Behavioural responses of farm mink towards familiar and novel food

The study aimed to (i) describe the response of farmed mink towards familiar and novel food, and (ii) assess the suitability of using novel food in order to measure fear responses in mink. A total of 48 farm mink from two behaviourally selected genetic lines were caged individually with one standardised daily feeding. The experimental feedings were carried out in a balanced order on 2 successive days. Behaviour of the mink was video recorded for 10min after food provision. In general, the mink were reluctant to approach and eat the novel food compared to familiar food, which indicates a neophobic feeding strategy, i.e. increased latency to come close to (P<0.01) and eat (P<0.001) the novel food, and a higher frequency (P<0.001) and a longer duration (P<0.001) of sniffing. Provision of unknown food items may be used to evaluate fear responses in mink since mink respond reluctantly towards novel food. However, high inter-individual variation in the present study obliterated a previously shown difference between confident and fearful mink, suggesting that this method for measuring fear responses in mink is appropriate only on a large animal material.     

Behavioural responses to video playbacks by zebra finch males

A major problem for communication research is to provide standardized stimuli and to disentangle the relative contribution of different sensory channels to the compound signal and its effectiveness. Video techniques have frequently been used for this purpose. Fifty Hertz cathode ray tube (CRT) screens cannot be used for birds because their flicker frequency is lower than the time resolution of at least songbirds. Thin film transistor (TFT) screens have successfully been used to present video clips of behaving conspecifics. We show here that they are indeed transmitting video images in a way that enables zebra finches to react appropriately to live video images of conspecifics and that the test birds are able to detect small differences in the behaviour of the stimulus animals. Adding acoustic information strongly enhanced the reaction to the video clips.     

Behavioural responses of wildlife to urban environments

Increased urbanization represents a formidable challenge for wildlife. Nevertheless, a few species appear to thrive in the evolutionarily novel environment created by cities, demonstrating the remarkable adaptability of some animals. We argue that individuals that can adjust their behaviours to the new selection pressures presented by cities should have greater success in urban habitats. Accordingly, urban wildlife often exhibit behaviours that differ from those of their rural counterparts, from changes to food and den preferences to adjustments in the structure of their signals. Research suggests that behavioural flexibility (or phenotypic plasticity) may be an important characteristic for succeeding in urban environments. Moreover, some individuals or species might possess behavioural traits (a particular temperament) that are inherently well suited to occupying urban habitats, such as a high level of disturbance tolerance. This suggests that members of species that are less ‘plastic’ or naturally timid in temperament are likely to be disadvantaged in high‐disturbance environments and consequently may be precluded from colonizing cities and towns.     

Behavioural responses to dimethyl disulphide by Aleochara bilineata and Aleochara bipustulata

Adult Aleochara bipustulata L. and Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae) are predatory on immature stages of cabbage root fly Delia radicum (L.) (Diptera: Anthomyiidae). Larvae of the two Aleochara are parasitoids of D. radicum pupae. Female Aleochara lay eggs near D. radicum puparia; the newly‐hatched Aleochara larvae enter puparia and consume the contents. Delia radicum‐infested roots of brassicas give off dimethyl disulphide (DMDS). In the field, DMDS attracts adult Aleochara to pitfall traps but does not enhance the biological control of D. radicum. In the present study, we investigate the behavioural responses of the Aleochara to DMDS in still air, as well as in moving air in a Y‐tube olfactometer, and also investigate the influence of DMDS on host selection. In larvae of both Aleochara species, DMDS induces a restricted‐area search in still air, resulting in elevated frequencies of attack of D. radicum puparia close to a source of DMDS. In the olfactometer, newly‐emerged virgin adults of both sexes of both Aleochara species choose alternatives to DMDS, older recently‐mated females are attracted to DMDS, and older males and older mate‐deprived females show no preference. Mating status of males determines the switch of their response to DMDS from avoidance to indifference. We conclude that DMDS is an important cue for host‐finding, although other cues are involved in mate‐finding. We discuss the implications for use of DMDS to enhance D. radicum mortality and for parasitism of nontarget species if A. bipustulata is introduced to Canada for biological control of D. radicum.     

Behavioural and metabolic responses of the Antarctic sea star Odontaster validus to food stimuli of different concentration

Experiments were carried out to study the behavioural and metabolic responses of the Antarctic sea star, Odontaster validus, to different concentration of food signals (glutamic acid, aspartic acid, glicyne, alanine, tyrosine and a mixture of 11 amino acids). Stimulus concentration increase caused a rise in both the percentage of reacting animals and in the reaction intensity. At low stimulus concentration, O. validus reaction consisted of tube foot waving, and only high concentrations elicited a complicated sequence of several types of behaviour. The metabolic rate of small O. validus was more sensitive to chemical stimuli than of large individuals, with small sea stars reacting even to low signal concentration. It can be speculated that small body size can be a factor restricting sea star capabilities and influencing its reaction to chemical signals.     

Behavioural responses of marine poikilotherms to pollutants.

Selected behavioural responses of marine fishes and invertebrates which are reportedly capable of disruption or impairment by petroleum, heavy metals, pesticides and other pollutants are listed. The usefulness of these and other performance functions to regulatory agencies charged with formulation of saline water quality criteria appears somewhat limited. At present, however, motor funcitons such as swimming performance, locomotion, and equilibrium, as well as physiological responses, especially respiratory patterns, may have some potential for biomonitoring of wastes discharged into coastal environments.     

Behavioural and sensory responses to some neem compounds by Pieris brassicae larvae

Abstract. The efficacy of a commercial product (Margosan-O) to inhibit feeding in Pieris brassicae L. (Lepidoptera: Pieridae) larvae was compared to that of three pure triterpenoids of botanical origin: azadirachtin and salannin (occurring in Melia azedurach ), and toosendanin (occurring in M. toosendan ). In dual-choice behaviour tests the order of antifeedant efficacy was: Margosan-O > toosendanin > salannin > azadirachtin. The ranking order of their capacity to stimulate the deterrent receptor located in the medial sensillum styloconicum appears to be: Margosan-O = toosendanin > salannin > azadirachtin. In addition to stimulating the medial deterrent cell, toosendanin inhibits the sugar receptor and the glucosinolate receptor, both located in the lateral sensillum styloconicum. The amino acid receptor in this sensillum, however, is not affected. In contrast, neither azadirachtin nor salannin influences the sensitivity of any of the receptor cells in this sensillum.
The adaptation rate of the deterrent receptor is low in comparison to that of the two sugar receptors.
A significant correlation is found between the antifeedant indices of the four neem compounds tested at three different concentrations, and the responses of the deterrent receptor to these compounds at similar concentrations. It is concluded that when this insect species feeds on its natural foodplant (i.e. cabbage), the deterrent effect of neem compounds is mediated solely via the medial deterrent receptor, whereas inhibitory effects on the sugar and glucosinolate receptors do not play a significant role.     

Behavioural responses to visual stimuli by the snail Littorina irrorata

The visual capabilities of gastropod molluses and most other invertebrates possessing structurally simple eyes are poorly known. We studied vision in untrained marsh periwinkles (Littorina irrorata) in the laboratory, using oriented movements toward test shapes as the response measure. This intertidal species is active when exposed at low tide, both during the day and at night, and it travels vertically on plant stems with a tidal rhythm. In detection tests, the estimated response threshold for a single vertical bar was 0.9°, while the response threshold for an equal-size horizontal bar was 2.4° or 3.7°, depending on bar position. Snails detected a 5°-wide bar in 4.3 1x of light and a 40°-wide square having about 95% reflectance (‘off-white’) on a white (100% nominal reflectance) background in 2800 1x. Discrimination tests revealed a strong preference for vertical bars over both diagonal and horizontal bars of the same width, but no preferences in several other situations. Various factors suggest that L. irrorata may see better than most other gastropods.     

Behavioural and heart rate responses to food limitation and predation risk: an experimental study on rainbow trout

Food-restricted rainbow trout Oncorhynchus mykiss maintained a lower basal heart rate than satiated fish, probably as a result of reduced metabolic rate. Food-restricted fish were also more active during feeding and were more willing to take risks than satiated fish. Both satiated and food-restricted fish were positioned lower in the tank after the predator attack. Heart rate increased more during feeding in the food-restricted fish compared to the satiated, but energy status had no general effect on the relation between heart rate and behaviour. Hence, the increase in heart rate was mainly a response to the more active foraging behaviour in the food-restricted fish. Moreover, behavioural activity in the food-restricted fish was associated with a higher heart rate after the predator attack than when the fish was undisturbed, which may reflect physiological preparation for flight. These findings suggest that behavioural and cardiac responses are coadapted to meet variation in food availability and predation risk in the wild.     

Behavioural responses of diverse insect groups to electric stimuli

Anecdotal evidence suggests that cockroaches respond to electrical appliances or outlets. Our objectives were to determine the effect of field‐inducing sources and field attributes on attraction of German cockroaches, Blattella germanica (L.) (Blattodea: Blattellidae), and to test those parameters found effective for attraction of B. germanica for attraction of other groups of insects. In two‐choice, large‐arena experiments, significantly more female, but not nymphal, B. germanica settled in or near electrified coils with static or fluctuating electromagnetic fields produced by low‐level direct current (DC) or alternating current (AC) sources than in control coils without current. Electromagnetic fields with the magnetic, but not the electric, component of the field nulled still attracted B. germanica, suggesting that the electric component of the field may contribute to the attraction or arrestment response of B. germanica. DC‐powered coils with static electromagnetic fields also attracted/arrested brown‐banded cockroaches, Supella longipalpa (Fabricius) (Blattodea: Blattellidae), common silverfish, Lepisma saccharina (L.), firebrats, Thermobia domestica (Packard) (both Thysanura: Lepismatidae), and European earwigs, Forficula auricularia (L.) (Dermaptera: Forficulidae), but they repelled American cockroaches, Periplaneta americana (L.) (Blattodea: Blattidae). If proven in field experiments, electrified coils as trap baits may offer non‐toxic alternatives to pesticides for selective insect control in urban environments.     

Behavioural responses of wheat stem sawflies to wheat volatiles

1 Adult wheat stem sawflies Cephus cinctus, pests of cultivated cereals that also infests wild grasses, migrate into wheat fields where they oviposit in elongating, succulent stems.
2 Volatiles released by wheat plants at susceptible stages were analyzed to determine potential semiochemical compounds. Seven major compounds were identified and quantified.
3 A Y-tube bioassay was developed to evaluate upwind orientation of adult sawflies in response to an airstream that passed over elongated wheat plants. The bioassay was also conducted with synthetic volatile compounds. The compounds were tested using a range of concentrations spanning those identified in the airstream passing over wheat plants.
4 A significant number of adult females were attracted to wheat plants when given a choice of either purified air or the air passing over plants.
5 A significant number of female C. cinctus were attracted to ( Z )-3-hexenyl acetate, β-ocimene, and ( Z )-3-hexen-1-ol, but were repelled by 6-methyl-5-hepten-2-one. Females did not respond to ( E )-2-hexenal, or ( E )-2-hexenyl acetate. The behavioural responses were concentration dependent; the highest tested concentration of ( Z )-3-hexenyl acetate was repellent to females of this species.
6 Adult males did not discriminate between air passing over wheat plants and air from a purified airstream. Males did not respond to any tested synthetic compound at any concentration.
7 The present study demonstrates for the first time that adult females of wheat stem sawfly display innate behaviours in response to synthetic volatiles. These results provide a basis for the potential development of resistant wheat varieties and for the development of semiochemically-based pest management.     

Behavioural responses to human‐induced environmental change

The initial response of individuals to human‐induced environmental change is often behavioural. This can improve the performance of individuals under sudden, large‐scale perturbations and maintain viable populations. The response can also give additional time for genetic changes to arise and, hence, facilitate adaptation to new conditions. On the other hand, maladaptive responses, which reduce individual fitness, may occur when individuals encounter conditions that the population has not experienced during its evolutionary history, which can decrease population viability. A growing number of studies find human disturbances to induce behavioural responses, both directly and by altering factors that influence fitness. Common causes of behavioural responses are changes in the transmission of information, the concentration of endocrine disrupters, the availability of resources, the possibility of dispersal, and the abundance of interacting species. Frequent responses are alterations in habitat choice, movements, foraging, social behaviour and reproductive behaviour. Behavioural responses depend on the genetically determined reaction norm of the individuals, which evolves over generations. Populations first respond with individual behavioural plasticity, whereafter changes may arise through innovations and the social transmission of behavioural patterns within and across generations, and, finally, by evolution of the behavioural response over generations. Only a restricted number of species show behavioural adaptations that make them thrive in severely disturbed environments. Hence, rapid human‐induced disturbances often decrease the diversity of native species, while facilitating the spread of invasive species with highly plastic behaviours. Consequently, behavioural responses to human‐induced environmental change can have profound effects on the distribution, adaptation, speciation and extinction of populations and, hence, on biodiversity. A better understanding of the mechanisms of behavioural responses and their causes and consequences could improve our ability to predict the effects of human‐induced environmental change on individual species and on biodiversity.     

Behavioural responses of piglets to different types of music

Music or other background sounds are often played in barns as environmental enrichment for animals on farms or to mask sudden disruptive noises. Previous studies looking at the effects of this practice on non-human animal well-being and productivity have found contradictory results. However, there is still a lack of discussion on whether piglets have the ability to distinguish different types of music. In this study, we exposed piglets to different music conditions to investigate whether the piglets preferred certain music types, in which case those types would have the potential to be used as environmental enrichment. In total, 30 piglets were tested for music type preference to determine whether growing pigs respond differently to different types of music. We used music from two families of instruments (S: string, W: wind) and with two tempos (S: slow, 65 beats/min (bpm); F: fast, 200 bpm), providing four music-type combinations (SS: string-slow; SF: string-fast; WS: wind-slow; WF: wind-fast). The piglets were given a choice between two chambers, one with no music and the other with one of the four types of music, and their behaviour was observed. The results showed that SS and WF music significantly increased residence time (P<0.01) compared with the other music conditions. Compared with the control group (with no music), the different music conditions led to different behavioural responses, where SS music significantly increased lying (P<0.01) and exploration behaviour (P<0.01); SF music significantly increased tail-wagging behaviour (P<0.01); WS music significantly increased exploration (P<0.01); and WF music significantly increased walking, lying, standing and exploration (all P<0.01). The results also showed that musical instruments and tempo had little effect on most of the behaviours. Fast-tempo music significantly increased walking (P=0.02), standing (P<0.01) and tail wagging (P=0.04) compared with slow-tempo music. In conclusion, the results of this experiment show that piglets are more sensitive to tempo than to musical instruments in their response to musical stimulation and seem to prefer SS and WF music to the other two types. The results also suggest a need for further research on the effect of music types on animals.     

Behavioural responses of three linyphiid spiders to pitfall traps

The behaviour of three linyphiid spider species (Araneae: Linyhiidae) towards pitfall traps was investigated in an experimental arena. Capture efficiencies were low with a mean of between 16 and 57 traps being encountered before spiders were caught. Survival time, trap encounter rate, trap entry rate and reactions towards vegetation were all found to be species-specific. These behaviours are considered to affect differentially pitfall trap efficiency and may partially explain the lack of clear relationship between pitfall trap catch and density found in published studies.     

Behavioural and electrophysiological responses by reproductive female Neogobius melanostomus to odours released by conspecific males

Behavioural and electrophysiological responses of reproductive and non‐reproductive female round gobies Neogobius melanostomus to water previously occupied by male round gobies (reproductive male water) were compared. Reproductive females spent more time than non‐reproductive females in a tank near the input of water conditioned from reproductive males. Also, reproductive females swam significantly faster than non‐reproductive females, suggesting that reproductive male odour may have activated spawning behaviour. Olfactory epithelial field potential measurement (electro‐olfactogram, EOG) showed that reproductive male water was a potent olfactory stimulus to reproductive females, but not to non‐reproductive females. Reproductive females responded significantly more than non‐reproductive females to solid‐phase (octadecylsilane) extracts of reproductive male water. Also, when these extracts were separated on reverse phase high performance liquid chromatography (HPLC), reproductive females showed noticeably greater responses than non‐reproductive females to the fractions that eluted between 30 and 40 min. The behavioural data support the hypothesis that reproductive male round gobies release compounds into the water that attract potential mates. The EOG data indicate that these compounds can be quantitatively extracted from the water and be partially purified by HPLC. The evidence is not sufficient to indicate whether or not the compounds are steroids. The relatively early elution time on HPLC, however, suggests that if these compounds are steroids, then it is more likely that they will be conjugated rather than free steroids.     

Behavioural responses of freshwater phytoplanktonic flagellates to a temperature gradient

Photoresponses of motile phytoplanktonic flagellates have been widely studied, whereas the behavioural responses of these organisms to temperature, and their potential ecological consequences, have rarely been considered. This study investigated the population responses and individual swimming trajectories of five phylogenetically contrasting species of freshwater flagellates exposed to a gradient of temperature in micro-scale preference chambers. Population responses demonstrated a species-dependent diversity in thermoresponsive behaviour. Across a gradient of 9.8 to 15.1°;C which simulated the typical range of temperature across a thermocline in a temperate monomictic lake, Ceratium furcoides, Chlamydomonas moewusii, Dinobryon sertularia and Plagioselmis nannoplanctica all preferred the highest temperatures. In contrast, Euglena gracilis preferred the lowest temperature. Analysis of the swimming behaviour of individual cells confirmed preferences and demonstrated that, in all species, a combination of tactic and kinetic reactions was responsible for these accumulations. For the first time, controlled positive and negative thermotaxes towards a temperature preference were identified. This thermotactic orientation, in conjunction with a reduction in directionality of response in the preference zone and with ortho- and klino-thermokinesis, enabled cells to maintain position at preferred temperatures. Specifically, in all species apart from P. nannoplanctica, significant ortho-kinetic increases in swimming speed permitted rapid movement of cells away from unfavourable conditions, while a reduction in speed and a klino-kinetic increase in rate of turning (in all five species) maintained position within favoured temperatures. This ability to detect, orientate and accumulate within a temperature gradient may be triggered by physiological processes and presents ecological advantages. Behavioural response to temperature may optimize growth, influence the spatial and temporal distribution of flagellates, particularly the diel position of cells during migration, and contribute to the delineation of niche separation.     

Behavioural responses of zooplankton to the presence of predatory jellyfish

The major objective of this study was to investigate the behavioural responses of several zooplankton species to the presence of the scyphozoan jellyfish, Catostylus mosaicus. Specific aims included: identifying taxa that were not captured by C. mosaicus; investigating whether some of these taxa were able to detect and avoid water that had been exposed to C. mosaicus; and determining if positive phototaxis of crab megalopae was suppressed in the presence of C. mosaicus. Zooplankton not caught by C. mosaicus were identified by comparing the zooplankton present in the water column to those on the oral arms of the jellyfish. C. mosaicus mainly caught mollusc veligers and copepods, but did not catch crab megalopae, small prawns or post-flexion fish larvae. The hypothesis that these taxa were able to avoid swimming in water exposed to C. mosaicus was tested using water-choice experiments in a flume tank. A significant proportion (18-25%) of larval barramundi (Lates calcarifer) avoided swimming in the plume of water that had been exposed to C. mosaicus but mud crab (Scylla serrata) megalopae and juvenile prawns showed no response. The effect of C. mosaicus on the positive phototaxis of S. serrata megalopae was tested using 1 m tall glass towers. Megalopae were exposed to one of four treatments: filtered seawater (a control), an oral arm of C. mosaicus, an oral arm that had been sealed in plastic, and mucus from C. mosaicus. Megalopae migrated higher into the water column in the control than in treatments containing cues from the jellyfish. These findings suggest that blooms of jellyfish may induce behavioural changes in some zooplankton.     

Behavioural responses of salmonid fry to low amino acid concentrations

The behaviour of start feed brown trout, Salmo trutla , and Atlantic salmon, Salmo salar , fry was observed in response to 5, 50 and 500 nM concentrations of L-alanine, _L-proline, L-arginine and glycine. In addition, salmon fry were tested with dilute concentrations of shrimp extract. Five behaviour patterns (snap, yawn, dart, twitch movements and active swimming) were shown in response to all amino acid and shrimp extract concentrations. Snapping, darting and active swimming increased in both species as a function of amino acid concentration, and in the salmon fry as a function of increasing shrimp extract concentration. Otherwise, the salmon showed twice as much yawning and more twitch movements than the trout, but the trout showed more active swimming than the salmon. Both species showed an increase in activity in response to L-proline at 5 nM, and the salmon also responded to L-arginine and glycine at this concentration. Both species first responded to L-alanine at 50 nM, but the trout did not respond to glycine until a concentration of 500 nM was presented. The salmon fry responded to shrimp extract at c. 10 ¹⁴g l^-1, but no differences in their activity were observed in response to concentrations between c. 10^-12 and 10^-6gl^-1.