Prey Chemical Cues Research Articles

Responses to prey chemical cues in wild-caught, adult gopher snakes (Pituophis catenifer).

Surface chemical cues from prey elicit elevated levels of tongue-flicking and striking behavior in many species of snakes and lizards. These responses are mediated by the vomeronasal system, and they may even occur in the absence of other sensory cues. How individuals of a species respond to prey chemical cues can reflect developmental, ecological, and evolutionary processes. Our focus in this study was ecologically based, and involved testing whether levels of chemosensory responding reflect the putative relative intake of prey types in nature. We tested 11 wild-caught adult gopher snakes (Pituophis catenifer) for their chemosensory responses, namely tongue flicking, in response to surface chemicals of natural prey items (rodent and bird) and to two control stimuli (distilled water and hexane). On average the snakes had significantly higher rates of tongue flicking toward prey cues than to control stimuli (p = .001). Responses to rodent and bird surface chemicals did not significantly differ from each other (p = .35). Tongue-flick responses to rodent surface chemicals were significantly higher than to both water and hexane (ps < .01), while responses to bird surface chemicals were significantly higher than to water (p < .05) but not to hexane (p = .12). (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Retraction Note to: Individual- and condition-dependent effects on habitat choice and choosiness

Research on consistent individual differences in behavior, or “behavioral syndromes”, continues to grow rapidly, and yet, the aspects of behavior under consideration have remained remarkably limited. Here, we consider individual variation in consistency of choice (termed here “choosiness”), as expressed during habitat choice. We repeatedly tested the responses of female Western Black Widows, Latrodectus hesperus, to two cues of habitat quality: prey chemical cues and variation in web site illuminance. We estimated females’ response by the distance they positioned themselves from (1) the source of prey chemical cues and (2) the darkest edge of our test arena. Individuals with low variance in their responses are deemed more “choosy”, whereas individuals with high variance are deemed less “choosy”. Generally, most females initiated web construction near the source of the prey chemical cues and tended to place themselves in low-light conditions. However, we detected strong, repeatable differences in females’ intensity of response, and within-individual variance of response (i.e., choosiness) was correlated across situations: females with highly consistent responses towards cricket chemical cues also exhibited highly consistent responses towards variation in light conditions. When deprived of food for extended periods, females were indistinguishable in their responses towards prey chemical cues, but tended to initiate web construction in brighter lighting conditions. Food-deprived females universally exhibited higher variance and diminished consistency in their responses (i.e., they were less choosy). Additionally, higher choosiness was associated with greater mass loss during choice trials, suggesting choosiness is energetically costly. Our results demonstrate that consistency of response to environmental cues is yet another element of behavior that varies among individuals and variation in choosiness could beget speed/quality trade-offs during animal decision making.

Response of bleached and symbiotic sea anemones to plastic microfiber exposure

Microplastics are emerging contaminants in the marine environment. They enter the ocean in a variety of sizes and shapes, with plastic microfiber being the prevalent form in seawater and in the guts of biota. Most of the laboratory experiments on microplastics has been performed with spheres, so knowledge on the interactions of microfibers and marine organisms is limited. In this study we examined the ingestion of microfibers by the sea anemone Aiptasia pallida using three different types of polymers: nylon, polyester and polypropylene. The polymers were offered to both symbiotic (with algal symbionts) and bleached (without algal symbionts) anemones. The polymers were introduced either alone or mixed with brine shrimp homogenate. We observed a higher percentage of nylon ingestion compared to the other polymers when plastic was offered in the absence of shrimp. In contrast, we observed over 80% of the anemones taking up all types of polymers when the plastics were offered in the presence of shrimp. Retention time differed significantly between symbiotic and bleached anemones with faster egestion in symbiotic anemones. Our results suggest that ingestion of microfibers by sea anemones is dependent both on the type of polymers and on the presence of chemical cues of prey in seawater. The decreased ability of bleached anemones to reject plastic microfiber indicates that the susceptibility of anthozoans to plastic pollution is exacerbated by previous exposure to other stressors. This is particularly concerning given that coral reef ecosystems are facing increases in the frequency and intensity of bleaching events due to ocean warming.

Perch, Perca fluviatilis show a directional preference for, but do not increase attacks toward, prey in response to water-borne cortisol

In freshwater environments, chemosensory cues play an important role in predator-prey interactions. Prey use a variety of chemosensory cues to detect and avoid predators. However, whether predators use the chemical cues released by disturbed or stressed prey has received less attention. Here we tested the hypothesis that the disturbance cue cortisol, in conjunction with visual cues of prey, elevates predatory behavior. We presented predators (perch, Perca fluviatilis) with three chemosensory choice tests and recorded their location, orientation, and aggressive behavior. We compared the responses of predators when provided with (i) visual cues of prey only (two adjacent tanks containing sticklebacks); (ii) visual and natural chemical cues of prey vs. visual cues only; and (iii) visual cues of prey with cortisol vs. visual cues only. Perch spent a significantly higher proportion of time in proximity to prey, and orientated toward prey more, when presented with a cortisol stimulus plus visual cues, relative to presentations of visual and natural chemical cues of prey, or visual cues of prey only. There was a trend that perch directed a higher proportion of predatory behaviors (number of lunges) toward sticklebacks when presented with a cortisol stimulus plus visual cues, relative to the other chemosensory conditions. But they did not show a significant increase in total predatory behavior in response to cortisol. Therefore, it is not clear whether water-borne cortisol, in conjunction with visual cues of prey, affects predatory behavior. Our results provide evidence that cortisol could be a source of public information about prey state and/or disturbance, but further work is required to confirm this.

Strong negative effect of diurnal rainfall on nocturnal activity of a wandering spider in Central Amazonia

Rainfall is a common phenomenon in tropical forests influencing the behavior of many animals, however, little is known about its post-occurrence effect on behavior. We investigated the effect of diurnal rainfall on the nocturnal activity of the wandering spider species Phoneutria reidyi in nights without rainfall. Our study included two different areas and periods: a coconut plantation, located 108 km from the city of Manaus, containing an area of 80 m x 80 m with 105 palms, from July 2014 to July 2015; and an area of 80 m x 80 m in a rainforest fragment in Manaus, from December 2015 to March 2016. Each night, we counted active spiders (found outside refugees) searching carefully on the vegetation and on the ground using a headlamp between 19:00-00:00. Spiders were not captured to avoid the effect of disturbance, and were measured by approaching a caliper rule. We used an index to measure the diurnal rainfall effect (DRE) which was the percentage of change in the number of active spiders at night after a diurnal rainfall, considering 100 % the number of spiders active at the previous or following night, without previous rainfall during the day. This pairwise approach was used to avoid seasonal bias and included 15 pairs of nights in the plantation, and 15 pairs in the forest. A total of 2 243 active spiders were counted. The number of active spiders was always smaller in nights after diurnal rainfall, with a mean reduction of 53.4 %. The abundance of active spiders reduced significantly in both areas after a diurnal rainfall, and the effect was not different between areas. Larger spiders (mostly adults) reduced their activity (-62.8 %) more than smaller spiders (juveniles, -48.5 %). The amount of rainfall during the day had no effect on the nocturnal activity, i.e., the effect of strong diurnal rainfall is similar to the effect of a weak rainfall. The air temperature did not change significantly at night after diurnal rainfalls. The seasonality of rainfall apparently has a weak or absent effect on the abundance of P. reidyi , which was approximately constant through one year. We believe that the moisture, which may affect the chemical cues of prey, is the major cause to reduce the active spiders after rainfall, but we discuss other potential causes. Smaller individuals are probably more active under less favorable conditions due to the stronger need of food for growing. If this effect of rainfall on the behavior is common for wandering spiders in general, the rainfall events may have important consequences for the entire community of arthropods and small vertebrates. We suggest that studies based on relative abundance of spiders should take in account this potential effect in collection and analysis of data.

Strong negative effect of diurnal rainfall on nocturnal activity of a wandering spider in Central Amazonia

Rainfall is a common phenomenon in tropical forests influencing the behavior of many animals, however, little is known about its post-occurrence effect on behavior. We investigated the effect of diurnal rainfall on the nocturnal activity of the wandering spider species Phoneutria reidyi in nights without rainfall. Our study included two different areas and periods: a coconut plantation, located 108 km from the city of Manaus, containing an area of 80 m x 80 m with 105 palms, from July 2014 to July 2015; and an area of 80 m x 80 m in a rainforest fragment in Manaus, from December 2015 to March 2016. Each night, we counted active spiders (found outside refugees) searching carefully on the vegetation and on the ground using a headlamp between 19:00-00:00. Spiders were not captured to avoid the effect of disturbance, and were measured by approaching a caliper rule. We used an index to measure the diurnal rainfall effect (DRE) which was the percentage of change in the number of active spiders at night after a diurnal rainfall, considering 100 % the number of spiders active at the previous or following night, without previous rainfall during the day. This pairwise approach was used to avoid seasonal bias and included 15 pairs of nights in the plantation, and 15 pairs in the forest. A total of 2 243 active spiders were counted. The number of active spiders was always smaller in nights after diurnal rainfall, with a mean reduction of 53.4 %. The abundance of active spiders reduced significantly in both areas after a diurnal rainfall, and the effect was not different between areas. Larger spiders (mostly adults) reduced their activity (-62.8 %) more than smaller spiders (juveniles, -48.5 %). The amount of rainfall during the day had no effect on the nocturnal activity, i.e., the effect of strong diurnal rainfall is similar to the effect of a weak rainfall. The air temperature did not change significantly at night after diurnal rainfalls. The seasonality of rainfall apparently has a weak or absent effect on the abundance of P. reidyi, which was approximately constant through one year. We believe that the moisture, which may affect the chemical cues of prey, is the major cause to reduce the active spiders after rainfall, but we discuss other potential causes. Smaller individuals are probably more active under less favorable conditions due to the stronger need of food for growing. If this effect of rainfall on the behavior is common for wandering spiders in general, the rainfall events may have important consequences for the entire community of arthropods and small vertebrates. We suggest that studies based on relative abundance of spiders should take in account this potential effect in collection and analysis of data.

Observations on the chemosensory responses of the midget faded rattlesnake (Crotalus oreganus concolor): discrimination of envenomated prey in a type II venom species

Rattlesnakes use prey chemical cues for ambush site selection and for relocating envenomated (E) prey following a predatory strike. The ability to discriminate between E and non-envenomated (NE) prey cues has been widely studied in rattlesnake species that produce type I venoms, which show high levels of snake venom metalloproteinase (SVMP) activity and low lethal toxicity [lethal dose which kills 50% of test animals (LD50) >1.0 µg/g]. However, E vs. NE prey discrimination studies have not been conducted on rattlesnake species that produce a type II venom that consists of low SVMP activity and high lethal toxicity (LD50 <1.0 µg/g). In the current study, long-term captive Crotalus oreganus concolor, which produce a type II venom, were tested for their ability to discriminate between chemical cues of natural (Sceloporus undulatus and Peromyscus maniculatus) and non-natural (Hemidactylus frenatus and Mus musculus) prey cues, as well as for their ability to discriminate between E and NE mouse carcasses, when prey envenomation occurred by a conspecific. Snakes showed significant levels of tongue flicking towards the chemical extracts of P. maniculatus and M. musculus, suggesting that C. oreganus concolor exhibit both innate and experience-based plasticity in response to prey chemical cues. In addition, C. oreganus concolor were able to discriminate between E and NE prey sources, when envenomation occurred by a conspecific, indicating that a type II venomous species can also discriminate between E and NE chemical cues.

Delicate fangs, smart killing: the predation strategy of the recluse spider

Prey consumption depends on the predator's ability to locate, capture and handle prey. We investigated these three steps in interactions between the delicate-bodied recluse spider Loxosceles gaucho (Araneae) and a heavy-bodied and armoured harvestman, Mischonyx cuspidatus (Opiliones). Although previous research suggested that the hard integument of such harvestmen protects them from being preyed upon by spiders larger than Loxosceles , indirect evidence suggested that Loxosceles spiders can subdue these prey. In the present study, we tested the following three hypotheses with regard to L. gaucho : (1) spiders use chemical cues left by prey to select foraging sites; (2) vibratory cues of prey are essential information in the predatory process; and (3) the spider's web sheet allows adequate handling of prey so vulnerable body regions of the prey can be bitten. To understand how a delicate predator can overcome the defences of a heavy-bodied and well-defended prey, we also quantitatively described the spider's behaviour. To test hypothesis 1, we compared the time spent in areas with harvestmen, crickets and no cues. For hypothesis 2, we compared latency to bite and number of bites in the presence or absence of vibratory information, and for hypothesis 3, we compared latency to detect prey, latency to capture prey and predation success. All three hypotheses were rejected. Loxosceles gaucho seems to be exceptional among spiders by not needing its web, indirect prey chemical cues, or prey's substrate borne vibrations to hunt the tested prey. What enables L. gaucho to prey upon M. cuspidatus is its unique hunting strategy, compared to previously studied spiders: it touches the prey with its tarsi possibly to locate weak parts of the prey's body, such as joints and distal parts of the legs, then it delivers several bites to these vulnerable areas. Our study is the first to document and describe how recluse spiders overcome the defences of an armoured harvestman.

Prey detection in juveniles of an agamid lizard, Calotes versicolor (Daudin, 1802) (Reptilia: Squamata)

The relative importance of visual and chemical cues of prey in their detection by the juveniles of Calotes versicolor was studied using laboratory-born, 2-month-old individuals starved for 48 hrs. Grasshoppers served as the prey in all experiments. In trials with deionized water and cologne water (pungency control), the lizards showed no tongue flicking. Presentation of prey-body chemical cues on cotton swabs also did not evoke tongue flicking in test lizards indicating a lack of response to different odors through the vomeronasal olfactory system. The same test lizards lunged at the transparent glass beaker housing an active prey, with their mouth open as if to catch it. They showed no tongue flicking. In contrast, when an immobile prey was presented similarly the test lizards ignored it. Apparently, chemical cues are of little value in prey detection in C. versicolor. The study shows that C. versicolor juveniles use visual cues and prey movements in detection and capture of prey.

Chemosensory response in stunted prairie rattlesnakes Crotalus viridis viridis

Abstract Rattlesnakes use chemical stimuli in ambush site selection and for relocation of envenomated prey through strike-induced chemosensory searching. Shifts in responsiveness to prey chemicals have been documented in many snakes, and often correlate with prey commonly taken as snakes increase in age and size as well as geographical locations of the species. For instance, neonate rattlesnakes that prey primarily on ectotherms responded most strongly to chemical cues of commonly taken lizard prey, whereas adult rattlesnakes that prey primarily on small mammals responded significantly to chemical cues of commonly taken rodents. In the current study, 11 Prairie Rattlesnakes Crotalus viridis viridis which were classified as large neonates based on measures of snout-vent length (SVL) and body mass, yet chronologically were at or near adulthood, were tested for their responsiveness to chemical extracts of natural and non-natural prey items. Although the snakes had eaten only neonate lab mice (Mus musculus), they responded significantly more to chemical cues of natural prey items and particularly to chemical cues of prey normally taken by subadults (Peromyscus mice and Sceloporus lizard). These results suggest that ontogenetic shifts in responsiveness to natural prey chemical cues are innately programmed and are not based on body size or feeding experience in C. v. viridis. This does not imply, however, that growth and experience are without effects, especially with novel prey or rare prey that have experienced recent population expansion.

Responses of Eastern red-backed salamanders (Plethodon cinereus) to chemical cues of prey presented in soluble and volatile forms

Terrestrial salamanders are able to detect prey items using chemical cues, but the nature of the cues involved is uncertain. This study aimed to tease apart the roles of the soluble and volatile components of prey cues detected by Eastern red-backed salamanders (Plethodon cinereus), assuming the likelihood that these different components are respectively detected by the vomeronasal (accessory) and main olfactory organs. Wild-caught salamanders were exposed to control or soluble and volatile cricket cues in two different behavioural assays conducted in the laboratory. The first series of assays focused on localized presentation of soluble cues on the substrate, and the second on point sources of volatile cues delivered through plastic tubes. Room temperature was varied across experiments. Salamanders increased chemoinvestigation of the substrate via nosetapping when soluble prey cues were distributed non-uniformly on the substrate. In the warmer of two temperatures tested, salamanders additionally showed a spatial preference for location of soluble cue deposition. Attraction to a point source of volatile cues was not evident when examining the responses of salamanders grouped together; however, investigation of the volatile point source was significantly correlated with side preference only when both soluble cues and a volatile point source were present. The latter suggests that a subset of salamanders were attracted to the point source of volatile cues in the presence of soluble cues on the substrate. This study indicates that soluble prey cues alone are sufficient to trigger salamander foraging behaviour, and that temperature influences this foraging response. It supports the notion that the vomeronasal system plays an important role in prey detection, but suggests that volatile cues are also investigated by some salamanders when soluble prey cues have been detected.

Ontogenetic shift in response to prey-derived chemical cues in prairie rattlesnakes Crotalus viridis viridis

Abstract Snakes often have specialized diets that undergo a shift from one prey type to another depending on the life stage of the snake. Crotalus viridis viridis (prairie rattlesnake) takes different prey at different life stages, and neonates typically prey on ectotherms, while adults feed almost entirely on small endotherms. We hypothesized that elevated rates of tongue flicking to chemical stimuli should correlate with particular prey consumed, and that this response shifts from one prey type to another as individuals age. To examine if an ontogenetic shift in response to chemical cues occurred, we recorded the rate of tongue flicking for 25 neonate, 20 subadult, and 20 adult (average SVL = 280.9, 552, 789.5 mm, respectively) wild-caught C. v. viridis to chemical stimuli presented on a cotton-tipped applicator; water-soluble cues from two ectotherms (prairie lizard, Sceloporus undulatus, and house gecko, Hemidactylus frenatus), two endotherms (deer mouse, Peromyscus maniculatus and lab mouse, Mus musculus), and water controls were used. Neonates tongue flicked significantly more to chemical cues of their common prey, S. undulatus, than to all other chemical cues; however, the response to this lizard’s chemical cues decreased in adult rattlesnakes. Subadults tongue flicked with a higher rate of tongue flicking to both S. undulatus and P. maniculatus than to all other treatments, and adults tongue flicked significantly more to P. maniculatus than to all other chemical cues. In addition, all three sub-classes demonstrated a greater response for natural prey chemical cues over chemical stimuli of prey not encountered in the wild (M. musculus and H. frenatus). This shift in chemosensory response correlated with the previously described ontogenetic shifts in C. v. viridis diet. Because many vipers show a similar ontogenetic shift in diet and venom composition, we suggest that this shift in prey cue discrimination is likely a general phenomenon among viperid snakes.

Interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator–prey system

The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system. Dragonfly nymphs (Aeshna cyanea) and newt eggs (Ichthyosaura alpestris) were subjected to fluctuating cold and warm thermal regimes (7-12 and 12-22°C, respectively) and the presence/absence of a predator or prey chemical cues. Preferred body temperatures were measured in an aquatic thermal gradient (5-33°C) over a 24-h period. Newt T (p) increased with developmental temperature irrespective of the presence/absence of predator cues. In dragonflies, thermal reaction norms for T (p) were affected by the interaction between temperature and prey cues. Specifically, the presence of newt scents in cold regime lowered dragonfly T (p). We concluded that predator-prey interactions influenced thermally-induced plasticity of T (p) but not in a reciprocal fashion. The occurrence of frequency-dependent thermal plasticity may have broad implications for predator-prey population dynamics, the evolution of thermal biology traits, and the consequences of sustaining climate change within ecological communities.

Visual and Chemical Prey Cues as Complementary Predator Attractants in a Tropical Stream Fish Assemblage

To date, little attention has been devoted to possible complementary effects of multiple forms of public information similar information on the foraging behaviour of predators. In order to examine how predators may incorporate multiple information sources, we conducted a series of predator attraction trials in the Lower Aripo River, Trinidad. Four combinations of visual (present or absent) and chemical cues (present or absent) from each of two prey species were presented. The occurrences of three locally abundant predatory species present within a 1 m radius of cue introduction sites were recorded. The relative attractiveness of cue type to each predator was directly related to their primary foraging modes, with visual ambush predators demonstrating an attraction to visual cues, benthivores to chemical cues, and active social foragers demonstrating complementary responses to paired cues. Predator species-pair counts were greatest in response to cues from the more abundant prey species, indicating that individuals may adopt riskier foraging strategies when presented with more familiar prey cues. These differences in predator attraction patterns demonstrate complementary effects of multiple sensory cues on the short-term habitat use and foraging behaviour of predators under fully natural conditions.

Responses of red-backed salamanders to soluble and volatile cues of prey

Event Abstract Back to Event Responses of red-backed salamanders to soluble and volatile cues of prey Angela Telfer1* and Frederic Laberge1 1 University of Guelph, Integrative Biology, Canada Red-backed salamanders use chemosensation to aid in foraging for prey items, but the roles of soluble and volatile cues have not been investigated separately. According to the Volatility theory of olfactory subsystem function, soluble and volatile cues may be detected separately by each system, with the vomeronasal system responsible for detection of soluble cues and the main olfactory system of volatile cues. However, the Learning theory proposes more complementary roles for both systems that can depend on previous experience. We investigated salamander responses to prey extracts presented in soluble or volatile forms separately, and presentation of both extracts at the same time. Experience with the assay and room temperature (15°C and 21°C) were also varied to investigate if these factors would influence responses. Two behavioural assays were designed to explore salamander responses to localized sources of soluble or volatile cues, respectively. The first (preference assay) presented a choice between a control on one side of the substrate and soluble prey cues on the other, with either control or volatile prey cues disseminated throughout the testing arena using a syringe. The second (attraction assay) presented a choice between a localized source of volatile prey cues leaching from inside a tube on one side and a control tube on the other, with either soluble prey cues or a control present across the entire substrate. Salamander location and chemoinvestigation of the substrate (nosetapping) were measured in both experiments. Investigation of the tubes was also measured in the second experiment. In preference assays, salamanders naïve to the assay showed spatial preferences for prey cues in the warmer temperature, but this was not seen when salamanders were tested in the cooler temperature or when they had previous experience with the assay. In addition, naïve salamanders increased nosetapping in the presence of combined soluble and volatile cues regardless of temperature, but this was not seen in experienced salamanders. In attraction assays, responses to chemical cues were more nuanced and only apparent when examining correlations of salamander behaviours within treatments. Salamanders generally showed significant correlations between overall tube investigation and locomotion regardless of treatment. However, only salamanders receiving soluble and volatile prey cues at the same time showed correlations between investigation of the source of volatile prey cues and side preference, suggesting increased attraction to the tube containing volatile prey cues. This study indicates that prey cues alone are sufficient to trigger salamander foraging behaviour, and that the roles of temperature and previous experience should be considered when conducting olfactory experiments with terrestrial salamanders. While no conclusions can be made on the roles of the two olfactory subsystems without further work, the observed increases in nosetapping support the notion that the vomeronasal system plays a role in prey detection. Nevertheless, results from both preference and attraction assays suggest volatile cues are also important, especially in warmer temperatures. Keywords: amphibian, nosetapping, prey chemical cues Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster (but consider for student poster award) Topic: Sensory: Olfaction and Taste Citation: Telfer A and Laberge F (2012). Responses of red-backed salamanders to soluble and volatile cues of prey. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00075 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 26 Mar 2012; Published Online: 07 Jul 2012. * Correspondence: Miss. Angela Telfer, University of Guelph, Integrative Biology, Guelph, Ontario, N1G2W1, Canada, angelatelfer@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Angela Telfer Frederic Laberge Google Angela Telfer Frederic Laberge Google Scholar Angela Telfer Frederic Laberge PubMed Angela Telfer Frederic Laberge Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Chemical prey cues influence the urban microhabitat preferences of Western black widow spiders, Latrodectus hesperus

Spiders are important predators in terrestrial ecosystems, and several spider species have been shown to use chemical cues to locate prey. However, the extent to which chemical prey cues actually drive habitat use by individual spiders remains unclear. In this study we tested whether Western black widow spiders, Latrodectus hesperus Chamberlin & Ivie 1935, can detect chemical cues left by potential prey items and adjust their habitat preferences (i.e., web building behavior and refuge choice) accordingly. Using outdoor enclosures, we gave mature female widows the choice of microhabitat (rocks) previously housing cricket prey versus control rocks lacking cricket cues. Our results showed a significant preference by black widows to build their webs in areas that contain chemical prey cues. We discuss the implications of this finding for our understanding of urban black widow habitat use, population dynamics, and the potential for urban infestations.

RETRACTED ARTICLE: Individual- and condition-dependent effects on habitat choice and choosiness

Research on consistent individual differences in behavior, or “behavioral syndromes”, continues to grow rapidly, and yet, the aspects of behavior under consideration have remained remarkably limited. Here, we consider individual variation in consistency of choice (termed here “choosiness”), as expressed during habitat choice. We repeatedly tested the responses of female Western Black Widows, Latrodectus hesperus, to two cues of habitat quality: prey chemical cues and variation in web site illuminance. We estimated females’ response by the distance they positioned themselves from (1) the source of prey chemical cues and (2) the darkest edge of our test arena. Individuals with low variance in their responses are deemed more “choosy”, whereas individuals with high variance are deemed less “choosy”. Generally, most females initiated web construction near the source of the prey chemical cues and tended to place themselves in low-light conditions. However, we detected strong, repeatable differences in females’ intensity of response, and within-individual variance of response (i.e., choosiness) was correlated across situations: females with highly consistent responses towards cricket chemical cues also exhibited highly consistent responses towards variation in light conditions. When deprived of food for extended periods, females were indistinguishable in their responses towards prey chemical cues, but tended to initiate web construction in brighter lighting conditions. Food-deprived females universally exhibited higher variance and diminished consistency in their responses (i.e., they were less choosy). Additionally, higher choosiness was associated with greater mass loss during choice trials, suggesting choosiness is energetically costly. Our results demonstrate that consistency of response to environmental cues is yet another element of behavior that varies among individuals and variation in choosiness could beget speed/quality trade-offs during animal decision making.

The Relationship Between Foraging Ecology and Lizard Chemoreception: Can a Snake Analogue (Burton’s Legless Lizard,Lialis burtonis) Detect Prey Scent?

AbstractIn lizards and snakes, foraging mode (active vs. ambush) is highly correlated with the ability to detect prey chemical cues, and the way in which such cues are utilized. Ambush‐foraging lizards tend not to recognize prey scent, whereas active foragers do. Prey scent often elicits strikes in actively‐foraging snakes, while ambushers use it to select profitable foraging sites. We tested the influence of foraging ecology on the evolution of squamate chemoreception by gauging the response of Burton’s legless lizard (Lialis burtonisGray, Pygopodidae) to prey chemical cues.Lialis burtonisis the ecological equivalent of an ambush‐foraging snake, feeding at infrequent intervals on relatively large prey, which are swallowed whole. CaptiveL. burtonisdid not respond to prey odour in any manner: prey chemical cues did not elicit elevated tongue‐flick rates or feeding strikes, nor were they utilized in the selection of ambush sites. Like other ambushing lizards,L. burtonisappears to be a visually oriented predator. In contrast, an active forager in the same family, the common scaly‐foot (Pygopus lepidopodus), did tongue‐flick in response to odours of its preferred prey. These results extend the correlation between lizard foraging mode and chemosensory abilities to a heretofore‐unstudied family, the Pygopodidae.

Turbidity and foraging rate in threespine sticklebacks: the importance of visual and chemical prey cues

AbstractIn aquatic habitats turbidity can affect the foraging efficiency of visual predators, directly influencing their capacity to detect prey. In a laboratory study we tested the effect of different loads of suspended sediment upon the foraging rates of threespine sticklebacks (Gasterosteus aculeatus). We compared the foraging rates of fish under a series of different turbidity treatments, testing fish originating from four habitats within a single drainage basin that differed in a number of environmental parameters including turbidity. Although we found habitat specific differences in foraging rates, these did not correspond to local turbidity levels. The findings of a follow up experiment revealed habitat-specific variation in boldness, which may be indirecly linked to the observed differences in foraging rate. The main finding of our study was that turbidity alone had no impact upon their prey capture rates, but that high turbidity in combination with saturation with prey odour extract caused prey capture rates to fall significantly. This suggests that olfactory cues can be more important than visual cues in determining foraging performance in this species, potentially influencing how they cope with naturally occurring periods of turbidity, and how they adapt to human-induced eutrophication.

Relationships between chemosensory behaviour and foraging mode within lacertid lizards

We assess associations between chemosensory capacity and foraging mode within lacertid lizards. Species of Lacertidae differ considerably in indices of foraging mode, and therefore seem well suited to test the adaptive nature of a coupling between foraging and sensory ecology. We observed tongue-flick (TF) rates of members from eight species in the field and in experimental conditions with no prey stimuli, with chemical stimuli, with visual stimuli and with both chemical and visual stimuli. All species increased TF rates in response to both purely visual and purely chemical prey cues, and the increase was most pronounced when both types of stimuli were offered simultaneously. Absolute TF rates in experimental conditions differed considerably among species, and species means obtained in experimental situations correlated closely with those observed in the field. Species that spend a relatively large amount of their time budget actively searching for food tend to use their vomeronasal system more frequently. Although all species in our study retained the capacity of recognizing prey chemicals, our data corroborate the idea of a functional link between an active foraging style and the usage of chemical information.