Alarm cues

Chivers, D. P., Kiesecker, J. M., Anderson, M. T., and Wildy, B. A. R. (1996). Avoidance response of a terrestrial salamander Ambystoma macrodactylum) alarm cues. Journal of Chemical Ecology 22,1709-1716. 

Shabani S, Kamio M, Derby CD (2008) Spiny lobsters detect conspecific blood-bome alarm cues exclusively through olfactory sensilla. J Exp Biol 211 2600-2608... 

Ferrari MCO, Messier F, Olivers DP (2008) Variable predation risk and the dynamic nature of mosquito antipredator responses to chemical alarm cues. Chemoecology 17 223-229... 

In this chapter, we review the ways whereby lobsters chemically communicate with each other and the contexts in which they do it. We make a distinction between different types of chemicals. Based on the terminology of Wyatt (Chap. 2), we use semiochemicals as chemicals involved in animal interactions and pheromones as a subset of semiochemicals used in intraspecific contexts. We also use cues as chemicals that benefit the receiver and not necessarily the sender, with a prime example being alarm cues released in the blood of injured conspecifics. 

Hemolymph is the source of alarm cues in P. argus, it causes conspecifics to spend more time inside their shelters and counters the effect of food-related chemical cues (Shabani et al. 2008). Alarm cues are detected by aesthetasc che-moreceptors. Spiny lobsters with ablated aesthetascs do not respond to hemolymph with an alarm response indeed, spiny lobsters without an olfactory sense respond to hemolymph as if it were an appetitive cue and advance towards its source (Shabani et al. 2009). This is due to the fact that hemolymph contains many food-associated compounds that spiny lobsters detect through their non-olfactory antennular che-moreceptors (Steullet et al. 2001, 2002 Schmidt and Mellon, Chap. 7). Interestingly, hemolymph from P. interruptus or blue crabs (Callinectes sapidus) did not... 

Hermit crabs are always faced with multiple sensory inputs in their natural environments and seem to be capable to integrate multiple sources of chemical information (Fig. 15.5). Some intrinsic factors of the receiver, such as its shell status (but also its hunger level, reproductive state, etc.), may determine the appropriate responses for a given environmental context these responses may also depend on extrinsic factors, such as resource availability and variability. In essence, the hermit crabs responses to aggregation/alarm cues appear to be particularly complex, as a reflection of the behavioral flexibility that makes the... 

Hazlett BA, McLay C (2005b) Responses of the crab Heterozius rotundifrons to heterospecific chemical alarm cues phylogeny vs. ecological overlap. J Chem Ecol 31 683-689... 

Mirza RS, Chivers DP (2003) Response of juvenile rainbow trout to varying concentrations of chemical alarm cue response thresholds and survival during encounters with predators. Can J Zool 81 88-95... 

Wisenden BD, Rugg ML, Korpi NL, Fuselier LC (2009) Estimates of active time of chemical alarm cues in a cyprinid fish and am amphipod crustacean. Behaviour 146 1423-1442... 

Crayfish Metolac. Activity to alarm cue Higher activity and Wolf and... 

Crayfish (Orconectes rusticus) exposed to non-lethal levels of the herbicide metalochlor experienced a decrease in the ability to perceive chemical stimuli as a consequence they were less efficient in locating food and did not behave appropriately to alarm cues (Wolf and Moore 2002). 

Effects on Detection of Alarm Cues, on Fright Responses and Inducible Defense... 

Several fish and crustacean species use chemical alarm cues to avoid predators. The odors are either released by damaged conspecifics or in the feces by the predator preying on the fish or crustacean species (e.g. Ferrari et al. 2007 Hazlett, Chap. 18). Detection of predators is under strong selection as it is important for prey to be able to detect, avoid the predator and assess the risk of being in a certain environment. 

Decrease in pH in the water have been shown to affect the responses to alarm cues in fish either due to suggested changes in the molecules themselves (e.g. Leduc et al. 2004) or possibly due to effects on the olfactory receptors (Thommesen 1983). 

Ferrari MCO, Brown MR, Pollock MS, Chivers DP (2007) The paradox of risk assessment comparing responses of fathead minnows to capture-released and diet-released alarm cues from two different predators. Chemoecology 17 157-161... 

Leduc AOHC, Kelly JM, Brown GE (2004) Detection of conspecific alarm cues by juvenile salmonids under neutral and weakly acidic conditions laboratory and field tests. Oecologia 139 318-324... 

LOCAL PREDATION RISK ASSESSMENT BASED ON LOW CONCENTRATION CHEMICAL ALARM CUES IN PREY FISHES EVIDENCE FOR THREAT-... 

Assessment of local predation risk based on damage-released chemical alarm cues is widespread among freshwater fishes (Chivers and Smith, 1998 Smith, 1999 Wisenden, 2000). Such alarm cues are typically released following mechanical damage to prey, as... 

Such alarm cues are t) ically released following mechanical damage to prey, as would occur during a predation attempt. When detected by nearby conspecifics and some sympatric heterospecifics, these alarm cues can elicit dramatic, short-term increases in species typical antipredator behaviours (Chivers and Smith, 1998). Recent studies by Mirza and Chivers (2001, 2002, 2003) and Chivers et al. (2002) have shown that individuals responding to chemical alarm cues gain significant survival benefits associated with an increase in antipredator behaviour. 

My goal in this paper is to briefly describe the role of chemical alarm cues in local risk assessment, focusing on threat-sensitive trade-offs. Specifically, I will address the following questions (1) do prey fish show graded responses in overt antipredator responses with decreasing stimulus concentration, (2) are prey fish able to detect chemical alarm cues below their minimum overt behavioural response threshold, and (3) do prey fish exhibit threat-sensitive changes in behaviour in response to alarm cues at concentrations below the minimum overt response threshold ... 

Recent evidence has shown that individuals are able to detect chemical alarm cues well below the overt behavioural response threshold. Fathead minnows were able to acquire the recognition of the chemical cues of a novel predator (yellow perch, Perea flavenscens) if the predator odour was paired with H3NO at concentrations as low as 0.1 nM (25% of the previously demonstrated minimum overt response threshold) (Brown et al., 2001c). Mirza and Chivers (2003) likewise found that juvenile rainbow trout did not exhibit any overt antipredator response (i.e. not different from a distilled water control)... 

Figure 1. A simplified graphical representation of the behavioural response intensity of individual prey as a function of relative chemical alarm cue concentration. Bold line denotes overt antipredator response curve, dashed line denotes covert response curve. Shaded area between overt response threshold (BRTotot) and covert response threshold (BRTcowt) represents concentration range in which we would expect to see threat-sensitive behavioural responses.

Finally, the difference between the overt and covert response thresholds (Figure 1) suggests that there exists a range of concentrations over which individual prey can detect an alarm cue, but do not exhibit an overt antipredator response. Recent studies have begun to examine the role of chemical alarm cues over this low coneentration range. 

EVroENCE FOR THREAT-SENSITIVE BEHAVIOURS IN RESPONSE TO LOW CONCENTRATIONS OF CHEMICAL ALARM CUES... 

There remains the possibility that sub-threshold concentrations of chemical alarm cues may provide information leading to immediate changes in behaviour, even in the absence of an overt antipredator response. These threat-sensitive changes in behaviour may include 1) increased vigilance towards secondary predator cues such as visual information, 2) an increase in risk-aversive foraging tactics and 3) context dependent behavioural shifts in response to conspecific chemical alarm cues. 

Brown, G.E., Poirier, J.-F. and Adrian, J.C., Jr. in review. Assessment of local predation risk the role of subthreshold concentrations of chemical alarm cues. Behav. Ecol. 

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