow water area where they were daily provisioned with fish by tourists and fishermen. The three males often produced pops when accompanied by single female consorts into the shallows. Fortuitously, the males often remained at the surface where pops were audible in air, enabling us to identify the popping individual. All 12 of the female consorts in the study turned in towards males at a higher rate when the males were popping than when they were not popping. All 19 occurrences of one form of aggression, 'head-jerks', were associated with pops. We conclude that pops are a threat vocalization which induces the female to remain close to the popping male during consortships.
Distance and Social Recognition in Hens: Implications for the Use of Photographs as Social Stimuli
Authors: Stamp Dawkins Marian 
Published: April 2008

AbstractThe role of close (less than 30 cm) examination or scrutiny of other birds in social recognition was confirmed by showing that before approaching a hen whose identity was unknown, hens behaved similarly whether that bird was familiar or unfamiliar to them, but after examining the other hen they temporarily kept further away from unfamiliar hens (Expt 1). Hens chose flock-mates rather than unfamiliar birds as feeding companions even when all that was visible of the target birds were their heads and necks, confirming the role of these regions in recognition (Expt 2). They showed this preference for familiar birds whether they could see either the front or the side views of the heads of the target birds but attempts to confirm this result with photographs rather than live birds resulted in no significant preference being shown (Expts 3 and 4). The reasons for this lack of transfer from live birds to photographs and its implications for presenting artificial visual stimuli such as photographs and video to hens are discussed.
Lek-Like Spawning Behaviour and Different Female Mate Preferences in Roach (Rutilus Rutilus)
Authors: Wedekind Claus 
Published: April 2008

AbstractI studied the scarcely known mating system of roach. Individually marked fish were kept in a pond with a glass wall that allowed observations of spawning. The roach showed a lek-like mating system which has not been described previously, with bourgeois males and reproductive parasites (i.e. simultaneous parasitic spawning), both tactics used by the same individuals. Females had the possibility to choose freely among the males but could probably hardly avoid multi-male fertilization. Most females spawned repeatedly during the observation period. They showed strong individual preferences with different females preferring different males or spawning sites.