bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acquired Recognition of Chemical Stimuli from Pike, Esox lucius, by Brook Sticklebacks, Culaea inconstans (Osteichthyes, Gasterosteidae)
Authors: Chivers Douglas P. , Brown Grant E. , Smith R. Jan F. 
Published: May 2010

AbstractIn this study we test whether brook sticklebacks (Culaea inconstans) can acquire predator recognition through releaser‐induced recognition learning, i.e. simultaneous exposure to aversive ('releasing') stimuli and neutral stimuli causing learned aversion to the neutral stimuli. We exposed wild‐caught pike‐naive brook sticklebacks (collected from a creek containing fathead minnows, Pimephales promelas, but not pike, Esox lucius) to chemical stimuli from pike that were mixed with brook stickleback skin extract, fathead minnow skin extract, or a control of distilled water. In subsequent tests 2 d later, when only pike stimuli were presented, sticklebacks conditioned with stickleback skin extract and fathead minnow skin extract exhibited antipredator behaviour (i.e. increased schooling and movement toward the substrate), while those conditioned with distilled water did not. Sticklebacks conditioned with stickleback skin extract responded to pike with a more intense response, in terms of movement toward the substrate, than those conditioned with fathead minnow skin extract, suggesting that conspecific skin extract may be a stronger stimulus than heterospecific skin extract for learning recognition of predators. To our knowledge this is the first study to demonstrate that an acanthopterygian fish can acquire predator recognition through the pairing of conspecific alarm pheromone with the cue of a predator. Furthermore, our results are the first to demonstrate that fish can acquire predator recognition through the pairing of a heterospecific alarm pheromone with the cue of a predator. These results suggest that brook sticklebacks will benefit by being in close proximity to fathead minnows. Acquired predator recognition has long‐term consequences in mediating predator‐prey interactions.
Predation Risk Influences Reproductive Behaviour of Iowa Darters, Etheostoma exile (Osteichthyes, Percidae)
Authors: Chivers Douglas P. , Wisenden Brian D. , Smith R. Jan F. 
Published: May 2010

AbstractIn this study we tested the effects of predation risk on reproductive behaviour of Iowa darters (Etheostoma exile). We recorded the frequency of courtship behaviour (head shaking) and spawning acts for 30 min before and after removing an opaque barrier to expose groups of darters to (1) an empty tank (the before‐pike treatment), then (2) a tank containing a pike (the pike treatment), and finally (3) an empty tank (the after‐pike treatment). In response to the pike, darters performed significantly less reproductive behaviour than before exposure to the pike. Furthermore, darters performed proportionally less reproductive behaviour in the area in the immediate vicinity of the pike where risk of predation was highest. However, darters continued to occupy the risky area while exposed to the pike. Removal of the barrier in the absence of the pike (the before‐ and after‐pike treatments) had no effect on the overall level of reproductive behaviour, the proportion of reproductive behaviour performed in the immediate vicinity of the pike tank (the risky area), or use of the risky area.
Chemical Recognition of Risky Habitats is Culturally Transmitted among Fathead Minnows, Pimephales promelas (Osteichthyes, Cyprinidae)
Authors: Chivers Douglas P. , Smith R. Jan F. 
Published: May 2010

AbstractFathead minnows (Pimephales promelas) have an alarm substance (AS), or 'Schreckstoff', in epidermal club cells. Mechanical damage to the skin, as caused by a predator attack, releases the AS. The area in which conspecifics detect AS may be considered dangerous or risky because of the high probability of a subsequent predator attack. We exposed fathead minnows to water from one of two habitats (an open‐water site and a vegetated‐cover site) that we mixed with either AS or a distilled water control. Upon subsequent exposure to water from these habitats alone, minnows showed an antipredator response to the water they experienced in conjunction with AS, but not to water they received in conjunction with the distilled water control. These results confirmed that minnows can be conditioned with AS to recognize chemical cues from high‐risk habitats. Naive minnows present during the fright response of conditioned minnows also exhibited antipredator behaviour, and subsequently responded when tested alone. Our results demonstrate that learned recognition of high‐risk habitats can be transmitted culturally, which may allow minnows to lower their risk of predation.
Natal Dispersal and Philopatry in the Carnivorous Marsupial Phascogale tapoatafa (Dasyuridae)
Authors: Soderquist Todd , Lill A. 
Published: May 2010

AbstractThe proximate and ultimate causes of dispersal in semelparous carnivorous marsupials (Phascogalinae) have previously been hypothesized to be maternal aggression and inbreeding avoidance, respectively. This study tests these hypotheses by exposing 26 litters of Phascogale tapoatafa to a diverse range of social and environmental conditions that potentially affect dispersal (e.g. supplemental feeding, post‐weaning desertion by the mother, orphaning, and release of subadults into unoccupied habitat). The mean dispersal age was 162 ± 5.6 d, which is about 3 wk after weaning is complete. Juvenile dispersal was strongly male biased under all conditions, suggesting that extrinsic proximate causes do not adequately account for male emigration. Home range establishment by males was contingent on the presence of females. Half of the monitored daughters were philopatric, and others typically settled adjacent to the natal site, thus possibly enhancing their reproductive potential by occupying an area of known resource quality. Because philopatry increases the risk of incest, females may be selected to preferentially mate with unrelated males (immigrants), when they are available, to avoid inbreeding. If so, the presence of immigrant males would reduce the probability of locally born, related males reproducing at their natal site. Thus inbreeding avoidance by females may create local mate competition among males and select for male dispersal. Emigration also ensured that males avoided inbreeding, but, if they dispersed into unoccupied habitat, male P. tapoatafa often returned to the natal area. This 'boomerang strategy' of returning to mate with related females suggests that, in the absence of conspecifics along the dispersal path of a male, mate competition will be weak at the natal site and female mate choice will not preclude related males. Thus while inbreeding avoidance by either or both sexes is perhaps the most parsimonious explanation of male‐biased emigration, dispersal patterns were apparently strongly influenced by additional factors, so that the ultimate causation of the dispersal regime may be more complex.
Nest Defence of Nesting Chinstrap Penguins (Pygoscelis antarctica) against Intruders
Authors: Viñuela Javier , Amat Juan A. , Ferrer Miguel 
Published: May 2010

AbstractWe tested some predictions of parental investment theory by studying the aggressive behaviour of colonial nesting chinstrap penguins (Pygoscelis antarctica) against human intruders into their nesting territories. We tested for differences in the aggressive behaviour of penguins according to offspring age (eggs vs. chicks), offspring number, nest location in the colonies (central vs. peripheral) and sex. Offspring age was the main factor influencing nest defence, although nest location and sex were also important. Chicks were defended more strongly than eggs, in accordance with changes in the reproductive value of offspring, and this increase in aggressiveness was not related to revisitation of the same individuals. The level of aggression of penguins breeding in central sites was higher than that of peripheral birds, a difference that could be due to the lower residual reproductive value of central‐nesting, probably older, birds. The stronger aggressiveness of males could be due to a combination of factors related to sexual selection and life‐history traits. Offspring number did not affect the level of nest defence.
Behavioural Flexibility in a Small African Antelope: Group Size and Composition in the Oribi (Ourebia ourebi, Bovidae)
Authors: Arcese Peter , Jongejan Gwen , Sinclair A. R. E. 
Published: May 2010

AbstractIndividually identifiedOurebia ourebi(Bovidae) were observed in Serengeti National Park for 1–8 mo, annually, from 1987 to 1993 to study flexibility in the size and composition of territorial groups. A total of 236O. ourebiwere resighted over periods of 1 yr or more. The modal number of adults in groups was three in all years (range: 1–7; x̄ = 3.1, SE = 0.2, n = 5 yr; 136 groups overall); maximum group size with adolescent young and calves was eight. In 32% of 136 identified groups, two adult males were resident for at least 1 yr, as were three adult males in 4% of all groups. Groups with up to three adult females were common (range: 0–5). Overall, 25% of 32 adult males and 27% of 26 adult females were still present on the territory where first identified after 4 yr. Only 14% of 35 male‐female dyads remained intact over the same period.O. ourebiin Serengeti appear to be primarily polygynous, with a moderate rate of yr‐to‐yr residency in particular groups, and with a low rate of long‐term pairing between males and females. Groups with more than one adult male are not unique to Serengeti but their significance has not been previously considered. Comparisons acrossO. ourebipopulations in Africa show that polygyny is positively correlated with the ratio of adult females to males, population density, mean group size, and the prevalence of multi‐male groups, but there is less evidence that these variables influence the number of adult males in groups. Experiments are required to determine how demography, predation pressure, and the quality and distribution of food influence group size and composition inO. ourebiand other small antelope.
Familiarity with Intruders Modulates Agonism towards Outgroup Conspecifics in Wied's Black‐tufted‐ear Marmoset (Callithrix kuhli: Primates, Callitrichidae)
Authors: French Jeffrey A. , Schaffner Colleen M. , Shepherd Rebecca E. , Miller Marnie E. 
Published: May 2010

AbstractEncounters between individuals in established groups have important implications for demographic processes. While most intergroup encounters in callitrichid primates (marmosets and tamarins) are characterized by intense agonistic exchanges, some interactions occur in the absence of aggression. This paper investigates the role of familiarity among partners in determining the quality and intensity of aggression during stranger encounters in Wied's black‐tufted‐ear marmoset (Callithrix kuhli). Resident male and female pairs were presented on several occasions with a single male or female intruder. Half of the intruders were housed in cages in colony rooms distant from the residents, and the other half of the intruders resided in cages in the same room as the residents. Aggression was higher in male residents than in females, and males showed significantly higher rates of agonistic interactions with unfamiliar intruders of both sexes. The behaviour of the intruder did not differ according to its degree of familiarity to the residents, although aggression by resident males and submission by intruders were highly correlated in encounters with unfamiliar, but not familiar, intruders. Resident pairs approached each other more often after intruder trials than before. The results of this experiment suggest that familiarity among individuals in neighbouring groups is sufficient to modulate aggression during encounters. Since home‐range overlap among free‐ranging black‐tuftedear marmosets is extensive, differential familiarity among groups may have important implications for dispersal‐related processes.
Do Great Tits (Parus major) Prefer Ectoparasite‐free Roost Sites? An Experiment
Authors: Merilä Juha , Allander Klas 
Published: May 2010

AbstractTo investigate whether great tits (Parus major) avoid roosting in flea‐(Ceratophyllus sp.) infested nest boxes, roost‐site selection in relation to naturally occurring flea numbers was studied in two nest box areas on Gotland, Sweden. In one area (A), every second nest box was provided with an old tit nest, while the rest were cleaned and left empty. In the other area (B), a choice was offered between empty boxes and boxes containing old collared‐flycatcher (Ficedula albicollis) nests. Great tits clearly preferred to roost in empty boxes in area A, but not in area B. However, there was no statistical evidence for differential preference in the two areas — a result consistent with the finding that there was no difference in flea numbers between old tit (area A) and flycatcher nests (area B). The interpretation that roost‐site choice was affected by parasite load was further supported by the fact that individuals roosting in boxes with an old nest preferentially chose boxes with low flea numbers.
Active Acoustic Gleaning from the Water Surface by the Indian False Vampire Bat, Megaderma lyra
Authors: Marimuthu G. , Habersetzer Jörg , Leippert Dieter 
Published: May 2010

Abstract1 The method employed by the Indian false vampire bat Megaderma lyra (body mass about 40 g) to detect and capture prey from the surface of an artificial pond in an outdoor enclosure was studied. Frogs (Rana tigerina) (body mass about 10 g) were used as prey. The bats exhibited searching flights at the surface of the water for a few minutes in darkness, detected a stationary frog with its head jutting out of the water, and with a dart captured the frog in the mouth after hovering over it for about 2 s. The detected frogs did not show any movement when the bats hovered over them.2 When a freshly killed frog alone was available and pinned with its head protruding out of the surface of the water, the bats captured it after making fewer numbers of attempts in a shorter period of time compared with the capture of live frogs. The number of attempts and time taken to capture a frog increased when the frog's eyeballs alone were exposed above the water surface, and the bats failed to detect frogs when their entire head was submerged just below the water.3 Sound and video recordings showed that M. lyra continuously emitted faint ultrasounds while making searching flights at the pond. Apparently the bats made ‘early’ and ‘late’ detections, with higher repetition rates of sound emission in the case of the latter. A final buzz before capturing prey was not recorded and the change in the duration of emitted sounds during approach and after capturing the frog was marginal. The second harmonic at 43.6 kHz (SD 3.5 kHz) was more dominant and the duration was 1.0 ms (SD 0.2 ms).4 It is clear that M. lyra uses echolocation to detect and capture prey from the water surface. A comparison is made with an earlier report on M. lyra catching prey from the ground by a passive acoustic location.
Structure and Organization of Local Migrations in Brown Surgeonfish (Acanthurus nigrofuscus)
Authors: Mazeroll Anthony Inder , Montgomery W. Linn 
Published: May 2010

AbstractIn the northern Red Sea (Gulf of Aqaba, Israel), brown surgeonfish (Acanthuridae: Acanthurus nigrofuscus) migrate, in small groups, up to 1.5 km each day from nocturnal shelters to feeding sites in the morning, and from feeding sites back to shelters in the late afternoon. During the summer spawning season, groups of these fish undertake an additional migration of up to 1 km to and from sites of mass‐spawning aggregations. The total number of fish migrating to the Laromme feeding site was relatively stable (X̄ = 1018) throughout the study period (1988–1990). By contrast, the number of fish arriving at the Lighthouse spawning site fluctuated drastically (˜50‐ > 2000), with the largest number of fish recorded around the new moon and the lowest within 1–2 days of a full moon. Durations of the migrations to and from the feeding site were similar, as were the numbers of groups arriving and departing the feeding site. In contrast, the duration of migration and number of groups were much greater during arrivals at the spawning site than during departure, due to an explosive emigration from the site following mass spawning. Arrival and departure routes differed at both feeding and spawning sites, demonstrating that simple route‐reversal is not practiced by these fish. Exchanges of position by leading and following fish in groups were rare, suggesting that leadership may play important roles in determining specific routes. Surgeonfish returning from spawning in early evening ceased migrating at a specific time, rather than a specific place, and completed their homeward‐bound migrations the next morning.
Rabbit‐mothers' Diet Influences Pups' Later Food Choice
Authors: Altbäcker V. , Hudson R. , Bilkó Á. 
Published: May 2010

AbstractChoosing an appropriate diet raises special problems for generalist herbivores, especially in areas where most of the plant species are poisonous. This was the case in our study site, the Bugac Juniper Forest (Kiskunsag National Park, Hungary). The main herbivore of this forest, the wild rabbit (Oryctolagus cuniculus), can choose from about 70 plant species, but several of these are toxic or only of medicinal value. Moreover, even the nutritious species of the sparse vegetation are available only for short periods. The annual mortality rate is extremely high for the young, only those individuals survive that can find suitable places to hide and the least poisonous plants to eat. This selection pressure might force the pups to get information about the edible food types as early as possible, i.e. in the nest from their mother.This hypothesis was experimentally tested using domestic, chinchilla‐breed rabbits. Three groups of females were kept on three different diets during the gestation and lactation periods. Just after weaning, food choices of differently treated mothers' pups were tested in a three‐way food‐choice test lasting 1 wk. The first choices were registered and the amount of food eaten from the different food items was measured during each test session. Analysis of the results of the first choices revealed that the animals started to eat the same food their mother had eaten during pregnancy and lactation. Analysis of the consumed amounts also supported this finding. Pups of treated mothers significantly preferred the aromatic plants their mother had eaten previously, even if it caused serious disadvantages to the young by reducing the number of offspring and increasing the mortality rate of the pups. The results of these experiments suggest that food preferences in wild rabbits can be transmitted from one generation to the other by social learning, although, to keep a balanced diet in an ever changing environment, individual experience and learning are indispensable.
Vigilance, Flock Size, and Flock Geometry: Information Gathering by Western Evening Grosbeaks (Aves, Fringillidae)
Authors: Bekoff Marc 
Published: May 2010

AbstractVigilance (scanning) and other behaviour patterns were studied in free‐ranging evening grosbeaks (Coccothraustes vespertinus) at feeders to assess how flock size and flock geometry influenced the behaviour of individual birds. The present results indicate that the way in which individual grosbeaks are positioned with respect to one another affects many aspects of their behaviour, especially when a flock contains four or more birds. Birds in a linear array which have difficulty seeing one another, when compared with individuals organized in a circle which can easily see one another: 1. are more vigilant; 2. change their head and body positions more often; 3. react to changes in group size more slowly; 4. show less coordination in head movements; and 5. show more variability in all measures. These differences in behaviour can be explained from a cognitive ethological perspective that favours intentional or representational explanations. Specifically, the data suggest that individual grosbeaks, when scanning and moving about, are visually monitoring the flock in which they are feeding and gathering information about a number of variables including flock size, what others are doing, where others are, which individuals are present, phenotypic features of flock members, food resources, or the location of potential predators. Individuals likely use visual records of the behaviour and perhaps the phenotypic features of others, and this information influences various aspects of their behaviour.
Intruder Pressure Affects Territory Size and Foraging Success in Asymmetric Contests in the Water Strider Gerris lacustris
Authors: Jabłoński Piotr G. 
Published: May 2010

AbstractThe theory of evolutionarily stable strategies (ESS) in asymmetric contests predicts that the propensity of an individual to expose itself to risk during contests depends on the individual's resource‐holding‐potential (RHP) and on the value of the disputed resource (V) for the individual compared with that for an opponent. If encounters of a territory owner with individuals of high RHP and high food demands (V) increase in frequency, one should expect a decrease in total aggressiveness of the territory owner, and in consequence a decrease of its territory size. Such a decrease should result in a lower amount of food consumed by the territory owner. Using natural variability in RHP and V in Gerris lacustris, I experimentally tested these predictions. The average prey item has higher value (V) for reproductive female water striders (which probably transform most of their food into eggs), than for nonreproductive females and for males. Because males are smaller, they have lower RHP than females, as RHP depends on size. Thus the reproductive females are the class of individuals of high RHP and high food demands (high V). Most nonreproductive females defend food‐based territories. I observed two groups of water striders in a seminatural laboratory setting. As predicted, there was a negative correlation between the rate of encounter with reproductive females and size of the territory, and a positive correlation between territory size and number of Drosophila flies consumed by the owner. Territories were smaller in the group with high rates of encounter between territory owners and reproductive females. Territory owners caught the same number of Drosophila flies as non‐territorial individuals in this group. In contrast, in the group with fewer encounters between territory owners and reproductive females, territories were larger, and territory owners gained more food than non territorial water striders.