bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mate Choice by the Male Convict Cichlid (Cichlasoma nigrofasciatum; Pisces, Cichlidae)
Authors: Nuttall Daniel B. , Keenleyside Miles H. A. 
Published: May 2010

AbstractThe influence of standard length (SL) and maximum body width on the attractiveness of female to male convict cichlids was examined in a choice apparatus. Preliminary experiments showed that maximum body width (abdominal swelling), ovary mass and ovary volume of females increased significantly over the 7‐d post spawning period. Variation in body width explained a moderate amount of the variation in ovary mass and volume. Therefore, body width is a suitable indicator of gravidity. Male convict cichlids were offered a simultaneous choice between two females that varied in standard length (SL) and/or gravidity. Choice was determined by amount of time the male spent near each female. Males chose the larger of two females when both were gravid but showed no choice when neither was gravid. In general, males chose the gravid female when one was gravid and the other was not, regardless of the difference in SL between them. Choice of female by males was not influenced by female behaviour in the test apparatus. We suggest that mate choice by convict cichlid males is based primarily on female gravidity and secondarily on female SL.
Nest Site Quality, Female Mate Choice, and Polygyny in the House Wren Troglodytes aedon
Authors: Johnson L. Scott , Searcy William A. 
Published: May 2010

AbstractMany models proposed to explain the occurrence of polygyny in birds implicitly assume that females actively choose males offering the highest quality breeding situations. However, strong evidence of active mate choice by females in polygynous bird species is scarce. This study asked whether females in a polygynous population of house wrens Troglodytes aedon, a small, cavity‐nesting songbird, base their choice of a mate at least partly on characteristics of the nest site that he controls. Already‐mated males were randomly assigned one of two types of nest boxes to which they could attempt to attract secondary mates. Some males were given standard‐type boxes with small entrance holes in the front sides of boxes, while other males were given boxes with larger entrance holes located in the boxes' roofs. A preliminary experiment revealed that female house wrens overwhelmingly prefer front‐entrance to roof‐entrance boxes when both types of boxes are available on the same territory. Females chose mated males with front‐entrance boxes over mated males with roof‐entrance boxes significantly more often than expected by chance. This preference demonstrates that female house wrens do discriminate among potential mates and base their choice of a mate at least partly on characteristics of the nest site he has to offer. This observation is compatible with the hypothesis that female house wrens choose mated males because they gain access to high‐quality nest sites.
Acoustic Dueling in Tarbush Grasshoppers: Settlement of Territorial Contests via Alternation of Reliable Signals
Authors: Greenfield Michael D. , Minckley Robert L. 
Published: May 2010

AbstractA field study of disputes over ownership of mating territories by male tarbush grasshoppers (Ligurotettix planum) revealed that most contests were settled ritualistically via the antiphonal exchange of acoustic signals. Males used a special aggressive signal, referred to as the “shuck” call, in these encounters. Individuals that never produced shuck calls invariably departed the contested sites, and a playback experiment showed that shuck calls elicited higher response levels from males than sexual advertisement calls. Approximately 1/5 of all territorial contests escalated to biting, grappling, or kicking.The outcomes of territorial contests that were settled via purely acoustic encounters could not be predicted by the size of the participants. Prior residency was a predictor of winning in some contests, but often the competing males did not possess clear intruder/resident roles. However, a signal parameter that was a combined measure of the rate of shuck calls and their mean length predicted the winner of most acoustic encounters. Contests that escalated, though, were generally distinguished by participants that displayed comparable measures of all signal parameters save call length. A tradeoff occurred between call rate and length in most individuals. This, as well as the finding that call length did predict winning in escalated contests, implies that these signal parameters may reflect an individual's strength or motivation.Contests in which the signal parameters of the males were similar tended to be prolonged and escalated. This relationship suggests that individuals assess the signals of their rivals and depart if they cannot match their call rate and length. That both call rate and length are assessed may enhance the reliability with which signals can be used to predict a rival's fighting ability in the event of escalation. Various simple mechanisms for signal assessment are proposed.A second playback experiment suggested that the insects heard less effectively while they called. Timing mechanisms that preclude the overlap of calls during contests occur, and they may have evolved because of the importance of precise assessment of the signals of rivals. Such mechanisms circumvent the potential impairment in perception noted above and also generate a conspicuous feature of L. planum contests — mutual alternation of signals.
The Play Associations of Red‐necked Wallabies (Macropus rufogriseus banksianus) and Relation to Other Social Contexts
Authors: Watson Duncan M. 
Published: May 2010

AbstractThe partner preferences of a captive group of red‐necked wallabies (Macropus rufogriseus banksianus) during playfights were determined and the patterns of social relations formed compared to those in other social contexts. Wallabies preferred play‐partners of the same sex and of similar age and dominance status. Young males were most likely to initiate play. Females engaged in play almost exclusively with subadult males and, in particular, their male offspring. Play between females was not recorded. In play between males from different age classes, initiation and termination was independent of age. Termination was dependent on who initiated the interaction: initiators were less likely to terminate playfights than were recipients. Wallabies that had recently vacated the pouch were not the focus of social play in the colony.Agonistic interactions also occurred most often between wallabies of the same sex and similar age and dominance but older males were most likely to initiate interactions. Initiation and termination of agonistic interactions was age‐dependent: older wallabies almost always initiated and won encounters with younger partners. There was no correlation among male dyads between their rates of play and agonistic encounters, dominance reversals were more common in play than in agonism, and the patterns of wins and losses in play and agonism were not correlated. There was some suggestive, but inconclusive evidence that the proportion of time males spent in close proximity at food and water troughs was positively correlated with their rates of play and negatively with their rates of agonistic interactions. There was also some evidence that males that played together often had more frequent affiliative interactions than those that did not. However, there was no correlation between rate of play by males and the proportion of time they spent resting together. These results suggest that the function of social play in the wallabies was motor training and not socialization. In addition, they indicate that play and agonism are causally‐distinct categories of behaviour. Based on this interpretation, the relationship between play and serious fighting in macropods and in eutherian mammals is discussed.
Do Brown Hares Signal to Foxes?
Authors: Holley Anthony J. F. 
Published: May 2010

AbstractOf a total of 32 sedentary brown hares (Lepus europaeus) approached across open ground by foxes (Vulpes vulpes), 31 reacted when the fox was 50 m or less from them by adopting a bipedal stance directly facing the fox. Of five sedentary hares approached by foxes from nearby cover, none stood, three moved away and two adopted the squatting (primed for movement) posture. Hares stood before foxes in all heights of vegetation and on 42% of occasions were solitary. Hares did not stand before approaching dogs (Canis familiaris). The functions of this behaviour are considered and competing hypotheses of Predator Surveillance and Pursuit Deterrence are examined by testing predictions against results obtained. The results suggest that by standing erect brown hares signal to approaching foxes that they have been detected.
The Costs of Male Display and Delayed Plumage Maturation in the Satin Bowerbird (Ptilonorhynchus violaceus)
Authors: Collis Ken , Borgia Gerald 
Published: May 2010

AbstractThe costs associated with the evolution of male display traits has attracted much attention in regard to the type of traits that evolve and the timing of their expression. We investigate these costs by using testosterone implants to alter the development of male display traits in the satin bowerbird (Ptilonorhynchus violaceus). Testosterone implants advanced the development of adult display traits in males with juvenile plumage. We then measured the costs of early expression of these characters in treated males. Testosterone implants caused young males to (1) become more involved in behavior normally carried out by older males when visiting bowers, (2) build bowers, and (3) molt prematurely into an adult plumage. No difference was observed between the testosterone‐treated birds and controls in return rate or condition the year following treatment, suggesting that the physical costs of display are not high. We found that males in adult plumage are tolerated less, and are not displayed to as frequently as juvenile plumage males at the bowers of established bower holders. The causes of delayed plumage maturation are most consistent with the facilitated‐learning hypothesis. That is, early development of adult characteristics reduces the opportunity of young males to learn display behavior critical for later reproductive success.
Load Size Variation in the Eastern Chipmunk, Tamias striatus: The Importance of Distance from Burrow and Canopy Cover
Authors: Bowers Michael A. , Ellis Anthony 
Published: May 2010

AbstractWe examined the degree to which chipmunks foraging from dishes containing sunflower seeds varied cheek pouch load size according to both travel time (distance from burrows) and predation hazard (canopy cover). Results showed that larger loads were taken under cover at some distance from burrows than were taken from closer or more open sites. Distance effects appeared to reflect the influence of traveling times on quitting harvest rates as predicted by central place foraging models. Quitting harvest rates also appeared to be higher under low than under dense canopy cover; this trend was most pronounced at some distance from burrows suggesting that foraging decisions were made relative to both energetics and predator avoidance. Chipmunks appeared to employ a patch exploitation strategy that minimized the hazard:gain ratio.
Randomness in Ontogeny. On Antennal Grooming in the Milkweed Bug Oncopeltus fasciatus
Authors: Jander Ursula , Jander Rudolf 
Published: May 2010

AbstractMilkweed bugs (Oncopeltus fasciatus, Lygaeidae) groom the distal segment of each antenna between the tibial combs of both forelegs. Variable numbers of grooming strokes compose a grooming bout. A total of 112 spontaneous grooming bouts, comprising all developmental stages, were videotaped, the angular movements of the forelegs were digitized, and the outcomes computer‐analyzed. Individual strokes of forelegs were measured by their angular amplitude and mean angular elevation. These two measures are randomly combined in the first instar and then differentiate during ontogeny into two distinct types: small amplitude strokes of high average elevation and large amplitude strokes of lower average elevation. The sequencing of small and large strokes within bouts is largely (97%) random in all developmental stages. The outcome of the analysis fits the general empirical rule that premature action patterns are more random than mature ones. Some traits do not follow this rule and are persistently highly random. It is suggested that excessive randomness in premature behavior is due to genetic underdetermination, and that incorporation of non‐genetic information helps to specify the less random mature behavior. Developmentally persistent behavioral randomness is explained by the behavioral‐entropy principle: traits in behavior vary randomly unless randomness is selected against.
Self‐reinforced Behaviour Does not Explain Contra‐freeloading in the Mongolian Gerbil
Authors: Forkman Björn A. 
Published: May 2010

AbstractIn various situations animals prefer to work for food even when free food is available. Several hypotheses have been put forward to explain this phenomenon, most of them either suggesting that a learned behaviour may be self‐reinforcing or that the animal has to perform a certain species specific behaviour.Mongolian gerbils (Meriones unguiculatus) were used in the present study. Half of them were given access to a cage with one bowl with sunflower seeds, and another bowl with sand and 30 seeds, 20 min/d for 5 d. The amount of seeds eaten from each bowl and the time spent digging in the bowls, on the floor, and in the corners was recorded. The animals were then put in the same cage with one bowl with seeds but the other bowl now contained only sand (20 min/d for 5 d). For the other group the treatment was reversed.Almost all digging took place in the 30 seed bowl, and most seeds eaten were taken from this bowl. When this bowl contained only sand the amount of digging went down drastically for that bowl. Nor was there any compensatory digging on the floor or in the corners of the cage.The present results indicate that the self‐reinforcing hypothesis and the obligatory species specific response hypothesis are not enough to explain the contra‐freeloading phenomenon. A possible alternative hypothesis, that the behaviour is a way of exploring and reducing uncertainty is discussed.
Ecological and Behavioral Aspects of Nest Building in Wild Bonobos (Pan paniscus)
Authors: Fruth Barbara , Hohmann Gottfried 
Published: May 2010

AbstractData on nest building behavior were collected from free ranging bonobos (Pan paniscus). Considering the physical features of both nests and trees used for nest construction, bonobos appeared to show various preferences: (1) Trees with small leaves were chosen more frequently than expected; (2) The majority of nests were constructed in trees of the middle forest layer (15 to 30 m) and at a mean height of 16 m; (3) nests built during the day were located higher than night nests and differed in the general mode of construction (number of trees involved). Comparing nests made by mature males and females it became apparent that females (4) built nests higher, (5) constructed day nests more frequently and (6) used them for a longer time than males. Comparison of data collected at different study sites indicates site‐specific differences concerning selection of trees and location of nesting sites. Behavioral observations made clear that nests were not only used for rest but also for other activities like feeding, social grooming and play. Moreover, the study provided the first evidence that bonobos build nests also in order to avoid potential or imminent conflicts with other party members. Field observations indicate that these nests symbolize a taboo zone and show another facet of the social abilities of bonobos for the solution of intra group conflicts. It is suggested that this behavior derives from the spatial intolerance shown by females during the process of weaning.
Determinants of the Mating Success of Polyterritorial Pied Flycatcher Males
Authors: Rätti Osmo , Alatalo Rauno V. 
Published: May 2010

AbstractMuch attention has been paid to the polyterritorial mating system of some passerine birds. Here we report how a male's mating success is related to the behavioral traits of polyterritorial pied flycatcher (Ficedula hypoleuca) males. We found no evidence that the timing of polyterritoriality in relation to egg laying in the primary nest or the singing behavior of males have any influence on mating success. However, results show clearly that male mating success was improved with an increase in the distance between territories up to a distance of about 200–300 m whereupon there was no further enhancement of mating success. This finding is crucial for both the deception hypothesis and female‐female aggression hypothesis which have been put forward to explain polyterritorial polygyny. Males who establish a distant second territory seemed to allocate more time to singing there. The association, although weak, between singing activity and distance between territories makes it more difficult for females to use song rate as a cue to discriminate males with a secondary territory far from the primary territory, and these are the males that are least likely to feed the young of a second female. Males who established a second territory late in relation to egg laying in the primary nest did not take over a close second territory as might be predicted from female‐female aggression hypothesis.
Condition‐dependence and Sex Traits in the Male Great Bustard
Authors: Carranza Juan , de Trucios Sebastián J. Hidalgo 
Published: May 2010

AbstractSecondary sex traits involved in the courtship display of the male great bustard (Otis tarda) are analyzed in the light of condition‐dependence theory. Heaviest males at the start of the mating period further gained about 30% in body mass. Both display performance and development of morphological traits involved are mainly determined by body mass. Males who developed sex traits were among those in good physical condition, although not the current physical condition but weight of the male correlates with the development of sex traits. We discuss the idea that weight may be a good indicator of overall physical condition during development up to maturity, rather than just the current condition at a given season. Our results show a discontinuity both in display performance and in the development of morphological traits — i.e. birds of weight below a certain threshold neither performed the display nor fully developed the secondary sex traits. This constitutes evidence of cost reduction by males when expected benefits from mating are low, and is consistent with the viability‐conditioned expression of the traits.
Stages in Formation of Social Relationships — An Experimental Investigation in Kangaroos (Macropodoidea: Mammalia)
Authors: Ganslosser Udo 
Published: May 2010

AbstractA stage concept for the development of social relationships between unfamiliar individuals has been proposed by Kummer. This concept, originally derived from studies of Old World Primates, describes changes in developing relationships by types of interactive behaviour (fighting, presenting, mounting and grooming) that regularly occur in this sequence during the formation of dyads and triads. Kummer also formulated a set of rules predicting stage sequence, velocity, final stage, triadic and polyadic influences depending on individual status.The present investigation describes stages in the formation of relationships of macropodoids as well. Typical behaviour patterns for the sequence are avoidance, social exploration, aggression, one‐sided amicable behaviour, mutual amicable behaviour and in some species social play. Transition to new, especially nonaggressive stages, was found to be initiated by higher status animals. Duration, number of skipped stages, inversions (rare events!) and highest stage reached per dyad depend on the participants' status and triadic/polyadic influences, as predictable by Kummer's proposed rules.A comparison of 3 species demonstrates the influence of socio‐ecological factors that seem to be species‐characteristic. The stages can thus be used to describe not only different qualities of individual relationships but also ‘social dispositions’ sensu Mason.
Waving Display in Females of Uca polita and of other Australian Fiddler Crabs
Authors: von Hagen Heinrich‐Otto 
Published: May 2010

AbstractSince 1979 it is known that, in Australian species of Uca, female waving exists in addition to usual male display. The present paper deals mainly with female waving in U. polita studied in Darwin (North Australia). A few remarks on U. dampieri, U. vomeris, U. seismella and U. hirsutimanus are added. The species mentioned are members of two species groups or subgenera, which characterizes female waving as an ancestral (plesiomorph) trait.Frame by frame analysis of film sequences (open air shots) indicate homology of movements in the two sexes of U. polita. As in males, waving of females can be combined with locomotion on radial paths starting from the burrow entrance and the display is performed in series with a corresponding number of gestures. Unlike males, waving females mostly use both their chelipeds and tend to show shorter durations with regard to many of the waving parameters chosen. However, significant differences refer only to a limited number of parameters.The biological context of female waving was gathered from films and field observations. High intensity waving is released by conspecifics approaching from far (wanderers without burrows) and from the neighbourhood. Typically, only females and small males elicit high intensity display in a resident female. Waving normally stops in presence of larger males, especially of the male living in a resident breeding unit with the female in question.In spite of this, a pure agonistic (defensive) character of female waving is unlikely. Advertising of breeding condition seems to play a role similar to that in males. The few displaying females that exist in a given colony (about 2.5% in U. polita) show signs of special sexual excitement: brightening of carapace colours and sometimes spontaneous performance of waving, i.e. display immediately after emergence from the burrow in absence of any conspecific.
Population Differences in Responses of Fathead Minnows (Pimephales promelas) to Visual and Chemical Stimuli from Predators
Authors: Mathis Alicia , Chivers Douglas P. , Smith R. Jan F. 
Published: May 2010

AbstractFathead minnows (Cyprinidae: Pimephales promelas) from a population that is sympatric with predatory northern pike (Esocidae: Esox lucius) exhibited a fright reaction to the visual stimulus of a live northern pike significantly more often than minnows from a population that is allopatric with pike. The fright response included increased use of shelter, dashing and freezing. Minnows from the pike‐sympatric population also exhibited a significantly greater fright response, measured as a reduction in activity, following exposure to chemical stimuli from pike (i.e. water from a tank that had contained a pike) than did minnows from the pike‐allopatric population. There was no significant change in activity by minnows from either population following exposure to chemical stimuli from nonpiscivorous peacock gudgeons (Eleotridae: Tateurndina ocellicauda), suggesting that the difference between the two populations is specific to stimuli from pike rather than a general difference in response to chemical stimuli from heterospecific fishes. Fathead minnows apparently utilize at least a two‐tiered predator recognition system that incorporates both visual and chemical cues.