bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal Aggression in Red Swamp Crayfish (Procambarus Clarkii, Girard): the Relation Between Reproductive Status and Outcome of Aggressive Encounters With Male and Female Conspecifics
Authors: Figler Michael H. , Twum Maxwell , Finkelstein James E. , Peeke Harman V.S.
Published: April 2008

A series of experiments investigated intraspecific aggression by maternal (carrying eggs and/or hatched young) and non-maternal female red swamp crayfish (Procambarus clarkii) residents against intrusions by non-maternal female and Form I (reproductively active) male conspecifics. Each resident occupied an aquarium containing a shelter for 24 hours prior to the initial intrusion. The winner of each encounter was determined, as well as the pair member that initiated the aggressive interaction, and the relation between the initiation of aggression and contest outcome. The results showed that: (1) Maternal female residents were winners in 92% of the encounters with male intruders, and initiated aggression in a significantly higher proportion of encounters than the male intruders. (2) Maternal female residents were the winners in 75% of the encounters with non-maternal female intruders. The maternal residents also initiated aggression in a significantly higher proportion of the encounters than the non-maternal intruders. (3) Non-maternal female residents lost 77% of the encounters with non-maternal intruders. Also, the non-maternal intruders initiated aggression in a significantly higher proportion of the encounters than did the non-maternal residents. (4) Non-maternal female residents lost all of their encounters with male intruders. However, there was no significant difference in the proportion of the encounters in which aggression was initiated by residents or intruders. (5) For all experiments combined, maternal residents won a significantly higher proportion of their encounters than did non-maternal residents, regardless of whether the intruders were males or non-maternal females. (6) For the three experiments combined, the initiation of aggression reliably predicted contest outcome (i.e. the initiator of aggression ultimately won). The present results provide the first empirical demonstration, with appropriate non-maternal controls, of maternal aggression in decapod crustaceans. Also, the direct relation between reproductive status and contest outcome in both ovigerous and post-hatch P. clarkii are the first such data reported in crustaceans, in general. Finally, the findings of these experiments bear notable similarities to the results of maternal aggression research in other taxonomic groups.
Female Choice in the Midwife Toads (Alytes Obstetricans and a. Cisternasii)
Authors: Márquez Rafael
Published: April 2008

A previous study reported that large males had greater mating success than small males in two species of midwife toads. A behavioural mechanism that would explain such a pattern is sought. Dominant frequency is inversely correlated with male size in Alytes obstetricans and A. cisternasii. In both cases, two-speaker playback tests with synthetic calls show that females have a significant preference for calls with low frequencies. The results shows that female preference may impose directional sexual selection upon a static acoustic character that is correlated with male size. Male Alytes tend their eggs on land, but male size is not correlated with hatching success. Therefore female preference for larger males does not appear to directly increase female fitness.
Reproductive Isolation Among Lateral Plate Phenotypes (Low, Partial, Complete) of the Threespine Stickleback, Gasterosteus Aculeatus, From the White Sea Basin and the Kamchatka Peninsula, Russia
Authors: Ziuganov Valery V.
Published: April 2008

Reproductive isolation was investigated among sympatric lateral plate morphs of threespine stickleback from the White Sea basin and also among phenotypically similar morphs from the distant Kamchatka River basin (Lake Azabachije). Female choice tests show that gene flow is restricted among the completely plated and low plated morphs at both locations; behavioural isolation between these morphs is complete among Lake Azabachije fish, and nearly so (93% positive assortative mating) among White Sea basin fish. However, the experiments also demonstrate that there are no barriers to reproduction among the Azabachije and White Sea complete morphs, among the Azabachije low and White Sea complete morphs, nor among the Azabachije complete and White Sea low morphs. In addition, there is no evidence of barriers to gene flow among the low and partially plated morphs. Therefore, although gene flow is restricted among the extreme morphs within each locality, nevertheless gene exchange is possible, either directly or secondarily, among all phenotypes. The reproductive isolation between the complete and low morphs from the White Sea basin developed in situ no more than eight generations after the sticklebacks were introduced into an isolated freshwater pond. Therefore behavioural isolation can evolve very rapidly among the lateral plate phenotypes of Gasterosteus aculeatus.
Stability of Social Status in Wild Rats: Age and the Role of Settled Dominance
Authors: Berdoy Manuel , Smith Pete , Macdonald David W.
Published: April 2008

One way of understanding the evolution of social dominance is to establish which factors determine an animal's ability to dominate conspecifics. The dynamics of dominance between 20 adult male wild rats were investigated in a multi-generational, free-breeding colony in a large outdoor enclosure. Dominance relations between the adult males were stable and organised in a near-linear hierarchy. Dyadic interactions not fitting the social hierarchy, as well as challenges by subordinates and overt aggression by dominants were rare (< 5%) and principally occurred between animals of similar social rank. The correlates of social status within the colony show, for the first time in adult small mammals, that despite the significant role of body weight on the probability of winning contests, age was the most reliable indicator of adult dominance, with the higher ranking males being older but not necessarily heavier. Age also explained the outcome of 85% of agonistic encounters between dyads, compared with 65% for weights. The proximate mechanisms of age-related dominance fit better the 'previous outcome' hypothesis than the alternative 'fighting skill' or 'site dominance' hypotheses. The stability of dominance relations and the role of age, which in stable groups is equivalent with time spent in the colony, suggest that rats remain dominant over individuals that they have beaten in the past, long after initial body weight asymmetries have disappeared. The functional significance of the acceptance of subordinate social status is consistent with the fact that dominant individuals generally could not monopolize food resources or mates.
Tool-Set for Termite-Fishing By Chimpanzees in the Ndoki Forest, Congo
Authors: Suzuki Shigeru , Kuroda Suehisa , Nishihara Tomoaki
Published: April 2008

Observations strongly indicate chimpanzees (Pan troglodytes troglodytes) of the Ndoki forest use two types of tools, 'perforating sticks' and 'fishing probes' in combination for termite (Macrotermes muelleri) fishing. Perforating sticks were always made of small, stout branches or young saplings of Thomandersia laurifolia (Acanthaceae), about 10 mm in diameter, with lengths of about 50 cm. Fishing probes were made from the flexible stems of Marantaceae species, and were about five mm in diameter, with lengths of about 50 cm. Approximately 15 cm of one end of the tool was usually shaped into a brush. It is likely that chimpanzees make small holes in the termite mound wall to attain access into the termite nest inside, then they insert the probe into the holes and eat the major and minor soldier termites which bite the brush-like end. Of 214 chimpanzee feces collected, 50% contained termite remains of this species, and this fecal analysis shows that termite-eating behavior occurred all the year around, and did not correspond to the seasonality of rainfall or termite activity on the ground. Chimpanzees in the Ndoki forest seem to be able to obtain termitcs from the deep subterranean nest throughout the year by using their tool-set. Such a tool-set might be responsible for the higher frequency of termite-eating in Ndoki chimpanzees than those of chimpanzees in other sites who fish for termites using only probes. This newly described behavior shows that chimpanzees habitually manipulate a tool on an object which they previously modified with another type of tool.
Differential Costs of Locational and Social Dispersal and Their Consequences for Female Group-Living Primates
Authors: Isbell Lynne A. , Van Vuren Dirk
Published: April 2008

Individuals that disperse may leave familiar conspecifics (social dispersal), a familiar home range (locational dispersal), or both. Social and locational dispersal are not necessarily coincident in group-living animals. Here we differentiate among some potential costs of both social and locational dispersal in group-living mammals, including aggression from strangers and unfamiliarity with new habitats. As an example of the utility of distinguishing between social and locational dispersal, we examine patterns of female transfer in Old and New World anthropoid primates. The results suggest that in Old World primates, female transfer is more likely to be frequent in populations without female aggression between groups. In anthropoid primates, female transfer is more likely to be frequent in populations in which home ranges of groups overlap extensively with those of other groups. Female transfer between groups in Old World, but not New World, primates appears to be more common when females suffer few or no costs of social and locational dispersal. We suggest that when there are few, if any, costs of social and locational dispersal (inferred from moderate to extensive home range overlap and the absence of aggression between groups of females), female transfer in Old World anthropoids will be obligate when groups of females cannot be monopolized by a single male and conditional upon the behavior of individual males when groups of females can be monopolized by a single male. When costs of social and locational dispersal exist (inferred from minimal home range overlap and aggression between groups of females), female transfer will be conditional upon competition with other females in their groups.
The Role of Aggression in Song Tutor Choice in the Zebra Finch: Cause or Effect?
Authors: Jones A.E. , Slater P.J.B.
Published: April 2008

Young male zebra finches (Taeniopygia guttata) normally copy their song from one tutor when given a choice of two. Interaction is known to be a key feature of the learning process and this study examines the way in which one particular type of social behaviour, aggression, may affect tutor choice. Female raised zebra finches were given a choice of two song tutors, which had been pre-selected for differing levels of aggression, during the sensitive phase for song learning. A young bird was significantly more likely to learn from the tutor that was more aggressive to him, as found earlier by Clayton (1987). In addition, behavioural observations suggest that aggression towards the young bird was the cause rather than an effect of tutor choice. There was no significant relationship between the relative level of tutor aggression and the amount of his song copied. Changes in the level of aggression over the tutoring period are also discussed.
Male Mate Choice in a Natural Population of the Parasitic Copepod Lernaeocera Branchialis (Copepoda: Pennellidae)
Authors: Heuch Peter Andreas , Schram Thomas A.
Published: April 2008

Variations in age and sex structure of a natural population of the copepod Lernaeocera branchialis, parasitic on flounder, Platichthys flesus were examined in a 15-month study. Recent laboratory studies and literature on reproductive strategies indicate that male mate choice in this species should depend on the sex ratios of the parasite on its hosts, and on the age and mating status of females. Sex ratios suggested a strong intra-male competition for females. The ratio of chalimus 4 and virgin adult females (preferred stages) to adult males exceeded 1 female: 4 males on 50% of the hosts. In four out of the six sampling periods, more than 50% of hosts harboured more adult males than the total number of females. The males preference for the different female stages was estimated from the number of precopula and copula associations. The data were fitted to a logistic regression model. At most sex ratios, males preferred chalimus 4 and virgin adult females, and discriminated against younger stages. Mated females were about as attractive as the youngest larval stages at female-biased sex ratios, but they were chosen more frequently at strongly male-biased sex ratios. Most adult L. branchialis females had copulated more than once, and some had accommodated at least 5 ejaculates in the their sperm storage organs. The patterns of mate guarding and potential for sperm competition strongly suggest that L. branchialis males take the intrasexual competition into account when choosing mates. On this basis, they minimize guarding time and maximize the possibility of paternity.
Nest Defence By Yellow Warblers: Recognition of a Brood Parasite and an Avian Nest Predator
Authors: Gill Sharon A. , Sealy Spencer G.
Published: April 2008

Yellow warblers (Dendroica petechia) were exposed to taxidermic mounts of a brood parasite (brown-headed cowbird, Molothrus ater), avian nest predator (common grackle, Quiscalus quiscula) and control (fox sparrow, Passerella iliaca) during their laying and nestling stages to determine whether nest owners distinguish between the threats of brood parasitism and predation. Yellow warblers responded more intensely to the cowbird at the laying stage, performing two unique behaviours (seet calling and nest-protection behaviour) in response to this threat. By contrast, yellow warbler responses to the grackle were greater at the nestling stage, consisting largely of alarm calls (chip, metallic chip and warble calls). The sparrow model infrequently elicited aggressive behaviour from nest owners at either stage. These responses support the hypothesis that yellow warblers discriminate between threats of brood parasitism and nest predation. Yellow warblers may perform specific behaviours to cowbirds because defensive behaviours used against predators may be incompatible with cowbird deterrence. Female nest owners responded more frequently than males at the laying stage, and more intensely than males at both nesting stages. The distance that females and males approached the models and several aggressive behaviours were positively correlated. The greater responsiveness of females may be because they dominate their mates and because females are more experienced with intruders near the nest.
The Effects of Inbreeding On Aggression in Wild Male House Mice (Mus Domesticus)
Authors: Eklund Amy
Published: April 2008

This study examined the effect of inbreeding on aggression levels and competitive ability in wild male house mice. Wild mice were bred in the laboratory to produce males of three levels of inbreeding: male offspring of unrelated parents, male offspring of first-cousin parents, and male offspring of full-sibling parents. Paired encounters were staged between males of the three offspring groups, when the males reached maturity. Less inbred males won more encounters and tended to have higher scores of aggression level than more inbred males. If competitive ability in the laboratory is related to competitive ability in nature, wild mice from this population may benefit from avoiding inbreeding and the consequent decrease in aggression levels and competitive ability.
Ontogeny of Action Syntax in Altricial and Precocial Rodents: Grooming Sequences of Rat and Guinea Pig Pups
Authors: Colonnese Matthew T. , Stallman Elizabeth L. , Berridge Kent C.
Published: April 2008

Behavior occurs as coordinated patterns of serial order, with rules of 'action syntax'. Grooming behavior of adult rodents provides several striking examples of action syntax rules. The most stereotyped of these is a 'syntactic chain' pattern, which organizes up to 25 facial strokes and licking movements into a predictable sequence. This pattern previously has been found to be emitted by diverse rodent species from all major suborders: myomorph, sciuromorph, and caviomorph. In this study, we compared the postnatal ontogeny of grooming syntax in two rodent species: rat versus guinea pig. Rats are relatively altricial at birth, whereas guinea pigs are precocial. A day-by-day study of the fine-grain structure of sequential patterns was carried out during the first three weeks after birth, using slow-motion videoanalyses and a choreographic notation system for scoring behavioral grooming sequences. The results showed that substantial action syntax rules exist in guinea pig grooming even on the day of birth. For guinea pigs, postnatal grooming syntax development was limited to minor increments in the strength of the syntactic pattern and in postural control. By contrast, for rat pups, action syntax did not begin to appear until the second postnatal week, and developed gradually into the third week. The development of rodent syntactic patterns in both species appeared to be independent of the maturation of the movements that composed the pattern. Our results indicate that action syntax rules develop as hierarchical entities independent from constituent movements.
Sexual Imprinting in Female Zebra Finches: Changes in Preferences as an Effect of Adult Experience
Authors: Oetting Sabine , Bischof Hans-Joachim
Published: April 2008

It has been shown that sexual imprinting in male zebra finches can be seen as a two stage process with an early acquisition period, where a sexual preference is established, and a consolidation process, where the early acquired preference is linked to sexual behaviour and stabilized. The consolidation process can, by the appropriate experimental design, be delayed until adulthood. In the course of consolidation, the initial preference for the foster species can be altered by exposure to a female of another species. Our results indicate that sexual imprinting in females is also a two stage process. In contrast to males, the consolidation period, at least under the experimental design used in this study, is longer than that obtained for males. It is speculated that the speed of consolidation could be enhanced by additional stimuli influencing female mate choice, as for example breeding facilities.
The Evolution of Hornedness in Female Ruminants
Authors: Roberts S.C.
Published: April 2008

Females of many ruminant species possess horns or hornlike organs, but their precise function remains largely unclear. In this paper, four previous explanations for female hornedness are compared with a new hypothesis, the Female Competition Hypothesis, which suggests that horns initially evolved for reasons of intrasexual competition for resources with con-specifics, the level of competition being correlated with female group size. Each hypothesis is first reviewed and necessary predictions arising from each are generated. In order to test between these hypotheses, the incidence of female hornedness across the ruminants is then examined using a comparative method which takes account of the evolutionary history of each species, in order to control for effects of phylogenetic correlation. Group size and body size are found to be the only variables which predict hornedness successfully; however, when the influence of the other predicting variable is removed, only group size remains as a significant predictor. This analysis is found to support the Female Competition Hypothesis and is shown to be robust both in relation to adjustments in phylogenetic construction (e.g. the position of Aepyceros and Boocerus) and to intraspecific variation in horned condition (e.g. horned and hornless races of Oreotragus).
Parental Care and Polygyny in the Chiffchaff Phylloscopus Collybita
Authors: Rodrigues Marcos
Published: April 2008

The males of most bird species help to raise the young, and females may suffer costs from polygyny because of having to share the male parental care. In the chiffchaff (Phylloscopus collybita) nests of monogamously and polygynously mated females had similar success in relation to the proportion of fledged young. Overall, male chiffchaffs provided little assistance to females during the nestling period, but they increased help when the young left the nest. Females who choose already-paired males (secondary females) incurred lower reproductive success, because they were unable to start a second brood after raising their first brood. Primary and monogamous females which received male help in the form of food provisioning during the fledgling period were more likely to attempt a second brood. This is the first study that reports associated costs to secondary females due to the lack of paternal aid after the young have fledged the nest. However, secondary females still can obtain compensatory benefits, as predicted by the polygyny threshold model, since most of them settled in good quality habitats, close to the primary females.
The Influence of Siblings On Wild Infant Chimpanzee Social Interaction
Authors: Brent L. , Bramblett C.A. , Bard K.A. , Bloomsmith M.A. , Blangero J.
Published: April 2008

The presence or absence of older siblings influenced the social interactions of 17 wild infant chimpanzees between the ages of 6 and 24 months living at the Gombe National Park, Tanzania. The total amount of time spent in social interaction (contact, grooming and play) was similar for infants with and without siblings, as was the overall level of social interaction with the mother. However, subjects with siblings spent more time with their siblings, while subjects with no siblings interacted with other group members. These results indicate a possible set-point for infant chimpanzee social interaction. Developmental changes were also similar in both groups, but the infants with siblings had lower levels of interaction with the mother and higher levels of interaction with other group members during the age period of 12-18 months. The levels of social behaviors were not related to the sex of the infant.
Ontogeny of Diving Behaviour in the Galápagos Fur Seal
Authors: Horning Markus , Trillmich Fritz
Published: April 2008

We studied the ontogeny of diving behaviour in the Galápagos fur seal (Arctocephalus galapagoensis, Heller 1904). Six-month-old seals spent less than 12% of observation time at sea and were entirely dependent on maternal milk for nutrition. Maximum dive depths for this age group averaged 5.6 m, maximum durations 50 s (N = 12). Modal swim speeds averaged 0.55 m/s; maximum observed swim speeds ranged from 0.9-2 m/s (N = 5). Six-month-old seals swam distances of 2.9 km/24 hrs on average (N = 5). No diel patterns were apparent in their diving behaviour. One-year-old fur seals were the youngest age group to show substantial diving activity, reaching maximum depths of 47.5 m and durations of 2.4 min on average (N = 21). Modal swim speeds averaged 0.9 m/s, maximum speeds ranged from 1.4-2.3 m/s (N = 6). Total distances traveled averaged 15.4 km/trip to sea. Yearlings spent 23.9% of observation time at sea, the majority (> 95%) of that at night. This corresponds to the activity pattern of adult females who dive exclusively at night. Yearlings were the youngest age group to contribute to their own nutrition through independent foraging, but were still dependent on their mothers: no yearlings were successfully weaned in this study. 18-month-old seals were better divers, spending 27.6% of observation time at sea, mostly during the night. Maximum dive depths for this age group averaged 61.1 m; durations 3.1 min (N = 11). Modal swim speeds averaged 1.4 m/s (N = 4), and were comparable to modal speeds of two adult females of 1.2 and 1.6 m/s. Maximum speeds for these juveniles ranged from 2.2-2.7 m/s (N = 4); the two adult females reached 2.8 and 4 m/s respectively. Total travel distances averaged 42 km/trip to sea (N = 4 juveniles). These distances corresponded to those covered by two adult females, 43 and 45 km/trip. Two-year-old fur seals included the youngest that were successfully weaned in this study. They spent 35% of observation time at sea, primarily at night. Maximum dive depths averaged 69.7 m, durations 3.4 min (N = 20). Adult females were the best divers in this study, spending 49.5% of observation time at sea, almost exclusively at night. Maximum dive depths averaged 106.5 m, durations 4.5 min (N = 32). During ontogeny, age was the best predictor of time spent at sea. For animals older than six months, body mass was the best predictor for maximum dive depth as well as maximum and median durations. The physiological maturation process precludes weaning before the age of one year. After that, the diving capacity of young fur seals takes a central role in the weaning process, in conjunction with the temporal patterns of relative prey accessibility.
An Experimental Study of Cache Recovery By Hoarding Willow Tits After Different Retention Intervals
Authors: Brodin Anders , Kunz Camilla
Published: April 2008

We allowed seven willow tits, Parus montanus, to store and retrieve with retention intervals of 1, 7, 21 and 56 days, in four experimental rooms. Retrieval success decreased over time, indicating a decaying memory for cache locations. Compared to what could be expected by chance, retrieval success was better after all retention intervals. Our results suggest that - after the longer retention intervals - this might depend on preferences for certain types of caching locations rather than memory. If both general and individual preferences are controlled for, birds retrieved significantly better than expected one and seven days after storing, but not later than that.
Song Rate Correlates With Paternal Care and Survival in Willow Tits: Advertisement of Male Quality?
Authors: Welling P. Petteri , Rytkonen Seppo O. , Koivula Kari T. , Orell Markku I.
Published: April 2008

Dawn song in birds may advertise male quality in terms of parental care and/or survival. Males who sing most may also be the best parents, and eager singing may also reflect good chances of a male's or his mate's survival. These relationships were studied in the willow tit Parus montanus, a species with a simple and relatively non-variant song. Song output was expressed as the proportion of time a male spent singing at dawn. Later in the breeding season, two aspects of parental care, nest defence and feeding effort, were measured in the same males. High song output was associated with more intense nest defence behaviour (eager singers attacked the predator model more often and approached closer to it) and high nestling feeding effort. However, reproductive success was not associated with song output, although males with high song rates tended to be more likely to produce recruits. Males who survived to the next year had higher song intensity than males who did not survive, while female survival was not correlated with song output of her mate. The results suggest that dawn song in the willow tit advertises male quality. Some aspects of honest advertisement and female choice are discussed.
Song Tutoring Influences Female Song Preferences in Domesticated Canaries
Authors: Nagle Laurent , Kreutzer Michel L.
Published: April 2008

Laboratory experiments were designed to examine the influence of previous acoustic experience on later song preferences in female domesticated canaries (Serinus canaria). Young females were reared in acoustic isolation (five groups). In these five groups, one was reared without tutoring and four were exposed to taped tutoring songs (playbacks of three different songs, two conspecific and one heterospecific). One of the four tutored groups was exposed to all three songs, while each of the remaining groups was exposed to one of the three songs. When adult, all females were tested using copulation solicitation displays as an index of their song preferences. We demonstrated that females reared without tutoring were especially responsive to a particular domesticated canary song. This song contained a special song phrase type (Vallet & Kreutzer, 1995) that elicits high levels of sexual response. In general, a similar preference was also observed in the groups reared with tutoring. In addition, the females' preferences in tutored groups were also positively and strongly affected by conspecific songs, when these songs had been heard during the previous tutoring. In fact, females seemed to be able to selectively respond to a song containing a special song phrase, but were also able to learn conspecific songs.
Effects of Pair Bond and Presence of Conspecifics On Singing in Captive Zebra Finches
Authors: Dunn Andrew M. , Zann Richard A.
Published: April 2008

Undirected Song is commonly performed in wild and captive zebra finches and is typically given by males partly isolated from other members of the flock or colony. It has no territorial function nor it is used during precoital courtship; its frequency varies strongly among individuals. However, its rate of performance is severely limited by the close proximity of conspecifics, and this study investigated what social factors are responsible for this constraint in first-generation offspring of wild-caught zebra finches. The close presence of females caused a greater reduction in singing than did that of males. Familiarity between companions and the singer was also a factor that reduced the rate of singing. The more familiar the singer became with a female the more often he would sing in her presence, whereas the opposite occurred with males - singing was more prevalent with strangers than with familiar companions. Pair formation reduced a singer's sensitivity to inhibitory factors associated with the close proximity of conspecifics. Simple visual and auditory contact with a conspecific was not sufficient to constrain Undirected Singing, but intense, close range interactions appear to be necessary. It is hypothesised that Undirected Singing is used to attract females for pair formation or extra-pair mating, but the close proximity of male companions and/or the mate hampers this. However, in a competitive mate choice experiment there was no significant correlation between the rate at which a male gave Undirected Song and order of the pair formation. This suggests that Undirected Singing may not be crucial in the ultimate choice of a mate, but it may still be a useful cue at the outset of pair formation.
Female Choice of Males in Cuttlefish (Mollusca: Cephalopoda)
Authors: Geary Boal Jean
Published: April 2008

In captivity, male cuttlefish use visual displays to establish size-based dominance hierarchies and larger males obtain most of the copulations. This experiment was performed to determine if females prefer the larger, more dominant males and whether females use male visual displays to evaluate males. Twenty sexually mature, virgin female cuttlefish were given up to six opportunities to approach one of two males out of a pool of ten adult males, or to approach neither. Females did have significant preferences between males, but they were not related to male dominance. Females showed a consistent and significant preference for the more recently mated male. These preferred males were also more likely to mate again, when given the opportunity, than were less-preferred, less-recently mated males. Females also preferred males that showed fewer zebra displays. Viewing male-male interactions did not affect their choices. Results suggest that female preference could be based on chemical cues, while visual displays may function primarily as agonistic signals. Females who mated did so repeatedly before laying eggs, providing opportunity for sperm competition.
The Interpretation of Animal Psychology: Anthropomorphism or Behavior Reading?
Authors: Mitchell Robert W. , Hamm Mark
Published: April 2008

A perennial problem in the study of behavior has been the basis for anthropomorphic psychological terminology. Research has suggested that people use a nonhuman animal's perceived similarity to humans based on physical likeness, familiarity, phylogeny, and/or cultural stereotype to characterize it psychologically. One further hypothesis is that people use an animal's behavior-in-context to determine its psychological characterization. These diverse hypotheses were evaluated by providing undergraduates with narratives depicting mammalian (including human) behavior suggestive of jealousy or deception, and asking them to evaluate their degree of agreement or disagreement with particular psychological characterizations of the animal described. Narratives varied the species, the context in which a mammal's behavior occurred, and how strongly it was emphasized that the narrative was about a nonhuman (or human) organism. Species varied in their physical similarity, phylogenetic closeness or familiarity to humans, and/or cultural stereotype as human-like; behavior remained constant in all narratives. In general, variations in the context in which behavior occurred influenced psychological characterization, but variations in species and emphasis did not: psychological characterizations of all species were almost always similar. Nonscientists (and some scientists as well) apparently use a mammal's behavior-in-context (whether human or not) as evidence of its psychological nature, regardless of the mammal's physical similarity, familiarity, or phylogenetic closeness to humans, or the mammal's cultural stereotype; psychological terms are not used specifically for humans, but rather are depictive of behavior-in-context. Psychological terms set the stage for further investigation into an organism's psychological abilities; calling such terms 'anthropomorphic' inaccurately implies that they are extrapolated from human behavior, when they appear to be applicable to particular behavior-in-context, independent of the species behaving.
Female Activity Profile of a Polygynous Lizard (Anolis Carolinensis): Evidence of Intersexual Asymmetry
Authors: Nunez Steven C. , Jenssen Thomas A. , Ersland Kasey
Published: April 2008

1. The activity profile of free-ranging individuals should reflect how females and males are optimizing their respective reproductive efforts. By using the polygynous, sexually dimorphic lizard, Anolis carolinensis, we expected to find an example of pronounced intersexual asymmetry in daily activity patterns. 2. In contrast to males who should focus on blocking consexual access to resident females, we expected females to strategically facilitate egg production by minimizing conspicuous and unnecessary behavior, while feeding frequently from a defended food resource optimal to their needs. 3. During a 56 day period, we made a 90 h record of focal animal observations on 22 unmanipulated, reproductive females; then we compared this activity profile to a known profile for males. We found the following. 4. Females were 1.6 times more stationary (82% of day), moved 1/7th the distance (< 40 m/day), displayed at 1/8th the overall rate (< 14 displays/h), and used < 1/35th the number of displays in non-directed advertisement (1.6 displays/h) as males. 5. Females spent 1/30th the time (0.3% of day) in overt defense of territories 1/9th the volume (8 m3) as males. 6. However, both females and males had equivalent feeding rates (1.2 times/h), suggesting that the energetic needs of female egg production and male territorial maintenance are comparable. 7. The small, lightly defended territories and low feeding rates of females (along with their reptilian metabolism and insectivorous diet) indicate that females have a wide latitude in which to meet their energetic costs. 8. As expected, the proportion of intersexual contacts was similar between female and male profiles. Courtship and copulations occupied 3.2% and 3.9% of the females' day, respectively, with copula averaging 26 min in duration. 9. In a female activity profile which de-emphasized conspicuousness, we found little evidence for a pheromone-based alternative to visual signalling. 10. Predation, as an immediate threat to lizard activities, was not seen during three months of observations. We noted only four instances of avoidance behavior.
Male-Female Social Relationships in Wild White-Faced Capuchins (Cebus Capucinus)
Authors: Perry Susan
Published: April 2008

This paper describes male-female dyadic social relationships in C. capucinus, detailing the types of costs and benefits exchanged between the sexes. A single group of wild white-faced capuchin monkeys (Cebus capucinus) was studied in Lomas Barbudal Biological Reserve, Costa Rica, for 24 months. A total of 953 hours of focal animal data were collected on 4 adult males and 6 adult females. The patterning of social interactions was studied in an attempt to assess the outcome of disputes between males and females. In dyadic interactions, females avoided and cowered to males roughly 50 times more often than males avoided or cowered to females. Females responded fearfully to 12% of males' neutral approaches, whereas males never responded fearfully to females' neutral approaches. Males supplanted
Mate Choice and Aerobic Capacity in Red Junglefowl
Authors: Chappell Mark A. , Zuk Marlene , Johnsen Torgeir S. , Kwan Timothy H.
Published: April 2008

In 'good genes' models of sexual selection, females choose mates whose genes confer increased survival value to offspring. One possible index of male quality is aerobic capacity (the metabolic basis of sustainable exercise), which is likely to be important for fitness. If it is both heritable and ecologically valuable, high aerobic capacity would be a direct signal of male genetic quality. If aerobic capacity is phenotypically plastic but dependent on health, it may provide an indirect index of male quality in other heritable traits (e.g. pathogen resistance). We examined the relationship between courtship behaviour, aerobic capacity (measured as maximum rates of oxygen consumption), and mating success in red junglefowl (Gallus gallus). We also tested the effects of intestinal parasites (the nematode Ascaridia galli) and plasma testosterone levels on aerobic capacity and behaviour. We found no relationship between testosterone and behaviour, mating success, or aerobic capacity. A. galli infection changed the relationship between mass and aerobic capacity; infected males had lower aerobic capacity than uninfected males, but only for small males. Discriminant function analysis suggested that aerobic capacity and display behaviour, together with male ornaments (comb size and colour), were the most important factors determining the mating success of males. However, aerobic capacity and display rate were not strongly correlated, and the manner by which females can discriminate among males with differing aerobic capacity is unclear.
Does Reproductive Synchrony Limit Male Opportunities or Enhance Female Choice for Extra-Pair Paternity?
Authors: Kempenaers Bart
Published: April 2008

Breeding synchrony has been suggested as one factor that might explain the variation in frequency of extra-pair paternity, both between and within species. Reproductive synchrony might limit the opportunities for males to engage in extra-pair copulations (EPCs), because males face a trade-off with guarding their own fertile partner. Alternatively, breeding synchrony may promote extra-pair paternity, because of reduced male-male competition for EPCs or because of enhanced possibilities for females to assess male quality. In this study, I investigated the influence of synchrony on the occurrence of extra-pair paternity in the blue tit Parus caeruleus. Over four years, breeding synchrony and extra-pair paternity were positively related. Within a season, extra-pair paternity occurred independently of the timing of breeding. The fertile period of the extra-pair male's social mate and that of the extra-pair female often overlapped considerably. However, males who performed EPCs during the fertile period of their social mate were not more likely to lose paternity than males who performed EPCs after the fertile period of their mate. These data suggest that breeding synchrony has little influence on the occurrence of extra-pair paternity in the blue tit.
Metastenasellus Powelli Sp. N., a New Stenasellid Isopod Crustacean From Littoral Groundwaters of Southeastern Nigeria
Authors: Magniez Guy
Published: April 2008

Contrairement à tous les autres Sténasellides, qui vivent dans les eaux souterraines continentales (grottes, nappes phréatiques, sources thermales), la nouvelle espèce a été trouvée dans la zone oligohaline du littoral, près de Port Harcourt, Nigéria. Description de Metastenasellus powelli sp. n. affinités de cette nouvelle espèce, aire géographique et diagnose rénovée du genre Metastenasellus Magniez, 1966, liste des espèces connues à ce jour.
Range Extension of Paguristes Perspicax Nobili, 1906 (Decapoda, Diogenidae) Into the Northern Arabian Sea
Authors: Tirmizi Nasima M. , Siddiqui Feroz Akhtar
Published: April 2008

Paguristes perspicax wird erstmals aus dem nördlichen Arabisch See (bei Karachi) gemeldet und ausführlich beschrieben. Die Variationsbreite wird diskutiert.
Comparative Fecundity of Four Species of Crayfish in Southwestern Ontario, Canada (Decapoda, Astacidea)
Authors: Corey Susan
Published: April 2008

La fécondité de quatre espèces d'écrevisses a été étudiée: Cambarus robustus, Orconectes propinquus, Orconectes rusticus et Orconectes airilis. Les taux de fécondité ont été respectivement pour chaque espèce: C. robustus de 25 à 128, moyenne 64,9; O. propinquus de 26 à 195, moyenne 68,5; O. rusticus de 75 à 351, moyenne 161,8; O. virilis de 29 à 195, moyenne 139,1. La dimension (diamètre) des oeufs est constante dans une même espèce, mais présente d'une espèce à l'autre les variations suivantes: 3,69, 4,55, 6,88 et 40,03 mm3 chez O. propinquus, O. virilis, O. rusticus et C. robustus respectivement. Les pentes de régression de la fécondité en fonction de la taille varient également d'une espèce à une autre; les rapports entre le volume total des oeufs et la surface ventrale de l'abdomen sont similaires, et ceci montre que la fécondité est déterminée à la fois par la taille des oeufs et la surface ventrale de l'abdomen. Les résultats présentés ici sont comparés aux données antérieures de la littérature et quelques aspects écologiques sont discutés.
Morphologie Des Soies Des Appendices Buccaux Et Des Pattes D'Un Mysidacé Cavernicole
Authors: Crouau Y.
Published: April 2008

The mouth-parths and the thoracic appendages of the cavernicolous Mysidacea Antromysis juberthiei were studied by means of scanning electron microscopy to reveal the distribution and the fine morphology of their setae; twelve types of setae are reported; they are compared to antennary setae of the same animal previously studied and to setae of other Crustacea.
Growth of Pollicipes Pollicipes (Gmelin, 1790) (Cirripedia, Lepadomorpha) On the Sw Coast of Portugal
Authors: Cruz Teresa
Published: April 2008

Pollicipes pollicipes is widely used as food and is the subject of intensive fisheries in Portugal. Since November 1990 growth of this species was studied on the SW coast of Portugal. Two kinds of methods were used: (1) individual growth: the adjacent substrata were marked with polyester resin and the organisms were mapped and measured (Rostro-Carina length=RC) every month; 2) spatial variability of allometric growth: various biometrical measures were used for animals from different habitats; the relationship between these values and the organic weight were established. The results of these analyses suggest that there are spatial (due to tide and light related factors) and temporal differences (growth rates arc higher in spring and summer) in the growth of this pedunculate barnacle. In this study RC was the biometrical variable that best represented the linear growth of this species and we recommend its use for fishery control purposes.
Juvenile Morphology and Appearance of Sexual Appendages in Two Porcellanid Crabs, Petrolisthes Rufescens (Heller, 1861) and Pisidia Gordoni (Johnson, 1970) (Decapoda, Anomura, Porcellanidae)
Authors: Paul Ravindra , Sankolli K.N. , Shenoy Shakuntala
Published: April 2008

The porcellanid crabs in their larval phase show typical anomuran features but develop a crab-like form from megalopa through the juvenile instars. However, the adult species characters are not yet noticeable in the juvenile phase thus leading to confusion in identity both at specific or even at generic level. With attainment of the crab-like form, the reproductive appendages, like male pleopods, show a brachyuran pattern. In absence of external sexual dimorphism, sex determination is difficult in this group. Very little information is available as to how and when the sexual appendages start developing in Porccllanidae. With the purpose of tracing the development of the adult taxonomic characters and that of the reproductive appendages (and sex differentiation), the present paper describes the juvenile laboratory development of two porcellanid crabs, viz. Petrolisthes rufescens (Heller) up to instar III and Pisidia gordoni (Johnson) up to instar IV. Taxonomic features: In both the species the definitive adult features like those of the carapace front and its armature, the chelipeds and other pereiopods, the sternite of the third maxillipeds, etc., develop in the third instar. Sexual appendages: (a) In Petrolisthes rufescens the primary pleopods get totally reduced at least up to instar III and, therefore, the sexual appendages appear to be developing as a secondary series of pleopods, particularly in the female. (b) In Pisidia gordoni, at least in the male, differentiation starts from instar II onwards with the first pleopod modifying into a male appendage, while the remaining pleopods gradually become reduced.
Decapod Crustaceans of the Albanian Coast
Authors: Vaso Andrian , Gjiknuri Leke
Published: April 2008

A summary of the results of the study of Albanian Decapoda is presented. Hundred-and-four species from the Albanian coast are reported here, 10 of which are new records for the country. Data on the geographical and bathymetric distribution as well as on the biotopes and abundance are presented. Species groupings are based on these data. Information about the reproductive period is given for some species.
Later Stage Larvae of Panulirus Guttatus (Latreille, 1804) (Decapoda, Palinuridae) With Notes On the Identification of Phyllosomata of Panulirus in the Caribbean Sea
Authors: Baisre Julio A. , Alfonso Irma
Published: April 2008

Larval stages VI to X of Panulirus guttatus from Cuban waters are described. The principal differences with the larvae of the other two Caribbean species of Panulirus are discussed.
Larval Development of the Spider Crab Acanthonyx Petiverii H. Milne Edwards, 1834 (Decapoda, Majidae) in the Laboratory
Authors: Hiyodo Célia Mary , Fransozo Adilson , Negreiros Fransozo Maria Lúcia
Published: April 2008

The larval development of Acanthonyx petiaerii H. M. Edwards, 1834, was studied in the laboratory through eggs hatched from ovigerous females collected in Ubatuba, state of São Paulo, Brazil. The rearings were carried out in a climatic room with constant temperature (25° ±1° C) and salinity (34,5‰). The larvae were maintained individually and the food consisted of Artemia nauplii. The larval development of A. petiverii consists of two zoeal stages and a megalopa. All the larval stages were drawn and described in detail. Tables include those presenting morphological characters that allow the identification of zoeae and megalopa of A. petiverii. A comparative study was realized with previously studied majid species that occur in southern and southeastern Brazil.
A New Mountain Slater, Ligia Taiwanensis (Isopoda, Ligiidae) From Taiwan
Authors: Lee Jeng-Di
Published: April 2008

A new oniscoid, Ligia taiwanensis, from a mountain stream in southern Taiwan is described.