Predator detection

Miller L.R. and Gutzke W.H.N. (1999). The role of the vomeronasal organ of crotalines (Viperidae) in predator detection. Anim Behav 58, 53-57. 

The zebrafish, Danio rerio, was chosen as model of a simple vertebrate olfactory system. Zebrafish use their sense of smell in feeding, predator detection and reproduction (van den Hurk et al. 1987), and many naturally relevant odorants are known, such as amino acids, bile acids, nucleotides and pheromones (Carr 1988). We have used a combination of neuroanatomical, molecular biological and neurophysiological techniques to characterize spatial patterns in the olfactory epithelium and the olfactory bulb of zebrafish. 

The ideal way to bioassay a mammalian pheromone is to experiment with freely moving animals in a natural setting, and intact social units. The year-round family territories of the North American beaver. Castor canadensis, provide such an opportunity. Being largely nocturnal, beaver have depended on their chemical senses for social communication, food selection, and possibly other behaviors such as orientation in space, and predator detection and avoidance. 

One example for a chemically defended zooplankton species is the Antarctic pteropod Clione antarctica. This shell-less pelagic mollusk offers a potentially rich source of nutrients to planktivorous predators. Nonetheless fish do not prey on this organism, due to its efficient chemical defense. In a bioassay-guided structure elucidation, pteroenone 37 could be isolated and characterized as the main defensive principle of C. antarctica [82,83]. If embedded in alginate, this compound is a feeding-deterrent in nanomolar concentrations. This unusual metabolite is likely to be produced by C. antarctica itself and not accumulated from its food, since its major food sources did not contain any detectable quantities of 37. 

Systematic error is also known as bias. The bias is the constant value difference between a measured value (or set of values) and a consensus value (or true value if known). Specificity is the analytical property of a method or technique to be insensitive to interferences and to yield a signal relative to the analyte of interest only. Limit of reliable measurement predates the use of minimum detection limit (MDL). The MDL... 

Abstract For most mammals, the ability to detect odours and discriminate between them is necessary for survival. Information regarding the availability of food, the presence of predators and the sex, age and dominance status of conspecifics is odour mediated. Probably because of this extraordinary reliance upon odour cues, mice and rats have developed the ability to learn and remember information associated with olfactory cues as effectively as primates recall visually related cues. As a result, these rodents have become the model of choice to study the neural and cognitive processes involved in olfactory discrimination. In this paper, we describe some of the more ethologically based tasks used in assessing olfactory discrimination and the advantages and disadvantages of the different methodologies employed. 

My study shows the value of sampling throughout the year and across different seasons. This seasonal variation in response would obviously not have been detected had the study been conducted at only one time of the year, even if the time of year was replicated. Although Borowski (1998, 2002) showed that responses of voles to predators are variable throughout the year, many subsequent studies have been restricted to a single season. Valuable information about species behaviour is likely to be missed by such an approach and I believe that a single season approach is fundamentally flawed. 

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