Mating Tactics in Male Grey-Cheeked Mangabeys (Lophocebus albigena)

Reproductive tactics of males can change with individual quality, relatedness and social structure. Here we describe the behaviours of male grey-cheeked mangabeys towards other males, and females and their offspring ( Lophocebus albigena ) in relation to male status (high-ranking/low-ranking/transient) and group composition in Kibale National Park, Uganda. High-ranking males had the highest mating success, frequency of loud calls, mate guarding and aggression towards females and males. Only transient males were often observed to be aggressive towards juveniles, while some high-ranking males provided infant care. Mating tactics of high-ranking males varied greatly among the five studied groups, probably as a function of the intensity of male–male competition. These results are discussed with regard to the role of male–male competition and behaviours that could affect female mate choice as tactics to obtain reproductive success.     

Detecting an Effect of Group Size on Individual Responses to Neighboring Groups in Gray-Cheeked Mangabeys (Lophocebus albigena)

International Journal of Primatology - Evolutionary game theory posits that competitive ability affects the initiation of conflicts. When contests occur among groups, competitive ability is...     

Correction to: Genetic Analysis of Migration Pattern of Female Bonobos (Pan paniscus) Among Three Neighboring Groups

International Journal of Primatology - The original version of this article unfortunately contained mistakes. The changes are shown below:     

Patch Time Allocation by a Parasitoid: The Influence of Con-specifics,Host Abundance and Distance to the Patch

Patch residence time is at the core of models of decision making by foragers living in patchy environments. We studied patch residence time (PRT) of Ibalia leucospoides, a parasitoid of the woodwasp Sirex noctilio, as assigned to 4 treatments (recent feeding and/or oviposition experience) foraging in an array of host-infested pine logs. We tested the effects of distance from release point, host abundance, and the number of con-specifics at the time of arrival, on patch (pine log) residence time. PRT depended on a combination of patch quality (number of hosts in a log) and distance from the release point. Neither the presence of con-specifics on the patch, prior exposure to hosts, nor feeding prior to the experiment affected the time spent on a patch. We conclude that PRT in I. leucospoides meets Marginal Value Theorem predictions qualitatively, overruling the effects recent oviposition experience, access to food and contact with conspecifics. These findings are in line with the reported pro-ovigeny in I. leucospoides as well as the strong spatial aggregation of hosts in the field.     

Fluorescence Resonance Energy Transfer (Fret) to Follow Ribozyme Reactions In Real Time

Abstract

Fluorescence resonance transfer (FRET) was applied for real time monitoring of ribozyme reactions. Group I ribozyme ligation was followed with two separate, fluorescent-labeled RNA substrates. For hammerhead ribozyme cleavage, a double-fluorescent-labeled substrate was used. For the first time we analyzed multiple turnover conditions. Real time monitoring permits convenient analysis of ribozyme kinetics and the sequence-specific, quantitative detection of RNAs in femtomole amounts.     

Behavioural Responses of Dusky Dolphin Groups (Lagenorhynchus obscurus) to Tour Vessels off Kaikoura, New Zealand

Background

Commercial viewing and swimming with dusky dolphins (Lagenorhynchus obscurus) near Kaikoura, New Zealand began in the late 1980s and researchers have previously described changes in vocalisation, aerial behaviour, and group spacing in the presence of vessels. This study was conducted to assess the current effects that tourism has on the activity budget of dusky dolphins to provide wildlife managers with information for current decision-making and facilitate development of quantitative criteria for management of this industry in the future.

Methodology/Principal Findings

First-order time discrete Markov chain models were used to assess changes in the behavioural state of dusky dolphin pods targeted by tour vessels. Log-linear analysis was conducted on behavioural state transitions to determine whether the likelihood of dolphins moving from one behavioural state to another changed based on natural and anthropogenic factors. The best-fitting model determined by Akaike Information Criteria values included season, time of day, and vessel presence within 300 m. Interactions with vessels reduced the proportion of time dolphins spent resting in spring and summer and increased time spent milling in all seasons except autumn. Dolphins spent more time socialising in spring and summer, when conception occurs and calves are born, and the proportion of time spent resting was highest in summer. Resting decreased and traveling increased in the afternoon.

Conclusions/Significance

Responses to tour vessel traffic are similar to those described for dusky dolphins elsewhere. Disturbance linked to vessels may interrupt social interactions, carry energetic costs, or otherwise affect individual fitness. Research is needed to determine if increased milling is a result of acoustic masking of communication due to vessel noise, and to establish levels at which changes to behavioural budgets of dusky dolphins are likely to cause long-term harm. Threshold values from these studies would allow managers to set appropriate operational conditions based on quantifiable criteria.     

Responses to lactation and cold exposure by deer mice (Peromyscus maniculatus)

Recently, much interest has been expressed in understanding how animals use phenotypic plasticity of tissue size and function to meet increased metabolic demands. We set out to learn (i) whether female deer mice (Peromyscus maniculatus) given lactation (two to seven pups per litter), cold (5 degrees C), or cold plus lactation as energy demands display phenotypic plasticity in organ size and function; (ii) whether that plasticity is similar to laboratory mice given the same demands; and (iii) whether lactational performance in deer mice is derived from limits on central or peripheral organs. We found that deer mice responded to lactation by increasing digestible food intake and increasing the masses of the stomach, small intestine, cecum and liver, and the length of the small intestine. Heart mass was lower in lactating than in nonlactating mice. Cold exposure also caused increases in digestible food intake and increases in the masses of the small intestine, kidney, and heart. We conclude that deer mice display organ tissue plasticity in response to both lactation and cold exposure in a similar manner to laboratory mice. We also conclude that deer mice are not limited by central processing organs because they are able to increase digestive organ size continuously with increased energetic demands.     

Photosynthetic Responses to Dynamic Light Environments by Hawaiian Trees : Time Course of CO(2) Uptake and Carbon Gain during Sunflecks

Gas exchange responses to rapid changes in light were studied in a C₃ tree, Claoxylon sandwicense Muell-Arg and a C₄ tree, Euphorbia forbesii Sherff that are native to the understory of a mesic Hawaiian forest. When light was increased to 500 micromoles per meter per second following a 2 hour preexposure at 22 micromoles per meter per second, net CO₂ uptake rates and stomatal conductance gradually increased for over 1 hour in C. sandwicense but reached maximum values within 30 minutes in E. forbesii. Calculation of the intercellular CO₂ pressures indicated that the primary limitation to CO₂ uptake during this induction was nonstomatal in both species. The photosynthetic response to simulated sunflecks (lightflecks) was strongly dependent on the induction state of the leaf. Total CO₂ uptake during a lightfleck was greater and the response was faster after exposure of the leaf to high light than when the leaf had been exposed only to low light for the previous 2 hours. During a series of lightflecks, induction resulted in increased CO₂ uptake in successive lightflecks. Significant postillumination CO₂ fixation was evident and contributed substantially to the total carbon gain, especially for lightflecks of 5 to 20 seconds' duration.     

浑善达克沙地典型灌木和草本植物对模拟降雨的不同反应(英文)

To assess the ecophysiological responses and adaptive strategies to rainfall exhibited by different plant functional types, we compared gas exchange, leaf water potential (ψleaf) and PS photochemical efficiency (Fv/Fm) between Hedysarum fruticosum Pall. (shrub) and Salsola collina Y. L. Chang(herb) under a series of simulated rainfalls. The experiment was conducted in Hunshandak Sandy Land, North China. The values of net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (gs), Fv/Fm and ψleaf always elevated with the increasing amount of simulated rainfall. Whereas water useefficiency (WUE) maintained constant in H. fruticosum while always decreased in S.collina. Both speciesfully recovered their Pn and Fv/Fm 3d after rainfall, while gs and ψleaf recovered only within 2 d. However, the response patterns were obviously different. H.fruticosu promote its physiological traits within 5-15 mm rainfall but no further positive enhancement was noted when rainfall was larger than 15 mm. In S.collina, however, the enhancement continued with more water applied. We inferred that H.fruticosum and S.collina responded similarly to rainfall in time courses but differential to simulated precipitation change. S.collina was likely to be physiologically sensitive to instant increasing soil water, that can be regarded as a prodigal water use type; whilst H.fruticosum was a conservative water user.     

Reduction of Pear Psylla Damage by the Predatory Bug Anthocoris nemoralis (Heteroptera: Anthocoridae): The Importance of Orchard Colonization Time and Neighboring Vegetation

This 5-year field study was aimed at assessing the importance of predatory arthropods in suppressing pear psylla, Cacopsylla bidens (Sulc), and reducing damage caused by psylla in pear orchards in northern Israel. Correlative data suggest that Anthocoris nemoralis (Fabricius) is the only naturally occurring predator in the system that may reduce pear psylla damage; densities of other predacious taxa in the system (Araneidae, Orius spp., Chrysopidae and Coccinellidae) were not correlated significantly with psylla numbers in the orchards. However, A. nemoralis entered pear orchards at least a month after the beginning of pear psylla activity, apparently too late to prevent fruit damage. Data suggest that A. nemoralis reproduction is lower on both wild and cultivated pears than on Rhamnus, Laurus and Pistacia trees in nearby woods. Furthermore, A. nemoralis populations build up on the wild trees in March, but appear in orchards only in late May. We propose that planting R. alaternus trees near pear orchards could enhance the level of biological control of pear psylla by A. nemoralis. Preliminary results indeed show that pear psylla densities were lower on pear trees grown near Rhamnus alaternus trees than on distant trees.     

Photothermal Time for Flowering in Lentils (Lens culinaris) and the Analysis of Potential Vernalization Responses

Two cultivars of lentils, Laird and Precoz, were subjected to18 potentially vernalizing treatments, comprising constant temperaturesof 1, 5 or 9 °C in factorial combination with photoperiodsof 8 or 16 h for 10, 30 or 60 d. These seeds or seedlings, togetherwith non-vernalized seeds (as controls), were then transferredto four different growing regimes (‘day’/‘night’temperatures of 18/5 °C or 24/13 °C, factorially combinedwith photoperiods of 11 or 16 h). Variation in the number ofdays from sowing to first flower (f) in the growing regimesfor the controls conformed to the equation I/f = a+b+cP, whereis mean temperature (°C), P is photoperiod (h) and a, band c are genotype-specific constants. Accordingly, when theenvironment varies during development, the photothermal timerequired to flower in day-degrees (°C d) is given by 1/babove a base temperature defined as —(a+cP)/b. Most variationin time to flower could be accounted for by the photothermaltime accumulated in the two successive environments. Therefore,there was no evidence of a specific low-temperature vernalizationresponse in either cultivar. Neither was there evidence of ‘short-day’vernalization, i.e. advancement of flowering resulting frompreliminary short-day treatments. A potential error inherentin the predictive model described arises because it ignoresthe presence of a pre-inductive, photoperiod-insensitive phase;but agro-ecological considerations suggest that this error maynot be important in practice. Lens culinaris, lentil, flowering, photoperiodism, vernalization, photothermal time, screening germplasm     

Gamma Aminobutyric Acid (GABA) and Plant Responses to Stress

4-aminobutyrate (GABA) is a non-protein amino acid that is widely distributed throughout the biological world. In animals, GABA functions as the predominant inhibitory neurotransmitter in the central nervous system by acting through the GABA receptors. The neuromuscular system enables animals to escape from environmental stresses. Being nonmotile, plants have evolved chemical responses to mitigate stress. Mechanisms by which GABA may facilitate these responses are discussed in this review. Environmental stresses increase GABA accumulation through two different mechanisms. Stresses causing metabolic and/or mechanical disruptions, resulting in cytosolic acidification, induce an acidic pH-dependent activation of glutamate decarboxylase and GABA synthesis. Extremely marked declines in cytosolic pH occur under oxygen deprivation, which is the primary stress factor in flooded soils, and this stress induces the greatest accumulation of GABA. Other stresses, including cold, heat, salt, and mild or transient environmental factors, such as touch, wind, rain, etc. rapidly increase cellular levels of Ca²⁺. Increased cytosolic Ca²⁺ stimulates calmodulin-dependent glutamate decarboxylase activity and GABA synthesis. A review of the kinetics of GABA accumulation in plants reveals a stress-specific pattern of accumulation that is consistent with a physiological role for GABA in stress mitigation. Recent physiological and genetic evidence indicates that plants may possess GAB A-like receptors that have features in common with the animal receptors. The mechanism of action of animal GABA receptors suggests a model for rapid amplification of ion-mediated signals and GABA accumulation in response to stress. Metabolic pathways that link GABA to stress-related metabolism and plant hormones are identified. The survival value of stress-related metabolism is dependent on metabolic changes occurring before stress causes irreversible damage to plant tissue. Rapid accumulation of GABA in stressed tissue may provide a critical link in the chain of events leading from perception of environmental stresses to timely physiological responses.     

Growth Responses of Dwarf Bean to Infection by Pseudomonas phaseolicola (Burk) Dows

At an early growth stage inoculation of both unifoliates ofdwarf beans with Pseudomonas phaseolicola (Burk) Dows. Race1 inhibited trifoliate production, but inoculation of one unifoliateonly reduced subsequent leaf expansion, and the opposite uninfectedunifoliate became significantly larger than unifoliates on uninfectedplants. Inoculation of the first or second trifoliates or thecotyledonary node at a later developmental stage all reducedprimary-shoot growth by 25 to 30 per cent, but there were markeddifferences in the extent of secondary-shoot development inleaf axils below the inoculation point. The growth effects were related to the distribution and activityof the bacterial toxin within the plant, particularly to differencesin the rate of invasion of apical regions. The primary toxineffects appear to be on apical function and leaf expansion.     

Foraging Behavior and Patch Time Allocation by Fopius arisanus (Hymenoptera: Braconidae), an Egg-Larval Parasitoid of Tephritid Fruit Flies

This study quantitatively describes the host-searching behavior of Fopius arisanus (Sonan) (Hymenoptera: Braconidae), an important egg-larval parasitoid of tephritid fruit fly pests, on coffee berries infested with host eggs of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). We also investigate the parasitoid's response to local variation in host patch quality. The temporal pattern of behavioral organisation was examined by constructing an ethogram. The parasitoid spent over 90% of its foraging time in detecting and locating hosts after arriving on a host-infested fruit, and displayed a relatively fixed behavioral pattern leading to oviposition. Patch residence time increased in the presence of host-associated cues, following successful ovipositions, and with increasing size of host clutches per fruit, but decreased with each successive visit to the same host patch and with increasing availability of alternative host patches. The parasitoid females discriminated against previously parasitized hosts and spent significantly less time and searching effort on patches previously exploited by herself or by conspecific females. The effective host-searching behavior, perfect host discrimination ability, and success-motivated searching strategy shown by F. arisanus ensured a thorough exploitation of host resources by this parasitoid.     

Photothermal Time for Flowering in Faba Bean (Vicia faba) and the Analysis of Potential Vernalization Responses

One cultivar and one land-race of faba bean were subjected to18 potentially vernalizing pre-treatments (constant temperaturesof 1, 5 or 9 °C factorially combined with photoperiods of8 or 16 h d^–1 for 10, 30 or 60 d), and then transferredinto four different growing regimes (‘day’/‘night’temperatures of 18/5 °C or 24/13 °C factorially combinedwith photoperiods of 11 or 16 h d–1). Control plants weregrown entirely in the latter four regimes. The times from sowingto appearance of first open flowers were recorded for all plants.Control plants of the land-race Zeidab Local flowered soonerin long days and in the warmer regime. Pre-treatment reducedthe subsequent time to flower in the four growing-on regimesbut most of the variation in the total time to first flowerfor the pre-treated plants was accounted for by differencesin the combined photothermal time accumulated in the two successiveenvironments - which was predicted by a simple photothermalmodel. Thus, there was neither a specific low-temperature nora short-day vernalization response in this accession. Similarly,no true low-temperature or short-day vernalization responsewas detected in the cv. Maris Bead. However, this UK cultivarflowered later than predicted in the 24/13 °C regime, indicatingthat the 24 °C ‘day’ temperature was supraoptimal.Delays to flowering at 24/13 °C were, however, less evidentwhen plants were grown in long days or following prolonged (30–60d) pre-treatments at cool temperatures. Viciafaba faba, bean, flowering, photoperiodism, vernalization, photothermal time, screening germplasm.     

How Nestling Tree Swallows (Tachycineta bicolor) Integrate their Responses to Hunger and Signalling by Nestmates

Young animals in a broad range of taxa solicit care from their parents with begging displays, which are used at least partly for competition among brood or litter mates. The effect of other begging offspring on an individual’s own begging display varies across studies, however, increasing its intensity in some, but not changing, or even decreasing it, in others. One possible reason for this discrepancy is that the potential pay‐off for more intense begging depends not only on how intensely an individual’s brood or littermates are begging, but also on how long that individual has been without food. Surprisingly, however, no studies have focused on how begging responses vary when both factors are varied simultaneously. We therefore examined how nestling tree swallows, Tachycineta bicolor, respond to nestmates in relation to both their own hunger levels and the begging intensity of nestmates. During a period of food deprivation, we played focal nestlings parental contact calls either alone (control) or with the begging calls of a nestling deprived of food for 30–50 (low intensity) or 100–110 min (high intensity). Nestlings called for longer in response to the low‐intensity playback, but, surprisingly, not in the high‐intensity playback, in which they instead delayed the onset of their calling. All these responses to nestmates were independent of how long the responding nestling had been deprived of food. Thus, even in the seemingly intensely competitive environment of a passerine brood, offspring do not necessarily respond to nestmates with escalation. This may be because de‐escalation is the best competitive option in some circumstances, or because begging has other functions besides advertisement of individual need and competition over food allocation. Certainly, the results illustrate the need for studies of how nestmate interactions vary across a broad range of contexts.     

Patch Time Allocation by the Parasitoid Diadegma semiclausum (Hymenoptera: Ichneumonidae). III. Effects of Kairomone Sources and Previous Parasitism

We investigated the effects of kairomone sources and previous parasitism on the patch-leaving behavior of Diadegma semiclausum, a solitary endoparasitoid of larval Plutella xylostella. Individual female wasps were released onto an experimental plant, and were allowed to freely leave for an alternative host plant placed upwind of the experimental plant in a wind tunnel. In one experiment, the experimental plant was either intact, contained host damage alone, or contained both hosts and host damage. In another experiment, the plant was infested with either unparasitized hosts, hosts parasitized previously by the female herself, or parasitized by Cotesia plutellae, another larval endoparasitoid of P. xylostella. We analyzed the influence of kairomone sources, host types, and within-patch foraging experience on the patch-leaving tendency of D. semiclausum by means of the proportional hazards model. Presence of host damage, and unsuccessful host encounters as a result of host defenses decreased the parasitoids' patch-leaving tendency, while successful oviposition, self-superparasitism, and rejection of parasitized hosts increased their patch-leaving tendency. A conceptual model of the parasitoid's patch-leaving behavior is proposed on the basis of the results of current and previous studies.     

Responses of rectal pumping to oxygen lack by larval Calopteryx splendens (Zygoptera: Odonata)

Abstract. Larvae of most stadia of Calopteryx splendens (Harris) have been shown to pump water in and out of the rectum for much of the time. In each cycle of pumping there are from three to seven inhalant stokes which progressively fill the ileum with water. A short pause intervenes before a strong compression of segments 5–8 expels the water in a jet. The pattern resembles the gulping ventilation of aeshnid and libellulid dragonfly larvae. Larvae made hypoxic or otherwise stressed show a rise in the frequency and amplitude of pumping. The increase in frequency is brought about by a reduction of the pause duration, while the gain of amplitude results from a rise in both the number of inhalations/cycle and the magnitude of the stroke volume of each inhalation. Some evidence concerning the role of stretch receptors in the execution of the cycle is presented. It is proposed that rectal pumping promotes the exchange of ions and dissolved gases between the rectal water and the hindgut epithelia, supplying mainly the chloride-absorbing cells in the rectal pads. Pumping also stirs the water in the vicinity of the caudal lamellae which are probably the insect's major sites of gaseous exchange.