bluuebunny/crossref_metadata_2025 huggingface dataset:
Cooperative Interactions and Environmental Control in the Intertidal Clustering of Nerita Textilis (Gastropoda; Prosobranchia)
Authors: Chelazzi G. , Deneubourg J.L. , Focardi S.
Published: April 2008

1. Somalian populations of the intertidal gastropod Nerita textilis Gmelin show a vertical separation between resting (mid-upper eulittoral) and feeding (lower eulittoral) zone. During high tides and mostly diurnal low tides some snails remain scattered (SF), while other form aggregations (AF) at lower levels of the rocky shore. During the mostly nocturnal low tides both SF and AF migrate downward to feed on microalgae. 2. Lower and upper aggregations are mostly frequented around neap (NT) and spring tides (ST), respectively. Clustering significantly reduces the exposure to waves during high tide, and probably overheating and dehydration during diurnal low tide. 3. About 90 percent of the total population enters into the cluster system throughout each NT-ST-NT cycle. Clustering begins to increase at NT and falls at ST, reaching a maximum (52 percent of the population) between NT and ST. The relative frequency of transition between SF and AF shows a spike after NT and falls after ST. The inverse transition (AF to SF) is negatively correlated to the amount of AF. 4. Return to the original cluster after one feeding excursion is high (76 percent) and decreases slightly at increasing intervals (about 40 percent after 14 feeding migrations), but it becomes significantly lower after one or more rest phases spent in SF. 5. The field study suggests that the periodical (NT) increase in density at the lower rest-zone (tide-pools belt), long-lasting chemical marking of collective rest sites and releasing mucus trails during feeding excursions cause the clustering. According to this hypothesis, a primer group stops at each aggregation site at NT, mostly returning to it by self-trailing after each feeding migration, while the progressive recruitment of snails from SF is caused by the interindividual trail-following during the return migration from the feeding ground. 8. The same model can explain the clustering behaviour of other intertidal gastropods, though the importance of the different parameters (periodical variation in zonation, marking of rest places, trail-following) probably vary among the different species.
The Occurrence, Context and Functional Significance of Aggressive Begging Behaviours in Young American White Pelicans
Authors: Cash Kevin J. , Evans Roger M.
Published: April 2008

Aggressive behaviours occurring in association with about 90% of all feedings developed in American white pelican chicks approximately three weeks old. These behaviours involved aggression directed toward self (Convulstion) and other young (Aggression). Observation of feedings revealed that: (1) when both Convulsion and Aggression occurred before or after a given feeding, convulsion bore a closer temporal relationship to the feed itself than did Aggression, (2) the frequency of both Aggression and Convulsion prior to feeding increased as the length of the begging bout increased, (3) the frequency of Convulsion and Aggression following feeding was not related to the duration of the feed but did depend on the amount fed (as measured by throat distension). Observations of identifiable parents and chicks revealed that most chicks receive a single feeding each day, each parent returning to the colony every two days. The frequency of multiple feeds given to the same chick on the same day or (by the presumed same parent) two days later was not related to the frequency of Aggression or Convulsion given after a feeding. The close association of these displays with feeding and low-intensity begging suggests that they function primarily as begging displays or, for Aggression, to drive other young away from the parent food source. Evidence suggesting that Convulsion may be a manifestation of parent-offspring conflict is discussed. Alternative proposed functions of Convulsion and Aggression are not supported by data collected in this study.
Rutting Behavior in African Elephants: the Phenomenon of Musth
Authors: Poole Joyce H.
Published: April 2008

1. The physical and behavioral characteristics and the temporal patterning of musth were studied over a ten-year period in a free-ranging population of African elephants. 2. Males spent more time in association with females during musth than during non-musth periods. 3. Males were more aggressive during their musth periods than during non-musth. 4. The occurrence and duration of musth were age-related: no male under 24 years was seen in musth; bouts of must among younger individuals were short and sporadic, while older males experienced longer more predictable periods of musth on an annual basis. 5. Although males in musth were observed year-round, the frequency of musth males was highest during and following the two rainy seasons and, in general, good rainfall years had higher frequencies of males in musth than did poor rainfall years. 6. The number of males in musth per month correlated closely with the number of females observed in estrus. However, since the period of estrus lasts only four to six days (Moss, 1983), while musth may last several months, the onset of musth was not necessarily triggered by the onset of estrus in a particular female. 7. The musth periods of different males were asynchronous and each male came into musth at a specific time of year. This period was relatively consistent from one year to the next, particularly among the older males. 8. Males in musth advertised their heightened sexual and aggressive state through visual and olfactory signals and by vocalizing. It is suggested that these signals function to announce identity, condition and location to both rival males and to potentially receptive females. 9. The physical and behavioral characteristics and temporal patterning of musth in African and Asian elephants are compared and found to be remarkably similar. 10. The physical and behavioral manifestations of musth in elephants are similar to those described for other male mammals during rut. Since estrus in female elephants is less clumped relative to most ungulates, male elephants have a different temporal pattern of rutting. Although the musth periods of male elephants are asynchronous the phenomenon can functionally be considered a rutting period.
Temporal and Structural Analysis of Affiliative Vocal Exchanges in Squirrel Monkeys (Saimiri Sciureus)
Authors: Masataka Nobuo , Biben Maxeen , Symmes David
Published: April 2008

Affiliative, aggressive, and vocal behaviors were observed in a group of five adult female squirrel monkeys. Affiliative partner preferences were correlated with use of the chuck vocalization. Mutually preferred partners exchanged chucks more often and with shorter latencies of response. Animals with few affiliative contacts were more likely to repeat themselves, and to obtain responses at longer latencies. Chuck exchanges neither follow nor precede changes in nonvocal behavior. Structural differences associated with the position of a chuck within a sequence were found. The peak frequency attained by several acoustic features of chucks was higher in chucks that followed closely another chuck compared with chucks that followed a silent period. We have termed these vocalizations "answer" and "question" chucks respectively. Among answer chucks, those that terminate an exchange have higher peak frequencies than those that become part of a longer sequence. These results are viewed as evidence for flexible use of signals in an exclusively linguistic context, and may be an example of categorical prosody.
Distribution and Variability of Song Types in the Wood Thrush
Authors: Whitney Carl L. , Miller Joan
Published: April 2008

Compared to the song of other oscine species, wood thrush song shows little macro-geographical variation: 1) Most song types defined for a local population are widespread over the geographical range, 2) the relative abundances of different song types are similar in samples taken from different locations, and 3) a given song type is no more variable in structure over the geographical range than within a local population. Wood thrush song also shows little microgeographical variation. The degree of song type sharing does not vary as a function of the distance between males in a local population. Song remains stable over time in a local population, as indicated by a similarity in the relative abundances of song types in samples taken 14 years apart. Regarding the distribution of song types among repertoires, 1) Different combinations of song types within repertoires occur no more or less often than expected by chance, 2) different versions of a single song type are distributed at random among repertoires, 3) large repertoires do not contain a greater proportion of rare (unclassified) songs than small repertoires, and 4) rare songs are not clustered in the repertoires of certain individuals.
How Long Will Newts Wait? an Experiment To Test an Assumption of a Causal Model of the Courtship of the Male Smooth Newt, Triturus V. Vulgaris
Authors: Halliday T.R. , Houston A.I.
Published: April 2008

The NEWTSEX model simulates the behavioural transition between two parts of newt courtship, Retreat Display and Creep, and models the interaction between four causal factors: the behaviour of the female, the male's spermatophore supply, his need for oxygen, and feedback from the male's own behaviour. The model predicts that, if feedback from the female is witheld at a critical point (Tail-touch), the male will revert from Creep to Retreat Display after an interval, the duration of which is proportional to his spermatophore supply. The results of an experiment in which the female's behaviour was controlled support this prediction, but a high level of variance in the results suggests that respiratory constraints on male courtship behaviour require further investigation.
Behavioural and Breeding-Habitat Related Aspects of Sperm Competition in Razorbills
Authors: Wagner Richard H.
Published: April 2008

I observed razorbill copulation behaviour to examine the ability of males to assure their paternity in the presence of sperm competition. While males in colonial species are generally unable to guard their mates throughout the female's fertile period, male razorbills suffered a special problem in that females actively sought extra-pair copulations (EPCs) and did so in two separate locations, the colony and ledges outside the colony called "mating arenas". Most within-pair and extra-pair copulations were performed in the mating arenas (74% and 82%, respectively). Individuals were consistent in their attendance in one of the two arenas, depending upon the accessibility of the breeding site from the arena, and the attendance of other individuals from the same sub-colony. Individuals were also consistent in their occupation of specific sites within the arenas, and usually attended these sites between years. Attendance in the relatively small arenas brought individuals from the sparser colony into much closer proximity than when they attended their nesting sites. The higher density in the arenas was associated with females receiving EPC attempts three times more frequently upon arrival in the arenas than in the colony. Females resisted most EPC attempts, but a high proportion (50%) of females accepted at least one EPC prior to egg-laying. Mating arena attendance by males was aimed at obtaining EPCs when their mates were absent, and at attempting to assure their paternity when their mates were present. Paternity assurance was accomplished by a) inhibiting their mates from accepting EPCs, b) depriving other males access to the female, and c) copulating with the female frequently. Males did not guard their mates effectively in that they were absent from the mating arenas during a large proportion (34%) of their mates' arrivals. The principal male strategy for gaining paternity assurance was apparently to attempt frequent copulations with their mates. Males achieved cloacal contact (and presumably insemination) with their mates approximately 80 times during the 30 days preceding the laying of the single egg, and the number of days males attended the arenas was positively correlated with the number of
Ideal Free Distribution and the Mechanism of Patch Profitability Assessment in Three-Spined Sticklebacks (Gasterosteus Aculeatus)
Authors: Krause Jens
Published: April 2008

In this paper I tested four factors that might be involved in a fish's choice of a food patch: a) shoal size present in the patch b) food delivery rate c) conspecific's feeding rate d) excitement of conspecifics Single sticklebacks were presented with a choice between two display shoals feeding at different rates but were prevented from entering the food patch by a glass sheet. When size of display shoals was equal and food delivery rate different sticklebacks spent more time near the shoal with the higher food delivery rate. When the same two different food delivery rates were presented without display shoals, test fish spent about equal amounts of time in both halves of the test tank. In a third experiment different shoal sizes (5 vs 2) were presented while keeping food delivery rate constant (5 vs 5 prey items; thus individual payoffs were in the ratio 1:2.5). The test fish spent more time with the larger shoal during the prefeeding period but significantly reduced this time during the feeding period and increased it again after feeding had stopped indicating a trade-off between safety and energy intake. A final experiment investigated the influence of excitement in display shoals on the test fish's choice. The test fish was given a choice between two display shoals (20 hungry vs 20 satiated fish). During the prefeeding period, fish in the hungry shoal showed biting rates 10 times higher than that of fish in the satiated shoal (directed at the tank interior). The test fish showed no preference, indicating that biting rate/fish is not an important factor. However, the test fish turned to the hungry shoal immediately when a clay ball (which stimulated feeding movements) was introduced into each of the outer compartments. I conclude from these experiments that neither shoal size nor food delivery rate alone play a role in the initial choice among patches. Rather an individual's initial choice of patch appears to be influenced by the excitement that conspecifics show to food, which in nature may lead to selection of the more profitable patch.
Foraging Strategies of American White Pelicans
Authors: McMahon Blair F. , Evans Roger M.
Published: April 2008

Foraging strategies employed by American white pelicans were studied at a riverine site in Manitoba, Canada, during the breeding season in 1985 and 1986. Six strategies were identified during both diurnal and nocturnal foraging periods. Sit-and-wait was the least common strategy (four instances). Mobile individuals were common but had low rates of bill dipping and prey capture, as did relatively rare and uncoordinated aggregations. A degree of flock coordination occurred in following flocks, characterized by foragers following one after the other, with occasional synchronization of bill dipping among flock members. The largest number of pelicans foraged within more or less circular groups called nuclei. Synchronous bill dipping and apparent herding of prey towards shore were common within nuclei. The most highly coordinated strategy, semicircles, involved small numbers of foragers (2 to 30 birds) that maintained their positions relative to one another, usually in a semicircle but sometimes moving to a closed circular pattern. The greatest degree of synchronized bill dipping occurred in semicircles. Small inter-bird distances and synchronized bill dipping in nuclei and semicircles may enhance their effectiveness in driving or herding clumped fish prey. Foraging strategies could be arranged along a continuum based on degree of coordination, ranging from mobile individuals, then uncoordinated aggregations, through increasing degrees of coordination in following, nuclei, and semicircles. Along this continuum, prey size and capture rats were greatest for the more highly coordinated strategies, while less coordinated strategies appeared to be involved primarily in searching. Switching among strategies fit along the same continuum, with a tendency to switch from less to more coordinated strategies when prey were located and to return to less coordinated search when capture rates declined. Video analysis of captures within large nuclei and observations of positional shifts among foragers in nuclei and following flocks indicated that all individuals within a coordinated group potentially benefited from the presence of others, supporting the view that coordinated foraging strategies in this species are examples of true cooperative foraging. The range of strategies, and interplay among them, appear to provide the American white pelican with a highly effective group foraging system for harvesting mobile, clumped fish prey.
Effects of Primary Imprinting On the Subsequent Development of Secondary Filial Attachments in the Chick
Authors: DE VOS Gerrit J. , VAN KAMPEN Hendrik S.
Published: April 2008

This study reinvestigates the effects of primary imprinting of chicks with either a naturalistic stimulus or an artificial object on subsequent imprinting with artificial objects. Initial experience with a live chick (group C) or a yellow cylinder (group Y) had differential effects on the development of a secondary filial attachment in chicks. In chicks of both groups, growth of attachment to the novel imprinting object manifested itself rather abruptly, but the change in response to the novel object occurred later in C- than in Y-chicks. There was no difference between the groups in the outcome of secondary imprinting: chicks in groups C and Y eventually became equally strongly attached to their novel imprinting stimulus, and when exposed to a third object, chicks in both groups imprinted equally well on this object. Thus, (1) initial imprinting on a naturalistic stimulus postponed, but did not block secondary imprinting on an artificial object, and (2) within the lengths of exposure used, the capacity to form new filial attachments was not limited, contrary to the prediction of the competitive exclusion model for imprinting. Secondary imprinting was delayed for a longer time when chicks were exposed to the novel imprinting stimulus in an unfamiliar environment. This indicates that induction of fear in chicks interfered with the occurrence of secondary imprinting. This effect may havc contributed to the difference between groups C and Y in the length of delay of secondary imprinting. Possibly, separation from the first stimulus and exposure to the second stimulus was more fearful to C-chicks than to Y-chicks. Introduction Imprinting was originally described by LORENZ (1935, 1937) as an irreversible process. This does not necessarily mean that a young animal cannot form secondary filial attachments after having been imprinted on a
Operational Sex Ratios in Seahorses
Authors: Vincent Amanda C.J.
Published: April 2008

Contrary to all expectations based on their male pregnancy, recent work shows that seahorses exhibit conventional sex roles in mating competition: male seahorses compete more to obtain eggs than females do to give their eggs away. This suggests that the operational sex ratio (OSR: the relative number of males and females available to mate) might be male-biased despite the length and limitations of male pregnancy. I here report a study of a laboratory population of the Sri Lankan seahorse Hippocampus fuscus. The OSR amongst mated seahorses is unbiased because males and females effectively have equal reproductive rates, although some evidence suggests that a female may have limited potential for a higher reproductive rate than her partner. In contrast, the OSR among mate-seeking seahorses is male-biased, because unmated (empty) males can prepare to mate more quickly and can remain ready to mate for longer than can unmated females. Thus, the OSR is male-biased in exactly that segment of the population which should compete for mates. These findings are compatible with the sexually monogamous mating pattern of many seahorse species.
The Development of Communication in Preterm Infant-Mother Dyads
Authors: van BEEK Y. , Hopkins B. , Hoeksma J.B.
Published: April 2008

The present study examines the effects of gestational age and birthweight status on the development of infant and maternal behaviour as well as the (mutual) predictability between partners during face-to-face interaction at 6, 12 and 18 weeks of corrected age. Subjects are healthy fullterm infants (N = 6) and three groups of healthy preterm infants: small-for-gestational age (N = 6), and appropriate for gestational age, the latter being born after a pregnancy duration of less than 32 weeks (N = 6) or between 32 and 34 weeks (N = 6). Using dyadic sequential analyses, based on log-linear modelling and information statistics, for each individual infant-mother pair at each age, the effect of both partners on the behaviour of the other was quantified, while accounting for autocorrelational effects. In the majority of cases the interactions could be labelled as showing 'bidirectionality', particularly at 18 weeks. Mothers were more likely to be influenced by the previous behaviour of the infants than vice versa. No group differences were apparent in the way mothers were influenced by their infants. However, the small-for-gestational age preterm infants were less likely to be influenced by maternal behaviour, particularly at 6 and 12 weeks of age. A lower variability was the most common finding in infants who were not predictable from the previous behaviour of the mother. At 6 and 12 weeks they were less expressive and more often showed a monotonous behavioural pattern in which 'looking at mother's face without positive expressions' was shown during most of the interaction. As this lack of variability was more often found in SGA preterm infants, they were less predictable from their mother's behaviour than the fullterm and AGA preterm infants. These data suggest that having a low birthweight for gestational age may be a risk factor for a lack of 'bidirectionality' during early mother-infant interaction.
Female Preference for Nests With Eggs Is Based On the Presence of the Eggs Themselves
Authors: Kraak Sarah B.M. , Groothuis Ton G.G.
Published: April 2008

In many fish species of which males care for eggs in a nest, including Aidablennius sphynx, females prefer to mate with males that already guard eggs. In this paper we present two aquarium experiments with this Mediterranean blenny to determine whether the females actually use the presence of eggs as a cue or depend on male display behaviour signalling the presence of eggs. In experiment 1 the test-female was presented with two nests, one with eggs and one without eggs, and only one male in a closed container between the two nests. This male only served to stimulate the female. In all tests females preferred to lay eggs in the nest already containing eggs. This shows that females of this species can base their choice on the presence of the eggs alone. In experiment 2 the test-female was presented with two males in nests of which only one had eggs. Transparent partitions deprived the female of the opportunity to inspect the nest contents. The male with and the male without eggs did not differ in time spent displaying towards the female, and the female did not show a preference for either male, based on visual cues or odours. After removal of the partitions the female visited both nests. The nest she visited first was equally likely to be the nest without eggs as the nest with eggs. In contrast, the female finally deposited eggs preferentially in the nest with eggs. We conclude that in this experiment females did not base their preference for males with eggs on male behaviour, but on the nest contents after inspection. This does not exclude an influence of male behaviour under other conditions. Furthermore, females generally deposit their eggs adjacent to as many as possible of the eggs already present, suggesting that females can localize and possibly estimate the amount of eggs already present.
Can Young Chimpanzees (Pan Troglodytes) Imitate Arbitrary Actions? Hayes & Hayes (1952) Revisited
Authors: Custance Deborah M. , Whiten Andrew , Bard Kim A.
Published: April 2008

Contrary to recent scepticism, systematic use of an experimental approach suggested by HAYES & HAYES (1952) shows that chimpanzees can imitate novel actions. Two chimpanzees imitated 13 and 17 novel arbitrary gestures, respectively. They were first taught to reproduce 15 gestures on the command, "Do this!", and then presented with 48 novel items. Using a rigourous coding system, two independent observers correctly identified a significant number of the chimpanzees' imitations (p < 0.0001). We conclude that after a period of tuition chimpanzees can go on to imitate arbitrary actions, providing evidence of a basic cognitive capacity for perspective-taking and cross-modal matching.
Male and Female Partner Preferences in a Captive Wolf Pack (Canis Lupus) : Specificity Versus Spread of Sexual Attention
Authors: Derix Ruud R.W.M. , Van Hooff Jan A.R.A.M.
Published: April 2008

Strong pair-bonding is typical for canids. In wolf packs consisting of several adult males and females, sexual interests may clash during the mating season. We expect that not only dominance-subordinance relationships but also partner preferences play a prominent role in the establishment of pair bonds in wolves. The objective of our study is to disentangle male and female components in the establishment of sexual relationships, and, in particular, the influence of partner preferences. A first-approach model suggests that males will attempt to maximize the number of fertilizations, whereas females will be selective in partner choice. We therefore determined behavioural measures of partner preference for each sex; namely 'Following sexually' in males and 'Presenting actively' in females. Matings corresponded more to the male than the female preferences. Males initiated courtship, whereas females influenced pair-bonding more by proceptive behaviour and by the rejection of male courtship. Whereas the dominant males focused more on one preferred female at a time, and might eventually switch and direct their preference to another female, the dominant females, and particularly the alpha female, spread their sexual interests over several males and associate with more than one male at a time. The ultimate reason for this might be that, in this way, a female promotes care-giving towards herself and her offspring by creating a 'paternity illusion' in those males.
Intraspecific Systematics of Gasterosteus Aculeatus Populations: Implications for Behavioral Ecology
Authors: Bell Michael A.
Published: April 2008

The threespine stickleback is widespread in diverse coastal marine and freshwater habitats of the Holarctic. Extensive information on its behavior and evolution provide an exceptional background for behavioral ecology. The behavioral phenotype links studies of proximate and ultimate (evolutionary) causes of behavior. Analyses of the ultimate causes of behavior should be placed in a phylogenetic context. There have been four phases of interpretation of phenotypic variation in threespine stickleback: (1) taxonomic, (2) dispersalist-neutralist, (3) adaptationist, and (4) adaptationist-phylogenetic. Gasterosteus aculeatus should be treated as a highly variable species complex. Phylogenetic inferences based on geographical location and allozyme and nucleotide variation facilitate discrimination between ancestry and local adaptation as ultimate causes of phenotypic variation among populations. The phylogeny of threespine stickleback populations and the use of phylogenetic information to analyze causation of pelvic girdle variation among populations are reviewed. Criteria for selection of populations and behavioral traits for comparative studies are discussed.
Role of the Three-Spined Stickleback Gasterosteus Aculeatus L. in the Food Ecology of the Spoonbill Platalea Leucorodia
Authors: Kemper Jan H.
Published: April 2008

In a five year study (1985-1989), the importance of the three-spined stickleback, Gasterosteus aculeatus to the spoonbill, Platalea leucorodia was elucidated. Both species migrate from distant areas to meet in polder areas as prey and predator, in the Netherlands. In the spring, spoonbills fly all the way from Afrika and the south of Spain to breed in colonies. As long as juvenile spoonbills are not able to fly, the demand for food is high, and the supply from the foraging areas is of vital importance. The availability of food in the foraging areas around one of the major spoonbill colonies was studied. Different food situations (prey items, prey density) were judged by means of the average food intake rate. Food situations in which prey items weigh over 2 gram, turned out to be most favourable. Prcy density was of less importance. Anadromous three-spined sticklebacks, migrate from the sea in the spring to breed in shallow ditches and back waters. Their body weight is about 2.5 gram which makes it an excellent prey for the spoonbill. Unfortunately, in the last decades, it has become very hard for the anadromous stickleback to migrate into polder areas. Modernisation of agriculture has led to a situation in which open connections between channels and polder area have disappeared. The presumed benefit of the anadromous stickleback for the spoonbill, was tested, by transporting 1,000 kilogram of anadromous sticklebacks to a polder area. The impact on the spoonbills was studied in a two year period. Since there was a distinct effect on the spoonbill, it was decided to design a fish ladder to enable anadromous sticklebacks to enter the polder again. The concept was tested in 1988. In 1989 a permanent construction was built.
Exploration, Aggressive Behaviour and Dominance in Pair-Wise Confrontations of Juvenile Male Great Tits
Authors: Verbeek Monica E.M. , Boon Anne , Drent Piet J.
Published: April 2008

In the development of social dominance, constitutional behavioural
characteristics may play an important role apart from morphological traits.
Previous work has shown that juvenile male great tits Parus major differ
consistently in their early exploratory behaviour and can be classified as fast
and superficial explorers or slow and thorough explorers. This study
investigated whether these individual differences in exploratory behaviour are
related to aggressive behaviour, and whether this affects dominance. In an
experimental set-up, pair-wise fights were observed. The obtained data were
corrected for possible influences of morphological traits. Consistent individual
differences in aggressive behaviour were found, indicating that juvenile great
tits can be characterised by that behaviour. Fast explorers started more fights
than slow explorers, and birds that started more fights also won more fights. An
additional experiment with pairs of fast and slow explorers confirmed that fast
explorers won more fights than slow explorers. In conclusion, we demonstrated
that individual differences in exploratory behaviour are related to aggressive
behaviour, which affects dominance. The striking agreement of these findings
with studies of rodents and pigs is discussed. It is suggested that the
behaviour of fast explorers agrees with an active style of coping with stress,
while the behaviour of the slow explorers resembles a passive coping style.
A Causal Ethological Analysis of the Courtship Behaviour of an Insect (the Parasitic Wasp Nasonia Vitripennis, Hym., Pteromalidae)
Authors: Jachmann F. , van den ASSEM J.
Published: April 2008

We focus on the causal organization of courtship behaviour of an insect, i.c. that of the pteromalid wasp Nasonia vitripennis, a parasite of the pupae of various flies. We observe uninterrupted displays of male Nasonia, and analyse temporal structures in order to infer causal relations between display elements. These relations are put to a test by manipulations: displays are interrupted at pre-defined points, or re-started after pauses of various durations, or specific motor patterns are prevented from being executed. The results are summarized in Fig. 13, in which we outline the structure of the underlying organization. The main conclusion is that the performance of courtship is a self-inhibiting process in which head-nodding behaviour (a component of the display) appears to play a key role. Inhibitive effects deteriorate during pauses in between displays (in a non-linear way), but also - albeit less extensively - in periods of non-nodding, during the display itself. We discuss the issue of similar or different principles of organization in courtship behaviour of insects and vertebrates. Although a common basis cannot be excluded, we have to leave open a more definite conclusion for the time being.
Form and Function of Habituation and Sensitization of Male Courtship in the Three-Spined Stickleback (Gasterosteus Aculeatus L.)
Authors: Peeke Harman V.S. , Figler Michael H.
Published: April 2008

A model female stickleback presented to a territorial male with a nest usually results in the male courting the model with a series of zigzag movements followed by a leading to the nest entrance. Following such a display, a live gravid female might follow, enter the nest, spawn and leave permitting the male to fertilize the eggs. Frequently, however, the female is not ready to spawn, and the male continues to court until, at some point, he ceases courting that female at least for a short period of time and directs his attention to another female. We propose that mechanisms involved in the modulation of this behavior may include habituation and sensitization in a way that is analogous to that apparently involved in territorial aggression and predation. This study demonstrates that habituation and sensitization do influence the behavioral decrement and reinstatement respectively of male courtship of a female model, and it may be that the stickleback uses habituation as one means of curtailing courtship towards unresponsive females, thus conserving energy and permitting redeployment of attention to other, possibly more responsive, females.
Dominance, Daily Activity and Winter Survival in Willow Tits: Detrimental Cost of Long Working Hours?
Authors: Lahti Kimmo , Koivula Kari , Orell Markku
Published: April 2008

Predation risk can vary both in space and in time. Dawn and dusk may present greater risk to diurnal birds, since their vision is not well adapted to dimness and both nocturnal and diurnal predators may be active at these times. If the birds are not time-limited, selection should favour activity patterns where crepuscular activity is avoided. Individuals in dominance-structured groups may differ in their time-limitation. The roost-entering and emerging times of willow tits (Parus montanus) spending the winter in flocks with a social hierarchy were examined. In early winter, dominants initiated their daily activities later and roosted earlier than subordinate individuals. As a result, the duration of roosting was longer for dominants than for subordinates. By the next breeding season, significantly more subordinates than dominants had disappeared (presumably died), and the individuals which disappeared had the longest days. There were no sex differences in daily activity in early winter, but in late winter, males emerged earlier in the morning than females. A feeding experiment revealed that the birds were restricted by food availability: the fed birds reduced their roosting period less than simultaneous controls. The greater change in the controls is understandable, because the days grew longer (and the roosting period thus shorter) during the experiment. We suggest that the longest active birds were forced to extend their day in order to obtain sufficient food, which perhaps resulted in greater mortality through predation.
Artificial Visual Obstruction, Antipredator Vigilance, and Predator Detection in the Thirteen-Lined Ground Squirrel (Spermophilus Tridecemlineatus)
Authors: Arenz Cody L. , Leger Daniel W.
Published: April 2008

Antipredator vigilance behaviour is affected by a number of variables, but studies reporting experimental manipulation of visual obstructions are generally lacking in the literature. We examined the individual antipredator behaviour of free-ranging thirteen-lined ground squirrels in 7 city parks in Lincoln, Nebraska, USA as they fed on peanut butter within small plexiglass boxes. Boxes differed in the position and amount of visual occlusion for a squirrel feeding in it: opaque, clear, opaque-sides, and opaque-top (also opaque on the end). We experimentally controlled environmental and contextual variables that have been identified as affecting vigilance behaviour. We filmed 38 ground squirrels as they fed in the boxes, and the results indicate that ground squirrels treat lateral occlusion as functionally identical to complete occlusion. Additionally, there were no significant differences in the squirrels' behaviours in the clear versus the opaque-top box. In 35 approach tests, a person walked toward individual ground squirrels as they foraged in one of the 4 box types. The distance at which the squirrels reacted did not differ among the 4 box types. The results of these two experiments suggest that thirteen-lined ground squirrels compensate for visual occlusion, primarily through increased withdrawals coupled with low-level vigilance postures and that the position of visual occlusion can be of greater importance than the absolute amount of occlusion.
A New Species of Cladocera, Moina Dodhui Sp. Nov., From Jabalpur, Madhya Pradesh, India
Authors: Rane Pramod D.
Published: April 2008

Description d'une nouvelle espèce Moina dodhui, district de Jabalpur, et Ujjain, Madhya Pradesh (Inde).
Moina Gouldejvi N. Sp. (Cladocera, Moinidae) From Central Asia
Authors: Mirabdullaev Iskandar M.
Published: April 2008

A new species of Cladocera, Moina gouldeni, is described from Kazakhstan and Uzbekistan. It is compared with the related species M. belli and M. macrocopa.
The Larval Development of a Fresh-Water Prawn, Palaemonetes Zariquieyi Sollaud, 1939 (Decapoda, Palaemonidae), Reared in the Laboratory
Authors: Guerao G.
Published: April 2008

The larval development of the fresh-water prawn Palaemonetes zariquieyi Sollaud, 1939 is described and illustrated in detail. Egg and larval sizes are given. Three larval and one postlarval stages are distinguished, and their characteristics are compared with those of Palaemonetes species.
Aquaria Experiments On Habitat Choice of Littoral Shrimps of the Faroe Islands
Authors: Berggren Matz
Published: April 2008

An experiment was performed in habitat choice of littoral shrimps from the Faroe Islands. All shrimps were collected in the algal zone, where they have different choice of habitat. This experiment shows that some species of shrimps have a very significant habitat choice under light conditions (Eualus gaimardii, Hippolyte varians and Lebbeus polaris). Between Hippolyte varians and Eualus pusiolus, competition in habitat selection may take place among 'Leaf-like' red algae. During dark most shrimps move around and do not stay at any specific habitat.
Biometry of Decapod Crustaceans in the Cantabrian Sea
Authors: Rodríguez-Marín Enrique
Published: April 2008

In this paper the biometric relationships between the different body parts of decapods are described, allowing the reconstruction of size and biomass (weight) of each sample from its hard parts (chelae and cephalothorax). The usefulness of this study lies in the interpretation of the feeding habits of demersal fish which feed on decapod crustaceans, since the slow digestion of hard skeletons of Decapods gives rise to the appearance of numerous hard parts in fish stomach contents.
The Use of Protein Electrophoresis for Determining Species Boundaries in Amphipods
Authors: Stewart Barbara A.
Published: April 2008

The use of protein electrophoretic data for determining species boundaries in amphipods is addressed. Analysis of published literature on genetic differentiation in amphipods showed that pairs of allopatric populations which have genetic identities (I) above a value of 0.85 probably represent intraspecific populations, whereas pairs of populations which have genetic identities below about 0.45 probably represent different species. It was recommended that if I values fall between 0.45 and 0.85, additional factors such as evidence of a lack of gene flow between the populations, and concordant morphological variation should be considered.
Découverte De Bitias Brevis (Rathbun, 1906) à mAdagascar (Decapoda, Pandalidae)
Authors: Crosnier Alain , Fransen Charles H.J.M.
Published: April 2008

Pandalus brevis Rathbun, 1906, based on an Hawaiian specimen and never rediscovered until now, was found in Madagascar and is redescribed. The reexamination of Rathbun's type reveals that this species belongs to the genus Bitias Fransen, 1990, which with Billas stocki Fransen, 1990, includes now 2 species which are compared.
The Sensory Tubercle On the Eyestalk of the Shrimp Crangon Crangon (Linnaeus, 1758) (Decapoda, Caridea)
Authors: Chaigneau Jean , Besse Colette
Published: April 2008

Many podophthalmous Crustacea present a more or less salient external structure near and in proximal position to the compound eyes. It is called sensory pore, eye papilla or eye tubercle, according to shape and author. Some SEM and TEM ultrastructural studies on several Caridea and Penaeidae have revealed a complex structure with at least two chemoreceptor-like organs: the main sensory pore (MSP) and the lateral sensory pore (LSP). MSP is a thin discoidal cuticular zone perforated by micropores. Beneath it there is a layer of sensory-like cells, each with two ciliary outer segments branching into a sub-cuticular cavity. The dcndrite parts of the sensory cells are surrounded by supporting cells. The tissue organisation reminds of that of a Vertebrate olfactive mucosa. The LSP consists of a cluster of bipolar sensory cells often ending in a pit similar to an invaginated chemoreceptive seta, found in Arthropoda. The present study deals with the common shrimp Crangon crangon (Linnaeus, 1758), which displays a highly salient conical papilla. This differs in shape from the sensory pores anatomically studied so far. Ultrastructural observations show an important LSP which ends at the tip of the cone rather than in a pit. The equivalent of the MSP is sunken into the base of the cone. This pattern is original and closer to that found in the Penaeidae than to that of the Caridea observed. Therefore, the MSP-LSP complex of Decapoda, in spite of a similar basic structure, presents very different external aspects in different species. It is also confirmed that this complex is very close to, but separate from, the internal organ of Bellonci.
Nebalia Lagartensis (Leptostraca) a New Species From the Yucatan Peninsula, Mexico
Authors: Escobar-Briones Elva , Villalobos-Hiriart José Luis
Published: April 2008

A new species of Nebalia is described from Ría Lagartos in the Yucatán Peninsula, Mexico, increasing the number of described species in this genus to 13. The species closely resembles a complex of species recognized for the tropical western Atlantic that will need further study. The importance of the shape of the denticles on the dorsal plconal segments 6 and 7 as a taxonomical character is discussed.
Nouvelles Récoltes Et Nouvelles Espèces De Majidae De Profondeur Du Genre Oxypleurodon Miers, 1886
Authors: De Forges B. Richer
Published: April 2008

Majid crabs of the genus Oxypleurodon from Indonesia, New Caledonia and Wallis and Futuna Islands, are studied here and their morphological characteristics precised. The position of this recently rehabilitated genus in relation to the two most closely similar genera Sphenocarcinus A. Milne Edwards, 1878 and Rochinia A. Milne Edwards, 1875, can now be reexamined. Two new species are described, O. tavaresi sp. nov. from Wallis Is., and O. karubar sp. nov. from the Moluccas.
Geosesarma Notophorum Sp. Nov. (Decapoda, Brachyura, Grapsidae, Sesarminae), a Terrestrial Crab From Sumatra, With Novel Brooding Behaviour
Authors: Ng Peter K.L. , Tan Cheryl G.S.
Published: April 2008

A new species of terrestrial crab, Geosesarma notophorum (Grapsidae, Sesarminae), is described from Pulau Lingga, an island east of Sumatra, Indonesia. Geosesarma notophorum belongs to the G. malayanum group of species, but can be distinguished from congeners in having iridescent green eyes, the shape of its carapace, form of its external orbital tooth, and structure of the male first pleopod. The female is unusual in carrying the young crabs on its back.
The Presence of Ridgewayia Marki Minorcaensis N. Ssp. in the Western Mediterranean
Authors: Carola Marta , Razouls Claude
Published: April 2008

Fifteen specimens of Ridgewayia marki minorcaensis n. ssp., collected from Calan Porter Cave, Minorca (western Mediterranean) on 18 July, 1988, are compared with closely related species. The presence of a hitherto undescribed structure on the basis of the right fifth leg of the male justifies establishing a new subspecies. This is the second record of this species, next to that from the Bermuda islands, and thus represents an interesting geographic distribution. The presence, in the same cave, of Exumella polyarthra Fosshagen, 1970, until now found only in the Bahamas, might pose the hypothesis of a relict character of these Mediterranean populations.
Cancer Armadillus Herbst, 1790, the Valid Name for Demania Bangladeshensis Ng, Huda & Banu, 1987, and Demania Indiana Deb, 1987 (Decapoda, Brachyura, Xanthidae)
Authors: Ng Peter K.L.
Published: April 2008

The identity of Cancer armadillus Herbst, 1790, a name not used since it was first established, is clarified. It is shown to be a species of Demania Laurie, 1906 (Brachyura, Xanthidae), a genus of poisonous Indo-West Pacific crabs. Herbst's species is regarded as conspecific with Demania bangladeshensis Ng, Huda & Banu, 1987, and the holotype of D. bangladeshensis is here designated as the neotype of Cancer armadillus. Demania indiana Deb, 1987, is also here regarded as a junior synonym of Demania armadillus.
Idotea Chelipes (Pallas, 1766), Esptce Polytypique: Description De Ses Sous-Espèces (Isopodes, Valvifères)
Authors: Charfi-Cheikhrouha Faouzia
Published: April 2008

The polytypy of Idotea chelipes is defined on the basis of morphological criteria. A new subspecies Idotea chelipes mediterranea of western Mediterranean ponds is described. Idotea bocqueti of the east coast of Tunisia is considered here to be a subspecies of I. chelipes. The nominate form of that species, Idotea c. chelipes inhabits the East Atlantic, North Sea and Baltic. A detailed diagnosis of Idotea chelipes bocqueti is given.
The Genus Mica Budde-Lund, 1908 and a Redescription of Mica Tardus (Budde-Lund, 1885) (Isopoda, Oniscidea)
Authors: Carolina Di Maio Maria , Caruso Domenico
Published: April 2008

The authors compared the genus Mica with Agabiforrrcius, Leptotrichus and Lucasius. They studied the type-material of Lucasius pallidus and Mica tardus, kept in some European museums. They redescribed and illustrated Mica tardus, also using specimens of their own collection; this species has often been mistaken for Lucasius pallidus. They also gave the geographic distribution of Mica tardus.
Redescription of the Arctic-Boreal Species Calathura Brachiata (Stimpson, 1853) (Isopoda, Anthuridea, Paranthuridae)
Authors: Negoescu Ileana , Brandt Angelika
Published: April 2008

Calathura brachiata (Stimpson, 1853) has been found in the North Atlantic, north of Iceland and northeast of Greenland; 750 specimens have been investigated. Although this species is quite large and widely distributed, the identification was complicated by the fact that the synonymy with Calathura norvegica (Sars, 1872) and Anthura arctica (Heller, 1875) had not yet been satisfactorily resolved. Moreover, the descriptions of these species were either incomplete, or it was difficult to recognize the species from the illustrations. We therefore present a complete redescription of manca stages 2 and 3, as well as of an adult female, on the basis of our material from the North Atlantic, together with a redescription of an adult male based on museum material.