Predator chemical cues affect prey feeding activity differently in juveniles and adults

2012 ◽  
Vol 90 (1) ◽  
pp. 128-132 ◽  
Author(s):  
Bradley R. Johnston ◽  
Markus Molis ◽  
Ricardo A. Scrosati

Nonconsumptive predator effects on prey behaviour are common in nature, but the possible influence of prey life-history stage on such responses is poorly known. We investigated whether prey life-history stage may be a factor affecting prey feeding activity responses to predator chemical cues, for which we used dogwhelks ( Nucella lapillus (L., 1758)) and their main prey, barnacles ( Semibalanus balanoides (L., 1758)), as a model system. Barnacles use their modified legs (cirri) to filter food from the water column. Through a manipulative laboratory experiment, we tested the hypothesis that the presence of dogwhelks affects the frequency of leg swipes differently in juvenile and adult barnacles. Juveniles showed a similar feeding activity with and without nearby dogwhelks, but adults exhibited a significantly lower frequency of leg swipes when dogwhelks were present. Such an ontogenetic change in the response of barnacles to predatory cues might have evolved as a result of dogwhelks preferring adult barnacles over juvenile barnacles, as found previously. Alternatively, barnacles could learn to recognize predator cues as they age, as shown for other prey species. Overall, our study indicates that the nonconsumptive effects of predators on prey need to be fully understood under consideration of the possible ontogenetic changes in prey responses to predator cues.

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 147 ◽  
Author(s):  
Patricia Diel ◽  
Marvin Kiene ◽  
Dominik Martin-Creuzburg ◽  
Christian Laforsch

Phenotypic plasticity in defensive traits is an appropriate mechanism to cope with the variable hazard of a frequently changing predator spectrum. In the animal kingdom these so-called inducible defences cover the entire taxonomic range from protozoans to vertebrates. The inducible defensive traits range from behaviour, morphology, and life-history adaptations to the activation of specific immune systems in vertebrates. Inducible defences in prey species play important roles in the dynamics and functioning of food webs. Freshwater zooplankton show the most prominent examples of inducible defences triggered by chemical cues, so-called kairomones, released by predatory invertebrates and fish. The objective of this review is to highlight recent progress in research on inducible defences in freshwater zooplankton concerning behaviour, morphology, and life-history, as well as difficulties of studies conducted in a multipredator set up. Furthermore, we outline costs associated with the defences and discuss difficulties as well as the progress made in characterizing defence-inducing cues. Finally, we aim to indicate further possible routes in this field of research and provide a comprehensive table of inducible defences with respect to both prey and predator species.


2005 ◽  
Vol 53 (2) ◽  
pp. 73 ◽  
Author(s):  
Daniel Ramp ◽  
Ben G. Russell ◽  
David B. Croft

When prey species encounter the scent of a predator they must make a decision on how to respond. This may be either to ignore, flee, hide or alarm call. While many species are able to derive detailed information from the chemical cues associated with predator scent, for some the decision to respond is often made without being able to identify the actual location and intentions of the predator. Depending on the sociality and ecology of the species, it may pay to flee or to engage in predator inspection where knowledge is impure. We tested for this in two sympatric marsupial macropodids, the parma wallaby (Macropus parma) and the red-necked pademelon (Thylogale thetis), as little is known of how these species detect and respond to olfactory cues of predation risk. We observed that, when presented with a synthetic predator scent mimicking dog urine, the social forager, T. thetis, tended to spend more time close to the predator odour, while the solitary forager, M. parma, exhibited an aversive response. The results suggest that social and ecological constraints on the sensory modalities used in predator detection may influence how macropodids respond to olfactory predator cues.


2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.


Botany ◽  
2014 ◽  
Vol 92 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Christopher R. Webster ◽  
Michael A. Jenkins

We investigated the influence of chronic herbivory by white-tailed deer (Odocoileus virginianus (Zimmermann, 1780)) on the age structure and morphology of Trillium catesbaei Elliott. At sites with contrasting histories of deer abundance (Cades Cove, high; Whiteoak Sink, low), we measured morphological characteristics and determined minimum plant age for 60 plants (30 per site) in the single-leaf life-history stage. We chose this stage because its presence is considered an indication of successful reproduction by the previous generation, but its value could be inflated if plants regress or remain in this stage for extended periods. Our results suggest that T. catesbaei may spend upwards of a decade in this stage. Cades Cove single leaves were significantly older (p = 0.011) than those at Whiteoak Sink. Rhizome recession (decay of the oldest portion) was more common at Cades Cove, suggesting greater regression to this stage from three-leaf stages. Although minimum plant age was significantly associated with vegetative attributes (p < 0.002) at Whiteoak Sink, these attributes were decoupled at Cades Cove (p ≥ 0.642). Collectively, our results suggest that chronic herbivory may lead to a long and regressive residency period in the single-leaf stage. Consequently, in Trillium populations heavily impacted by deer, the number of single-leaf plants may be a poor indicator of reproductive success and population viability.


2020 ◽  
Vol 101 (3) ◽  
pp. 710-717
Author(s):  
Zachary K Lankist ◽  
Christine R Maher

Abstract Heterospecific competitors can use chemical cues left by dominant species to avoid aggressive interactions. Similarly, prey avoid chemical cues from predators at feeding sites, presumably because risk of death outweighs the benefit of food. This study addressed the lack of information regarding mammals’ avoidance of direct cues from competitors and also examined how indirect cues, i.e., vegetative cover, affect foraging behavior. To test if chemical cues and vegetative cover alter the number of visits by prey species and time spent at feeding plots, we observed snowshoe hares (Lepus americanus) in plots containing coyote (Canis latrans; predator) and moose (Alces alces; competitor) urine across a spectrum of vegetation densities. Snowshoe hares significantly reduced number of visits to plots that contained coyote or moose urine. In plots treated with coyote urine, number of visits decreased significantly as plots became more densely vegetated. Neither chemical cues nor vegetation density affected time spent in plots. These results suggest that competition between snowshoe hares and moose has selected for an avoidance response. This study also reinforces the idea that an increase in vegetation density could prove disadvantageous to prey, perhaps because some predators use dense vegetation to their advantage.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5744 ◽  
Author(s):  
John M. Carroll ◽  
Morgan B. Church ◽  
Christopher M. Finelli

The salt marsh periwinkle, Littorina irrorata, exhibits a spatial refuge from predation by climbing the stems of Spartina alterniflora in order to avoid benthic predators. Salt marsh periwinkles have a broad geographic distribution, and for many species, responses to predators also varies with biogeography. This study sought to determine if the geographical location of the home marsh influenced the response of periwinkles (climbing height) to blue crab predator cues both via air and water. Snails from Louisiana (LA) climbed higher in general than those from North Carolina (NC), regardless of chemical cue. However, LA snails climbed 11 cm higher in the presence of waterborne predators than control snails with no cue, while NC snails only climbed five cm higher in the same comparisons. Airborne chemical cue tended to have snails climbing at intermediate heights. These responses were significantly enhanced when both populations of snails were housed together. Periwinkle response to predator cues was stronger in LA than NC, and so it is possible that the behavioral response of these snails to predators varies with biogeography of the home marsh. Also interestingly, the results of this study also suggest that cue delivery is probably occurring via mechanisms other than water, and potentially via airborne cues. Therefore, salt marsh periwinkles likely respond to numerous cues that initiate behavioral responses, including airborne cues, and these responses may vary by home-marsh geography.


2018 ◽  
Vol 221 (8) ◽  
pp. jeb171629 ◽  
Author(s):  
Manuela Truebano ◽  
Phillip Fenner ◽  
Oliver Tills ◽  
Simon D. Rundle ◽  
Enrico L. Rezende

Author(s):  
André M. de Roos ◽  
Lennart Persson

This chapter discusses a variety of positive interactions between predators foraging on different stages of the same prey species, which all emerge owing to the biomass overcompensation that may occur in prey life history stages in response to increased mortality. These interactions include emergent facilitation of specialist predators by generalists that forage on the same prey individuals as the specialists, but in addition forage on smaller or larger prey individuals as well. Furthermore, the chapter shows that two predators that specialize on different life-history stages of prey can facilitate each other to the extent that one predator relies on the presence of the other for its persistence. A stage-specific predator may act as a catalyst species, which promotes and in fact is necessary for the invasion of another predator species, but is subsequently outcompeted by the latter.


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